I just had my 2004 2500HD into the local Chevy dealer for a free oil change they were giving away for Chevy Owners Appreciation days. I have had the truck for 20 months and it has 17000 miles on it. Everything was fine except for the engine coolant. The repair guys said they tested it and it was only good down to -10 F. They recommended a flush and fill. WTFO...This stuff is supposed to be good for 5 years or 150000 miles. They had no answer for this. They also didn't know how cold the coolant should be good for. Does anyone know anything about this stuff. Should I be concerned? The radiator and reservoir have never been opened and is full.
Gunner