GMC Complaints

Driving 30 MPH on 4 lane city road when engine shut off with many warning lights. Vehicle dead in the road, needed to be towed to dealership where I was informed that the engine had "locked up" They said they have seen many of these 6.2L engines locked up.

Transmission failure at a little over 120,000 miles while towing a side by side on the highway. This highway has a speed limit of 80 which is dangerous when the vehicle stops working properly for myself and any other drivers in itself. Earlier this year the transmission had been updated due to a recall and was deemed to work good by the dealership but didn’t notice any difference. Had an engine light pop up a couple hours before but no messages or any other signs to inform me of the issue and was still working fine with no struggle until it gave out

The contact owns a 2024 GMC Yukon. The contact stated that while driving at a slow speed in the driveway, the vehicle inadvertently lost motive power but immediately restarted. After restarting the vehicle, the vehicle briefly returned to normal functionality, but the failure became a regular occurrence. No warning lights were illuminated. The vehicle was not taken to the dealer or an independent mechanic. The vehicle was not repaired. After investigating the failure, the contact related the failure to NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling). The VIN was included, but parts were not yet available. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA Hotline for assistance. The failure mileage was 26,000.

The contact owns a 2023 GMC Sierra 3500. The contact stated that while driving approximately 60 MPH, the messages "Service Charging System" and "Service Diesel Emissions System" were displayed, and suddenly the power steering and power brakes malfunctioned, causing the contact to almost lose control of the vehicle. The cause of the failure was not yet determined. The local dealer was notified of the failure. The manufacturer was not yet contacted. The failure mileage was 79,000.

Torque Converter failure confirmed by dealer: was driving at high way speeds when I noticed a slipping sensation from the transmission upon any sort of acceleration. No warning lights were illuminated or any symptoms leading up to the failure. This could have potentially caused me to lose any form of acceleration that would enable me to get off of the highway or away from a situation requiring sudden acceleration.

The contact owns a 2017 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed and coming to a stop, the steering wheel seized. There was no warning light illuminated. The contact stated that while attempting to make a turn, the steering wheel became difficult to maneuver. The dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 118,000.

While trailering a large RV the information center sent me two warnings. The first was trailer brakes disconnected the second was service trailer brakes. Took it to the dealer they were unable to replicate so they blew me off.

My 2020 GMC Terrain brakes pump failed causing me to hit the median wall on the highway.

After each rain or hand car washing, the OEM sunroof has a gurgling sound when driving at speeds above 25 mph. This does not clear for miles, or over time (at least 1 day without water). Water appears to be passing through the seal into the drainage gutter, but not completely draining out through the drains. Its been in service twice to have the drain lines cleared, and the issue remains. This has been present on other car manufacturers as a "wind pressure issue" where the force of driving causes wind pressure to push what water hasn't drained back up into the sunroof. Fix was extending the drain lines at output. GMC unable to repair.

I purchased a 2025 GMC Denali a few months ago. At approximately 7,000 miles, the front brakes failed unexpectedly and were replaced by the dealership. However, by 14,000 miles, I began experiencing brake issues again. Before I could return the vehicle for service, I was driving on the turnpike when the engine suddenly seized without warning. This created an extremely dangerous situation—vehicles behind me nearly collided as I lost power and control. I managed to pull over safely, but the tow truck operator struggled to load the vehicle due to all four wheels locking up and the engine being completely seized. Once the vehicle was inspected at the dealership, I was informed that the engine had failed and would need to be replaced. I am aware of the recurring issues associated with the 6.2L GMC engines and related component failures, and I no longer feel safe driving this vehicle. Given the repeated mechanical failures and the serious safety risks involved, I am formally requesting that GMC initiate a buyback of this vehicle. I believe this situation qualifies under lemon law protections and warranty obligations, and I urge GMC to take immediate action to resolve this matter.