GMC Sierra Complaints (2026)

171 consumer complaints on file.

#11768529October 2, 2026
POWER TRAIN, ENGINE, UNKNOWN OR OTHER
The powertrain/transmission is malfunctioning. The vehicle shutters, vibrates, and surges forward when coming to a stop, as if it wants to take off on its own. These symptoms began within the first couple of days after purchasing the vehicle on XXX. The valve body was replaced, but the issue continues. The vehicle is available for inspection. GM Case Number: XXX Dealership TAC Case: XXX This creates a serious safety risk. When stopping, the truck shutters and unexpectedly tries to lunge forward, which could cause a collision with another vehicle or pedestrian. The unpredictable movement makes it dangerous at intersections, stop signs, and in traffic. The dealership has reproduced the issue multiple times and performed diagnostics, but the shuttering and surging continue. The vehicle was last inspected around XXX. On XXX, I called GM to speak with [XXX] for an update on when a GM representative/technician would inspect the truck. I was told the case had been closed even though no resolution or inspection occurred, and [XXX] never called me back. No other agencies have inspected it. There were no warning lamps. Symptoms began within days of purchase and include shuttering, vibration, surging forward when stopping, and inconsistent acceleration. These symptoms occur daily and have worsened over time. 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
#11767996September 30, 2026
ENGINE
I was driving home on the evening of September 12th 2026 and when I exited the interstate and came to a stop at the traffic signal my vehicle died and I had to have it towed. There was no way to flat tow because we couldn’t get it into neutral without the vehicle’s engine running. Once the vehicle’s engine died it would not restart. Had this happened while still on the interstate causing my vehicle to be disabled in the lane of travel it could have been deadly since it was 10 p.m. in the evening and dark outside. Anyhow had the vehicle towed to the dealership for diagnosis and the engine spun #7 rod bearing which ruined the entire engine at just 15,182 miles.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11768027September 30, 2026
POWER TRAIN
The contact owns a 2026 GMC Sierra 1500. The contact stated that while driving 5 MPH, the vehicle independently shifted into park(P). The check transmission warning light was briefly illuminated. The failure was a recurring failure. The dealer was contacted. The manufacturer was contacted by phone and made aware of the failure. The failure mileage was approximately 2,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11768111September 30, 2026
ENGINE
Dealer confirmed 6.2 V8 engine failed at a little over 4000 miles. Dealer stated it was the bottom of the engine. Probably the same failure the 21-24 recall is for.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11767822September 29, 2026
POWER TRAIN
engine stall on the highway
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11767825September 29, 2026
ELECTRICAL SYSTEM
The vehicle lost power after sitting for a week. start up with a jump, but the battery doesn't hold a charge after that.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11767598September 28, 2026
ENGINE, FUEL/PROPULSION SYSTEM, POWER TRAIN
Truck was sold to me and the dealership said the truck did not have the defect and the oil was changed to a thicker oil as a precaution. 4,000 miles later the engine failed, was diagnosed as catastrophic engine failure due to the known recall, and was replaced, new engine is now making the same rod knocking noise.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11767616September 28, 2026
AIR BAGS, ELECTRICAL SYSTEM
Truck has airbag service issues since day 1. I’ve taken to the dealership and they can’t find any issues even though the service safety system continues to appear. Ac issues and charging issues as well. I’ve attached documentation.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11767225September 27, 2026
ENGINE
2026 GMC Sierra 1500 Denali 6.2L , with 3550 miles; started ticking and another mile to get home started knocking, had truck for less than a month, had it towed to the dealer they said will get a new engine, they can't even five me a time frame for the new engine replacement.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11767261September 27, 2026
ENGINE
I purchased this vehicle on May 28th 2026. At that time I was told there were no problems with the 6.2L engine. The problems they have had didn't affect the 2026 Denali 1500 6.2L's. After hearing about numerous 25's and 26's engine failures I decided to have my first oil change at 1540 miles. I asked the dealership to give me the oil filter so I could open it and examine it. I found excessive metal in the filter, indicating to me that the engine is failing. I contacted the dealer, they told me to go to GM Customer service. They told me there is nothing they can do unless the check engine light comes on or there is noise in the engine or it blows up. In which case people have reported traffic hazards getting to the side of the road without power or even the rear wheels locking up. One incident shows the vehicle had a fire and completely burned up. I made a vacation trip without incident and put another 825 miles on the truck, at which time I swapped out the oil filter and opened it up and found more metal particles. Common sense tells me that the engine is self destructing and will at some point fail. The manner in which that happens is the safety issue. I have reported this issue to the dealer and GM and they say just keep driving it. Putting myself and my family at risk. I know I am not the first one to have a bad engine in my new GMC Denali. There are just way too many defective engines in these vehicles to feel safe after buying such and expensive vehicle. Don't get me wrong, I love the truck!! I just would like to know it has a dependable engine to keep me safe while driving it!!
