GMC Complaints

I was traveling north on interstate 95 and approaching my exit ramp. I was initially in the inside lane of travel. I accelerated to merge into the outside lane, between two other vehicles, and then onto the exit ramp. Once on the exit ramp, I let off of the throttle and the engine suddenly shut down. I noticed a message on driver information center instructing me to shift the vehicle into neutral and press "start again". The engine had shut down without any warning whatsoever. I complied with the instructions to no avail. The truck is over half full of fuel. I was within an hour of home after completing an approximately 8 hour, 500 mile, round trip over 2 days of driving. After this event, I connected an OBD2 scanner and the only code found was P25A2 brake system control module. I placed the truck in park and tried repeatedly to start the engine. It would not turn over, crank or start. I had power to all systems and no other codes. I had to have the truck towed from the scene. The truck's performance had previously been flawless during this entire trip and had given me no warning whatsoever of the sudden engine shutdown. This is extremely dangerous and a safety concern.

Driving on the highway and the vehicle began making a strange noise. Went immediately to a dealership and they identified a bearing had come loose in the engine and the engine has to be completed replaced. Cost of almost $11k and the engine is on back order with no definite availability date. Vehicle was in excellent condition, all scheduled maintenance at the dealership. No issues until this. Approximately 80k miles m.

Bad torque converter with 56000 miles and a month out of warranty and GM says to bad.

As we were driving, without warning, the engine started to rumble and clank. We had to pull off the road in a neighborhood and have it towed to the dealership. Thankfully, we were driving on side/neighborhood roads at the time. If this would have happened on the highway it could have been very dangerous. They'll dealership said it was unsolvable and we needed to purchase an entirely new engine.

Driving at 55 mph and my 6.2L engine stalled and seized up. Had it towed to GMC dealership and the verified it had seized.

May 2023 we took the car to the GM dealership for a electronic recall. We reported a rattling noise at that point in time. Whatever repair was done that the car ran w/o any noise for nearly a year. April 2024 the catalytic converter failed at just 61K miles on this vehicle. The mechanic at the same dealership noted a broken mounting bracket and replaced the catalytic converter. October 24 2024 at 76K miles the car started making the same noise. The mechanic at the same dealership noted a loose mounting bracket due to an excessively vibrating catalytic converter, a crack on the cat converter, a leak and sequentially damaged front pipe. They noted they made all of those repairs. They noted they test drove the vehicle and verified the car was repaired. October 26, 2024 after those final repairs the car made a loud revving noise and emitted a smell of sulfur. The next day the car died on the road while driving. Every system of he vehicle shut down and I narrowly avoided getting hit from behind. On 11/2/24 We had the car towed to the dealership again. The mechanic noted the recent replacement on the cat converter & oil had leaked intermixing. That caused the motor to seize and the car to stop working while I was on the road driving. I can't imagine what could've happened to me had it stop on the highway at 65mph.

Vehicle started jumping and switched into 4WD while reversing. There was no inclement weather or slipping to prompt this. Service 4WD warning had been showing intermittently for a week or two and service appointment had been scheduled. At service appointment, confirmed that 4WD switch was faulty and needed to be replaced.

Engine catastrophic failure while under extended warranty. Engine failed in February of 24 however I had told dealership I was having troubles with Engine and shifting also tires from 1st 11000 miles it also kept reduce power on me and basically shut down 3 times in middle of hwy. The 6.2 engine locked up on the mechanic who was test driving it. Took 3 months

I was driving home from work at around 60 mph. Very sunddly their was a rattling metal sounds and then vehicle struggled to maintain speed. Before pulling off the highway at the next exit. On the exit ramp the engine turned off and would not turn back on. The vehicle was also stuck in neutral and not able to shift out of neutral for towing. There was no worning lamps or messages even after the noise and reduced power. Vehicle was towed to local dealership on Tuesday evening, as this was not scheduled it took them to diagnosis the issue as engine failure and recommending to replace the engine. The vehicle is a 6.2L GMC Yukon Denali with 23k miles. All service has been done at the dealer with no outstanding work prior to the engine failure. Where it gets more disappointing is the lack of information for time to fix. The replacement engine was ordered by the dealer on February 14th. As of February 28th they did not have any information....So i called GMC on that 1800 number listed on GM Document DCS6866 referencing customer satisfaction program N232413430. The first agent disconnected without filing a case. The second agent had to restart the process and was told that there was nothing they would do for 14 days after the case was opened before it would be elevated. When talking to the agent they denied any information related to the GM Customer Satisfaction Program or any knowledge of what seems to be a wide spread defect on 6.2L engines. The service and support for a $90k vehicle from, in fairness they have provided access to rental vehicle from a local auto shop. The vehicle is far smaller and different from our vehicle we purchased. The vehicle is still sitting at the dealership service center and is not functional until the engine is repalced.

AFM lifters failed which caused cam shaft to collapse under 35k miles. Had to remove while front end to repair