2021 Gmc Sierra 1500 Engine Problems

Your engine is shutting off completely when you stop at red lights or stop signs, leaving you stranded in traffic and unable to move when the light turns green. This creates a serious safety risk of being rear-ended by other vehicles. Even after having your engine replaced, the problem persists and appears to be related to your truck's automatic stop-start system. The fix will likely involve diagnosing and repairing or reprogramming the auto stop-start system components.

Your 6.2L engine developed severe knocking and lost oil pressure shortly after the dealer performed a recall diagnostic and oil service. You're concerned that the recall fix may not be effective, especially since you were stranded and unable to pick up your child from daycare, and you've heard reports of replacement engines failing as well. The dealer is requiring you to tow the truck at potentially your own expense to determine if it qualifies for recall coverage. Resolving this will likely require the dealer to diagnose the engine condition and potentially replace or rebuild the engine block and related components.

Your engine has failed twice in roughly 6,000 miles of driving. The dealer confirmed that a valve dropped and damaged the cylinder wall, causing the engine to lock up without any warning lights. Your truck is currently at the GMC dealer waiting for a third replacement engine.

Your truck is experiencing severe engine problems including shuddering, rough running, and loss of power while driving at highway speeds. The check engine light came on along with a low oil pressure warning, and the engine won't restart after stalling. Even after replacing the torque converter under warranty, the issues continued and have now progressed to complete engine failure. Your engine will likely need to be replaced, which may involve diagnosing the underlying cause (possibly related to oil pressure or ignition timing based on the P0016 code) before a full engine swap is performed.

Your 2021 GMC Sierra 1500 with a 6.2L V8 engine experienced sudden engine failure without warning while driving under normal conditions. The engine threw a connecting rod and became completely inoperable, with no prior warning signs like knocking, overheating, or check engine light despite proper maintenance with manufacturer-recommended oil. This sudden loss of power created a serious safety risk while driving, especially at highway speeds. The repair will likely require complete engine replacement or rebuild.

Your engine has experienced repeated lifter failures at 5,000 miles, 86,000 miles, and 126,000 miles, each time causing a loss of power and requiring engine replacement. While some replacements were covered under warranty, you had to pay out-of-pocket for at least one engine. The replacement engines have limited remaining warranty coverage, so future repairs may be your responsibility.

You took your truck to the dealer because of an unusual engine sound, but they found nothing wrong. Four days later, a rod bearing failed while you were driving, leaving your truck unable to run. The dealer may need to inspect and potentially replace the rod bearing and perform a full engine assessment.

Your engine started making a low knocking noise while moving slowly in a parking lot and at low RPM during light acceleration. After a couple miles, you heard a chirping or squeaking sound under light throttle around 1500 RPM, followed by rough running. The engine then shut off while you were driving 45-50 mph, and when you tried to restart it, the engine locked up completely with only clicking sounds from the starter. The vehicle was towed to the dealership for diagnosis, which likely involves inspection of the engine internals, fuel delivery system, and ignition components to determine what caused the failure.

Your truck's engine coolant control valve is failing, causing the engine to unexpectedly go into reduced power mode while driving on the highway — limiting you to about 50 mph even when you need to go faster. This creates a serious safety risk, especially on highways with higher speed limits. Both a dealership and independent mechanic have confirmed the problem, and GM has issued a service bulletin and special coverage program for exactly this issue on your vehicle model. The repair will involve diagnosing and replacing the faulty coolant control valve.

Your engine stopped working suddenly without showing any warning signs, even though you've kept up with regular maintenance. This unexpected failure left you stranded and required engine service or replacement.

Your engine is losing power and making a knocking sound while driving. Multiple warning lights appeared at once: check engine (flashing), check brake system, check SRS (airbag system), and check parking brake. A mechanic diagnosed that cylinder 6 in your engine has failed and is no longer firing. The fix will likely involve replacing or rebuilding the engine, or potentially just addressing the specific cylinder through head work or valve train repair.

Your check engine light came on and stayed on, and your truck entered limp mode (reduced power) while driving at various speeds. You also noticed the radiator fan running constantly. Your dealer diagnosed a faulty coolant control valve that needs replacement. Replacing the coolant control valve should resolve these issues.

Your truck triggered a P1098 error code and was diagnosed with a failing coolant control valve by a certified technician. GM has issued special warranty coverage for this known problem, but your truck's VIN wasn't included in the coverage even though it matches the affected model year and engine type. The fix will involve replacing the coolant control valve.

Your 2021 GMC Sierra 1500 is making abnormal sounds while idling and using more fuel than normal, even after the dealer performed an engine test and changed your oil to a higher viscosity. You refused to bring the vehicle back for a follow-up engine test, so the underlying issue remains unrepaired. The fix will likely involve additional engine diagnostics and possibly replacing engine components like gaskets, valve covers, or the PCV system to address the noise and fuel consumption problem.

At 22,000 miles I experienced issues while driving on a 150 mile trip. We frequently take this particular drive. We choose to driver later in the evening to miss commuter traffic. This even we pull over for a late dinner and hear a loud ticking noise while the the truck seems to lose power. I turn the vehicle off and start it again and its worse, it barely idols and shuts down. I'm in a parking lot and drive down the block to a gas station where serves only gas and no mechanics onsite. I turn off the car and wait 5 mins and restart, same results but this time all the warning lights come on. We end up finding a hotel and in the morning i find a Chevrolet dealership down the block, I ask if I can take it in, there the advisor connects to my obd port and says there are many issues and needs to see a mechanic. I manage to get it towed 80's to the original dealership. Advisor says the engine is bad and replaces it. Now my vehicle has 38,000 miles and I run into the same issue, loud ticking sounds and low power. Immediately I drive it home and the next day have it towed to the dealership to have it looked at. The advisor said during their analysis they saw metal in the air filter so another engine has to ordered and installed.

Loss of power code p0016 now truck won't start

Burns excessive amounts of oil between oil changes.All cars were covered under the g.M recall mine fell, one month behind.But this motor is the exact motor that has been recalled to put in a heavier weight oil.Please expand the recall.So my truck can go in.

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving 65 MPH, the vehicle was shaking abnormally with the check engine warning light illuminated. The contact pulled over to the side of the road and had the vehicle towed to the residence. The contact referenced NHTSA Campaign Number: 25V274000) (ENGINE AND ENGINE COOLING) as a possible cause for the failure. A dealer was not contacted. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was 66,456.

The oil consumption is abnormal and burns almost 2.5 to 3 quarts between oil changes. This can be a heavy risk to the engine if I don’t check on it every couple weeks. I don’t think after the price I’ve paid for this truck that I should have this concern and this should not be the case

My 6.2 engine locked up and left me stranded. Had it replaced with s new engine on 10/31/2025 and I'm having problems again with it. As well as my 10 speed transmission slipping and hunting for gears

There is an active recall for the 6.2 L engines, which is what I have and it’s an issue with burning oil and catastrophic engine failure due to rods and bearings. And I just got this vehicle in November and I have already went through 15 quarts of oil in two months so I’m waiting for my engine to blow up going down the road to cause a wreck like has happened to multiple vehicles already and I also have a rod knock now due to this issue so it could be any time now that my engine fails and I end up getting hurt or my family I took it to the Chevy dealership and I have called GM to do an oil consumption test and to put in a claim so that way if it does fail, then it has paperwork to follow, but it is a major safety concern but something needs to be done considering there’s already 600,000 recalls on this issue already there needs to be more for the rest of the people that are having this issue like myself and I’m spending $50,000 on this truck for the engines to fail and me end up dying before something‘s done. and it’s also very distracting as you’re driving down the road and your vehicle tells you that you’re low on all so you have to try to find a way to get off the highway to have someone bring you all so you can continue to drive and it’s not just a cordial. It is up to 5 quarts of all at a time.

For the second time since I have owned the vehicle that was purchased brand new. The engine seized during driving on the highway and began making loud noises that was knocking and jerking the vehicle. The issue occurred initially around 15,000 miles and was diagnosed as lifter failure, was repaired and returned in July 2022. At 64,000 miles on January 15, 2026, while on an interstate the engine did the same thing and the vehicle went into limp mode. It has been diagnosed as lifter failure this second time and is awaiting appropriate repairs. Both incidents put myself in passengers at danger due to the nature in which the vehicle entered limp mode on the highway.

The engine has a knocking sound. I took it into the dealer and they replaced the exhaust system thinking that was the problem. However, the knocking still happens intermittently. I have video documentation of the noise.

2021 gmc purchased brand new Truck had complete engine failure lifters and rods were replaced at 7000 miles under factory warranty lost complete engine power GMC says we are not on any recall and they refused to buy back the truck or give me an extended warranty they said this year 2021 with 5.3 doesn’t have engine issues.

Motor was chugging took to a dealership on march 22 was told I had a collapsed lifter I was told my cost would be 4800 gm would cover half which was fine then when the work was done the dealership took it for a test drive while they were on the test drive the motor locked up they originally told me it was a cam bearing later I found out through paperwork that was emailed to me that it was a main bearing which is consistent with the recall but my vin number hasn’t came up it’s a 2021 gmc sierra 1500 with a l87 6.2 and it cost me 6200 I was 10,000 miles out of warranty

Faulty lifters replaced on passenger side. Had only 25000 miles on engine. GM extended warranty on thousands with this engine but not mine. Have only 28000 miles on truck and just turned 5th year so warranty is void. GM should extend warranty on all vehicles with this engine.

TRAVELING ON INTERSTATE GOING AT THE POSTED SPEED LIMIT AND TURNED OFF THE INTERSTATE ONTO MY EXIT TURN AND VEHICLE ENGINE STARTED KNOCKING AND ENGINE SHUT OFF OIL WARNING LIGHT CAME ON ALL WHILE TRYING TO STOP THE VEHICLE AT THE CROSS TRAFFICE STOP SIGHN AND ENDED UP STOPPED IN THE MIDDLE OF ANOTHER HIGHWAY BARLEY MISSING THE CROSS TRAFFIC COMING AT ME FROM BOTH DIRECTIONS. THIS HAPPENED AT I94 AND COUNTY HIGHWAY 34 AT BARNESVILLE MINNESOTA EXIT. THIS SUDDEN ENGINE FAILURE NEARLY KILLED ME AND THE 2 VEHICLE DRIVERS THAT NEARLY STRUCK MY TRUCK FROM BOTH DIRECTIONS. GMC WOULD NOT HELP ME WITH MY REPAIR OF OVER $11000.00 DOLLARS FOR A NEW CRATE MOTOR FROM GMC. SITING MY TRUCK DID NOT FALL UNDER THE L87 RECALL. FAILURE ROD BEARINGS AND CRANK BEARINGS WITH A TON METAL SHAVINGS IN THE OIL AND FILTER. NO WARNING THIS WAS GOING TO HAPPEN. MY TRUCK HAD 95000 MILES ON IT WHEN IT NEARLY KILLED ME AND OTHERS. INDEPENDENT SERVICE CENTER JOHNSONS AUTO REPAIR IN MOORHEAD MN INSTALLED THE NEW CRATE MOTOR FROM LUTHER GMC FARGO ND.

