2,253 of the
11,637 complaints filed about the GMC Sierra 1500
are about the engine —
100% of everything owners reported.
The worst model year for it is 2021.
I did not have anyone tell me about recalls concerning my GMC SLT, when can I have what ever it takes to send me info concerning lifters, these have not had any issues yet. Will I have someone to contact me about possible lifter issue. Current miles are 18129. Thanks for your attention. MCG
NHTSA complaint #11764116 — an unverified report by a vehicle owner.
At just below 5,000 miles of use, my new 2026 GMC Sierra At4 (6.2L V8 engine) is currently undergoing a total engine replacement arising from traces of metal being detected in the oil filter. Although covered by GMC Warranty since it is essentially a brand-new vehicle, I wanted to report this issue as it is most likely part of the large GM recall pertaining to this L87 engine since I am concerned this is related to ongoing 6.2L L87 engine failure investigation. It is expected to be out for around 4-6 weeks with a new engine incoming and would want to be covered if the new engine fails in the future with any issues relating to this case.
NHTSA complaint #11764094 — an unverified report by a vehicle owner.
on Friday the 11th the vehicle quit running had to be towed and left me stranded in the middle of an intersection. This is a second vehicle from GM with the 6.2 L engine that has done this to me. The dealer says it’s catastrophic engine failure, and they’re gonna replace the engine. I was told that GM Edward repaired this issue but is still selling brand new trucks with this motor that has this failure, they can lead people stranded in very compromising positions.
NHTSA complaint #11764203 — an unverified report by a vehicle owner.
The catastrophic power failure with no warning on my 2017 GMC Sierra, at 87450 miles completely contaminated the engine oil cooling lines with metallic debris and fractured structural mounts. The servicing dealership replaced the transmission but is refusing to remediate the engine line contamination without out-of pocket payment. The vehicle cannot be safely operated without causing terminal engine failure on the highway, creating a imminent mechanical and traffic safety hazard.
NHTSA complaint #11763735 — an unverified report by a vehicle owner.
Since I purchased my vehicle in 2021, I continued to have issues with my oil pressure light coming on usually about 2000 - 3000 miles past the oil change. When checking oil, I would find that it was low 2 quarts of oil each time. I reported this to the GM Dealer and they did oil consumption tests and determined the oil loss was within GM tolerances. So apparently it is ok to burn a quart of oil every 1000 - 1500 miles. Then fast forward to January 2025, apparently my rear main seal was blown out. Unfortunately by then my Powertrain warranty had expired. So that cost $3,794. Now fast forward to March 2026, I hear a noise in my engine and notice it is leaking oil again. Upon taking it back to the dealer, they tell me the engine needs replaced or rebuilt. The rear main seal is bad again, a lifter bad and they specifically say "The engine still has excessive blowby due to stuck piston rings or a scored cylinder". This is the first time it was ever reported to me that the engine as blowby. Regardless of all this, I had to replace this engine with less than 117,000 miles on it. I was reporting the oil issue when it was well under the powertrain warranty, but the first Oil Consumption test was done at 51,946. So again under powertrain warranty. However I continued to tell them about it until these issues occurred. Now I have $10,912.75 invested in repairing/replacing an engine. I pushed it to GMC Customer service and they didn't want to help. However when investigating this issue with other mechanics, they all seem to know about all the issues these L87 engines have. Then I found out that 2021 - 2024 L87 engines were recalled, but my 2019 was not. It appears my engine has similar issues as the recall. I was just lucky enough that nothing happened while I was driving. So I asked that if a recall occurs that GMC should be responsible for refunding all of this money as they should have taken care of it when I told them 100,000 miles ago.
NHTSA complaint #11763704 — an unverified report by a vehicle owner.
Check engine light came on my vehicle (104,000/mi) and fans came on while truck was off. Took to dealership and techs diagnosed vehicle as having bad "coolant flow control valve". Dealership ran VIN check as there is a GM "extended special coverage program" N252508341 for the LM2 motor, which my vehicle has. However, N252508341 only applies to vehicles in CA. The dealership did not cover my repair. I filed a complaint with GM who denied it due to the program being only applicable to CA trucks. I was advised to file a complaint with NHTSA as the only avenue with recourse. I would like if NHTSA intervened and made GM honor the program in all 50 states and I be offered a refund for the $2500.00 repair I had to pay for. Thank you.
