GMC Complaints

The contact owns a 2024 GMC Sierra 1500. The contact stated that while vacationing in Canada and driving at various speeds, the vehicle jerked, and the vehicle failed to accelerate as intended while depressing the accelerator pedal. In addition, the RPM fluctuated, and the engine revved abnormally. The contact stated that the vehicle failed to reverse(R) as intended. The contact was able to coast to the side of the road while in LIMP Mode. The vehicle was towed to a dealer, where it was diagnosed, and it was determined that the transmission had failed and needed to be replaced. The contact was informed that when the dealer contacted the manufacturer to order a new transmission, the manufacturer refused and informed the dealer to repair the current transmission. The vehicle was repaired. The contact stated that a week later, the vehicle experienced another failure. The contact stated that on a separate occasion, while approaching a stop sign, the brake pedal was depressed, and the engine revved unintendedly. The contact used force to depress the brake pedal. The failure persisted. The vehicle was taken to a dealer back in the USA; however, no cause for the failure was found. The vehicle remained at the dealer unrepaired. The manufacturer was notified of the failure and was awaiting the results of the diagnostic test. The failure mileage was approximately 9,000.

This vehicle experienced catastrophic engine failure while I was on vacation 400 miles from home. I have researched this failure and there is a class action lawsuit against GMC. My truck has been at the dealer for 25 days and still waiting for authorization from Fidelity Warranty Services. Considering it’s such a common problem I feel GMC should be paying for this. At the very least the warranty company is aware of this problem and purposely delaying the authorization to repair. I just bought a new camper which I cannot use. I am fisherman and cannot use my boat. My beach pass is also on the vehicle. So essentially my summer has been ruined by a company that produced a faulty vehicle and didn’t discord this information to me.

The contact owns a 2022 GMC Terrain. The contact stated that upon approaching an intersection with a red light, the contact depressed the brake pedal, and the vehicle lost automotive power. The vehicle came to a stop at the light. The contact attempted to restart the vehicle; however, the vehicle failed to restart. The vehicle was towed to an independent mechanic to be inspected, and the contact was advised that the vehicle needed to be diagnosed by an authorized GMC Dealer. The local dealer was contacted; however, the vehicle was not diagnosed or repaired. The contact was advised that the VIN was not under recall. The manufacturer was notified of the failure. The approximate failure mileage was 21,000.

Subject: Urgent Vehicle Safety Complaint – 2019 GMC Sierra Denali Escalating mechanical and electrical failures — many beginning before 100,000 miles, and continuing as of today, at approximately 110,000 miles. These issues have made the vehicle unreliable and unsafe to drive. Since purchasing the vehicle, I have had it serviced regularly and reported that it was driving rough, jerking into gear, and showing early signs of engine and transmission problems. These issues were noted during multiple multipoint inspection services, yet no lasting solutions were provided. Major issues have included: •Engine performance failures •Fuel injector malfunction •Serpentine belt and idler pulley damage •A/C compressor belt failure •Power steering malfunctions •Vehicle stalling at traffic lights •Loss of power on major highways •Rear window water leaks •Significant and ongoing electrical system problems •Shaking when brakes applied after having brakes and rotors replace in March •Screen monitor going out after paying over $ 900 dollars for updated software and repairs to the electronic component that cost over $2500. Despite continued maintenance, on Thursday, July 3, 2025, my truck began losing power and smoking heavily while driving on a busy highway in Georgia. My grandchild, who was riding with me, yelled, “Grandma, it’s smoking — please get out!” as we pulled off the road in fear of a fire. This terrifying incident left us stranded and emphasized just how dangerous this vehicle has become. I filed a formal complaint with the GMC Corporate Office, but no support provided or an investigation. Over the past six months, I have spent more than $5,000 trying to keep this vehicle operational. So many critical systems have failed, despite consistent maintenance, raises serious concerns. Finally, the fuel injector repaired 3 days later a message on dashboard displaying service Tire monitor system and steering wheel shaking when brakes are applied.

