2021 GMC Sierra 1500 engine problems

ENGINE

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.

ENGINE

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.

ENGINE

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.

ENGINE

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

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.

ENGINE

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.

ENGINE

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.

ENGINE

Transmission failed, Value Body is listed by dealer as the cause. GMC is saying that my vehicle is not part of the recall, even though it is part of the same model, same years as well as the same problem, the value body on the transmission. See estimate from dealership Tucks GMC Hudson, MA TRANSMISSION REPLACEMENT WITH BYPASS VALVE $6800.00 RADIATOR REPLACEMENT LEAKING $1980.00 ABS TRACTION LIGHT WHEEL SPEED SENSOR $395.00 CHECK ENGINE LIGHT IS ON NEEDS PCV VALVE HOSE AND SOLENOID $430.00 OIL LEAK BETWEEN ENGINE AND TRANSMISSION ?

NHTSA complaint #11762717 — an unverified report by a vehicle owner.

ENGINE

I was notified my lifters in my 6.2 L V8 would need to be inspected for any defects. When I purchased my vehicle from Car Max here in Jackson, MS, I received a notification from the dashboard that the engine oil was low and to add oil. I turned around and took it back to the dealership as soon as possible. This happened on the first day of owner ship with in 5 minutes of driving off from the lot. I Car Max told me to just add oil and bring them the receipt and they would reimburse me. I chose not to and asked them to service the vehicle to avoid any issues with my warranty or my Car Max Shield Warranty. 2,000 miles later the same notification came across the dashboard again. I took it back to Car Max immediately and they ended up sending it off to my local GM dealership for service. They topped it off with oil after inspecting it for any leaks in the engine. None were discovered. After the 3rd notification about the engine oil level being low after close to 3,000 miles, they serviced the vehicle and put the vehicle under the Oil Consumption Watch. This took place from October 2025 through September 2026. After multiple visits, they informed me they would need to perform further test to see if the lifters were failing and that I would be responsible for the labor fees estimated at around $632.82. I informed them I have Car Max’s 150,000 mile warranty. Fidelity Insurance company informed me they would need to send an inspector out to the GM dealership. Before this takes place, they would need the vehicle to undergo various tests and I would be responsible for the labor fees. Should the engine components be found worn down. Fidelity would not cover the repairs. Should the engine components be found defective, they would cover the replacement part but not the label. Labor costs would estimate around $2,978.95. I asked the GM dealership to share this information with me in writing for documentation purposes. I asked for my vehicle to be parked until further notice.

NHTSA complaint #11762400 — an unverified report by a vehicle owner.

ENGINE

Lifter locked up causing bent push rod. This situation caused truck to strand the driver without warning. Truck needed to be towed. This repair was performed by the dealership and is a known issue with 6.2 L engine.

NHTSA complaint #11761850 — an unverified report by a vehicle owner.

ENGINE

Transmission stopped at 29,000 miles, engine died and was replaced at 32,000 miles

NHTSA complaint #11761314 — an unverified report by a vehicle owner.

ENGINE

Loss of power, had engine repaired, replaced passenger side head and cylinder. Now drivers side is having the same issue.

NHTSA complaint #11761457 — an unverified report by a vehicle owner.

ENGINE

Cam Shaft and Lifter failure. Lifters were replaced 3 times

NHTSA complaint #11761107 — an unverified report by a vehicle owner.

ENGINE

My vehicle is on a recall list. Took it to the dealership for engine vibration test. They changed oil and put on a new cap. My engine blew up a couple weeks later. They replaced my motor. It blew up on the mechanics test drive. I'm now waiting on my 3rd motor. They have had it for over 5 months now.

NHTSA complaint #11760218 — an unverified report by a vehicle owner.

ENGINE

2021 GMC Sierra 1500 equipped with 6.2L L87 engine. At approximately 97,000 miles, the engine developed a significant knocking noise. I immediately took the vehicle to an authorized GMC dealership for diagnosis. The dealer determined that the engine required replacement but advised that my VIN was not included in GM Recall 25V-274. The dealer quoted approximately $15,000 for replacement. I subsequently had an independent repair facility replace the failed engine with a genuine GM replacement engine at a cost of approximately $12,400. I am reporting this because the failure appears similar to the L87 engine bearing/crankshaft failures addressed by Recall 25V-274, despite my VIN not being included in that recall.

NHTSA complaint #11760249 — an unverified report by a vehicle owner.