Complete engine power loss.

mechanical and electrical issues with my GMC Sierra Elevation Duramax Diesel, purchased in 2021. Despite multiple dealership visits, diagnostic evaluations, repairs, and software updates, these issues persist and have significantly impacted the reliability and safety of the vehicle. In December 2025, my vehicle was taken to the dealership for diagnostics and a third software update intended to resolve recurring engine-related faults. Throughout 2025, the check engine light illuminated on approximately 30 occasions, confirmed by at-home diagnostic scans. The same diagnostic code related to the 1) SCR NOx Catalyst Efficiency Below Threshold Bank 1 Catalyst 2 P2C7A - Engine I 2) Exhaust Gas Recirculation (EGR) Cooler Efficiency Below Threshold P14D9 - Engine has appeared repeatedly since the vehicle was first purchased in 2021. Additionally, on approximately 15 occasions in 2025, the vehicle failed to start. When pressing the ignition button, the engine screeched while attempting to turn over for 20 to 45 seconds, after which the vehicle powered off entirely. After waiting approximately 10 minutes, the vehicle would then start normally. Notably, during these no-start events, no check engine light or diagnostic code appeared, and the engine light and starting failure have never occurred simultaneously. hese same concerns were explicitly explained to service technicians during the most recent recall repair in 2025. I was informed that a software update would resolve the issue. However, the problems have continued. A similar frequency of failures occurred throughout 2024. At that time, GMC advised that the issue was likely the vehicle’s battery. Acting on this recommendation, I had the battery replaced at my expense in October 2024 by the dealership. This repair did not resolve the issue. From the time of purchase in 2021 through January 2024, these same symptoms occurred approximately 10 times, demonstrating a long-standing and unresolved defect.

Had a "Trans Hot Warning" light. Dealership said it was internal valve body failure. They said there is recall on this for other engine types even though this is same issue. I think GMC needs to expand their recall.

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the engine seized. The contact was unaware of a warning light being illuminated. The contact stated that while attempting to start the vehicle, the vehicle failed to start. The vehicle was towed to the dealer, where it was diagnosed with engine failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The contact referenced an unknown engine recall; however, the VIN was not under recall. The manufacturer was made aware of the failure, and a case was filed. The contact was advised to report the failure to the NHTSA Hotline. In addition, the contact was informed that the VIN for the vehicle was a Canadian VIN, and the mileage was displayed in kilometers. The failure mileage was approximately 120,000.

The contact owns a 2021 GMC Sierra 1500. The contact had received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling). The vehicle was taken to the dealer where an inspection was performed on the engine. The contact was informed that the vehicle had passed the inspection, and the mechanic added a higher viscosity oil, installed an oil fill cap, replaced the oil filter, and updated the Owner's Manual. The contact stated that the remedy failed to address or repair the possible defect with the engine. The contact stated that the remedy resulted in a higher cost for oil changes, and fuel economy had decreased from 21 miles per gallon to 18 miles per gallon. The manufacturer was made aware of the issue and the contact was provided a case number. The contact stated that the vehicle had not been repaired. The failure mileage was unknown.

Heard a ticking noise then check engine light started blinking along with service esc and parking brake. Took it to the dealer and I had a bad lifter again. I was previously repair for lifters under warranty a little over 2 years ago.

The engine is knocking and running rough. I took it to Christian Brothers Automotive in Newnan Ga and the advised engine replacement.

The contact's grandson owns a 2021 GMC Sierra 1500. The contact stated that after the vehicle was purchased from a private seller and driven 258 miles, while his grandson was merging off the exit ramp, the engine seized. The low oil pressure warning light was illuminated. The contact stated that the check engine warning light was illuminated prior to the failure. The vehicle was towed to the contact's residence. The contact scanned the vehicle and retrieved DTCs: P0011, P0016, P006DD, and P0521, stored DTCs: P06DD P0011, and permanent DTCs: P0011 and P0016. The engine was replaced by the contact. The local dealer was contacted for parts. No further information was available. The manufacturer was not contacted. The failure mileage was approximately 100,148.

I just surpassed my extended warranty (5 year/100,000 miles) by a couple of thousand miles and my coolant control valve has gone out. The problem is so common that the part is on back order for months at a time. GM says that they issued special coverage for 2020-2022 models, but my dealer is telling me that my VIN is not covered. They want to charge me $2,400 to replace it. This is insane. It’s a very common problem that they know about and it’s going to almost break me. We need help!

ENGINE BURNING OIL AND BLOWING WHITE SMOKE OUT TAIL PIPES. HAVE TO ADD OIL EVERY 1500 MILES OR SOONER IF TOWING. HAS BEEN AN ISSUE SINCE FIRST OIL CHANGE. VEHICLE IS NOW AT 88057 MILES

The contact owns a 2021 GMC Sierra 1500. The contact received the recall letter for NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling). The contact called the local dealer, who confirmed there was no information from the manufacturer to move forward. The vehicle was not diagnosed or repaired. The manufacturer was not contacted. The contact had not experienced a failure.

While traveling to work at 75mph, a sudden an unexpected malfunction of internal engine components caused a loss of propulsion.

Took the vehicle to the dealer because of an engine noise. It had issues with the valves knocking when it had around 1000 miles. I took it in and now the truck has around 67,000 miles and I’m being told it needs a new engine because of a bent rod in the engine. I was told that I need a new engine. Previously I had a lot of other issues with the front wheel hubs clicking. But, this truck didn’t even make it to 5 years and now it needs an engine.

I own this 21 GMC Sierra with a 6.2L. This vin is not part of your current recall. But my truck is at a dealership waiting on a replacement engine. I was told that the engine locked up in the bay. Not sure if any lights came on before the engine failed, the dealer did not go into that much of detail. The truck is sitting outside waiting on the engine, not sure if gm made then do any failure analysis or just said its a 6.2 were sending an engine.

On [XXX], at approximately 15,873 miles and while on the freeway approximately 30 miles from my home, my GMC Sierra 1500 with the L84 engine experienced a failure of the DFM lifter assembly. This required a significant engine disassembly and the replacement of multiple valvetrain components. This repair was performed at Gold Rush Chevrolet in Auburn, CA, as documented in the enclosed service invoice. GM has issued Technical Service Bulletins and product communications addressing similar lifter failures in Gen V small-block V8 engines with DFM/AFM, including Service Update N212353840, PIP5776, #19-NA-219, and related updates. Industry coverage and owner reports and current Class Action Lawsuits indicate that these failures can recur, even after initial repairs, due to the high cycling frequency of the DFM lifters. Given the nature of the defect and GM’s documented acknowledgement of the issue, I am requesting that GM extend the powertrain warranty coverage for the engine and related valvetrain components for a period of 10 years,100,000 miles as a goodwill policy adjustment. A warranty extension would ensure customer confidence and protect against the significant cost of a repeat failure. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V27400 (Engine and Engine Cooling). The vehicle was taken to the dealer, where the contact was informed that the vehicle failed an inspection. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. In addition, the contact was advised that parts were not yet available. The contact was advised that it was unsafe to release the vehicle to the contact with the recall unrepaired. The contact was advised that the repair would take two weeks for completion. The contact stated that the vehicle had been at the dealer for more than two months. The manufacturer was made aware of the issue but provided no assistance. The contact stated that he needed the vehicle to use. The contact was advised that the vehicle was number 1,000 on the list for the repair. The failure mileage was 71,000.

After having transmission issues which was replaced under warranty, within 300 miles, the engine failed. The vehicle has now been sitting at the dealership since October 7, 2025 waiting for a replacement engine. There is no timeline available for the replacement engine as they are currently backordered. Absolutely ridiculous.

Vehicle showing signs of a failing coolant flow control valve and/orcoolant temperature sensor. - AC takes a long time to cool down - Engine fan will stay on after the vehicle is shut off - I often see the notice of “A/C Off Due To High Engine Temp” From what I can find, this issue I’m experiencing is a known point of failure in this vehicle make/model/year. On 10/10/2025, I took the vehicle to Fountain Buick GMC Service in Orlando, FL. The service manager recognized the symptoms immediately, and even knew right away that the part to fix it was on back order - further bolstering that it is an issue that GM is aware of and deals with regularly. Per the service manager, GM’s initial response was to issue a “pay to play” software update that is covered under the 3yr/36,000 warranty, but not the 5yr/100K. Out of warranty, this “solution” costs $499.99, and has a < 10% degree of success. If the update doesn’t fix the issue, then it would be covered. However, the need for the software update was not communicated to consumers. Regardless, since the issue is not yet severe enough to be recognized via code (despite symptoms, pictures, and video), GM will not take any action under warranty towards fixing it at this time. The vehicle’s 5yr/100K warranty expires on 10/15/2025. If the code throws on 10/16/2025, it will not be covered under warranty, but *may* be covered under dealer assistance. And regardless, the $499.99 charge will apply, independent of warranty coverage. More important than the money is the safety. The engine’s temperature is not being regulated, the symptoms I’m experiencing are terminal, and this issue will not be fixed on its own.

The contact owns a 2021 GMC Sierra 1500. While the contact's husband was driving at an undisclosed speed, the contact noticed an abnormally bumpy ride. The contact felt as if the vehicle was driving over rocks. The check engine warning light was illuminated. The vehicle was taken to the dealer where it was diagnosed with engine failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The contact received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, parts were not yet available for the recall repair. In addition, the contact stated that the vehicle had been at the dealer for more than two months awaiting parts. The manufacturer was made aware of the failure and a case was filed. The failure mileage was approximately 80,000.

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the part to do the recall repair was not yet available. The contact then received a notice that parts for the recall were available. The vehicle was taken to the dealer, and the contact was informed that the recall remedy was for the dealer to use a higher viscosity oil. The contact expressed concerns that the remedy was not a sufficient repair and that the engine was still vulnerable to failure. The vehicle was repaired under the recall. The manufacturer was not made aware of the failure. The contact had not experienced a failure.

Engine lifters bent a pushrod and scratched my camshaft in my engine causing me to be stranded with minor children. 3rd time since I bought this in 2021 that I have had engine faults in this truck.

