GMC Complaints

The transmission went out. Torque converter put metal all through the transmission. While driving at highway speeds in traffic almost got rear ended

Car consuming too much oil, engine oil very low every 2000 miles. GM claims that 2000 is acceptable but new oil should go to 4000 at the least. Will not do anything to the engine or pistons and claim that car has too many engine hours due to idling which I do not do. They are unwilling to fix this problem, been dealing with them for over a year and my warranty is about to expire. There are many complaints online about this same issue.

At cold start-up, engine (6.2) makes a metal-to-metal grinding sound for 60-90 seconds. After warm-up, a steady tick on the right side of the engine while running. I contacted GM and they said, " this was normal at start up". however, with me being a mechanical engineer, all of my school and working experience tells me anything grinding metal to metal is not good.

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving at 50 MPH, the transmission independently downshifted and the rear wheels seized. The contact stated that the rear wheels skidded. In addition, the contact noticed an abnormal clunking sound. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The dealer was made aware of the failure. The contact stated that the failure occurred immediately after the recall repair under NHTSA Campaign Number: 24V797000 (Power Train) was performed by the dealer. The manufacturer was not made aware of the failure. The failure mileage was unknown.

Looks like this is a ongoing issue with my vehicles engine. The truck has 40k miles on it and the entire engine blew.

A little over a month after purchasing my brand new Hummer EV 2X I was driving and then I lost all power, brakes, steering, and had to coas t to a stop. My rear motor blew and snapped my trans axle. I had only 2,000 miles on the odo. This vehicle is riddled with issues that limit its ability to use safely.

The contact owns a 2024 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle lost motive power. No warning light was illuminated. The vehicle was towed to a local dealer, where it was diagnosed that the engine had failed and needed to be replaced. The vehicle was repaired at the contact's expense. The manufacturer was made aware of the failure. The failure mileage was approximately 6,000.

The check engine light would intermittently turn on since purchasing my brand new vehicle in 2022. The service center kept it for several weeks, but could not find a problem. They said it was a “bad batch of gas” the first time I brought it in. The second time they said it was an engine misfire. They said as long as the light flashes but doesn’t stay on, it is not concerning. March 13, 2025 as I was driving my car down the road my car suddenly shifted to neutral. I had to coast to the side of the road (with my children in the car). I turned my car off and it would not turn back on. I had it towed to the dealership and they said the engine had failed. They replaced it, but could not tell me if they replaced it with the same version engine or not. The dealership did not supply any paperwork of the repair when I picked up my vehicle.

The engine locked up while driving down my driveway at 5mph. It’s at the dealership awaiting a new engine install that is on back order.

Complete engine failure due to lifters going bad in return had to replace the entire thing