Three problems related to engine and engine cooling have been reported for the 2025 GMC Sierra 2500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2025 GMC Sierra 2500 based on all problems reported for the 2025 Sierra 2500.
Burning an unusual amount of oil. Have seen several instances of blue smoke in the exhaust. Have had to add over a quart of oil twice in less than 6500 miles.
We were towing a fifth wheel camper with our truck on an interstate highway in pennsylvania when our serpentine belt burst suddenly and without warning. Our truck is a 2025 model with only 10,000 miles driven. We lost all power steering and power brakes of both the truck and the camper and the motor shut off while we were driving at 65 mph. My husband struggled to gain control of the truck and camper which was severely fishtailing and was eventually able to get over to the shoulder and stop the vehicles. We were towed to a GMC dealership where a factory technician happened to be on site providing an in-service for the dealership's service team. He inspected our truck and we were told that he said that GMC is aware of catastrophic failures in these serpentine belts. We were also told that he took photos and was sending a report to the GMC factory regarding our situation. When the serpentine belt blew, it damaged fan blades, shroud, oxygen sensors and our air conditioner belt (which fell off 200 miles later). We had absolutely no warning of the sudden catastrophic failure of the serpentine belt and came close to losing our lives. Our biggest concern is that the serpentine belt was replaced with the exact same model of belt that failed. What does it take for a company to recall a known defective belt? a fatality? we were very fortunate to have walked away without injury or losing our lives. We have written a letter to GMC but they have not contacted us as of yet.
The contact owns a 2025 GMC Sierra 2500. The contact stated that while driving at an undisclosed speed, the vehicle failed to accelerate as intended while depressing the accelerator pedal. The check engine warning light was illuminated. In addition, the contact stated that the rpm was fluctuating while driving. The vehicle was towed to a local dealer however, the vehicle was not diagnosed or repaired due to the warranty. The manufacturer was made aware of the failure. The failure mileage was approximately 600.