GMC Complaints

I'm experiencing constant transmission shuddering at constant speed between 25 and 40 mph. This is a know issue, General Motors known issue, with the 8 speed transmission installed in this vehicle. TSB 18-NA-355 was issued in August of 2019 for this issue, but general motors refuses to recall all affected vehicles. Something needs to be done about this!

When driving down the interstate the vehicle sways and makes steering challenging. Potential lack of control when hitting bumps on road at highway speeds. Taken to the dealership that sold the vehicle. They confirmed the issue. No warnings lights or notifications at this time.

On June 19th, 2025, I was driving to work when my truck began to lose power, and the check engine light came on. The error on the display is Loss of Engine Power. I took it immediately to Oreilly's so they could run the free engine light check. When they got the report, the employee was amazed that there were over 45 problem codes showing up. As I drive the vehicle there is a pull back from the engine before it starts to pick up speed. On braking as well there is a little kickback before it comes to stop. It takes more foot pressure to pick up speed. The Truck using up more fuel because of this issue. I took the truck to a local certified mechanic, and he ran the diagnostics as well and it came up with the over 45 problem codes as well. His recommendation unfortunately was to take into the dealership so they could check it and see if they have a solution for this engine malfunction and error codes.

Shift to park issue. This 2019 Acadia Denali has been serviced twice for a shift to park issue:(It’s a known problem that occurs when Acadia vehicles fail to recognize that the gear shifter is in the park position). The first time was under warranty in 2022 and it has just been serviced again for the same problem. The system is the same as the older GM recall for this problem and the recall should also include this model as well but unfortunately it does not.

Vehicle equipped with 6.2l v8 engine. Have been experiencing hesitation upon acceleration, decrease in power/reduced performance, trouble starting, abnormal shifting (particularly from 2nd to 3rd and 3rd to 4th gear) for about two months. On two separate occassions(once about 1yr ago and the second time about a week ago) during normal use of the vehicle, the car started to shudder and the CEL began flashing. Both times I immediately pulled over and shut off the vehicle. Fluids were good, car has never overheated, regular maintenance has been performed as well. When I turned the car back on, the light was off and didn't show any signs that there was an issue. Two days ago during normal use of the car at about 35mph, a loud knocking/ticking sound started. I was about 1/8 mile from my destination so I attempted to make it there. Driveway is uphill and when I accelerated to get up the hill the sound got much louder and ticking was twice as fast. Shut off the car, let it cool, and knocking sound was just as bad the next time I started the car. Had the car towed to prevent damaging the vehicle further. This car is financed and i have three payments left on the 54 month contract. Today i reached out to the dealer about the issue and asked if I should bring my car to their service dept. I explained how i have been experiencing most of the issues that GM has identified as warning signs that indicate a potential engine failure and I was told theres no way my car has a recalled engine and the guy laughed at me when I tried to give him the information I found on the NHTSA website. Not really sure who I'm supposed to call to get some help with this issue.

The rear hatch would open but then start to slowly drop. The local dealership diagnosed the problem and told me the pump needed to be replaced but quoted $1000. I chose not to have the repair done at that time but recently the hatch opened and then dropped suddenly hitting me on the head. There were earlier model recalls for this problem but not on the 2015. This is a potentially dangerous condition.

The contact owns a 2017 GMC Acadia. The contact stated that while driving approximately 10-15 MPH, the vehicle made an abnormally loud blower motor sound while accelerating, before the vehicle lost motive power. The transmission was shifted to neutral(N) and pushed to the side of the roadway. The TPMS warning light was illuminated. The vehicle was towed to an independent mechanic who determined that the transmission clutch had failed, and the transmission needed to be rebuilt or replaced. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was contacted and confirmed there was no recall coverage or warranty coverage on the VIN for the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 132,000.

Vehicle's 10 speed transmission on numerous occasions has locked the wheels at high rates of speed on the highway, causing the vehicle to veer across several lanes and almost crash. Vehicle will not always engage in drive selection causing a filed accident while trying to go from reverse to drive.

DURING AN OIL CHANGE IN MAY I WAS INFORMED THAT MY FRAME WAS EXTREMELY ROTTED AND WAS IN JEOPARDY OF CRACKING IN HALF . THE FURTHER I DIG INTO THIS, I'M FINDING THAT GM IS AWARE OF THIS ISSUE. THE VEHICLE IS AVAILABLE FOR INSPECTION.

Engine code P1098 indicating failure of Cooling Control Valve (CCV) at 2.5 years old, 49k miles. Display on dash indicates acceleration reduced warning, fan in engine bay running at high level while actual temperature reads normal.