On [XXX] while traveling on a highway, the vehicle lost drive power—the gear selector would not remain in Drive and reverted to Neutral for approximately 10 minutes. This created a serious safety hazard due to sudden loss of propulsion in moving traffic. The event was captured by OnStar, which emailed an automated incident alert. I later received a GM safety recall notice concerning potential engine loss of propulsion for vehicles with the 6.2L L87 engine (NHTSA 25V-274 / GM N252494000/001/002). I presented the vehicle to Ewing Buick GMC (Plano, TX) on July 23, 2025 for recall service and retrieved it on July 28, 2025. Approximately one week later, during an interstate trip to Kansas City, the engine catastrophically failed about one hour from my destination, leaving the vehicle disabled on the roadway shoulder. Roadside assistance towed the truck to Briggs Auto (KS). Briggs Auto diagnosed engine failure and ordered a replacement engine. I was informed the engine is on back-order with no estimated arrival, and the shop is under-staffed, prolonging repairs. The vehicle remains out of service. The sequence—pre-recall loss of propulsion, post-recall service, and then engine failure within a week—shows a serious safety defect that can lead to sudden loss of power at highway speeds, risking a crash. Frequency: Loss of propulsion occurred at least twice (March highway incident; subsequent engine failure in early August). Warning Lights/Messages: [Gear refuse tom shift to Drive mode.] Injuries/Crashes: None, but risk was substantial due to sudden power loss. Dealer Involvement: Ewing Buick GMC (recall visit); Briggs Auto (diagnosis/engine order). Attachments/Supporting Docs: OnStar email, recall notice, repair orders, tow documentation, photos/video. Please investigate whether 2024 GMC Sierra trucks with the 6.2L L87 engine continue to pose a loss-of-propulsion risk after recall service and whether parts shortages/back-orders are delaying effective remedy INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION

I have a 2020 sierra 1500 6.2 with 86,000 miles. I have only had this truck 6 months. This was inspected before I purchased with no engine issues. Since purchasing we have driven less than 6000 miles. While driving my vehicle the rod in the engine failed and started knocking. I am a mechanic and I am GMC master certified. Both myself and the owner of the shop I work at diagnosed the vehicle with a bad engine. We looked at the recall for the 6.2 engine and noticed that many of the 2020 vehicles with this engine have the same issue that is currently being recalled for this specific engine. I called GMC and they won’t fix the issue that the vehicle is having. They won’t perform the recall and again I have only had this vehicle for 6 months and with 86,000 miles should not be having this issue. I am GMC certified and told them that I looked into the recall and they them selves state that some of the defective engines got out into the 2020 models.

When I turn the ignition off it sends me a message that I must shift to park. The car is in park at that time that I get the message. I restart the car and move the shift to reverse or drive and move the car and place in park and that may correct the problem or I may have to do this once, twice even three times before it corrects. The warning bell will continue to ring and the radio continues to play until I can get the situation corrected.

I was driving on the highway & my brakes failed. My brake pedal was completely hard & could not be used. i had to steer onto an exit ramp & be towed to the dealership. There was absolutely no warning of this happening. Once at the dealership, they confirmed it was my vacuum pump that blew up, which damaged the camshaft & caused pieces of metal to be floating around in my engine. The greater portion of the repair was covered under warranty, however, I had to pay $350 out of pocket. This could have been catastrophic. I or others on the road could have been injure for worse. This system failure should be fixed immediately and owners be compensated. I do not feel safe driving myself or my family in this vehicle after experiencing this occurrence.

The contact owns a 2022 GMC Yukon XL. The contact stated while driving at an undisclosed speed, there were two loud pops followed by an abnormal rattling sound coming from the engine compartment, before the vehicle lost motive power. The vehicle was pulled over to the shoulder of the roadway, where the vehicle failed to restart. No warning lights were illuminated. The vehicle was towed to the dealer, who diagnosed a failure with the connecting rod bearings. The vehicle was repaired. After investigating the failure, the contact related the failure to NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling). The VIN was included. 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 60,000.

Check engine light came on for the first time. Engine started knocking, had loss in power, took it to the closest shop. Initial report was lifter failure, after taking apart the engine for lifter replacement they deduced the bad lifters also were accompanied by camshaft damage, and bad heads. Overall resulting in engine replacement being required. Again, first time the check engine light has come on.