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11767221September 27, 2026
ENGINE
2026 GMC Sierra 1500 Denali 6.2L , with 3550 miles; started ticking at 45 MPH and another mile to get home started knocking, had truck for less than a month; no warning lights. I had it towed to the dealer. They said it needed a new engine, no time frame for repair.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11767126September 26, 2026
ENGINE
With 10000 miles on my 6.2 liter the engine failed. Cause was main bearing failure. Needed full engine replacement.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11766683September 24, 2026
ENGINE
2026 GMC Sierra SLT with 3.0 Duramax diesel engine. While driving down the road with the cruise set to 55 MPH on 8/29/26, the engine started to run rough. I slowed down, but this did not seem to help; I sped up, and the problem persisted no matter what I did. Service traction control and service ESC displayed on the dash. I drove to the dealership; their service department was closed because it was Saturday. I took my salesman for a ride so he could witness the issue firsthand. He confirmed something was not right, and they put me into a loaner vehicle. The truck has 848 miles on it. Service diagnosed it as a fuel issue in cylinder 2, replaced the injector, but the issue did not go away. GM TAC team advised replacing the motor; that is what I am currently waiting on. The dealer has the motor and is awaiting the install.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11766503September 23, 2026
FUEL/PROPULSION SYSTEM
Fuel Filter and High pressure Rail System The truck started shuddering and began to go into limp mode also shifted into neutral byitself No It was inspected by the dealership shop and now insurance Check engine light came on and code P1089
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11766519September 23, 2026
POWER TRAIN, ENGINE
While turning right and at a slight incline the truck engine turned off, the transmission made a grinding noise, the truck went into neutral and the dash stayed “Press Start Button”. This is the second time this has happened within 5000 miles of the struck being purchased. Several others have reported the exact same issue on Facebook forums.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11765942September 21, 2026
ENGINE
The contact owned a 2026 GMC Sierra 1500. The contact stated that while accelerating from a red light at 15 MPH, the vehicle sputtered and shook before finally moving forward. The contact stated the failure was a recurring failure. The contact associated the failure with NHTSA Action Number: EA26005 (ENGINE). The dealer was contacted. The failure mileage was approximately 160.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11765646September 20, 2026
ENGINE
Engine blew on a 2026 GMC AT4X with the 6.2 motor. Has been inspected and confirmed by dealership. No warning on failure, was passing a car when power was lost and warning system said restart engine.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11765513September 19, 2026
POWER TRAIN
Very similar to NHTSA complaints 11752469;  11762072 ; 11761966 ; 11761844;  11755200 while turning left into my 6 degree inclined drive at a slow rate of speed under 5 mph, my 2026 GMC Sierra SLT X31 with 1500 miles suddenly slams into park and shuts down. "Press start" shows on display and am able to start the truck. Twice the "Service Transmission" light has displayed. I took it to the dealer after two incidents and they could not replicate. Since getting it back from the dealer, I've had six more incidents and am taking back to the dealer with more information for them. The last incident, I was prepared for it and felt the truck begin to shut down and slammed on the brake before it shut down.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11765185September 18, 2026
ENGINE
The 6.2L L87 V8 engine in my 2026 GMC Sierra 1500 suffered a sudden, catastrophic mechanical failure and shut down completely while driving at 65 mph with only 6113 miles on the odometer. There were no dashboard warning lights prior to the seizure, resulting in a sudden and dangerous loss of power. I was towing a 30 foot camper at the time and passing an 18 wheeler, it was truly a dangerous situation at the time and my wife and I feel very fortunate that we that we didn’t have a fatal accident.The dealership confirmed a total engine failure/seizure and had to replace the entire engine assembly under warranty."
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11765327September 18, 2026
ENGINE
My 2026 GMC AT4X 6.2 liter engine had a lifter fail for #5 cylinder due to a faulty designed crankshaft bearing causing a knocking with the engine running. It required the engine to be replaced by GMC at only 7100 miles. The dealership admitted it was a defective/incorrectly manufactured part that caused the failure. I wanted to report this since GMC had said this issue had been corrected on the 2026 model year engine, but I have been reading that this issue is still occurring in the new vehicles and at a very low mileage instance. Mine failed at only a little over 7,000 miles.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0

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