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle inadvertently lost motive power. The contact was able to pull over to the shoulder of the roadway, where the vehicle failed to restart. No warning lights were illuminated. The vehicle was not taken to the dealer or an independent mechanic. The vehicle was not repaired. After investigating the failure, the contact related the failure to NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); the VIN was included, but parts were not yet available. The manufacturer was not notified of the failure. The failure mileage was 60,000.

See attached document for complaint. I am writing as the owner of a 2021 GMC Sierra 1500 equipped with the 6.2-liter engine that has recently been included in a significant recall. I've been advised that the engine may need to be replaced entirely. As you can imagine, this is extremely concerning given the scale of the defect and the vital role this truck plays i'n my dayto- day responsibilities.

See attached document for complaint.

See attached document for complaint. This law firm represents [XXX] . [XXX] owns a GMC truck with VIN: xxxxxx which is subject to the above referenced recall. Please accept this letter as Mr. [XXX] 's written complaint due to his dealer's failure to remedy the defect covered under the above referenced recall. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure.

Complete engine failure on July 17, 2025, related to current recall for defective engine parts on 6.2L V8 L87 engine. Towed to dealer same day. Dealer continues to report no ETA available on replacement engine. Dealer has had possession of my unrepaired truck for 46 days now and counting.

I receivd a recall on my 2021 GMC Denali 1500 , 6.2 engine Recall # N252494000. made an appointment with Carroll GMC, at 1455S. Tamiami Trail, Venice , Fl, on 7/29/25 at 11AM. I showed up for my appointment and they denied checking my truck on the recall stating they did not have the remedy to fix the problem so therefore they were not going to check my truck for the recall...... I have a trip coming up and now I a afraid to go on the highway in case my truck loses power and I get in an accident............ MY truck should have been checked for the recall regardless of the remedy to fix it..So at least I know weather it is safe to drive or not

The contact owns a 2021 GMC Sierra 1500. The contact stated that the engine was previously replaced under warranty. The contact stated that the vehicle had been experiencing excessive oil consumption and required three quarts of oil every 30 days. The contact received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the part to do the recall repair was not yet available. The contact stated that while driving 70 MPH, the vehicle shuddered abnormally and there was an abnormal metallic sound coming from the engine before the vehicle lost motive power. There was no warning light illuminated. The contact was able to pull over to the side of the road. The vehicle failed to restart and was towed to the residence. The local dealer was contacted and informed the contact that a service advisor would return the call. The vehicle was not diagnosed or repaired. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was not made aware of the failure. The failure mileage was approximately 129,000.

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000 (ENGINE AND ENGINE COOLING); however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure.

⸻ Background: •2021 GMC Sierra Denali – 6.2L V8 •VIN included in GM’s engine defect recall (connecting rod/crankshaft) •Recall status shows “No current remedy available” •Defect acknowledged by GM can cause “engine damage, loss of propulsion, or complete engine failure.” Timeline of Events: •~1 month ago – Truck began running rough with noticeable ticking/knocking noise. •Dealer could not schedule appointment for 3 weeks. •08/08/2025 – Dealer inspection confirmed failed lifters and damaged camshaft. •Repair estimate: $9,300 (see attached dealer estimate). Connection to Recall: •Lifter and camshaft are internal engine components dependent on the same lubrication and oiling system as the crankshaft/connecting rods cited in the recall defect. •The defect’s potential to contaminate oil and cause internal engine damage makes this failure consistent with recall-related damage.

This recall has been coming for some time now its out and GM still has no plan or action. This is our only auto and my understanding if this issue happens it could cause loss of life. I am concerned for my wife driving to work every day and what happens if we want to take a trip. We need resolution on this. Apr 24,2025 Manufacturer Recall NumberN252494000 NHTSA Recall Number25V274 Recall StatusRecall Incomplete, remedy not yet available [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the part to do the recall repair was not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The contact stated that the check engine warning light was illuminated. The vehicle was taken to the dealer, where it was diagnosed with engine failure. The dealer informed the contact that there was no anticipated date for the recall repair parts availability. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 137,000.

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000(Engine and Engine Cooling); however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was not made aware of the issue. The contact had not experienced a failure. VIN tool confirms parts not available.

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000(Engine and Engine Cooling); however, the part to do the recall repair was not yet available. The contact stated that while driving 30 MPH, there was an abnormal knocking sound coming from the engine compartment, and the vehicle lost motive power. The contact was able to pull over to the side of the roadway. No warning light was illuminated. The vehicle was towed to a dealer, where it was determined that the engine needed to be replaced. The vehicle was repaired. The contact stated that prior to the engine failure, the transmission was replaced. The dealer was contacted regarding the recall remedy, but the dealer was unable to provide an estimated time of availability. The contact stated that the manufacturer exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the failure. The failure mileage was approximately 20,000. VIN tool confirms parts not available.

Coolant Control Valve is faulty. Part number 24001355 for my GMC Diesel Sierra 1500. The check engine light goes on and sometimes the engine power will be cut in half to protect the engine. It can be inspected when needed. My truck cannot go as fast and the Engine fans sound very loud to cool down the engine. I was 3 hours away from my house when this happened the first time and I wasn’t sure I would make it home. I had to let the engine cool down for about 6 hours after I pulled off of the highway. This has happened two times so far and happens when the AC is on and sometimes when you use the remote start it won’t start the truck remotely and the check engine light goes on. The problem started in July 2025 with 51,000 miles. The engine control module code is P1098. I have asked my GMC dealership to look at the issue and they have told me that the part is backlogged for at least 2 months and they will not look at my truck until the part is available. I haven’t had any other issues with the engine so far and this was the first time a check engine light has gone on.

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving approximately 40 MPH, the check engine warning light started flashing and the vehicle was shaking with a misfire coming from the engine. Additionally, there was black and greyish smoke coming from the tailpipe. The Roadside Assistance request message was displayed on the instrument cluster. The vehicle was taken to a dealer where it was diagnosed with a misfire. The vehicle was not repaired. The vehicle was taken to the residence, but the failure persisted. The vehicle was taken to an independent mechanic to be diagnosed, and it was determined that the lifter had dropped, and the engine needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was unknown.

The contact owns a 2021 GMC Sierra 1500. The contact stated that there was an abnormal change with the RPM. There were no warning lights illuminated. The contact received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the part to do the recall repair was not yet available. The local dealer was contacted. The dealer received an email from the manufacturer, but the verbiage was incorrect to move forward with the repair. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The failure mileage was approximately 39,000. VIN tool confirms parts not available.

The coolant control valve (Part # 24001355) has failed. Apparently this is the case with many vehicles and GM will not/can not get replacement parts. This should be a recall.

P1098 Code - Coolant Control Valve on/off/on/off.

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle stalled, lost motive power, with smoke came from the engine compartment. There was no warning light illuminated. The vehicle was towed to the residence. The contact attempted to start the vehicle and noticed a knocking sound coming from the engine with the check engine warning light illuminated. The contact received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling). The dealer was contacted and informed the contact that parts were not yet available. The dealer informed the contact that the vehicle had a Salvage Title and would not be repaired under the recall. The manufacturer was made aware of the failure, and a case was opened. The failure mileage was approximately 48,000. VIN tool confirms parts not available.

When I started my truck in the morning I noticed the check engine light came on and my engine fan started running really loudly. I shut my truck off and let it sit for 5 minutes and restarted it in hopes the check engine light would not appear. Unfortunately it did come back on and the engine fan began running really loudly again. I drove the truck to the nearest mechanic and you could feel the truck was trying to counter the problem by forcing me to drive it in a lower speed. After taking it to a shop to get it scanned to see what the code was. The mechanic said it was reading code P1006 three times. He said this coolant system and is why my engine fan was triggered to run really loudly. But the engine was not over heating as all other indicators showed that temps were normal. The mechanic believes it could possibly just be a faulty wire. However after talking to GM he said if it is this coolant part that needs to be replaced, it could take up to months to fix as the part is on national backorder. Doing more research, it appears others have had this same problem and GM even knew shortly after this model was released that this would happen.

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling). The contact stated that while driving at approximately 50 MPH, there was a loud squeaking sound coming from the front driver’s side of the vehicle before the vehicle lost power. Simultaneously, the check engine warning light started blinking. The vehicle was pulled over to the side of the road and the sound became louder, before becoming a knocking sound. The vehicle was restarted, and the failure persisted. The vehicle was towed to the residence. The vehicle was not diagnosed or repaired, but a dealer stated that there was as recall associated with the VIN; however, parts were not yet available to repair the vehicle. The manufacturer was not notified of the failure. The failure mileage was approximately 128,000. VIN tool confirms parts not available.

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000 (ENGINE AND ENGINE COOLING); however, the part to do the recall repair was not yet available. The contact stated that while the vehicle was stopped, the vehicle idled intermittently. In addition, an abnormal sound was coming from the left side of the engine. The vehicle was not diagnosed or repaired. The local dealer was not contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was not made aware of the issue. The failure mileage was unknown. VIN tool confirms parts not available.

My 2021 GMC Sierra 1500 with L87 engine, covered by recall 25V274. None of my local dealers are inspecting for this recall. This truck is my daily driver and I routinely drive on interstates for my work. GM has been slow to address this major manufacturing defect and has not remedied the problem. My truck is no longer worth what is was previously and is lowering trade in or sale value. I am requesting that GM buy back my vehicle due to ongoing safety risks and loss of value.

Was informed from by GM that my vehicle is involved with a recall an still hasn't been repaired

On Dec 27 I noticed a skip in my engine when I started the truck. I took the truck to Cronic Buick GMC on Jan 6 for an inspection. They reported to me that the engine failed.Seized up. I reported the incident to my extended warranty company Warranty Solutions. They refused to do the repair because I was late for an oil change in 2022. After 3 weeks and no cooperation I contacted GM customer service. I was assigned an agent that help initiate the engine repair . The repair was completed on April 12 (3 months after the failure). I paid $4600 out of pocket for a portion of the engine repair .

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000(Engine and Engine Cooling); however, the part to do the recall repair was not yet available. The contact stated that while driving at approximately 60 MPH, the check engine warning illuminated and the vehicle stalled. The contact pulled to the side of the road and attempted to restart the vehicle, but the vehicle failed to restart. The vehicle was towed to the residence. The contact stated that the failure had previously occurred several times while driving. An unknown local dealer was contacted and informed the contact that the recall parts were not available. The vehicle was not diagnosed or repaired. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was contacted and a voicemail message was left, but the manufacturer had not returned the contact's call. The failure mileage was approximately 70,000. VIN tool confirms parts not available.

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the part to do the recall repair was not yet available. The contact stated that the vehicle was experiencing rough idling, with the RPM fluctuating while driving. The local dealer was contacted. The vehicle was not diagnosed or repaired. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was not made aware of the issue. The failure mileage was approximately 32,000. VIN tool confirms parts not available.

