GMC Sierra Complaints (2021)

671 consumer complaints on file.

#11726248March 23, 2026
POWER TRAIN
I've been to the dealership a few times due to the truck jerking violently under very light acceleration when its trying to shift gears. also there was a few times that the rear wheels have locked up while driving.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11726343March 23, 2026
ENGINE
L87 engine failure 4 months after it passed the recall test. Experienced shuddering and rpm fluctuation with the cruise control set. Was thinking torque converter. Got it replaced under warranty and the the issues were still there. A week after new TC the truck was running very rough driving down the road. Check engine light along with a low oil Pressure warning and Lost all engine power going 60mph. Would not re fire. Had to coast to a stop with no headlights on only fog lights. Truck is at dealership now will be needing a new engine. P0016 engine code. The truck was in the shop multiple times for misfire and rpm’s jumping and cruise control turning off on its own.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11726209March 22, 2026
ENGINE
I am filing a complaint regarding a catastrophic engine failure in my 2021 GMC Sierra 1500 equipped with the 6.2L V8 engine. While driving under normal conditions, the engine suddenly failed without warning and threw a connecting rod, rendering the vehicle inoperable. There were no prior warning signs such as knocking, overheating, oil pressure issues or even a check engine light. The vehicle has been properly maintained, including regular oil changes using manufacturer-recommended 0W-40 oil. This failure created a serious safety concern due to the sudden loss of power while driving, which could have resulted in a dangerous situation, especially at highway speeds or in traffic. I am aware that General Motors has issued a recall and/or is aware of similar failures involving the 6.2L engine in certain 2021 vehicles. However, my vehicle’s build date falls just outside the currently defined recall range, despite experiencing the exact same type of catastrophic failure described in those cases. My build date is 12/20 and the recall was issued for 3/21. Given the similarity of this failure to known issues, I believe this defect extends beyond the currently identified recall population. This raises concerns that additional vehicles, including mine, are at risk of sudden engine failure without warning. I am requesting that National Highway Traffic Safety Administration investigate this issue further and consider expanding the recall to include additional affected vehicles outside the current build date range.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725796March 20, 2026
POWER TRAIN, FUEL/PROPULSION SYSTEM
The DEF tank in my truck is defective and its the second time in the last 14 months it has broke. The part is now back ordered and according to the dealership this is a nationwide issue regarding these specific trucks. I have contacted around 10 dealers in my area and all tell me the same thing that they have multiple trucks waiting on the same issue. I have not had my truck for over 2 months and have no idea when i will be getting it back due to dealership having no idea when the part will be released due to the back order. This seems to a huge issue with these trucks and GM is doing nothing to help resolve it. I've reached out to GM directly and get no assistance and now have made 2 payments on my truck and the dealership refuses to give me a loaner vehicle. i am looking for some help or relief on what to do to go about my issue
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725695March 19, 2026
UNKNOWN OR OTHER
When my android auto does not connect, it essentially disables the whole infotainment system which is incredibly distracting and dangerous while driving. I am requesting that this be fixed so that I can still use some of the infotainment system but they are redusing to to do anything to fix the issue. The dealer has advised that they are unable to fix the issue because it is software related but yet the software team is saying it is a dealer issue. Please help me get a resolution to this issue!
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725266March 18, 2026
ENGINE AND ENGINE COOLING
The contact owns a 2021 GMC Sierra 1500. The contact stated that on Aug. 14, 2025, the PICO engine test was completed on the vehicle under NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling). The dealer stated that the engine had passed the test, and the engine oil was changed to a higher viscosity oil, and the oil cap, oil filter, and the page in the Owner’s Manual were updated. The contact stated that the vehicle was making abnormal sounds while idling, and the fuel consumption had increased. The dealer was contacted and advised the contact to bring the vehicle back to have the engine test performed again; however, the contact refused. The vehicle was not repaired. The contact stated that the engine test had not been performed on the vehicle and that the vehicle was unsafe. The manufacturer was informed of the failure and informed the contact that the vehicle was repaired. The failure mileage was approximately 44,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725006March 17, 2026
ENGINE
at roughly 5,000 miles had lifter failure which caused loss of power. That was repaired under warranty. Same issue at 86,000 miles - loss of power. New engine which I had to pay for. Same issue at 126,000 miles. New engine required. Covered under warranty. Side note. New engine will only have balance of warranty from 2nd engine or about 5,000-6,000 miles. first incident Feb 2001, second incident about Nov 2004, third incident Mar 2026.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11724712March 16, 2026
ENGINE
Loss of power, and knocking from the engine while driving. Check brake system, check srs, check parking brake and check engine light flashing came on at the same time. The problem has been reproduced at a mechanics shop and has been determined that cylinder 6 is dead.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11723255March 10, 2026
ELECTRICAL SYSTEM, ENGINE