ENGINE

I had the L87 recall completed, and the vehicle passed inspection. The dealership completed the required protocol and replaced the engine oil with 0W-40. Approximately 6,000 miles later, while traveling at about 75 mph and six hours from home, I experienced a brief loss of power followed by an immediate return of power. My wife and I noticed it but, with no warning lights or alerts, continued driving while monitoring the vehicle. About 10 miles later, we began hearing a faint squealing noise that progressively became worse. I was able to exit the highway safely, but once I came to a complete stop, the engine shut off and would not restart. I had the vehicle towed to the nearest dealership, where it was determined that I had suffered a catastrophic engine failure. No loaner vehicle was available, leaving my family stranded six hours from home with an inoperable vehicle. It took approximately seven to eight weeks for the repair to be completed. When I received the vehicle back, I immediately noticed something still was not right. At around 40 mph and 1,000 RPM, the truck would shudder or hesitate. My local dealership diagnosed a poor spark plug connection on cylinder #3, which was causing arcing and a misfire. After the connection was repaired, the issue was resolved. My local dealership is currently working with the repairing dealership to address several minor workmanship issues, including wire clips, fittings, and missing bolts. This entire event was unexpected. There were no warning lights, alerts, or unusual noises before the initial loss of power. The only indication of a problem was the sudden power loss followed shortly thereafter by a horrific screeching noise. Thankfully, I was able to safely exit the highway and bring the vehicle to a stop. Considering I was traveling at 75 mph, the situation could have been much worse.

NHTSA complaint #11760250 — an unverified report by a vehicle owner.

ENGINE

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at 60 MPH, the vehicle began to shake uncontrollably. A knocking sound was heard from the engine, and the vehicle entered limp mode. No warning lights illuminated. The contact was able to coast the vehicle to the residence. The vehicle was later towed to the dealer, where it was diagnosed that the engine failed and needed to be replaced. The contact associated the failure with NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling). The vehicle was not repaired. The manufacturer was notified of the failure and informed the contact that the VIN was not included in the recall, and the contact was advised to file a complaint with the NHTSA Hotline. The failure mileage was 81,000.

NHTSA complaint #11760298 — an unverified report by a vehicle owner.

ENGINE AND ENGINE COOLING

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at 60 MPH, the vehicle began to shake uncontrollably. A knocking sound was heard from the engine, and the vehicle entered limp mode. No warning lights illuminated. The contact was able to coast the vehicle to the residence. The vehicle was later towed to the dealer, where it was diagnosed that the engine failed and needed to be replaced. The contact associated the failure with NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling). The vehicle was not repaired. The manufacturer was notified of the failure and informed the contact that the VIN was not included in the recall, and the contact was advised to file a complaint with the NHTSA Hotline. The failure mileage was 81,000.

NHTSA complaint #11760298 — an unverified report by a vehicle owner.

ENGINE

Driving on the highway lost proportion/acceleration, loud knocking coming from the engine

NHTSA complaint #11760509 — an unverified report by a vehicle owner.

ENGINE AND ENGINE COOLING

The contact owns a 2021 GMC Sierra 1500. The contact stated that the vehicle was experiencing excessive oil consumption. The low oil level was observed, and the oil warning light illuminated. The vehicle was previously serviced at the dealer, where it was discovered that the oil was 3 quarts low at approximately 56,653 miles. The vehicle was returned to the dealer, where an oil consumption test was performed. After driving 3,000 miles, it was observed that the oil level was 2 quarts low on July 16, 2024. The dealer confirmed there was no recall coverage, and the vehicle was not repaired. The contact associated the failure with NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the dealer and manufacturer confirmed the VIN was not included. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 59,075.

NHTSA complaint #11759955 — an unverified report by a vehicle owner.

ENGINE

While driving down an isolated 2 lane road in West Texas, the engine in my 2021 GMC Sierra 1500 began making knocking sounds and vibrating badly. The truck's acceleration was extremely sluggish and the vibration worsened at slow speeds. I was able to slowly make my way back towards a dealership, where the diagnostic teardown revealed a bent pushrod and camshaft damage.

NHTSA complaint #11759357 — an unverified report by a vehicle owner.

ENGINE

For close to one year, there feels like a catch, grind, stall, or slight shake, mostly while the vehicle is shifting gears, made worse or noticed more by higher speeds like driving on the highway vs. slow city streets. It's difficult to explain or assess so not sure if it is the engine or transmission. With the open recall from GMC on some vehicles with the same engine as mine it is concerning that maybe it should have been included.

NHTSA complaint #11759464 — an unverified report by a vehicle owner.

ENGINE

1. What component or system failed or malfunctioned, and is it available for inspection upon request? The engine oil consumption system/engine is experiencing excessive oil consumption. My 2021 GMC Sierra is equipped with the 6.2L engine, and the engine is consuming oil at a rate that I believe is abnormally high. The vehicle and engine are available for inspection upon request. I am also concerned that my vehicle may be affected by an engine-related recall or safety campaign associated with this engine. When attempting to verify the recall status, the system appears to have an error and is not identifying my vehicle. I am requesting that the vehicle’s VIN and engine configuration be manually verified against all applicable recalls and safety campaigns. 2. How was your safety or the safety of others put at risk? The excessive oil consumption creates a potential safety concern because I am concerned that the engine could become critically low on oil while I am driving, potentially resulting in engine damage, loss of power, or complete engine failure. This could occur while traveling at highway speeds or in an area where it may be difficult or unsafe to stop. I regularly travel with my family, which increases my concern about the possibility of an unexpected engine failure and the potential risk to my passengers and other motorists. 3. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes. I previously addressed this issue with Newton Chevrolet in [XXX], and later took the vehicle to Malcolm Chevrolet in [XXX], after continuing to experience concerns about excessive oil consumption. Malcolm Chevrolet tested the vehicle and confirmed that it is consuming oil at an excessive rate. The prior visit to Newton Chevrolet and the subsequent confirmation by Malcolm Chevrolet demonstrate that this concern has been reported and evaluated by more than one dealership. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA complaint #11758686 — an unverified report by a vehicle owner.