Replacement part needed is COOLANT CONTROL VALVE according to diagnostics at local GM dealer service department after noting check engine light was on. YES, it is available for inspection. Told unsafe to drive as it would very likely overheat or worse. It has been in the shop for a month (as of June 11, 2025) awaiting a backordered part, which we’re told is a national backorder. No loaner vehicle available and told by service department that they have had another truck in for same problem for several months and that this problem is very common. PLEASE HELP us with getting the part needed!

See attached document for complaint.

The coolant control valve on my truck is causing issues. From doing research, this is an ongoing issue with the 3.0 duramax. The part is on nationwide backorder and I cannot drive my vehicle in reduced engine power because the only way I can get to work is by taking the interstate. It is madness that GM has not issued a recall or done anything to rectify this issue. Many GMC owners are paying on vehicles that they are unable to drive which is assanine. This part needs to be readily available due to the NUMEROUS complaints that have already been submitted in regards to this part.

The contact owns a 2021 GMC Sierra 1500. The contact stated that upon starting the vehicle, there was an abnormal knocking sound coming from the engine. The abnormal sound ceased once the vehicle had accelerated; however, the abnormal sound returned while the vehicle was idling. The check engine warning light was illuminated. The vehicle was taken to the dealer where it was diagnosed that the ball bearing caused a misfire, and two cam lifters needed to be replaced. The vehicle was repaired. The contact picked up the vehicle and on the way home, the engine failed. The contact took the vehicle back to the dealer. The technician test drove the vehicle with the contact as a passenger, and the check engine warning light illuminated. In addition, there was an abnormal sound coming from the engine. The vehicle failed to accelerate as intended while depressing the accelerator pedal. The contact was informed that the engine failed and needed to be replaced along with the fuel body system. The contact was informed that as per GMC, the oil needed to be changed to an oil with a thicker viscosity. The fuel body was replaced, and the oil was changed. The manufacturer was made aware of the failure and offered the contact an amended warranty. The contact was informed that GMC had elected to participate in the procedures under the Song Beverly Act. The failure mileage was approximately 50,000.

The contact owns a 2021 GMC Sierra 1500. The contact stated that upon starting the vehicle, the vehicle was idling abnormally, prompting the contact to turn off the vehicle. The contact stated that the check engine warning light was illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the lifter in cylinder #4. The contact stated that the lifter had collapsed into the engine, causing damages to the engine and camshaft. The vehicle was repaired. The manufacturer was not notified of the failure. The failure mileage was 98,000.

It started with a emergency brake light coming on, shortly (2 miles) later it started misfiring on cylinder #1 after replacing coil pack plug wire and plug. It then started smoking bad out of the exhaust. I knew GM was having recalls on the 6.2 engines so I hauled it to the dealer. They told me it was a bad engine and since it had aprox.62,000 miles on it and no recall it wasn't covered. Since then the dealer called the factory service rep. and he agreed to replace the engine at a 50% reduction in the price, but had no idea when they could get me a replacement engine. After a few days of research on my part I called the dealer again to get a price on how much it was going to cost me? The owner of the dealership ask me to give him a few more days to ask the rep. if he would agree to 100%. My problem now is I don't have it to drive, I can't sell it. and no idea how long it will be before it can be repaired. Plus I am still making payments on it. It is available for inspection at the dealer. If I had of continued to drive, it could have locked up causing a catastrophic accident. In my research it looks like these problems started in 2019 not late 2020 when mine was built. NC has lemon law complaints going back to 2019 that have been paid out. I currently own a #1 2007 GMC Yukon Denali 6.2 with aprox.389,000 miles and only replaced the transmission recently. #2 A 2008 GMC Sierra Denali 6.2 with 279,052 miles, new transmission. #3 A 2011 GMC Yukon Denali 6.2 with 234,361 miles and #4 a 2017 Cadillac Escalade 6.2 with aprox. 102,000 miles. All of these are working and driving on a daily bases. I have a lot of faith in these 6.2 engines until now, I will no longer be buying any more of these engines even though 1 out of 5 aint bad. Thank you for your consideration and for what you do. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2021 GMC Sierra 1500. The contact stated that occasionally while attempting to start the vehicle, the engine hesitated to turn over. The contact stated that the failure progressed, and the vehicle no longer started as needed. The check engine warning light was illuminated. The contact stated that two local dealers were contacted; however, the contact was advised that to diagnose or repair the vehicle, might take several months. The vehicle was towed to a local independent mechanic, where it was diagnosed with camshaft sensor failure. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 83,000.

Safety recall, unsafe

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000 (ENGINE AND ENGINE COOLING); however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. VIN tool confirms parts not available.

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000 (ENGINE AND ENGINE COOLING); however, the part to do the recall repair was not yet available. The contact stated that while driving 70 MPH, the vehicle failed to accelerate as intended while depressing the accelerator pedal. No warning lights were illuminated. The contact stated that several minutes later the vehicle functioned as designed. The local dealer was contacted; however, the vehicle was not diagnosed or repaired. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was not made aware of the issue. The failure mileage was approximately 38,000. VIN tool confirms parts not available.

I heard a ticking in the engine and noticed multiple warning lights in the dashboard. I called the GMC dealer and was told the next opening was several weeks away. I was also told that it would be OK to drive the vehicle which I did (~10 miles) and parked the truck in my driveway until I could get the truck in for a diagnostic evaluation. The service department at the GMC dealer where the vehicle was purchased identified a defective camshaft/lifter as the source of the noise and lights. The service manager recommended either an engine rebuild at their shop or purchase a replacement motor from the GMC inventory network. The serial # of the old motor is: 126852545. The serial # of the new motor is: 40208378. The cost of the new motor, replacement of required fluids and parts and labor was $12,360. 100% of the repair was paid by myself. The .pdf of the service record (RO #: 9189240) exceeds the 10 MB limit and cannot be uploaded. I have a hard copy if needed. The dealership where the vehicle was purchased and serviced is: TULLEY Buick - GMC - BMW - Mazda P.O. Box T 147 Daniel Webster Highway South Nashua, New Hampshire 03060 (603) 888-0550 www.tulley.com

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at various speeds, the check engine warning light illuminated, and the engine fan activated and operated at a very high velocity. Additionally, the message "Engine Power Failure" message was displayed, and the vehicle stalled. The vehicle was taken to the local dealer who diagnosed that the engine coolant control valve was faulty and needed to be replaced. The contact was informed that the parts were on backorder and no repairs were performed. The manufacturer was not yet contacted. The failure mileage was 48,000.

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving at various speeds, the check engine warning light illuminated, and the engine fan activated and operated at a very high velocity. Additionally, the message "Engine Power Failure" message was displayed, and the vehicle stalled. The vehicle was taken to the local dealer who diagnosed that the engine coolant control valve was faulty and needed to be replaced. The contact was informed that the parts were on backorder and no repairs were performed. The manufacturer was not yet contacted. The failure mileage was 45,000.

I had an engine warning warning light on my dash around May 5th. A notice of reduced speed also lit up my dash while I was on the freeway. I scheduled a service for May 15th and was told the engine coolant flow control valve needed to be replaced. I was also told there was a backlog of other vehicles waiting for the same part. It has been over a month and I am still unable to drive my truck which I use for work.

My Truck has been consuming oil since new, latest documented consumption test was 1.25 quarts in 1967 miles. GM dealership said that is normal and no further diagnosis is required. GM says acceptable consumption is 1 quart per 2,000 miles. This truck has a 6.2L engine that is not under the current recall ( N252494000 ). The engine problems affect more vehicles that the current recall and should be investigated.

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the part to do the recall repair was unavailable. The dealer was not contacted and confirmed that parts were not yet available. The manufacturer was not made aware of the failure. The contact had not experienced a failure. VIN tool confirms parts not available.

Engine seized while at idle speed and has to be replaced. It was a catastrophic event, but not covered under the current recall for 6.2L L87 engines.

I’m filing a complaint regarding GM Recall N232404000/N232404002, which affects the L87 6.2L V8 engine in my 2021 GMC Sierra 1500 AT4. This recall is tied to a serious defect that can cause sudden loss of propulsion due to internal engine failure. My vehicle has shown symptoms since purchase — including engine ticking, unusual noises, and low oil levels — all documented by dealership service records. GM originally instructed dealers to replace engines based on build date, which made sense given the nature of the defect. But now they’ve changed the remedy midstream. Instead of replacing potentially defective engines, they perform a PicoScope test, and if it “passes,” the only action taken is replacing the oil with a different grade. This does nothing to resolve the underlying issue. How does a manufacturer go from replacing engines due to internal failure risks to simply changing the oil and calling the problem solved? This undermines the purpose of a safety recall and places future liability on the consumer. A known internal mechanical defect cannot be fixed with an oil change, yet GM is closing out cases this way. Now I’m stuck with a vehicle I can’t fully trust — one that may still fail unexpectedly — and possibly face diminished resale or trade-in value due to an engine that other buyers will view as unreliable or patched over. GM is leaving owners with the long-term risk while clearing their books of liability. I urge the NHTSA to investigate whether this revised approach truly meets federal recall standards.

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the part to do the recall repair was unavailable. The dealer was contacted; however, the contact was informed that parts were not yet available for the recall repair. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. VIN tool confirms parts not available.

Unknown There is a recall on the this model but with different motor but when I took mine in they said it was a.manufactured defect but I was out of warranty because I purchased it cash and didn't get extended warranty now im having to replace and pay for a head and new engine over 10,000 when vehicle doesn't even have 70,000 miles it started with a engine light going on amd off for 2 weeks then it just stopped working It's too coincidental that the sister truck make n model to this had a recall for exactly what is wrong with mine

We have the 6.2 liter GM engine that has lost propultion. We are not covered in the recall and are 30,000 miles above the milage warranty, but still within the time portion of the warranty. GM payment assisitance has only offered us $1600 to help with replacing our engine. The dealership told me their warranty parts price was higher, so it really didn't offset any cost. This is our ONLY vehicle for our small appliance repair business. Our vehicle was manufactured at the plant in Canada where all the other faulty engines were manufactured. Please consider widening the recall to include our vehicle.

My GM 6.2L V8 engine has seized in less than 100K Miles. Thankfully not whilst driving and being potentially harmful to myself or others with the catastrophic failure. This problem is being widely report and continually occurring. GM is saying that I am not included in the massive recall for this, However NHTSA notes the vin range as NR and indicates incidents are still occurring. Seems to be a real lemon situation here and even bigger a letdown to uphold consumer safety.

