GMC Sierra Complaints

15,732 consumer complaints on file.

#11764196September 14, 2026
POWER TRAIN
Transmission shifting hard in first few gears and only 87,000 miles on Transmission.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11764203September 14, 2026
ENGINE
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11764209September 14, 2026
ENGINE AND ENGINE COOLING
The contact owns at 2021 GMC Sierra 1500. The contact stated that while driving 60 MPH, the engine was overheating. The message "Reduce Engine Power" was displayed. The contact shifted to neutral to reach the dealer. The contact associated the failure with Special Coverage: N252508341; however, the VIN was not included. The dealer diagnosed the vehicle with coolant control valve failure, and the vehicle was repaired. The manufacturer was made aware of the failure and stated that the cost of the repair was not covered under the special coverage program. The failure mileage was approximately 94,328.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11764211September 14, 2026
SEAT BELTS
The backseat middle passenger seatbelt failed to release causing my [XXX] child to become stuck and restrained in the seatbelt blocking his circulation, therefore for the safety of my child I had no choice but to cut the seatbelt. I have tried to report it to the dealership and insurance company but both advised that this is not something that is covered by insurance or warranty. Is this a recall that the manufactory can repair? 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
#11764036September 14, 2026
ELECTRICAL SYSTEM, FORWARD COLLISION AVOIDANCE: WARNINGS, UNKNOWN OR OTHER
The front grille trim moulding failed and flew off on the highway. Also, the forward collision light on vehicle from the front camera not working and needing to be replaced.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11764047September 14, 2026
FORWARD COLLISION AVOIDANCE: ADAPTIVE CRUISE CONTROL
The contact owns a 2020 GMC Sierra Denali. The contact stated that while driving with Adaptive Cruise Control set to 55 MPH, the vehicle suddenly accelerated. The contact depressed the brake pedal to disengage the Adaptive Cruise Control settings, preventing the vehicle from crashing into the vehicle ahead. The contact stated that the failure had occurred while the Adaptive Cruise Control was engaged. The approximate failure mileage was 99,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11764094September 14, 2026
ENGINE
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11764107September 14, 2026
POWER TRAIN
The contact owns a 2022 GMC Sierra 1500. The contact stated that while driving 25 MPH, the contact entered a parking lot and shifted the vehicle into park and the message “Shift to Park” was displayed. Additionally, the check engine warning light illuminated. The contact stated that the failure had occurred on several occasions. Due to the failure, the contact was unable to start the vehicle. The failure mileage was approximately 74,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11763868September 13, 2026
ENGINE
No warning. It’s been replaced by Gm and a week later now it’s in the shop again because it’s acting up.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11763915September 13, 2026
STRUCTURE:BODY
I was driving down the George W. Bush Highway in Dallas, Texas, and the front top bezel above my grill flew off and went over the top of my truck. I have no idea if it landed safely or damaged other vehicles behind me because I was in very thick traffic. This is extremely dangerous as I could injured people driving behind me potentially impaling someone as I was going 70 mph per the speed limit. Just both are being recalls on the 2022 GMC model of my truck. The dealership refused to fix this for me and quoted me over $500 to get this repaired.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11763807September 12, 2026
UNKNOWN OR OTHER
As I was driving down the road, I heard a loud explosion. I looked around, didn't see anything that could've hit the truck. I thought it was possibly a gunshot that went off. After driving for another 3 or 4 minutes, I heard glass going everywhere. It was the moonroof that exploded. Thankfully, the sunroof cover was in the closed position. Otherwise, glass would've been all over the interior of the vehicle. I called the dealership to report the incident and to see if this was something that could be covered under warranty. I'm still waiting for a call back. I then called my insurance company to report what happened. I was told to seek a repair shop and collect all receipts for the claim. No warning lights have appeared in the vehicle yet. Since we were driving home from a vacation, we stopped and got a roll of vinyl sticker to cover the outside from rain.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11763825September 12, 2026
FUEL/PROPULSION SYSTEM
