Two problems related to engine cooling system have been reported for the 2004 GMC Sierra 1500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 GMC Sierra 1500 based on all problems reported for the 2004 Sierra 1500.
Heater core/no heat sometimes/found carpet wet on pass. Side. Seems in checking around hardly never@47,000 mi. Spent 1200. 00 to replace it. Apparently must remove seats, console,and entire dash to replace!!! im really,really made about this!!.
I also had to have the actuator replaced on my GMC 2004 truck. It was blowing hot when the a/c was on and should have been cooling. It was not cheap either, it also had to be recalibrated in the computer system. I didn't expect that to happen to a new vehicle.