GMC Complaints

My GMC Terrain was stopped in traffic at a Red Light. When I stepped on the gas pedal to proceed, the SUV shut-down. Could not move SUV in Traffic. Called Police and SUV was towed. SUV towed to GMC Dealer. The K111 Fuel Module was causing the problem. GMC Dealer Repair Shop removed and replaced the K111 Fuel Module. They claimed SUV is OK. I don't trust this SUV any longer. I read of similar problems with 2022 GMC Terrain and the Fuel Module defect causing the SUV to shut down. This is a safety hazard to the Driver and other vehicles on the highway.

Replacement part needed is COOLANT CONTROL VALVE according to diagnostics at local GM dealer service department after noting check engine light was on. YES, it is available for inspection. Told unsafe to drive as it would very likely overheat or worse. It has been in the shop for a month (as of June 11, 2025) awaiting a backordered part, which we’re told is a national backorder. No loaner vehicle available and told by service department that they have had another truck in for same problem for several months and that this problem is very common. PLEASE HELP us with getting the part needed!

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the part to do the recall repair was not yet available. The contact stated that the vehicle was experiencing rough idling, with the RPM fluctuating while driving. The local dealer was contacted. The vehicle was not diagnosed or repaired. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was not made aware of the issue. The failure mileage was approximately 32,000. VIN tool confirms parts not available.

The contact owns a 2023 GMC Acadia. The contact stated that after purchasing the vehicle, it was discovered that there was water and condensation inside the rear middle brake light assembly. The contact later discovered that during rainstorms, rainwater had leaked into the rear seating and hatch area of the vehicle. The vehicle was taken to the local dealer who determined that the failure was due to a manufacturing structural error and the vehicle needed body work to be performed to correct the failure. The vehicle was not yet repaired. The manufacturer was notified of the failure. The failure mileage was 5,200.

My 2023 GMC Sierra AT4 with the 6.2L L87 engine is showing signs of premature engine issues despite passing the recall inspection. I hear persistent lifter chatter, which is known to be a precursor to catastrophic failure in these engines. I no longer feel safe driving this vehicle due to the known defect with the crankshaft, rods, and valvetrain. GM issued a recall, but it appears to be incomplete and does not address the underlying issue in many vehicles, including mine. I am worried about sudden engine failure and safety while driving.

While driving to Lake Placid, NY, I experienced sudden loss of propulsion as I was driving approximately 60 mph. I was able to brake and pull over to the shoulder. I was not able to restart the vehicle - engine was dead. We were flat bed towed to a garage in Lake Placid where it was confirmed that the engine was inoperable. The vehicle is now at. GM dealer in Potsdam, NY. I believe this engine should be part of the recall!!

The coolant control valve is faulty and is on national backorder causing months of my truck sitting in the shop. This is not an isolated issue. GM is claiming it is not covered under warranty, but the part design is clearly a serious issue.

On 5/22/2025, I filed a complaint with NHTSA, complaint number 11662650. In the complaint, I reported issues regarding safety concerns that began around October 2023 and were shortly after reported to GMC. Some of the reported issues were concerns with oil consumption due to warning lights coming on; parking warning sensors intermittently coming on; and what appears to be suspension issues as there continues to be a knocking, cracking, and snapping noise coming from the front suspension when making a left or right turn, along with a bumping when in motion, among other issues such as Infotertainment that continues to be an issue. Recently, we took our SUV to a GMC authorized dealer since it was still under warranty and these issues continued to persist and it is getting worse. The vehicle was left around 5/28/25 and picked up on 6/17/25. However, less than a couple of weeks after, we started experiencing the same issues with the suspension as the knocking, cracking, snapping, and bumping is getting more obvious and worse, and it appears is affecting the steering and alignment of the SUV. Please update this information as there is a major concern with safety of the vehicle. Attached are some of the service records related to these issues. Should you need any additional information, please advise. Thank you.

2011 GMC Sierra Frame Failed Pennsylvania State Inspection due to Driver Side Frame Rust/hole. The section of the frame must be replaced due to rust(Improper coating... The truck has only 69700 miles on the odometer.

The Active Fuel Management (AFM) system malfunctioned causing not all engine cylinders to fire at critical times, thus causing a safety issue when the vehicle has insufficient power traveling at highway speed. The AFM is intended to transition from 8 cylinder power to 4 cylinder power to save fuel. However it malfunctioned so that it couldn't transition back from 4 cylinder power. The malfunction occurred while driving at highway speed, approximately 70 mph and towing a trailer. There were no warning messages or other symptoms prior to the failure. This malfunction necessitated removal and replacement of the engine. A certified mechanic completed the repair work.