ENGINE

While driving my son to school we were driving 45 mph and the entire engine shut off and lost all power. Engine would not restart. Took it to the dealer and was told the engine was dead.

NHTSA complaint #11758744 — an unverified report by a vehicle owner.

ENGINE

I purchased this truck from a used car dealer. It had received the fix in January this year. They sold it to me I put 15,000.00 down and financed 15,000.00. I had the truck two weeks and was driving down the road to pick up some tools from a friends. I pulled from a drive way I heard a pop likei hit something In The road nothing was in the drive or road I could have hit. I made it two stop signs to make the turn too go pick up the tools and as I am slowing down to stop the stuck shuts off at like 45 miles an hour and leaves me comming to a stop with a truck crank crank crank no start. Cause it said shift I to neutral to restart. I did and the engine went to cranking over and o er really fast. And I was Abel to get control and get stopped at stop sign blocking the stop sign and a guy with a boat behind me. My friend came with his truck and pulled me from intersection up into His yard. And I had car lot I bought it from come get it they tried to finance me a motor thru there prefers dealer. I went to them they explained that the cams and timing chain was staying still as they turned the engine Over by hand. The timing chain stayed staionary. I researched the truck online figured out there is a l87 recall and had it taken to dealer they are offering good will payment on labor because it is 6, 000 miles past the 150000 dead line Wich I only placed just over a thousand of the 156000 miles on this truck. I have been without this truck for 31 days as of today. And I feel they should replace entire engine. I Am so frustrated with this cause I already payed 15000 and don’t have the money to fix this truck.

NHTSA complaint #11758633 — an unverified report by a vehicle owner.

ENGINE

2021 6.2L GMC Sierra Denali. Has the L87 engine that is recalled but yet my truck doesn’t fall under the recall although the recall is for 2021-2024 engines. Everything that the engine recall states is the issue with my truck, I have service report from dealership stating that there is wear/breakage of cam shaft/crank shaft amongst other things including cylinder 3 and 5 misfiring , bearings broken , filings in the oil , banging in the engine and safety lights on. My local GMC dealership recommended that the only acceptable action was to replace the engine at my cost of course. This is unacceptable of a supposed reputable large corporation not caring about the “little guy”. The truck only has 136000 kms on it and I was only going 60 km/hr when this happened. Please help as I feel GM knows this engine is faulty but somehow has managed to escape a recall on my vin number

NHTSA complaint #11756392 — an unverified report by a vehicle owner.

ENGINE

P1010 and P2B86 engine code, constant cooling fan on engine. Confirmed by dealership, quoted for coolant control valve. VIN not included in special coverage N252508341 for this known issue. Limited engine power alert, unable to maintain speed on highway. Dangerous condition traveling under speed limit.

NHTSA complaint #11753912 — an unverified report by a vehicle owner.

ENGINE

Engine temp rises way above mid-level and will stay there for several minutes before cooling back down to normal temps. 2 different mechanic shops have told me it's the coolant control valve, but want $2500 to fix it. This service bulletin is for the same year, make, model, and motor as my truck, but the dealership said it wasn't covered.

NHTSA complaint #11753949 — an unverified report by a vehicle owner.

ENGINE

2021 Harley Davidson Sierra 4WD, 6.2L L87. Started the truck in the morning and immediately heard intermittent, very loud banging noise coming from engine. Shut truck down quickly and had it towed to dealer. Diagnosis was bent pushrods & failed lifters which were replaced under warranty. Factory warranty expired only 4 months after this failure, and the recall does not include my VIN so I did not get an extended warranty or any other protection. GM has yet to even reimburse the tow bill. Completely unacceptable for a truck that was well over $100k when new.

NHTSA complaint #11753693 — an unverified report by a vehicle owner.

ENGINE AND ENGINE COOLING

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving approximately 70 MPH, the vehicle suddenly lost motive power, decelerated, and failed to properly accelerate while depressing the accelerator pedal. The check engine warning light was illuminated. After exiting the freeway, the vehicle stalled. The vehicle was towed to the residence and then later towed to the dealer for assistance. The contact was informed that there were metal shavings inside the engine oil. The contact was informed that the engine needed to be replaced. The vehicle was not yet repaired. The contact was informed that the VIN was not included in NHTSA Campaign Number: 25V274000 (ENGINE AND ENGINE COOLING). The contact stated that the vehicle had experienced the failure listed in the recall. The manufacturer was not yet contacted. The failure mileage was 149,000.

NHTSA complaint #11753444 — an unverified report by a vehicle owner.