Following the remedy of the engine recall in 2025, the truck started having intermittent electrical issues (i.e. warning lights on dash turn on/off: service 4WD, Loss traction Control, etc) come one while the truck is being driven. If the truck is turned off while the dash warning lights are on, it will NOT Start for about 24 hours. If the warning lights are ignored, eventually they will go off on their own. Additionally, the truck is having "no-start" problems (randomly the truck does not start, then after a few days it starts). A New development, when backing up there is a scraping/squealing sound (possibly universal joint). Truck has been back to the dealership that replaced the engine block for the recall and they have failed to identify any issues as these problems are intermittent. Engine Recall Replacement Invoice (Attached)
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11723154March 9, 2026
ENGINE
Took it to dealer for engine sound said nothing was wrong 4 days later rod bearing went out while driving. Truck no longer able to drive
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11722805March 8, 2026
ENGINE, UNKNOWN OR OTHER
[XXX] we bought our 2021GMC Sierra 1500 from Dealer with 39842 on it. we drove the truck 2910 miles when we checked the oil it was 2 quarts low at 42752. we added oil at that time and called our local dealer to make appointment . appointment at Bowser route 51 Pleasant Hills PA 15236 They informed us they would have to charge us for an oil change to start an oil consumption test on 10/23/25 miles 43829. 11/24/25 brought back to Dealer they said the oil was full yet i checked it in morning it was1/4 low. 1/7/26 brought back to dealer this time they let our truck sit over night the best way to check it and found it to be 3/4 low with only 1,698 miles driven also the antifreeze reservoir was low also they topped off both. 3/8/26 I Checked it ,its now 1 quart low with 1,097 miles driven milage on truck now is 46,623. Summarize GMC will not even look into why my truck is using oil not once my truck is still under warranty where is the consumer protection. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11722817March 8, 2026
POWER TRAIN, ENGINE
Driving down the road and engine shut off and would not start back. Had it towed to dealer and it needed a motor replacement. Waited over a month for the shop to finish it. New motor has 3k miles on it and is making noise, transmission is stuttering hard and the air conditioning quit working all around the same time. Had to take the truck back to the dealer after the replacement motor was installed because of a faulty “new” starter.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11722823March 8, 2026
POWER TRAIN, SUSPENSION
Transmission Shuttering which was confirmed from from GMC dealership , but refused to do any repairs after confirmation or diagnostic and test driving. Demanded a 220$ fee be paid before releasing my vehicle back. Also gave GMC Bulliten # 25-NA-148 which states the same issues I'm currently having.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11722653March 7, 2026
ELECTRICAL SYSTEM, UNKNOWN OR OTHER
Rear tailgate on my 2021 Sierra opens or drops when wet. This seems to only happen in a heavy rain or after a truck wash. This problem has been recognized by the manufacturer and the dealer. There is no warning other than the constant clicking of the electric switch allowing the tailgate to drop. This problem has been recalled on the 3/4 & 1 ton trucks but not the 1/2 ton. The tailgate and switches are the same on all 3. Because my vin# does not show for this recall I had to pay for the replacement
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11722468March 6, 2026
POWER TRAIN
The valve body failed, brought it in to a GMC dealership 3 months ago they told me the valve body is on back order. Last week they received the new valve body installed it and tried to program it. While programming it, the brand new valve body failed. So now I am stuck again with no ETA of when a new valve body will be sent to the dealership to fix the issue. this is obviously an issue with the make and model and in my opinion should be a recall. I do not feel safe if I ever get my truck back from this issue due to ongoing valve body failures nation wide and two on my end.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11722534March 6, 2026
ENGINE, FUEL/PROPULSION SYSTEM
Engine developed a low knock type noise just above idle while beginning to move in the parking lot. It was also noted pulling away from an intersection at low rpm under light acceleration. Oil pressure was normal, 30 psi and approximately 50-60 at cruising speed. Low level knock began earlier in the day but no other symptoms. Oil level was checked and found to be at proper level. At mile 2 into my trip a chirping/ squeak type noise was heard under light throttle and light load at approximately 1500 rpm. The noise stopped when accelerator was released. Rough running sensation followed the noise under the load. Noise returned when the accelerator was pressed and then the engine stopped running while traveling 45-50 mph. Placed the shifter to neutral and attempted to restart, engine rolled slowly for a brief moment and then locked up entirely. Starter only clicks when attempted after that. Vehicle left me stranded with no heat on the shoulder of the highway in the dark in Northern Michigan on March 5, ambient temp was 28 degrees. Vehicle towed to closest dealership which is also where it was purchased for inspection on 3/6/2026. General motors customer care contacted and case opened. No assistance with repair at time of callback.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11722047March 4, 2026
POWER TRAIN
With the cruise set at 55-60 mph the Rpms will jump, along with a slight shudder feeling. Cruise control has turned off a few times due to this. Cruise set at 25mph and would shudder/lunge forward. Torque converter is showing it’s slipping and will need replaced. No check engine lights.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11721466March 2, 2026
POWER TRAIN
Per GMC dealership, this vehicle suffered a Transmission valve body failure and they are recommending replacement of the entire transmission.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11721586March 2, 2026
POWER TRAIN
My vehicles transmission is part of a recall but my vin is not registered for this recall repair. Please assist.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11720586February 26, 2026
POWER TRAIN
Engine coolant control valve failure. This is a widespread issue on 2020-2022 3.0L Diesel trucks and it hasn’t been addressed by GM, leaving owners to pay out of pocket for a faulty part.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0

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