GMC Complaints

Hello so I notice 3 weeks ago my headlights keep cutting off and on then a week later my radio stopped working, The floor of the driver side is always wet after it rains. I noticed one day the rain started dripping on my feet when I drive after a big rain fall, I believe the car is not sealed properly and now water is coming out from the airbag signs in my vehicle and the car starting to smell like mildew. I think water is sitting in certain parts of my vehicle. I'm not sure what to do.

I am submitting this complaint to report what I believe is a serious safety-related defect involving the General Motors 6.2L L87 V8 engine installed in my 2026 GMC Sierra Denali. On July 10, 2026, while driving on a public highway near Bogata, Texas, the engine suddenly began making severe mechanical noises before catastrophically failing without warning. The engine seized completely while the vehicle was in motion. At the time of failure, the truck had only 13,517 miles. The sudden loss of engine power left my wife and me stranded on the roadside. Had this occurred while crossing an intersection, merging into traffic, passing another vehicle, towing a trailer, or traveling in heavier traffic, the consequences could have been far more serious.

Black hood center molding broke off, hit the windshield and blocked driver view.

Top Grill/Hood trim piece - it is separate from the main Grill. It detached and flew off at interstate speed. Thank God it missed several cars behind me. The passenger side corner came loose and before I could safely make my way off the interstate the piece ripped all the way across and flew over the top of the truck. May have gone 30 feet in the air prior to landing on the asphalt between the two lanes.

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the transmission was shuddering, especially while driving uphill. The dealer was contacted, and the vehicle was diagnosed and determined to have a failure associated with a GM TSB for the incorrect transmission fluid inside the transmission reservoir. The vehicle was not yet repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 38,875.

The contact owns a 2022 GMC Terrain. The contact stated that while driving 40 MPH, the vehicle lost automotive power. No warning light was illuminated. The vehicle was pulled over to the side of the road. The “Low Fuel” message was displayed on the instrument panel. The contact stated that the vehicle failed to restart. The vehicle was towed to a local dealer where it was diagnosed and determined that the fuel pump was inoperable and needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 51,000.

The contact owns a 2023 GMC Terrain. The contact stated that while driving at various speeds, the vehicle unexpectedly decelerated and failed to properly accelerate. The service transmission and service fuel management system messages were displayed, and the check engine warning light was flashing with several other unknown warnings illuminated. The vehicle was taken to the local dealer and while test-driving the vehicle, the vehicle stalled. The vehicle was towed back to the dealer. The cause of the failure was not yet determined. The manufacturer was notified of the failure, and an engineer was sent to the dealer to inspect the vehicle. No further information was available. The contact stated that the transmission module was previously replaced, but the failure persisted. The failure mileage was 27,000.

The truck starting making a ticking noise within 24 hours the check engine light was on and it starting shuttering. I got it to the dealership were they informed me of lifters failure, and catastrophic engine failure. Dealer is recommending replacing engine since it's a 2020 and not part of recall.

The contact owns a 2012 GMC Acadia. The contact stated that while the vehicle was parked, after pressing the liftgate button the liftgate raised and crashed down independently after several seconds. No warning lights were illuminated. The contact researched and was made aware of an unknown recall; however, the VIN was not included. The vehicle remained at the residence. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 189,352.

I was driving on 96 W. in slow traffic on the freeway when the vehicle put itself in neutral and shut off