I am filing this complaint regarding a potentially serious safety defect involving my 2022 GMC Sierra 1500 Denali four-wheel-drive with the V8 5.3 engine. The vehicle had approximately 28,786 miles at the time of the incident. While traveling on an interstate highway in heavy traffic, my truck suddenly lost engine power. I was extremely fortunate that I was able to maneuver through traffic and get the vehicle onto the shoulder without being struck by another vehicle. A sudden loss of engine power under these conditions could easily have resulted in a serious or fatal collision. Immediately follow the incident Onstar detected diagnostic trouble code P129F The vehicle was subsequently taken to an authorized GM dealership. The dealership diagnosed the problem and replaced the fuel pump power control module to repair the vehicle. I have since learned that General Motors issued service bulletin 24 –NA-139 concerning this condition. The bulletin specifically includes 2022 GMC Sierra 1500 vehicles and identifies loss of power stalling and DTC P129F among the possible symptoms. GM states the condition may be caused by an internal short in the K111 fuel pump driver control module/fuel pump, power control module. I am particularly concerned that GM has been aware of this potential failure condition since at least 2024. A failure capable of causing a vehicle to suddenly lose engine power while traveling at Internet speeds presents amsafety hazard not only to the occupants of the affected vehicle but also to surrounding motorist. I respectfully request that NHTSA review this issue including other owner complaints involving error code P129F, fuel pump power control, module failures, stalling, or sudden loss of power in affected GMC Sierra and related to GMC vehicles and determine whether a safety defect investigation or recall is warranted. Vehicle: 2022 GMC Sierra 1500 Denali four-wheel-drive Engine: 5.3 L V8
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11763861September 12, 2026
ENGINE
Was driving the vehicle and started making a loud knocking noise and had a loss of power.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11763611September 11, 2026
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11763621September 11, 2026
ENGINE
The contact owned a 2020 GMC Sierra Denali. The contact stated that while the vehicle was parked, there was an abnormal knocking sound coming from the engine compartment. The check engine warning light was intermittently illuminated. The vehicle was taken to a dealer; however, the cause of the failure was not yet determined. The dealer advised the contact to purchase a new vehicle because the engine would eventually need to be replaced. The contact stated that at approximately 3,000 miles, there was an abnormal odor oil burning odor coming from the vehicle. The contact stated that the vehicle was consuming an excessive amount of engine oil and approximately 5 quarts needed to be added between scheduled oil changes. The failure mileage was approximately 25,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11763669September 11, 2026
TIRES:TREAD/BELT
Complete Tread/belt separation originating inside the tire. I have the complete tire and the complete tread. This happened at highway speed. I'm going to the dealer to get an inspection. The only symptom was a bad vibration before the tread separation. LT275/65R20E
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11763685September 11, 2026
UNKNOWN OR OTHER
I was driving today with product resting on the tailgate and the tailgate dropped while turning a corner, spilling product on the street. It was a residential street, thankfully, but it has happened on the highway. Previously, I had bikes resting on the tailgate and the same thing happen. Tailgate will randomly drop while driving, especially with a little weight resting on it. I close it completely, but doesn't seem to matter. It has become a concern and safety issue.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11763693September 11, 2026
SERVICE BRAKES
I was driving in town when all lights on the dash lit up, and I mean all of them. I was approaching a traffic light in low traffic in the 20-30mpg range. I went to apply the brakes and almost had none. If I was going to estimate how much braking was available, it would be in the 10% range. I drove at 20mph to the nearest dealer. They verified the issues. They reflashed the computer, drove the truck afterwards, and pumped the brakes. They told me they recommended an immediate master cylinder replacement. They had seen this twice already in the month of August. Both times prior to mine the reflash initially worked, but the problem returned within a week, and the master cylinders had to be replaced. The master cylinder replacement was a $2600 repair.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11763704September 11, 2026
ENGINE
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11763735September 11, 2026
POWER TRAIN, ENGINE
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0

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