GMC Complaints

Cracks in the rear sliding window plastic upper rail glass guide causing Rear window leaking water and causing mold from water leaking. GMC has a service bulletin number 18-NA-383 knowing of this issue and not telling customers purchasing the GMC vehicle. The service bulletin was released in 2019 before purchasing the truck and they still didn't inform the customers. My child rides in the back in a car seat and now has been breathing in this mold and mildew for how long. I have had my vehicle in with Titus will Gmc in olympia multiple times for service and inspection of various recalls and still didn't inform me of this issue.

I am filing a complaint about my 2024 GMC Acadia AT4, leased brand new from Frank's GMC in August 2024, now with a little over 8,000 miles. The brake pads are worn to 35% life, far below the expected 30,000-70,000 miles, with loud squealing, fluid leakage, and odors. This poses a severe safety risk to my family and others, as compromised brakes could fail. In October 2024, before my 3,000-mile oil change, I reported brake concerns to Frank’s GMC service manager, Javier, who advised waiting. After the November 2024 oil change and tire rotation, only three months after obtaining my vehicle, Javier claimed no issues, despite my prior warnings. The problems worsened, with squealing, leakage, and odors persisting. My March 19, 2025, service appointment was delayed, calls ignored, and follow-ups never occurred. Sales manager Khaled stated that owner Frank confronted Javier about avoiding service issues, yet no action was taken. I contacted ten GMC service departments in PA, CT, and MD; they reported similar AT4 brake issues, some citing total brake failure. I spoke with GM corporate supervisors, who referred me back to the dealer. Frank’s GMC inspections overlooked my concerns. A local police department safety inspection unit confirmed the issues, but no manufacturer or insurance inspections occurred. The vehicle is available for inspection. I urge NHTSA to investigate this premature brake failure and ensure the 2024 Acadia AT4’s safety. The email screenshot I included was sent in April. I contacted the same GMC dealerships that previously reported no issues to check for updates, and they confirmed a change. All of them now report the same problem with brake pads and/or brake failure. This issue is covered under warranty and should be replaced without issue, but dealers are not complying. If overlooked, this could become a national concern

I was driving home from work one day my truck started. Losing power I could press the gas to make the truck drive it started slowing down

Coolant bypass valve went out. The safety was questionable as the truck reduced speed rapidly makes the cars behind at risk. The problem is constant because my truck is not the only one in the shop for it. Only the dealership has inspected the truck. I bought my truck used so not sure if it appeared before I bought it but I only had my truck a week before it was in the shop. Waning lights came on and would only go off with a code reader/clearer.

My 2016 GMC Sierra 2500 with a 6.6-liter Duramax diesel V8 engine suffered a complete engine shutdown—an issue that is both hazardous and expensive to repair. Fortunately, mine failed in a parking lot. No warning lights or symptoms were present. Failure is instantaneous and can occur any time rendering the vehicle inoperable on high-speed highways, Intersections, etc. Failure always leaves vehicle occupants stranded, creating an unsafe and dangerous situation. My vehicle was towed to a GMC dealer. Repair costs could be as high as $15,000. The 6.6-liter Duramax diesel V8 engine is equipped with a Bosch ‘CP4’ high-pressure fuel pump. These pumps are unreasonably fragile and prone to catastrophic failure causing instant contamination of the entire fuel system with metal shavings. General Motors has agreed to pay $35 million to settle with owners following a class action lawsuit that accused the company of installing defective Bosch CP4 high-pressure fuel pumps in certain Chevrolet and GMC pickup models. This action covered only owners in California, Florida, Illinois, Iowa, New York, Pennsylvania, or Texas.

2018 Yukon Denali engine failed June 2024 due to the lifter being bent. The dealership Richey Cadillac in Daytona Beach estimated the repairs at $18,862 and were going to have my vehicle for months. I took it to my mechanic who rebuilt the engine for $7181 in 30 days. My safety was placed at risk because while driving I had to pull over since I had no control with the engine failure. There were no messages prior to the failure.

The contact owns a 2014 GMC Sierra 1500. The contact stated that while driving on the highway at 55 MPH, the vehicle lost automotive power and the steering wheel became stiff. The contact stated that the vehicle decelerated to 20 MPH, with several unknown warning lights were illuminated. The vehicle was taken to an independent mechanic where it was diagnosed, and the contact was informed that the engine had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 101,000.

The engine failed while driving. Dealership reviewed the issue and a new engine had to be installed to replace the defective motor. It failed due to a camshaft/lifter failure. After talking with the dealership, this appears to be a common failure in the 6.2L motors. It resulted in a bill in excess of $12,000 to repair. Similar to recall N252494000, the 6.2L motor has defective components causing premature failure that should be recalled.

The contact owns a 2015 GMC Yukon XL. While the contact's wife was driving 50 MPH, the engine seized. There were no warning lights illuminated. The contact stated that the vehicle failed to restart. The vehicle was towed to the dealer where it was diagnosed with engine failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. In addition, the contact stated that the vehicle failed to start several times; however, the battery and the alternator were replaced. The contact stated that the vehicle failed to start and was towed to the destination. The manufacturer was not made aware of the failure. The failure mileage was approximately 127,000.

The contact owns a 2020 GMC Sierra 1500. The contact stated while driving 5 MPH, the vehicle made an abnormal popping sound. The check engine and the ABS warning lights were illuminated. The messages "Parking Brake Service" and "ESC Service" were displayed. Additionally, the contact stated the vehicle experienced a reduced fuel range. The vehicle was taken to the dealer, where it was diagnosed that the lifters had fractured, causing damages to the engine. The dealer determined that the engine needed to be replaced, and the part was ordered. The vehicle was not repaired. The contact related the failure to NHTSA Action Number: PE25001 (Engine, Engine and Engine Cooling). The manufacturer was notified of the failure. The failure mileage was approximately 80,100.