GMC Complaints

I was driving on a two-lane road when unexpectedly my front moonroof spontaneously shattered sending glass down on top of me, the console area, and the passenger and rear seating areas of my 2025 GMC Acadia. It happened without warning and no external factors. It was a pleasant sunny November day. The moonroof was not open at the time. Fortunately no one else was in the vehicle with me at the time and no other cars were nearby since the two-lane is not a heavy traffic area. This put my safety at risk and could have put others at risk had others been in the vehicle or nearby since I was startled and had the natural reaction of crouching over and down in an attempt to protect myself therefore taking my eyes off the road and not paying enough attention to driving the vehicle. Glass could have fallen and hurt other passengers. The remaining moonroof glass crackled and I then looked up in shock wondering what happened and then feared glass fall into my eyes and immediately looked down away from the moonroof. I had just left my residence before the incident and was less than two miles from home. I found the next available place to turn around and drive back to my home and exit the vehicle. I then called the dealership I bought the vehicle from in January 2025, new. I also called GM Customer Service to seek assistance. The vehicle has 7125 miles. There were no warning signs. The incident happened today and no one has inspected the vehicle and its damage. A customer service case was opened with GM. I sent pictures to the dealer service manager who said he attached the pictures to my GM case online.

Engine failure at 38k miles No service lights on dash. GM says 4 months to get replacement motor with very little help on getting rental car

The contact owns a 2018 GMC Canyon. The contact stated that while driving at an undisclosed speed, there was an abnormal knocking sound coming from the engine compartment. No warning lights were illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the transmission. The contact was informed that the transmission needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 34,929.

The contact owns a 2019 GMC Sierra 1500. The contact stated that while driving at 25 MPH and making a turn, the vehicle lost motive power. There were several unknown warning lights illuminated after the failure. Upon investigation, the failure was related to NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling). The vehicle was towed to an independent mechanic, where it was diagnosed with lifter failure and camshaft damage. The vehicle was repaired. The local dealer was not contacted. The manufacturer was contacted and opened a case, and referred the contact to the local dealer for assistance. The failure mileage was approximately 86,960.

The contact owns a 2019 GMC Acadia. The contact stated that while driving at an undisclosed speed, the message "Steering Assist Fault - Drive with Caution" was displayed. The vehicle was taken to an independent mechanic, who retrieved DTC: P0128 (Engine Coolant Temperature Below Thermostat Regulating Temperature) and replaced the engine coolant thermostat. The manufacturer was made aware of the failure and advised the contact to file a complaint with the NHTSA Hotline. The failure mileage was 55,114.

On October 21, 2025, with only 4,197 miles on my Yukon, the vehicle suddenly died while in drive in a parking lot. The vehicle would not restart or shift into neutral. I contacted OnStar, who arranged for the vehicle to be towed to the nearest GMC dealership. Since that date, the vehicle has remained at the dealership and has been diagnosed as needing a complete engine replacement due to metal shavings found in the engine. There were no warning lights, messages, or performance issues prior to the failure. This incident was both unsafe and alarming, as the vehicle shut down unexpectedly without any warning while I was driving. I would like to understand how such a major failure could occur on a brand-new vehicle with so few miles.

Truck cut out going across the road almost got hit due to the vehicle stalling then about a mile down the road the check engine light came on parked it took it to my mechanic and after the incident it was throwing a cylinder misfire code. Cylinder one when the mechanic got in there was completely shot and I had to have a new motor. No warning no lights could have potentially caused a major accident.

We were traveling when it went into limp mode slowing our speed way down. We got it to a dealership and they determined low oil pressure and metal in the oil. My vehicle only has 1185 miles on it.

This is a report on an incident that happened a year ago. Vehicle was taken to GMC dealer who replaced the engine at our expense. Seems to be consistent with the problem on newer GMC's that have been covered by a recall. This 2020 is one of three GMC's owned by our company. This expense was in the $12,000 range. (The 2019 experienced similar issues in 2022 and the expense was $2800 ish, and in 2024 another $1200 ish. ) Dash lit up like a Christmas tree, all warning lights on. Stalled, barely moved.

The contact owns a 2022 GMC Sierra 1500. The contact stated that while operating the vehicle, the check engine warning light illuminated. The vehicle was taken to the local O'Reilly's, who diagnosed that the cylinder #2 glow plug had failed and needed to be replaced. The vehicle was not yet repaired. The manufacturer and local dealer were notified of the failure and informed the contact that the VIN was not included in the Manufacturer's Special Coverage that was related to the failure. The contact stated that the special coverage service was for the previous model years with a 3.0-liter turbo diesel engine that had experienced the same failure. The failure mileage was 38,773.