GMC Complaints

The original engine (6.2L L87) had to be rebuilt by GM because of lower engine knocking in June 2024, with 57,873 miles. The rebuilt engine had to be replaced with a remanufactured engine in October 2024, but had to wait until the completed work in December 2024. The remanufactured engine started knocking, and that engine was replaced in October 2025. All part of the L87 6.2L engine failures. Problem documented by dealerships. Components were brought to GM's attention. No warning lights or messages - just lower engine knock.

I’m not happy with just a change in oil viscosity because the car has already been on the road for 70000 miles before we were aware of the recall on the engine. Changing the oil viscosity doesn’t help when there is a underlying engine problem it should be replaced not just change your oil and send you on your way because now I’m always wondering and worried if the engine will still fail when my kids and wife are in the car. Furthermore I just had it inspected and the oil changed to new viscosity a week ago and the oil level is already half way on the dipstick so I’m taking back to the dealership to express my concern. If I would have known this was going to be an issue with this suv I would have purchased something else. I’d just like the engine replaced so that I don’t have to worry every time I pull out of the driveway with my family. My power steering assist still whines and there is no open recall on it. I think GMC should be responsible for replacing engines and power steering assembly and power steering motors on 2021 GMC YUKON DENALIS because of the wear and tear they have endured before the recall was taken care of by adding a different viscosity oil because the damage has already been done.

GMC Terrain with 12,564 total miles had experienced an engine failure. Under normal driving conditions, the car was sluggish and would not accelerate properly when pulling out into traffic or when getting on the freeway/interstate causing fear for driver safety and causing traffic slowdowns or congestion with a significantly increased risk of crash. While driving to work, the vehicle service engine light turned on and displayed "reduced engine power". Upon investigation the dealership found codes P0011, P0014, P0016, P0017, and quoted "Cylinder 4 intake rocker had fallen off and laying on head, found excessive debris and metal material around rocker 4, Found cylinder 2 intake rocker to be worn sideways. Found heavy damage to intake camshaft. Removed oil filter - found excessive metal in oil filter". Secondary issue, infotainment screen would randomly flash bright white on the right half, causing a major driver distraction. Engine, turbo, and infotainment system were all replaced, and vehicle returned 11.06.2025

I'm reaching out because I've encountered a really concerning issue with my 2025 GMC Yukon AT4 Ultimate. There's a really loud popping noise randomly coming from the speakers that's honestly quite startling and dangerous while driving. Most recently, it scared me so much that I swerved off the road and nearly crashed. If you review online forums, you will find that this has been experienced by other owners as well. I've tried to resolve this through your usual service channels, but my concerns have been dismissed without any recommended action to ensure my family's safety. After scheduling with my local GMC dealership they couldn't replicate the noise and sent me on my way. I also brought it up with GMC Customer Care, and they suggested I try to record the sound, or keep bringing it in for service if it happens again. The problem is if I tell them it keeps happening again, what good will it do? It's a loud pop coming from the back speaker area. Even if they had 7 technicians hearing it at the same time, how will that make a difference. I need them to start testing components and replacing them one by one until its resolved.

Repeated transmission issues with the 8 speed transmission due to the malfunctioning valve body. This has caused major safety issues and nearly killed my family with the vehicle locked up and wouldn’t shift on the interstate. The dealership did a warranty repair on the torque converter which made the symptoms slightly better until the vehicle was no longer covered by warranty, at which time all symptoms came back. GM knows their 8 speed transmission has an issue and hasn’t provided a solution. Now, due to the faulty valve body, I have to have my entire transmission replaced for $8000.

Driving through the intersection of N. Scottsdale Road and E. Bell Road in Scottsdale AZ my collision warning red light flashed on the screen and the engine turned off. This caused me to lose forward propulsion and forced me to navigate to the side of the road to avoid being hit by another car. At Van’s GMC, the service manager told me that we experienced a catastrophic engine failure and that the engine seized. Vehicle has been inspected, but I have not received an official diagnostic even though I have requested. There were no warnings or indications that the vehicle was compromised prior to the engine turning off.

Transmission feels like it’s slipping, almost like a jerky shift from any stop, seems like a common issue and should be recalled!

The contact owns a 2021 GMC Yukon. The contact stated while driving at an undisclosed speed, the engine seized. The brake pad sensor warning light illuminated. In addition, the contact stated that the vehicle continued to roll forward. The contact was able to drive the vehicle to the shoulder of the road. The contact stated while attempting to restart the vehicle, the vehicle failed to start. The contact stated that a nearby driver assisted by providing a jumpstart. The vehicle was driven to the residence. The vehicle was then taken to an independent mechanic where it was diagnosed with alternator failure. The contact stated that the vehicle was previously taken to two independent mechanics, and the vehicle was diagnosed with alternator failure. The dealer was made aware of the failure. The contact was informed that the failure was a known failure with similar vehicles. The manufacturer was made aware of the failure with the alternator and the brake pad sensor. The contact was informed that the repairs were not covered under warranty or recall. The failure mileage was approximately 95,000.

6.2L engine, collapsed hydraulic lifter AFM failure, required $7400 in total repairs. All lifters, camshaft, high pressure fuel lines, high pressure fuel pump, intake manifold & miscellaneous parts and gaskets replaced by selling Dealer at 94000 miles. No help of any kind from GM or Dealer. This is a WELL KNOWN FAILURE FOR THESE ENGINES!

While stopped at traffic signal, vehicle suddenly stops running. Restarted vehicle and had to feather the throttle to keep it running. Engine began to run normally so I continued driving. When I reached approximately 35 mph, a loud rattling noise started and experienced a severe loss of power. Fortunately I was able to safely get out of the traffic lanes to the side of the roadway. I inspected the vehicle, no oil leaks, no coolant or transmission leaks. No warning indicators on the dash. Oil pressure normal. Temperature normal. I limped the vehicle home to be towed to dealer. Approximately 2 months ago this vehicle passed the recall inspection and had the recommended oil change. There was a previous warranty repair performed on a stuck exhaust valve in the #8 cylinder. The vehicle was also brought in to the dealer for suddenly cutting off while driving approximately 50 mph. Again I was able to pull off safely. The vehicle then started normally and I proceeded to drive. The dealer inspected the vehicle and could not replicate the issue, and found no electrical or mechanical trouble codes. There were absolutely no warning indications prior to each of these events.