One problem related to radiator has been reported for the 2004 GMC Envoy. The most recently reported issues are listed below.
First of all my odometer gauge stopped operating. It remained on zero miles while I was driving the vehicle since November 2005. The whole dashboard cluster had to be reinstalled. Secondly; the service engine soon light began popping on and the Envoy was driving rough. I found out from a gm dealer that the clutch fan froze which caused the water pump to break and the radiator to over heat burst the radiator hose and spew out and leak all of the water and radiator fluid from the radiator. The Envoy is now not drivable. I have only had this 2004 Envoy since November of 2003.