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the low oil warning light illuminated. The vehicle was taken to the dealer but was not diagnosed or repaired. The manufacturer was made aware of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 67,600.

code P1098. Engine light comes on, power is reduced, coolant fan runs on high. Temp gauge fluctuates. This last for 20 minutes or so. The engine then returns to normal. After a few days the engine trouble light goes off. This happens every several weeks. Parts are backlogged and I understand this is a common problem with this engine. I have 64000 on it.

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving at an undisclosed speed, there was an abnormal rattling sound coming from the vehicle, with several unknown warning lights illuminated. The vehicle was driven to the residence. The vehicle was taken to the dealer where it was diagnosed with cam shaft and lifter failures. The contact was informed that the cam shaft and the lifters needed to be replaced. The vehicle was not repaired. In addition, the contact stated that when the vehicle was purchased in 2020, the failure had occurred; however, the repair was covered under warranty. The manufacturer was not made aware of the failure. The failure mileage was approximately 7,000.

While driving vehicle started running rough and exhaust was white from tail pipes, could not accelerate and warning lights were flashing. Limped to dealership and diagnosed with a bent rod and had to tear both sides of engine apart and replace heads on both sides due to bulletin for Gmail at 7500 miles. Why is this vehicle not part of the recall to protect my investment?

While the vehicle is traveling at highway speeds it is misfiring and sputtering, giving the feeling of a hard shift. When the vehicle is idling, the engine is sputtering like it’s going to shut off. If the truck were to shut down, as it seems to be trying to do, this could be deadly at highest speeds or intersections. The vehicle has been at a dealer since January 2025. They claimed to have fixed it but upon paying over $1200 and picking it up from the dealer, the problem persisted. We had to take it back to the dealer within 5 minutes of picking it with zero repairs and no estimated time of repairs ever since. No warning lights appeared at all.

So there is recall already for the engine but I’m not part of it which is weird cause my engine has been acting weird which I’m trying to take to dealer ship but they don’t want it due to I not being in the recall list. I have the engine 6.2 LTI have an 2021 GMC Sierra Denali

The camshaft cover in pre 2021 3.0L Duramax motors is leaking oil/def internally causing oil loss. This is something GM has noted in their TSB pages but has not issued a recall over. This is a hazard to emissions, oil consumption, and the def system. Also could result in premature engine failure.

-While driving the vehicle on the highway, abruptly lost power and RPM. Check engine light, along with multiple other warning lights lit up. When parking the truck soon after, had an associated rough idle with low RPM. The truck was then towed to GMC dealership. -Multiple fuel injectors failed, starting misfiring and caused damage to the engine. Unknown if previous injectors are available, replaced at GMC dealership. The damage resulted in recommendation to replace the engine. -Engine began misfiring while traveling at highway speeds, placing me at an increased risk of loss of control of the vehicle. -The problem was reproduced, confirmed, and inspected at a GMC dealership. -No warning lights or symptoms were present prior to accident. Incident occurred abruptly.

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving 75 MPH, the vehicle lost automotive power. The contact pulled over onto the side of the road, and upon parking on the side of the road, the message "Shift to Neutral" was displayed. The contact shifted into neutral, and the vehicle was restarted. The vehicle was taken to a local dealer, and was diagnosed, and the contact was informed that no cause for the failure was found. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 24,453.

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving at an undisclosed speed, the vehicle lost motive power, with several unknown warning lights illuminated. The vehicle was able to restart but went into LIMP Mode. The vehicle was towed to the dealer, where it was diagnosed that the cylinder head had failed and needed to be replaced. The vehicle was repaired. The manufacturer was made aware of the failure and referred the contact to the NHTSA Hotline for assistance. The approximate failure mileage was 43,000.

The contact owns a 2021 GMC Sierra 1500. The contact stated that the vehicle was experiencing excessive oil consumption. The low oil pressure warning light was illuminated. The vehicle was taken to the dealer, but the failure could not be duplicated. The vehicle was taken to the dealer several times, where an oil consumption test was performed. The contact stated that the oil consumption test was not completed. The contact stated that while driving 55-60 MPH, the contact noticed an abnormal oil odor, and the low oil pressure warning light was illuminated. The contact pulled over. The contact then noticed that a significant amount of oil was leaking onto the ground. The vehicle was towed to the residence of the contact's brother. The contact stated that upon inspecting the vehicle, the contact became aware that oil was leaking from the oil pan. The vehicle was towed to the contact's residence, where the contact added oil to the vehicle. The vehicle was taken to Beck & Masten GMC Coastal (200 US-77, Robstown, TX 78380), where the rear main seal gasket was replaced; however, the failure persisted. The vehicle was taken back to the dealer, where it was diagnosed that the alternator and the crankshaft hoses had failed due to excessive oil leaks. The dealer charged a fee for the alternator and the crankshaft hoses replacement. The dealer informed the contact that the rear main seal gasket replacement was covered. The dealer related the oil leak to the oil pressure. The vehicle was not repaired. The manufacturer was notified of the failure, and cases were filed; however, no further assistance was provided. The failure mileage was 44,000.

In February of 2025 my check engine light came on while i was at work. Went to the local auto zone to have the code read and it. Right after that i drove straight to Gay Family Auto. along the way there was a jolt followed by a stall The car behind me nearly re ended me. i made it to the dealership after inspection i was told i blew a rod and had metal shavings due to an engine failure. Up to this point i had no indication of any issues or dash board warnings. i was told i needed to provide all prof of oil changes which i did. after two months i get my truck back from GMC with a new motor. The new motor is now under recall for doing the exact same thing as my old motor. GM basically took out a faulty motor replaced it with a new one in hopes nothing happens. I reached out to GM and they told me to take it to a dealership for inspection. The dealership told me they wont touch it til GMC sends a solution. im currently driving a truck that could possiably fail again

The vehicle will crank and not start. Dealership said they cannot replicate the fault. Same problem occurred after with dealership not helping. I am a US Soldier currently stationed in Germany and continue to have the same problem every 2months. It will crank and not start. The truck will start on the second attempt after cranking for about 20seconds. The continued issue can permanently damage expensive repair parts that I will not be able to afford. I know I am not the only one with the same issue as I have talked to others and have no solution for this.

Coolant Control Valve (ccv) on these vehicles are notorious for breaking down/ becoming non-operative. I have been waiting for a part for months.

My vehicle suddenly stopped working in the middle of an intersection. A screen notification prompted me to restart it, so I pulled over safely, as there were no other vehicles nearby. However, I worry about the potential danger if this had happened on a freeway. After waiting, I tried restarting the vehicle, but it still wouldn’t work. The next day, I received an email from Carfax about an open recall for my vehicle due to engine issues, matching the symptoms I was experiencing. I scheduled an appointment for 4/28, and had the vehicle towed to Elk Grove Buick GMC. At GMC, they couldn’t offer immediate solutions, needing to diagnose the vehicle first. This process took about four days. During this time, I was advised to contact GM, as the vehicle was affected by the recall. I submitted a case to GM on April 28th, requesting compensation for a rental or loaner vehicle, a truck for my business needs. Without it, my business operations would suffer, leading to revenue loss. The dealership’s diagnosis found the engine seized due to a failed bearing. GM contacted me about the recall, initially mentioning the lemon law and a potential buyback, which I hadn’t considered. After I expressed a desire to repair the vehicle, they contacted the dealership for more information. GM later clarified that the vehicle wasn’t covered under the recall, citing the cause and symptoms as not meeting the recall’s criteria. This seems contradictory, as a failed engine doesn’t necessarily contradict the recall. GM stated they couldn’t provide a remedy, leaving me responsible for repair costs, and noted my vehicle’s 70,000 miles exceeded the power train warranty. Recall claims dealerships will inspect and, if necessary, repair or replace the engine. It’s confusing why my vehicle isn’t covered for repairs or assistance under this recall despite the engine failure. What is the law in terms of warranty as I was under the impression that warranty status is irrelevant in an active recall vehicle.

Engine failed GM made me pay for a new one. Second engine failed due to mechanics did not change out radiator. I now have a third motor with a recall. This vehicle has cost me a lot of out of pocket expenses, I believe GM owes me for the depreciated value plus lost wages. Maybe a buy back I'm not sure.

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving 65 - 70 MPH, there was a knocking sound coming from the vehicle and the vehicle shut off. There were unknown warning lights illuminated. The vehicle was towed to an unknown location. The local dealer was contacted. The vehicle was not diagnosed or repaired. The vehicle was taken to an independent mechanic who determined that there was a solid engine bottom and bearing failure. The contact was informed that the engine needed to be replaced. The vehicle was repaired. but the failure recurred, and the vehicle failed to start. The manufacturer was contacted and informed of the failure. The failure mileage was approximately 83,000.

The contact owns a 2021 GMC Sierra 1500. The contact was notified of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the part to do the recall repair was not yet available. The local dealer was made aware of the issue and confirmed that parts were not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. VIN tool confirms parts not available.

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed and making a turn, the vehicle made a loud banging sound and the vehicle shut off. No warning light was illuminated. The vehicle was towed to an independent mechanic, who determined that the engine had failed and needed to be replaced. The vehicle was not repaired. The contact related the failure to NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the VIN was not included in the recall. The manufacturer was not made aware of the failure. The failure mileage was approximately 80,000.

Vehicle has less than 64,000 miles and seems to be having engine issues. ESC message with engine power reduced. Cannot even drive the vehicle any longer. Cannot get it into a shop for a month and will have to have it towed.

I had purchased a 2021 GMC Sierra equipped with the 6.2 liter motor in October of 2021. Within two weeks, my engine was experiencing problems. There was no service lights on the dash, and my truck suddenly shut off while on a busy road. I was able to coast to the side of the road, however it was a driving lane with no shoulder which made the situation dangerous. I was able to restart the engine after some time, and eventually get the vehicle off of the roadway, thankfully I got out of the driving lane without being struck by another vehicle. The truck had approximatley 1000 miles at this time and was brand new. I ended up needing a complete engine replacement due to failed crank bearings and connecting rods. I was told it was a crankshaft issue. After the complete motor replacement, sometime during the next year I was experiencing oil burning issues. On this second motor, a GM dealer had to completley rebuild the top end of the motor and install new piston rings. This is now a total of two motor failues in under 30,000 miles.

First engine blown 31,904 miles, Lifter failure. Replaced with re-manufactured engine. Second engine failure at 68,000 miles, Piston rod failure. Piston blew thru engine block and engine bay caught on fire.

I wanted to reach out to see if there is anything in addition to the lemon law. I bought a 2021 GMC Sierra with 38,000 miles on it around March of last year. There was a motor defect which was covered by the warranty. I was driving and it stopped in the middle of the road so I had to safely maneuver out of the main road. The truck was towed to my house with 45,184 miles on it, until the GMC dealership could take it in to inspect. They did take a while to get me a rental because everything was backed up. They said they could rent me out a truck due to not being their brand and that it only covers a certain amount. It got taken in by the dealership on 7/15/2024 and ended up getting the truck back repaired on 8/27. I did get the truck back and have been having it, I am just worried about it breaking down or anything of that nature. I just wanted to know if there is any further process I should do or since they repaired it there should be no issue.

