GMC Complaints

6.2L engine lifters were replaced in 05/24. Complete engine failure in 09/25. Engine replaced with remanufactured engine. Fuel pump fail while driving on highway. Engine shutoff completely while driving 70mph. Prior to shut off engine struggled going over a bridge on I95 at 70 mph. Fuel pump failure happened 11/25 after ~900 miles on new engine. All service, maintenance and repairs completed by GMC dealership.

I bought my truck new in June 2025. On the night of December 29, 2025, with around 9,300 miles on the odometer, I began to hear a knocking sound coming from the engine while I was driving it back to my house from my mother's house. The sound got progressively louder and louder. The truck eventually displayed a "reduced acceleration drive with care" warning. I thought catastrophic engine failure was imminent and did not believe I could make it home. I called my in-laws (they were closer to my location than my house), agreed to park it there overnight, and thankfully made it to their house. The next day the truck was towed to the GMC dealership. A week later, GMC diagnosed this issue as a thrust bearing/crankshaft issue and agreed to replace the entire engine. A crankshaft issue in a new diesel engine should not occur, yet it did. My vehicle is currently being repaired, so the dealership said they had no repair records to provide me. This is the link to the video of the sound it was making after I made it to the in-laws: [XXX] I had just dropped off my [XXX] child with my mother about twenty minutes earlier. I was extremely close to being stranded on the side of the highway at night in the December cold with a [XXX] baby. Thankfully, that did not happen, but it was a close call. My cousin also has had a similar issue with the exact same make and model of his truck. I believe this engine is not being manufactured according to the design specifications and it is a danger to the public until the manufacturing issue with the supplier is adequately corrected. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Engine Failure confirmed by dealership. Engine being replaced. Knocking sound and went in to “limp mode” and check engine light. Dealer stated it had issue with crank shaft causing metal in the oil. 5,117 miles at time of failure. 3.0 L Duramax diesel

Driving down the road, the radio volume will randomly rapidly increase to full volume. There is no way to turn the volume down. This is very startlingly and can lead to an accident due to the driver panicking and trying to turn off the radio or turn the volume down. It has happened approximately 5 times since I have owned the vehicle. Thie first time was when the vehicle was only a few months old. It happens so infrequently that it cannot be reproduced. It has not been confirmed nor inspected by a dealer. There is no warning as to when it might happen, nor any similar circumstances when it happens. The only solution I have found is to stop, turn off the vehicle and open the door for a minute or two, which is difficult to do in traffic.

Powertrain System failure while driving, causing complete loss of power on road. The car lacks any accessible manual overrides to put in neutral or turn off parking break. This leaves the car stuck in park with all four wheels locked in the middle of the road in an incident with no safe way to move or tow the vehicle. When attempting to tow car must be dragged, and parking brake continuously engages. Tow attempt took nearly 3 hours to saddle the vehicle in the roadway. Vehicle currently awaiting formal inspection/repair from dealership.

I have a 6.2 engine that failed just recently had to get it rebuilt after hearing all the recalls for the other 612’s also have a 2023 GMC Denali Yukon also what does 6.2 on the recall

Driving at highway speed engine lost most power (limp mode), was able to get to an exit at low speed with flashers on but was creating a hazard on busy interstate. Dealer diagnosed truck needs new 3.0 liter duramax engine per GM TSB 25-NA-307, bad thrust bearing.

The transmission is shaky, Lower gears the truck seems to fight it way into the next gear, I feel this is happening around 3 to 5 gears. One garage told me the power converter was failing. I changed the transmission fluid and filter and it got better, but sill, this is an expensive truck. This is power train, this should be covered to 100,000 miles.

My telematics onstar unit went bad at 37,200 miles. No onstar, no SOS, no hands free driving, etc. I paid roughly 3k for the extended subscription servies for three years. Like many others who have this problem, dealer/GM will not replace the faulty unit even though I still had time left on my on my subscription. Apparantly its a common problem.

my truck has not been added to the 6.2 engine recall. I have several cases of friends and acquaintances who have had multiple engine failures (including replacements)with this same engine where their trucks shut down in the middle of the highway. I’ve tried speaking with GMCs customer warranty department to get details on why my engine has not been recalled and no one including them, my selling dealer or my service dealer can explain why it has not been recalled. I do not feel safe driving this truck and I’ve come to the point where I do not feel GMC has been honest with me about this engine. I’m actively reading dozens and dozens of cases each week where some GMC trucks are on their 3 or more engine. (engines produced in 2025 and late 2024). facebook page called gm 6.2l engine and bearing failure 2019-2024 discussion group has nearly 5,000 active members on it. I’m even getting conflicting information form gmc and dealers on what oil the truck should have.