2020 GMC Sierra 2500 Engine

The catalytic converter failed at 93,000 miles, and 64 months. GM says it is out of warranty.

Catastrophic engine failure after taking it in for the April 2025 recall. Complete engine replacement needed

Low coolant light keeps coming on and dealership checks and confirms coolant is not low. The end result is the sensor In the resivor is bad and requires the entire tank to be replaced rather than just the sensor

Check engine came on Sunday morning the code that through was P0 526 u062F. After calling the dealer and setting maintenance to be done one day later, the truck broke down while driving on the side of the road. The dealer is saying that the belt came off and the tensioner locked up doing damage to the fan clutch and connector. The case, because the code that ran is saying that the belt wasn’t going the speed that it was supposed to because the tensioner failed. The vehicle only has 55,000 miles on it.

I took my vehicle into the local dealership two weeks ago for the DPF emissions voluntary recall. Prior to the service I was getting 16.6 mpg for the 42000 miles on my truck. After the service, for the ~200 miles driven on same route and conditions commuting to and from work I have only been able to achieve ~13 mpg. There has been no other changes to my vehicle or operating conditions. When I took the vehicle in the advisor mentioned that it may take awhile for the service because “we have to download the update wirelessly.” While researching this issue the recall document specifically warns against wireless download of the update. I am not sure if this may be the result of not following the correct process or not and I am headed back to the dealer today. I also found several others posting on the diesel forums about similar significant loss of mpg after the update. Losing almost 25% fuel efficiency after the update is unacceptable and reflects the my previous experience of efficiency loss during an actual regeneration cycle prior to the update. The vehicle is acting as if it is running in a constant regeneration cycle. Unsure if this may lead to dangerous driving condition due to excessive stress and wear on the affected parts and engine.

TL* THE CONTACT OWNS A 2020 GMC SIERRA 2500. THE CONTACT STATED THAT WHILE DRIVING, HE NOTICED SMOKE ENTERING THE VEHICLE THROUGH THE AIR VENTS. THE CONTACT COASTED TO THE SIDE OF THE ROAD, EXITED THE VEHICLE SAFELY WITH HIS PASSENGER, UPON OPENING THE HOOD NOTICED THAT THE WHOLE ENGINE COMPARTMENT WAS ON FIRE. THE CONTACT STATED THAT THE FIRE DEPARTMENT ARRIVED BUT WAS UNABLE TO EXTINGUISH THE FLAMES AS THEY ALLOWED THE VEHICLE TO BURN UNTIL THE FIRE SELF EXTINGUISHED. THE DEALER NOR THE MANUFACTURER WAS MADE AWARE OF THE FAILURE. THE FAILURE MILEAGE WAS APPROXIMATELY 2,800. VIN WAS NOT AVAILABLE.