The contact owns a 2021 GMC Sierra 1500. The contact stated that there was an abnormal ticking sound coming from the vehicle while idling. There was no warning light illuminated. The vehicle was taken to an independent mechanic to be diagnosed. The contact was then notified of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the part to do the recall repair was not yet available. The local dealer was not made aware of the issue. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The failure mileage was approximately 33,000. VIN tool confirms parts not available.

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving approximately 55 MPH, the vehicle suddenly experienced a loss of automotive power. During the failure, the message "Shift into Neutral to Restart" was displayed. The vehicle was later towed to the local dealer, who diagnosed that the piston bearings had seized, causing damage to the engine. The engine was replaced along with the radiator, oil cooler and oil cooler hoses, intake manifold, mega fuse, and starter. The manufacturer was notified of the failure. The contact was informed that the VIN was recently included in the NHTSA Campaign Number: 25V274000 (ENGINE AND ENGINE COOLING). The contact stated that the vehicle had experienced the failure listed in the recall. The failure mileage was 122,691.

Motor seized up while going around 65mph. Truck lost all power and would not start brought to dealer and they said that it was the crankshaft bearings and something with the connecting rods, the deal told me that they don’t know what to do and is waiting on GM. There is a recall for these issues but no fix. I’m just waiting for the dealer to tell me what’s next but they don’t even know.

Engine light came on, went to the dealership where I bought the truck less then two weeks prior. The Chevy dealership ran diagnostic test on it. They said it was the Engine Coolant Control Valve. This is a common problem with the 3.0 Duramax diesel engine. I belong to a group on Facebook with the same truck as mine. they are all having the same issue. We are waiting for a recall. the part is on back order and cost $300 just for the part plus labor. I bought the extended warranty and they said it did not cover this part.

Had the car since 2021. Recently started shaking while driving over 45 mph. Took the car in gmc dealership where they told me it’s an engine issue and need a brand new engine. How would I need an engine having the car for 4 years? And there is no recall?

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving 70 MPH, several unknown warning lights illuminated, with the message to shift to neutral displayed. The contact pulled over to the right side of the road and attempted to restart the vehicle; however, the vehicle failed to respond as needed. An unknown dealer was contacted. The contact stated that the failure had occurred on several occasions. The vehicle was towed to the dealer, where it was diagnosed that the engine was damaged and needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure and offered a monetary payment. The approximate failure mileage was 80,000.

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving at an undisclosed speed, there was an abnormal sound coming from the engine compartment. The contact pulled over to the side of the road and discovered that the engine oil level was low. The check engine warning light was illuminated. The failure occurred on several different occasions. The vehicle was taken to a dealer, where it was diagnosed that the lifters needed to be replaced. The vehicle was repaired; however, the failure persisted. The vehicle was taken to a different dealer (Legacy Westbank Buick GMC; 3611 Lapalco Blvd, Harvey, LA 70058) to be diagnosed. The vehicle was not diagnosed or repaired. The contact was taken to a different dealer (Mossy of Picayune; 241 Frontage Rd, Picayune, MS 39466) where it was diagnosed that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 27,000.

Driving 75mph towing a 24' trailer and the motor just shut down and almost caused a massive pile up on [XXX] . INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

at 16,000 miles Bank 1 lifters fail and replaced under warranty. now at 90190 miles Bank 1 lifters have failed again this time damaging the camshaft. I have all the service records for this engine and I was verbally assured by GM in 2021 that they would cover this repair until 100,000 miles. I know from looking on Google and talking with service advisors at GM that the 6.2L ecoTec3 V8 engines are having multiple problems related to my issue. GM should be able to warranty this engine to 100,000 miles and from past experience this engine should last 200,000 with good service.

Driving on highway at approximately 70 mph and the engine completely cut off without warning. Error message on dash said put car in neutral and press the start button. After safely pulling over, the vehicle was never able to start or even crank. Towed back to the dealership. Catastrophic engine failure according to the dealership. Vehicle has the 6.2 V8 engine with known issues by GMC apparently. Only 32k miles and under warranty but dealership reports that replacement engines are on back order and they have not been able to source one.

Engine failure. Engine Locked up and truck shut down in the middle of the Freeway. Barely made it to the side of the road.

Lifter failure resulting in damage cam shafts

At cold start-up, engine (6.2) makes a metal-to-metal grinding sound for 60-90 seconds. After warm-up, a steady tick on the right side of the engine while running. I contacted GM and they said, " this was normal at start up". however, with me being a mechanical engineer, all of my school and working experience tells me anything grinding metal to metal is not good.

Engine seized and now we need a new motor

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving 60 MPH, there was an abnormal knocking sound coming from the engine compartment, after which the vehicle lost motive power. The contact was able to pull over to the shoulder of the roadway, where the vehicle failed to restart. The check engine warning light was illuminated. The vehicle was taken to an independent mechanic, who determined that the engine had seized. The contact was also informed that the fuse box needed to be replaced. The vehicle was repaired, but the failure reoccurred. After investigating the failure, the contact related the failure to NHTSA Action Number: PE25001 (Engine, Engine and Engine Cooling). The manufacturer was not notified of the failure. The failure mileage was 63,000.

I was driving 50mph when my check engine light started flashing. The engine had very little power and there was a new consistent engine knock. I took to GMC dealership and they informed me that half of the engine lifters failed and a pushrod was bent. There was no warning prior to the incident. I have had the vehicle serviced only at the dealership and have only used premium fuel. The truck has 88,000 miles.

I've now had 2 engines fail catastrophically, One at 19,191 miles and the second failure at 80,661. Both are the 6.2L engine. The first had crank bearings that were black. The second I was not informed of the cause but that it was seized leaving me stranded on the roadside.

While driving the vehicle shut off in the middle of the roadway. It sat in the road till it got towed. Brought it to the dealership where it was purchased and they said the engine was blown. Themis vehicle is equipped with the 6.2 motor. It happened February 16th. The dealership confirmed the engine failed. It is siting currently at the dealership and could be available for inspection.

Engine failed and had to be replaced. GMC was absolutely no help had to bring to local gas station where i had to pay almost $12,000 to get it fixed. The truck has been in shop frequently for oil issues with this motor but GMC just jerks you around. I am in sales and need my vehicle to support my family

My Vehicle went into the dealer on January 21, 2025. My initial complaint was tapping noise, I was advised that my vehicle had collapse lifters issue several days later I was informed that they have found metal shards in the lower end and found a bad crank bearing and crank. I was told that the vehicle will need an engine replacement, and that the engine is on back order with no date of fulfilment. My vehicle has 66,700 miles I was advised was out of warranty and that GM will only cover half of the estimated cost of 11,000.00.

AFM lifters failed which caused cam shaft to collapse under 35k miles. Had to remove while front end to repair

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at approximately 80 MPH, the vehicle stalled and failed to return to normal operation. No warning light was illuminated. The vehicle was towed to be diagnosed. The contact was informed that the rod bearings needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 134,000.

While driving on the highway the engine 6.2 GM seized suddenly at high speed. The truck shut off completely and left rolling without any control. I had work my way accross lanes to the breakdown lane. While doing so I was almost hit by an 18 wheel trailer truck, who luckily was able to change lanes to avoid hitting me. The reason I was almost hit was because of my low speed since I had now power or acceleration.

I purchased a new 2021 GMC Sierra Denali with a 6.2L engine on 03/05/2022. On November 10, 2022, I started the truck, and the engine seized up. The truck had 9018 miles on it and 274 engine hours. The main bearings and possibly the connecting rods bearings was the problem. On January 27, 2023, I finally got a new engine installed in my truck. I had to pay for the repairs.

Driver side lifters collapsed and push rods failed on freeway without warning at 12900 miles on truck.

lifters in the left and right side snapped into 3 pieces. Caused engine failure happened 2 different times. All before 50,000 miles. The first time was before 30,000 miles.

Engine failure

Engine knocking and metal in oil. Been to the dealership and even though it's under warranty they will not act on it due to no check engine light present. It's making it difficult to trust driving the vehicle anymore because of the thought of the engine shutting down without warning anytime. This complaint is documented and confirmed by a dealership. They made me pay the check out fee and recommended i keep driving the vehicle until the motor locks up.

I was notified at the dealership that my truck had metal in the oil that is causing the oil sensor pump to send a ln engine code. The fix is a new engine.

Lifter noises, error codes for misfires, lost power

Multiple injector and lifter failures. Occurred on 2 separate occasions. Taken to dealer the first time. Told injector failure and lifter failure. Less than a week later experienced multiple lifter failures. Taken to dealer again for repair. They only replaced some of the affected lifters, even though TSB from GM recommends replacement of all of them. Currently awaiting failure of additional components not replaced. There was no warning of either occurrence. Was only driving 45 mph on my way home the first time. The second occasion was on initial start up at Dr office. Opened a claim with GM on my own, as dealership was negligent or unwilling to contact GMC about these failures, even though I provided them with the appropriate TSB directly from GM.

I got off work started my truck heard a few pops. As I was driving the vehicle started jerking like the brakes were being applied. Then I noticed a yellow engine light and a ESC light come on. I pulled over to check vehicle and all the lights went off. Dealer was just a few miles away. So I started back up and drove to dealer. On the way to dealer vehicle started a tapping noise. Then a new message flashed something about my steering will be affected. I got I to dealer safely. Where I left the truck for repairs.

at 8500 miles the engine had lifter go out while I was driving down the highway cause to truck to vibrate and becoming on unsteady causing me to pull over in the middle of traffic. later at 36500 miles it had another lifter go out this time I was driving home at a slower speed but still cause me to have to pull over vert fast as the vehicle became unsteady and vibrated causing all the alarm to come on. Both times the truck was fixed under warranty nut they replaced it with the same parts that are causing the problems. Soon my truck will be off warranty and this will come out of my pocket.

I purchased this vehicle new in 2021. It is an Ultimate Denali trim level with a 6.2 engine. Within the first year, the driver's side head on the engine had a massive failure with only 7,000 miles. I started up the vehicle and was parked idling briefly when several light came on along with a rough idle and some exhaust smoke. I contacted On Star, who could not diagnose the problem. The vehicle was disabled and ended up being towed to the dealer, where it was being repaired for 10 days. The lifters, valves and push rods were replace. The mechanic admitted there was an internal GM problem with the 6.2 engine. I asked for the same repair be made on the passenger side head. The GM dealer refused, knowing of the faulty factory installed parts. The polished tailpipe tips were not replace and were stained by the black exhaust. They are still stained this day. I purchased this vehicle for my retirement to tow my RV. Now, I have been reluctant to travel because of the other head letting go on me somewhere out west, operating under a work load. I know of two other people who purchased new GM vehicles with the 6.2 engine, who experienced the same failure, with around the same mileage on their vehicles.