NHTSA complaint #11763611 — an unverified report by a vehicle owner.
I am writing to formally log a safety concern regarding my vehicle’s 6.2L L87 engine, specifically in relation to the known defects under NHTSA’s ongoing Engineering Analysis EA25007. The engine seized up while driving in traffic which has a safety impact on the occupants and other drivers. The vehicle was towed to GM and the they noted the the engine has catastrophic internal failure with large metal debris in the engine oil and filter. This is consistent with failures that other GM owners have experienced with GM's L87 engine. The initial recall (Recall 25V-274) for a specific manufacturing window (March 1, 2021, to May 31, 2024), the NHTSA launched EA25007 because it continued to receive a flood of complaints from owners whose vehicles fell outside that original recall window. That is me, I am outside that original window. But I am confident that the issue was known by GM and should have been handled several years ago with a wider recall window. Now I was exposed to a safety issue and I am stuck with a large repair bill. I think there is an even broader active investigation EA26005.
NHTSA complaint #11763284 — an unverified report by a vehicle owner.
Engine stop working, lots of black smokes through the exhausts and vibrating weird. Lifters failed amoung other parts and they deemed the engine bad so they replaced it with a new one. The new engine started to make the same weird noises.
NHTSA complaint #11763347 — an unverified report by a vehicle owner.
I purchased said vehicle with a little over 76,000 miles on XXX from NW Chevrolet, [XXX]. Dealership service the engine on XXX and remained on their lot until it was sold. While driving home, I smelled gas fumes coming into the cabin and the engine was misfiring causing slight hesitation in motor acceleration while adjusting to speed limits and climbing hills. I told management at the dealership about these issues on XXX. My vehicle is currently in the shop to fix the fuel injection system, spark plugs, grounding issues as of XXX to fix the dealerships mistake costing more out of pocket expense. Management will not do anything about it because it was sold (As Is) without a warranty which I refused to purchase through finance and interest charges on a car loan. I purchased a 4-year warranty through Endurance on XXX with a 30 day wait period before filing a claim. GM is letting their dealerships advertise and sell problem vehicles with known motor issues to consumers while marking up the sale price. Vehicles should never be sold until GM fixes all motor defects before advertising to the consumer. The consumer is at serious financial risk when getting an auto loan paying on a broken vehicle. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
NHTSA complaint #11763367 — an unverified report by a vehicle owner.
While driving on the highway, i went to pass someone and there was a big shutter in the engine and then a load ticking noise from the engine after. All of the lights came on and the vehicle was running rough
NHTSA complaint #11763458 — an unverified report by a vehicle owner.
I was driving home with my wife. The engine just cut off. No power to the gas pedal. Luckily we were able to coast long enough to find a shoulder to pull off onto. Truck wouldn’t restart. Had to call a tow truck and have it towed to the Chevy dealership. The engine was already repaired once. Ref number 11696129. I just got the truck back and fixed again. So far I’ve had to pay for 2 tows and 2 repairs costing be about 3000 dollars. Both repairs have been done at a Chevy dealership.
NHTSA complaint #11763011 — an unverified report by a vehicle owner.
Powertrain issues and a chassis issue that is extremely dangerous.Tailgate on rare occasions falls open by itself. There is a design flaw in the placement of the catalytic converters. The heat is burning up the fluid. I could not believe my eyes when I serviced the transmission. This is another shortcut by GM to save on the extra wiring needed for the oxygen sensors (2)in the converters and the two oxygen sensors downstream of the converters. There is plenty of room for the converters further down by the tail shaft to drive shaft connections. This is GM’s way of being cheap. Here’s the problem. The converters get way too hot. The fill plug for the transmission which is behind a low rent heat shield crumbled into my hands from excessive heat buildup. GM knows there is a problem with the fluid breaking down. Their bandaid answer is to use Mobil 1 fluid instead of the recommended Dexron 6. What needs to happen is a safety recall issued for the unwanted tailgate deploying all by itself. There needs to be a redesign in the exhaust system. The Transmission (8 Speed) has a catalytic converter exactly on both sides and the crossover pipe runs directly under the transmission sump pan. No wonder they are having issues with transmissions burning up. THIS IS A FIRE HAZARD !!! With the converters being so close to the exhaust manifolds, a leak from the engine or the transmission would be enough to ignite and possibly kill the occupants. All in the name of saving a few cents in wiring. Myself, I am a retired GM Mechanic. I started working at Sewell Cadillac in [XXX] in 1975. I have held the title of ASE Master Tech. Cadillac Master Tech. I have been a GM Shop Foreman and A GM Service and Parts Director in my Career. I retired from Federal Express as in charge of Fleet Maintenance and GSE(Aircraft Equipment). I have certifications from Mercedes, BMW, Toyota, Commander Loaders, Goodyear, and more. Given the right set of circumstances, it could end very badly. Dangerous Truck ! INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INF
NHTSA complaint #11763015 — an unverified report by a vehicle owner.
