GMC Sierra Reliability by YearBest & worst years, problems & recalls — NHTSA data

The transfer case leaked out all the fluid while driving over a period of time and damaged internal parts before the first oil change. This has happened 2 times now, and is currently leaking again with less than 10k miles.

Component / System Failure The exhaust system, specifically the exhaust manifolds and previously the EGR system components, appear to have failed or malfunctioned, allowing exhaust gases to enter the passenger cabin. The dealer initially replaced the EGR cooler diverter on December 23, 2025. However, the condition persisted. On February 3, 2026, cracked exhaust manifolds were identified by the dealership, and a major front-end teardown was advised to complete the repair. The vehicle is currently available for inspection upon request. ⸻ How Safety Was Put at Risk The malfunction allowed exhaust gases, including carbon monoxide, to enter the passenger cabin during vehicle operation. Carbon monoxide readings inside the cabin reached up to 50 parts per million (ppm) while driving. Carbon monoxide is a toxic gas that can cause: •Headaches •Dizziness •Impaired concentration •Nausea •Vision disturbances Because carbon monoxide is odorless and colorless, this presents a significant safety risk, particularly at highway speeds where driver alertness is critical. The exposure occurred while operating the vehicle in normal driving conditions. This created a potential risk of driver impairment and increased risk of collision. ⸻ Has the Problem Been Reproduced or Confirmed? Yes. The vehicle was presented to the dealership three times for the same exhaust intrusion concern: •December 16, 2025 •December 29, 2025 •February 3, 2026 During the February 3 visit, the dealership confirmed cracked exhaust manifolds requiring major disassembly for repair. The carbon monoxide readings were observed during vehicle operation. The exhaust odor and intrusion symptoms were consistently present following the first attempted repair. ⸻ Has the Vehicle Been Inspected by Manufacturer or Others? The vehicle has been inspected by the authorized dealership on multiple occasions. Two manufacturer customer care cases were opened.

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.

The contact owns a 2025 GMC Sierra 2500. The contact researched online and became aware that there was a recent recall under NHTSA Campaign Number: 25V815000 (Equipment) for the Owner's Manual. The contact stated that the vehicle was sold without the Owner's Manual. The contact stated that the manufacturer was called and was advised that the recall was only related to the 2026 Chevrolet Silverado models and the vehicle was not the same year, make or model. The contact was attempting to retain a physical copy of the Owner’s Manual and thought that it was a safety issue since there was a safety recall. The contact had not experienced a failure.

transmission locked up 8 times from 1,050 miles to current 3,885 miles. It has happens each time around 40 mph. Each time it’s like hitting the brakes. The 8th time it locked really hard like slamming on the brakes. I’m worried with winter months what will happen on snow/ice covered roads. Called dealership and was told GM refuses to do anything until it completely fails. It seems they know what the problem is but refuse to fix till the truck stops moving during complete failure. No warning lamps and dealer ship says they can’t replicate it.

i experience a steering wheel shimmy between the speeds of 70- 75 miles an hour

See attached document for complaint.

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 depressing the brake pedal to come to a complete stop, the brakes made a loud whistling and squealing sound. There were no warning lights illuminated. The vehicle was taken to the dealer, Bellamy Strickland Chevrolet GMC (145 Industrial Blvd, McDonough, GA 30253); who was unable to determine the cause of the failure. The dealer informed the contact that it was a known issue with no fix for the failure. The vehicle was not repaired. The vehicle was taken to a second dealer, who was also unable to diagnose the vehicle. The manufacturer was not informed of the failure. The mileage was approximately 5,000.

While towing a less than 2000 lb trailer I had total loss of power steering when speeds dropped below about 5 mph. I got off interstate and was turning right at the end of exit ramp and I could barely turn the vehicle. At the next stop sign it did the same thing. I stopped turned off the vehicle and restarted it and it continued this for the next few miles. Then just as suddenly as it started it stopped doing this and worked fine the rest of my trip.

We noticed that the brakes were really soft. We literally had to push on the brakes with excessive force. We took it to Lynch - West Bend, WI for a service call and was told that nothing was wrong with it. After leaving the dealership we did our own research (the hubby is a certified master technician himself). Come to find out through GM, contacts through TBM brakes and Duramax Forum.com "brake pedal effort" we found the issue and a solution and we fixed it ourselves. This truck is brand spanking new and the dealership threw their hands in the air with a safety issue and let us drive out of the parking lot. Imagine driving away after being told no issue to end up in an accident due to failed brakes. Who's to blame for that? Certainly not the customer. It was only when the new car sales manager took the truck for a drive, he agreed that there was a problem. - too late we took it home and fixed it ourselves. This problem needs to be looked into seeing its a known issue!

The passenger side rear wheel went into a pothole while making a right turn on a city street. This resulted in the right rear leaf spring breaking at the forward mounting point. This caused thr rear axle to swivel impacting the rear of the wheel well. The ESC malfunction indicator and impact sensor malfunction llights illuminated appropriately 2-3 miles later after I was in a highway. This is a significant safety concern as I was at an increased speed in heavy traffic by the time the lights illuminated. This not only puts the vehicle occupants at risk, this is potentially a significant risk to other motorist. There were no noticeable indications of damage besides pulling until I was at appropriately 55mph on the highway. The vehicle is currently at a dealership for repair.