Engine failed due to a loss of oil pressure. Rod bearing failed which cause metal to be dispersed throughout the engine causing the engine to seize from a sudden loss of oil pressure from oil pump failure. Engine was replaced in June 2024 failure happened in May 2024. While driving a system message came on DIC that stated pull over immediately to prevent engine damage and no oil pressure. I was driving uphill with cars on my right in the #2 lane. Engine shut off before I could pull over resulting in decreased braking power and a lack of steering. I almost hit 2 vehicles trying to pull over to get my family to safety on the right hand shoulder. I couldn’t pull over to the left hand shoulder as there was a guardrail in the way. When I got my vehicle pulled over the only thing that stopped my vehicle from going over the cliff was a bunch of wood chips on the right hand shoulder. From the time the warning lights came on to the time the engine shut off and seized was maybe 5 seconds. It took 31 days to replace the engine and the dealership did an inspection on the engine. There was absolutely no warning there was any problems until the lights came on. My wife and [XXX] and [XXX] were in the vehicle at the time this happened. It was so dangerous where we broke down California Highway Patrol stayed behind my vehicle with its lights on. It was also a fire hazard with the exhaust sitting on the dry bark. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The engine blew up at 67,000 mile while driving down the road. Not sure what happened but there was no warning signs at all. The dealership said they couldn’t know for sure what happened but most likely the oil pump went bad. I have spoken with a few people that have had this same problem with the 6.2 liter engine. It needs to be looked into because this could have caused a major accident on the highway.

On memorial day weekend 2023 my truck ,2021 GMC Sierra AT4 was making a awful noise. I pulled over and vehicle died. had it towed and the warranty covered new engine replacement at 54678 miles(large deposit of metal in the oil pan). June of 2024 again, traveling out of town and pickup making terrible noise and shaking at 76651 miles. Replaced lifters in vehicle. October 11, 2024 took vehicle in for oil change, drove 25 miles and vehicle making terrible noise. Pulled over and pickup died. Had it towed to dealer and they are saying it needs a new engine. ( 87000 miles) they are saying its out of warranty. There seems to be a serious problem with this engine( 6.2) in all the research I am finding. I now have a pickup that I am still making payments on , that I cannot drive.

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving 45 MPH, there was an abnormal ticking sound coming from the vehicle. The contact stated that several unknown warning lights were illuminated. The vehicle was placed on a trailer and was taken to an independent mechanic who stated that the lifter and cam shaft needed to be replaced. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was contacted and referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 133,000.

Per the dealership: Lifter failure, crankshaft failure, metal shavings in the oil. Complete engine failure.

The contact's husband owns a 2021 GMC Sierra 1500. The contact stated that while her husband was driving 80 MPH, the vehicle stalled. Additionally, the "Shift to Neutral and Restart" message blinked. The vehicle was steered to the side of the road where the vehicle failed to restart. The vehicle was towed to an independent mechanic where the failure was not able to be replicated. The vehicle was then towed to the dealer where it was suspected that the crankshaft bearing had seized, putting pressure on the starter, causing a short. The contact was informed that the engine needed to be taken apart for a proper diagnostic test. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 81,000.

The engine locked up on the truck due to bad lifters. It has the 6.2L engine and after talking to several mechanic shops and research online this is a very common issue. GM is having to put lots of new engine in under warranty due to this issue. They need to have a recall to fix a known issue that is costing people thousands of dollars to replace the whole engine in the truck. We was driving down the hey today and with no working at all the truck died and and would not crank back over. We had the truck towed to a repair shop to find out that our truck had the same issue that lots of people are having and now it’s gonna cost us several thousand dollars to have fixed when realistically GM should be paying to fix this problem.

On the evening of 5/6/24, my husband was driving home in our 2021 GMC Sierra 1500 when the truck started to run hard, shaking, and the check engine light came on and was blinking. He pulled onto the side of the road immediately and more messages were coming across the dashboard. The truck was towed to a dealership that same night. Once the dealership assessed what was wrong, we were advised by the dealership who confirmed the lifters failed. The truck is currently still sitting at the dealership as we're waiting for the parts because we've been told multiple times that the parts are on backorder. I understand the truck is available for inspection as its been sitting on the lot since 5/6/24. This is the first time this has happened to the truck, zero prior issues. The truck has great service records and has always been properly maintained. We are currently still under the manufacturer warranty. To date, the dealership is still in possession of the truck for 90 days, and we still do not have any ETA on when the parts will arrive/truck will be fixed.

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle failed to accelerate as needed and made an abnormal sound. The contact assumed that the sound was coming from the transmission and the vehicle was taken to a dealer. The dealer diagnosed the vehicle and suggested that the failure might be a pulley or a rod bearing failure. The contact took the vehicle to another dealer who confirmed a rod bearing failure. The manufacturer was not made aware of the failure. The vehicle was not repaired. The failure mileage was approximately 46,000.

The coolant control valve is faulty and needs to be replaced. GMC and the dealership know about the issue (Bulletin No. PIP5791), but are not fixing it in a timely manner. This is a safety concern as the system will automatically reduce engine power, which is a major concern when towing and/or in mountainous terrain.

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at approximately 75 MPH and depressing the accelerator pedal, the vehicle failed to accelerate as intended. The check engine warning light was illuminated. The contact stated that the vehicle would slow down as if it was losing motive power. The vehicle was driven to a local dealer where it was diagnosed that the coolant control valve needed to be replaced. The vehicle was not repaired due to parts not being available. The manufacturer was notified of the failure. The failure mileage was approximately 32,000.

I purchased this vehicle used with approx 16k miles on it. Not long after getting it - as I was driving it started dinging and then would shut off. Sometimes I’m in the fast lane going 75Mph and it’ll just shut off. The dealership can’t get it to repeat itself. They said they’ve heard of it happening before but it throws different codes. There’s no rhyme or reason to causing it to shut off, but here lately I don’t even get the warning bell. It just dies on me. As soon as i shift it to neutral and press start it’ll restart instantly. But it’s scary nonetheless, and causes me to drop speed instantly and poses a safety risk especially when I have semi’s or other vehicles close behind.

Lifters camshaft malfunction. Known issue with 2021 GMC Sierra 20,000 miles

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle was shaking with the check engine warning light illuminated. The independent mechanic was made aware of the failure; however, the vehicle was not diagnosed or repaired. The contact stated that the independent mechanic had previously replaced the lifters, but the failure recurred. The manufacturer was not made aware of the failure. The failure mileage was approximately 20,095.

DRIVING DOWN THE HIGHWAY THE ENGINE STARTED SKIPPING AND STARTED BLOWING OUT BLACK SMOKE, AND QUIT RUNNING IN THE MIDDLE OF THE HIGHWAY. FOUND OUT THE HAD A FACTORY LIFTER DEFECT ON MY MODEL AND A SERVICE UPDATE WAS SUPPOSED TO BE DONE ON THE TRUCK CHANGING OUT THE LIFTERS HOWEVER EVEN THOUGH I HAVE GONE TO DEALERSHIP FOR ALL THE MAINTENANCE THE SERVICE HAD NEVER BEEN DONE OR TOLD TO ME. THIS COULD HAVE BEEN VERY DANGEROUS JUST ENGINE FAILURE THE SERVICE BY GMC N212353840

I was operating my vehicle in northern Minnesota with a temperature well below freezing. Vehicle warning light came on that said "turn off vehicle" which I did. When I went to start it again it would not turn over. It appeared that a large amount of oil had expelled from the vehicle. It was very dangerous as I was in a very remote area with very poor cell service and extremely cold temperatures. I couldn't even run the vehicle to stay warm. The vehicle was towed to the nearest GMC dealership where they examined the vehicle and stated that the seal of the oil filter had blown off. They further stated that the oil filter which was installed by Valvoline was the wrong size. Valvoline tested the Champion oil filter and came back with findings that the filter was the correct size and noted no damage to the filter. Either there is an unknown problem with the GM engine or the Champion oil filter. Each corporation continues to point fingers at each others product.

2021 GMC Sierra 1500 AT4 6.2L engine, Little over 39000 miles, Purchesed May 2021. This is the second time the vehicle has had this issue. The first time was aprox 15000 miles. I reported the issue to NHTSA-ODI on 6 Dec 2021 tracking # 11442943. I was driving down the interstate I heard a rattling coming from the engine (same as I had heard with the first issue). The check engine came on I ask On Star to do a digonsotic report (see attached report). The report indicated a Fuel Management System issue detected advised to reduce vehicle speed and pay load as possible. I was told by GM certified mechanics that this issue could cause the engine to lock up and come to a complete stop on the roadway. I fill that these vehicle are unsafe to operate under these conditions and may cause serious accidents. GM has known about these issues with these vehicles for several years and has failed to correct the problem.

15000 MILES LIFTER FAILURE IN TRAFFIC HIGHWAY AT SPEED 70 MPH LOST POWER ENGINE FAILED MULTILANE HIGHWAY RUSH HOUR TRAFFIC NO WARNING FAILURE

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle went into Limp Mode with the check engine, DEF tank, and emission warning lights illuminated. The vehicle was taken to the dealer, and the dealer replaced several unknown sensors; however, the failure recurred. The dealer determined that the computer needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 35,000.

Engine lifters failure, caused ESC light to come on and check engine light and other dash lights. Lack of power from engine causing dangerous driving in traffic.

The contact owns a 2021 GMC Sierra 1500. The contact stated that the check engine warning light was illuminated and the vehicle failed to accelerate above 60 MPH. The contact took the vehicle to the dealer who diagnosed that the DEF tank had failed and needed to be replaced. The vehicle had not been repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 4,000.

The contact owns a 2021 GMC Sierra 1500. The contact stated that after starting the vehicle, the check engine light remained illuminated and the vehicle would not properly accelerate while depressing the accelerator pedal. The vehicle was taken to the local dealer who diagnosed that the engine valve lifter was faulty and needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure. The approximate failure mileage was 11,000.