Coolant Control Valve failure. This vehicle year is included in a GM bulletin that extends the Coolant Control Valve replacement coverage to 150K miles due to a faulty design. My is valve failing exactly as described in the bulletin and GM will not cover the replacement due to my vin number. The vehicle randomly goes into reduced power whereby it is prohibited from safely keeping up with traffic. Research shows that there are a significant number of owners in my same situation where GM is denying repair and replacement coverage.
NHTSA complaint #11762983 — an unverified report by a vehicle owner.
XXX 2021 GMC Seria 108,339 miles driving home from [XXX] in town and out of nowhere the lights on the dash light up I saw it say adaptive steering and something breaking. There was a lot going on as the steering was rapidly shaking limited breaking while trying to avoid a collision. The engine started a loud knocking sound and sudden smoking out tail pipes. I was able to get the truck stopped turned it off and sat there for a while trying to collect myself. Restarted the truck and slowly drove it to my home 2 miles away. It was flatbed to local GM dealer that quickly diagnosed it saying heavy smoke knocking needs New Engine! They won't confirm exactly what the internal engine failure is. Other than its Failed. The engine build date is 2020 day 350 My VIN is not currently in the current GM engine recall However it's certain this failure is totally related to GM's engineering design and Manufacturing issues. Look deeper into the recall date ranges this failure is clearly a victim. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
NHTSA complaint #11762994 — an unverified report by a vehicle owner.
Engine I believe The truck died while I was doing 78 MPH on the highway Dashboard stated “shift into neutral and press start” I pulled to the side of the road and did what it stated and it would not crank over. I also put it in park turned the vehicle off and back on to try to start it. The lights on the dashboard, all gauges, the AC, and everything works the truck just will not crank over. Check engine light came on but is not throwing any codes
NHTSA complaint #11763073 — an unverified report by a vehicle owner.
Catastrophic Engine Failure due to Lifter Failure at approximately 51,000 miles driven. This has been confirmed by the dealership and reported/escalated to General Motors. The truck is at the dealership for repairs. General Motors offered to cover 65% of the repair as a Goodwill sign. As the 60K powertrain warranty had expired. This truck has the same components that are covered under the recall for the same model year. However the recall only extends to March 1, 2021 Manufacture date. My truck was manufactured a few weeks prior to that so it was not included. GM refused even discuss this could be potentially due to a recalled issue. Multiple warning lights and error messaged were present on the dash indicating issues when it failed. Additionally, a loud metallic knocking noise was present at speed and idle. Power was significantly reduced and the engine was running very rough.
NHTSA complaint #11763103 — an unverified report by a vehicle owner.
Catastrophic engine failure at 77357 miles. I went to the local GM dealer and my VIN is not in the L87 engine recall. Not sure how to repair my truck , but feel like the engine should not have locked up with such low miles, and I done constant engine maintenance , meaning oil changes every 5K miles.
NHTSA complaint #11763146 — an unverified report by a vehicle owner.
The contact owns a 2023 GMC Sierra 1500. The contact stated that while driving 65 MPH, the engine made a clunking, knocking, and tapping sound. The engine was driving on seven of the eight cylinders. The contact slowed down and pulled over. The engine warning light was illuminated. The vehicle was taken to the local dealer and was diagnosed with a detached valve. The vehicle was repaired under an extended warranty. The dealer informed the contact that the failure might recur. The failure mileage was approximately 12,998.
NHTSA complaint #11763017 — an unverified report by a vehicle owner.