GMC Complaints

GMC refusing to provide new engine and repair. GM sent letter with no date for repair. GM will not provide alternate transportation. GM states engine failure could cause loss of power resulting in an accident but will not provide alternate transportation.

The contact owns a 2023 GMC Terrain. The contact stated while driving 15 MPH, the message "Engine Power Reduced” was displayed on the instrument panel. The contact stated that the vehicle the lost motive power in the middle of the roadway. The check engine warning light was illuminated. The vehicle was towed to the dealer, who diagnosed a failure with the high-pressure fuel pump, causing fuel to leak into the oil, resulting in damages to the catalytic converter and Oxygen sensor. The vehicle was not repaired. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA Hotline for assistance. The failure mileage was 41,000.

While merging into highway traffic the truck surged with RPM going to 5,000. Shortly after this event there was a grinding or rattling noise in the transmission bell housing along with unusual shifting behavior and a repeatble vibration + rotational noise between 50 and 60 MPH. The vehicle was brought to the dealer for inspection at least 4 times with claims they could not hear the obvious noise that did not go away. On the last drop off, I picked up the vehicle and the noise was gone but the shifting behavior and the constant vibration from the transmission still persists. The dealer said GMC would replace the transmission for approximately $10,000 but I would need to cover 50% of the cost. Vehicle had 35,700 miles on it and was 4 months beyond the 5yr warranty. Still unrepaired. No warning lamps, messages, or codes. Transmission component failure is imminent based on the vehicle behavior

I bought the truck 3.5 months ago with 66,000 miles with a recall (reprogramming) on the transmission already done according to the dealer. Then yesterday on 6/25 the truck stuttered then shifted hard. When I got to my destination it didn’t have reverse. But no warning lights. So I drove it to the dealer and before I got there it did it again and sent the truck into a power loss mode this time with a warning light. And would barely finish going up the hill with cars behind me. Now they are saying it needs a transmission but gm is only offering to pay half. Also saying the diesel would be covered but my gas isn’t even though I’m pretty sure they are the same transmission makes no sense. Lastly shouldn’t them offering to pay %50 show that they know they have a problem

The contact owns a 2020 GMC Terrain. The contact stated that the vehicle was taken to a dealer for an oil change. The contact stated that approximately 5 weeks after returning the oil change, while driving at approximately 65 MPH, the vehicle and steering wheel started shaking abnormally and the vehicle lost motive power. The contact stated that the traction control, check engine, and stabili-trak control warning lights were illuminated. The vehicle was taken to a dealer where it was diagnosed that there was no oil in the engine and the spark plugs and ignition coils needed to be replaced. The vehicle was repaired; however, the failure reoccurred three weeks later. The manufacturer was not notified of the failure. The failure mileage was approximately 37,000.

The contact owns a 2021 GMC Sierra 1500. The contact stated that occasionally while attempting to start the vehicle, the engine hesitated to turn over. The contact stated that the failure progressed, and the vehicle no longer started as needed. The check engine warning light was illuminated. The contact stated that two local dealers were contacted; however, the contact was advised that to diagnose or repair the vehicle, might take several months. The vehicle was towed to a local independent mechanic, where it was diagnosed with camshaft sensor failure. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 83,000.

Transmission has a shudder at lower speeds 1200 RMP area. Has been doing it since I bought the truck a few years ago. Took it back for warranty work and they claim this is a very common problem with this transmission. Claim that flushing the system would repair it, which it has not. Occasionally to will almost go out of gear, I have to try getting off the road safely to shut it off. After a few minutes, start it up and it will be back to normal. Also I’m on my 3rd starter. What appears to be another common issue with this model. Sometimes it fires right up, sometimes it’s very weak and others not at all and requires a jump start. All in all, recalls should’ve already been applied to these models. Pay way to much for junk!

The contact owns a 2024 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The dealer was contacted. The manufacturer was not made aware of the issue. The contact had not experienced a failure. VIN tool confirms parts not available.

The contact owns a 2023 GMC Yukon XL. The contact stated while driving 55 MPH on the highway, the contact heard an abnormal squeaky sound coming from the engine. The contact pulled to the side of the road, and the engine seized. There was no warning light illuminated. The vehicle was towed to a dealer, where it was diagnosed that the engine had failed and needed to be replaced. The vehicle was repaired. The contact later received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling). The contact related the failure to the recall. The manufacturer was not notified of the failure. The failure mileage was approximately 44,000.

I am writing to formally submit a serious safety complaint regarding the transmission in my vehicle, which nearly caused a life-threatening accident while driving under normal conditions. While traveling on a two-lane rural highway, I was attempting to climb a steep hill when the transmission suddenly began to slip. My vehicle lost power mid-ascent, despite steady pressure on the gas pedal. The RPMs shot up erratically, but the vehicle failed to accelerate. As I began to crest the hill, the transmission completely disengaged, forcing my vehicle into a free-roll situation. The danger escalated quickly. As I started to descend the hill, I attempted to downshift to control my speed—but the transmission would not respond. It slipped again, and I was essentially coasting with no engine braking. An 18-wheeler was behind me, approaching fast. I could see it barreling toward me in my rearview mirror, and I had nowhere to go. With the road shoulder too narrow and no pull-off in sight, I had to veer dangerously close to the edge to avoid being rear-ended. I truly believe that if the driver of the semi hadn’t taken evasive action, I would not be here to write this complaint today. This transmission failure is not only unacceptable—it is a critical safety issue. A vehicle should not lose all power and braking control during normal highway driving. This is not just an inconvenience or a performance issue. This is a defect that puts lives at risk. I am requesting that this transmission be investigated for an official recall. I have since learned that I am not the only one experiencing these symptoms, and it is only a matter of time before this defect causes a fatal accident. Please take immediate action to investigate this issue. I am willing to provide full documentation, diagnostic reports, and be available for further interviews if needed. Lives depend on it.