Vehicle has less than 10,000 miles. Started making a loud noise and shuddering in the engine while at speed on the highway. Made it to dealer but was concerned we were going to break down before making it safely there. Service manager strongly suspects engine lifters (he drove it briefly with me and says this is a known issue with this truck & they currently have 3 other trucks in the shop with this same problem. He said parts are a 3-4 month wait and vehicle is not driveable, will break down, but couldn’t say when - could be 10 minutes, an hour, or a day. This happened to me on 2/1/22, while out of town on vacation. An hour on the phone with GM and was passed around to 3 different individuals. GM would not provide a loaner vehicle - leaving me stranded out of state. I had to get a rental vehicle on my own, GM claims they will reimburse me for a portion of this after 6-8 weeks. GM will not tow the vehicle home to Virginia (vehicle is in NC). I had to turn in rental car once I returned home because I can’t afford to keep paying for this on my own and it’s not a truck, which I depend on. Dealer is unable to fully diagnosis and document until end of week 2/7 or early week 2/14 as they are very busy. Unacceptable on ALL levels.

Famous lifter issue in the l84 engine. Hundreds of documented complaints and current class action lawsuit. I had to stop on a busy highway and it caused unsafe passing and irritated humans.

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving 15 MPH and making a turn, the vehicle lost power steering assist functionality. Additionally, the brake pedal was depressed several times but failed to respond. The parking brake, traction control, brake, engine, and headlights warning lights were illuminated. The contact also stated that the warning message "Limited Power" was displayed. The contact stated that he depressed the brake pedal with his two feet from a standing position and the vehicle decelerated and he pulled into a driveway. The contact was able to continue to drive the vehicle. The vehicle was taken to the dealer who diagnosed that the vehicle software needed to be updated. The contact stated that the vehicle was repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 10,000.

On 11/19/2021. While on the express way our truck started sounding really bad. We drove it slower to a gm dealer in Highland MI. They said we had a misfire. And there was nothing they could do at this time. We drove a little further and it got worse. We had to stop at a rest area. After dark and in the freezing weather. We had it towed to a dealer in Frankenmuth MI. Our truck has 11,800 miles . It has a diagnostics report of Valve lifter defects left bank. Starter had to be replaced. And now gm wants to only fix to affected bank . But on the unsold trucks they will repair both banks as stated in service bulletin N212353840 . If we have one bad lifter they should all be replaced as for this not to happen again. As of 12/08 2021 it is still in the shop [XXX] Thank you INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6).

2021 GMC Sierra 1500 AT4 6.2L engine, Little over 15000 miles, Purchesed May 2021. Drivining down the interstate with out warning, engine starting making back fire sounding noise, with a noticeable loss of power, I requested On Star to do a vehicle diagnostics, no faults was reported, No check engine light, temp was normal, oil pressure normal. The noise was off and on at first and then remained constant. Fortunataly I was able to make it safely back to my residents. I parked the vehicle and did a scan code and it did not have any codes, I did a pending code scan and it had a P0300 code. I started the engine and the noise was louder at first and then got quiter after about 15 seconds of running the check enging light came on I shut the engine down and did another scan it gave me a P0302 code. I feel that the vehicle is unsafe to drive and could cause a accident if it locks up on the highway. I contacted GM and reported the issue, they said take it to a near by GM dealer, I told them that I felt the vehicle was unsafe to drive and they tried to contact me with road side assistance but I was unable to get anyone on the phone. I feel that GM is ingnoring a known issue and that this will result in accidents and possible loss of life.

Valve lifter defects. June, 2021: 7,619 miles: left side valve lifter defect necessitating need for valve, push rod replacement on left bank of engine November, 2021: 13,171 miles: right side valve lifter defecting necessitating need for valve and push rod replacement on right side of engine

a lifter went out. While driving on a turnpike going 80 mph the engine starting knocking. The truck had to be towed to a GMC dealership where they confirmed a lifter went bad. the truck is a v8 with 8,000 miles on. the dealership advised what the problem was and replaced 4 of the 8 lifters. No warning was given, as soon as the lifter went out there were all sorts of errors that started showing up including emissions issues.

While driving on the highway my truck started to buck and had a loud engine knocking noise. Speed was greatly reduced so much so that I was going under 45 mph in a posted 65. The check engine light did not come on. While sitting on the side of the highway there was a severe engine knock only when the revs on the engine were increased. Oil pressure and cooling temps were as they should be. The next day on the way to the dealership the engine started knocking. This time the check engine light came on, speed was greatly reduced at this time. After about five miles the knocking stopped and the check engine light went out. The Dealership checked it out and stated the lifters were bad. It seems that this is a known issue with GM. I was told by the Dealership that there were two other trucks ahead of me with the same issue. Also, because this is such a prevalent issue with GM, they cannot keep up with the demand for parts. My Dealership is waiting for a head gasket. GM has known about the faulty parts for approximately two years, and they are only replacing some of the faulty, poorly made parts, hoping the other side of the engine will not develop issues and fail. I feel this is placing the driver and occupants at risk while driving down the highway and not being able to maintain posted speed limits, or just locking up and engine, and coming to an abrupt stop.

The truck has 7500 miles on it and the check engine light keeps coming on then goes back off. It is impossible to schedule service as the light goes off before it gets to dealer. The when driving the truck many times the check engine light will flash for a minute or so and then remain on steady. This is very frustrating and the dealer has found nothing. It has happened probably 10 times since the truck was new and continues now. The truck was just serviced and the dealer found nothing causing this.

Bought GMC Sierra 1500 brand new. At approximately 2300 miles the engine light started blinking. I took it in and they said they couldn't find anything wrong with it. At 3700 miles it started again and I took it in. It has a bent push rod causing engine failure.

GM has a lifter problem that causes complete engine failure. When this happens the engine completely locks up rendering the vehicle completely shutdown. This is happening over and over in early stages of 2021 Chevrolet and GMC Vortec V-8s. Mine happened at 13000 miles on a 2021 6.2L GMC Denali, and GM is only fixing the problem partially and as I understand with the same defective product that just failed. Also it is known this failure likely will happen again as it is a design flaw. If this happens in the wrong traffic situation it will be very dangerous. I am very concerned. When my vehicle was towed to dealer they had 7 other 2021 complete engine failures just like mine waiting for repair.

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving in inclement weather, the vehicle stalled without warning. The contact looked under the vehicle and saw that engine oil was leaking from a puncture in the oil pan. The vehicle was towed to the local dealer however, the cause of the failure was not yet determined. The manufacturer was notified of the failure. The failure mileage was 5,800.

5300 miles and when you accelerate it knocks and or ticks, and loss of power all lights on dash came on

WHILE DRIVING DURING WINTER CONDITIONS WITH TEMPERATURE AT 3 DEGREES ON A RESIDENTIAL STREET WITH LIMITED TRAFFIC, THE DIESEL FUEL IN THE FUEL FILTER GELLED UP WHICH CAUSED THE VEHICLE TO DISPLAY REDUCE POWER MODE AND THEN IMMEDIATELY SHUT OFF AND WOULD NOT START. THE VEHICLE COASTED TO A STOP IN THE MIDDLE OF THE STREET WHILE IN TRAFFIC. THE OWNERS MANUAL LISTS UTILIZING TOP TIER DIESEL WHICH I DID. WHILE ADDITIVES ARE NOT NORMALLY NEEDED IN MOST STATES TO FUEL FOR FREEZING CONDITIONS EVIDENTLY THEY ARE NEEDED IN OKLAHOMA. THE FUEL FILTER HOUSING IS THE ONLY PLACE WHERE THE FUEL GELLED UP, WHICH APPEARS TO BE A THEME IN MOST GMC DIESEL TRUCKS AND DOES NOT EFFECT FUEL IN THE FUEL TANK DUE TO VOLUME. GMC HAS DONE NOTHING TO IMPROVE THE DESIGN OR INCREASE INSULATION TO THE THIN FUEL FILTER HOUSING. IF I HAD BEEN IN FAST TRAFFIC ON THE INTERSTATE IT WOULD HAVE RESULTED IN AN ACCIDENT AND POSSIBLE LOSS OF LIFE.

TL* THE CONTACT OWNS A 2021 GMC SIERRA 1500. THE CONTACT STATED THAT WHILE DRIVING AT 60 MPH, AN ABNORMAL NOISE APPEARED UNDER THE HOOD. WITHOUT WARNING AN EXPLOSION OCCURRED. THE CONTACT MANAGED TO VEER TO SHOULDER OF THE ROAD GET OUT THE VEHICLE TO CHECK AND SEE WHAT THE NOISE WAS. THE CONTACT NOTICED FLAMES APPEARED BY THE REAR WHEEL ON THE DRIVER SIDE. THE CONTACT GRABBED THE FIRE EXTINGUISHER AND EXTINGUISHED THE FLAMES. THE FIRE DEPARTMENT WAS CONTACTED HOWEVER NO REPORT WAS FILED. THE POLICE WERE CONTACTED BUT NO REPORT WAS FILED. THE VEHICLE WAS TOWED TO QUALITY BUICK GMC, INC (7901 LOMAS BLVD NE, ALBUQUERQUE, NM 87110 (505) 765 1300) WHERE IT WAS DIAGNOSED AND DETERMINE THE ENGINE WAS FAULTY THAT WOULD BE COVERED UNDER WARRANTIES TO REPAIR. THE VEHICLE WAS REPAIRED. HOWEVER, THE CONTACT FEELS UNSAFE DRIVING THE VEHICLE. THE MANUFACTURER WAS NOTIFIED OF THE FAILURE STARTED AND STARTED AN INVESTIGATION. THE FAILURE MILEAGE WAS APPROXIMATELY 2,800.

THE VEHICLE WAS BOUGHT BRAND NEW AND WAS ONLY DRIVEN FOR A WEEK. IT WAS IN MOTION ON THE FREEWAY WHEN THE ENGINE STARTED TO SOUND NOISIER THAN USUAL, LIKE THAT OF AN OLDER TRUCK. IT WAS HARD TO NOTICE ON HIGHER SPEEDS ON THE FREEWAY, BUT UPON SLOWING DOWN ON CURVES, IT GOT MORE OBVIOUS THAT SOMETHING WAS REALLY WRONG BECAUSE THE NOISE SOUNDED LIKE SOMETHING WAS LOOSE INSIDE THE ENGINE. THERE WAS NO 'CHECK ENGINE' LIGHT OR ANY OTHER WARNING LIGHTS. UPON EXITING THE FREEWAY, THE ENGINE SHUT OFF COMPLETELY WHILE IN MOTION. FORTUNATELY, I WAS ABLE TO PULL IN A PARKING LOT AND PARK IT SAFELY. THE ENGINE WOULD NOT START SAFELY AFTER THAT, AND 'CHECK ENGINE' ACTIVATED. THE VEHICLE IS CURRENTLY BEING DIAGNOSED AT A DEALERSHIP. LAST UPDATE WAS THAT THE ENGINE WAS BEING TAKEN APART COMPLETELY BECAUSE THEY SAID IT'S DEFINITELY INSIDE IT.