GMC Complaints

Vehicle shut-off while driving on the expressway, around 70-75mph. Upon vehicle turning off, I had no option but to "coast" off to the left side, which thankfully, freed me from traffic for the most part. If anyone who have been a foot over, they would've hit me. I have had numerous electrical issues with this vehicle and have taken it to the dealership but they have been "unable" to duplicate the issue. Vehicle was immediately taken to the dealership (and they still have as of this incident report submission). They told me last night that they will keep it again today and test drive it again to see if they can get it to do anything but if it doesn't show anything new, they have nothing to diagnose and will give me my car back. After requesting a copy of repair orders and a list of the history codes in my car, I am beside myself that anyone thinks giving me this vehicle back to drive is ok. See the history code report in documents uploaded. These are MAJOR safety failures in a large vehicle.

Engine with leas than 40,000 miles is consuming one (1) quat of oil every 2,000 miles. GM dealership showed me the internal GM service update stating the accepted rate of oil consumption for engines uses in the vehicles referenced is 1qt per 2,000 miles. That may seem acceptable because GM put it in a notice to dealerships but I assure you the end consumer would never buy this engine if this was explained prior to purchasing. There is a reason new cars to not consume oil (at least not at a level you need to add oil between oil change intervals) at this rate. Long term wear and tear on the engine - note Gm offered a warrantee covering 100,000 miles, which is nice but the problems will become more severe over time and miles. I consider this borderline criminal as it will surely cause engines to lock up.

Driving down the Interstate 35 in Tarrant County, Texas. Engine locked up. Towed to dealership. Dealership determined that engine is locked up. Had dealership verify oil level was okay and they confirmed that it was. Oil had been services two weeks ago. Engine is a 6.2 L but not the L87 block. Milage on the vehicle is 149,752.

The contact owns a 2014 GMC Acadia. The contact stated that for several years, the headlight bulbs were replaced several times. The contact used several different brands of headlight bulbs, but the bulbs failed prematurely. The contact stated that the headlight bulbs were dim while using the low beam or the high beam headlights. Additionally, the turn signals failed to properly operate while engaging the turn signal lever. The contact stated that the sound for the turn signals was occasionally inoperable. The vehicle was taken to the same independent mechanic, who was unable to determine the cause of the failure. The vehicle was not taken to a local dealer for a diagnostic test. The vehicle was not repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 135,000.

The contact owns a 2003 GMC Envoy. The contact stated that while in drive(D), the vehicle shut off and then restarted. The message “Service Engine Soon” was displayed. The vehicle was taken to the local dealer, where it was diagnosed and determined that the instrument cluster needed to be replaced. The vehicle was repaired, but the failure reoccurred. The vehicle was taken back to the dealer who installed the original instrument cluster, but the failure persisted. The manufacturer was not notified of the failure. The approximate failure mileage was 98,000.

Car does not turn off, says “Shift to Park” but car already is in park and car won’t turn off.

I was out one day for lunch and my brakes stopped working on my truck. I had the truck towed after I limped home in it. The master cylinder failed at 4,200 miles causing the brakes to fail. It was replaced by the dealership.

While driving home from Phoenix on Hwy 95, 30 Miles out of Tonopah on the way to Reno engine propulsion and the complete engine failure occurred while driving at 75 mph. No warning at all. No cell service, had to use Onstar to be our savior. Thank God they sent a tow truck, although my wife and I with 2 dogs had to wait 4 hours for the tow truck, while semi’s rolled by us going 80 mph. Dealer performed diagnostics on my truck and has to replace the engine due to engine failure. I had the recall completed in September with the new approved oil and cap. I know this is an ongoing problem with GM’s 6.2 engine. Complete engine failure while driving at 75 mph. No engine warning sign. Screen went blank. I will no longer trust this truck or have any confidence in the truck once I get it back. I sure hope GM pays for this. This has caused me endless anxiety.

February 28th 2026, I was driving on the highway with my children and suddenly without any prior warning my cars check engine light came on. It immediately starting losing power, made a knocking noise, and sounded like it was misfiring. Fortunately I was able to make it safely off the highway and have my car towed to the dealership. This was most definitely a life threatening situation which no one should have to face. The dealership dismantled my engine and i was advised the engine had an internal failure due to the valve lifter , rods , and camshaft damage. When looking online there are many complaints and lawsuits regarding this investigation of GMC’s 5.3 engine. I believe this was due to catastrophic damage of the components and there needs to be a recall regarding this issue. The car has always been properly serviced and regular oil changes.

The contact owns a 2018 GMC Sierra 1500 Denali. The contact stated that while driving at an undisclosed speed, and while the vehicle was parked, the running boards unexpectedly lowered. Additionally, there was oil leaking from the vehicle, and the check engine warning light was illuminated. The vehicle was taken to the dealer, where it was diagnosed with camshaft failure. The contact was informed that the camshaft needed to be replaced. The vehicle was repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 107,000.