Table 1 shows one common engine and engine cooling related problems of the 2025 GMC Sierra 3500.
| Problem Category | Number of Problems |
|---|---|
| Engine And Engine Cooling problems |
Oil cooler for truck is defective and thus allowed all oil to be mixed with the coolant. Gm is stating they will flush engine and replace with exact same part. Very common issue and sad to have a $100k truck and it is junk.
“I own a 2025 GMC sierra with 30,000 miles. The oil cooler failed and caused loss of oil pressure and potential internal engine damage. The dealership acknowledges the failure but refuses to escalate the case or perform a proper inspection. I am being instructed to continue driving the truck even though it may suffer catastrophic failure while driving. This is a safety hazard. ”.
The contact owns a 2025 GMC Sierra 3500. The contact stated that the transmission was shifting hard and was jerking while shifting gear. Additionally, the vehicle failed to accelerate above 50 mph. The messages “reduced acceleration” and “def low” were displayed. While refueling the vehicle, the fuel gauge failed to correctly display the level of fuel inside the fuel tank until the vehicle had been driven for approximately 20 minutes. The vehicle was taken to the dealer to be diagnosed, and the contact was informed that the transmission needed to be updated. The system was recalibrated; however, the failure persisted. The vehicle was taken to another dealer, george kell motors (3808 van dyke rd, newport, ar 72112); and the system was recalibrated. However, the failures persisted. While driving approximately 60 mph, the transmission was shifting hard, and the vehicle took over 2 hours to drive 19-miles. The engine temperature gauge fluctuated between 185 and 188 degrees. The vehicle was pulled over to the side of the road to cool down before continuing to drive, while not exceeding 40 mph. The vehicle was taken to a third dealer, fremont Chevrolet GMC riverton (1401 n federal blvd, riverton, wy 82501); who determined that the bell body needed to be replaced. The vehicle was scheduled to be repaired, but parts were on back order. The contact became aware that there was a recall related to failure; NHTSA campaign number: 26v129000 (fuel system, gasoline); however, the VIN was not included. The manufacturer was not made aware of the failure. The failure mileage was approximately 40,000.