One problem related to water pump has been reported for the 2005 GMC Envoy. The most recently reported issues are listed below.
I have a 2005 GMC Envoy and I have had to replace a water pump, a blower motor wiring harness that melted into my truck, the lights are half out on me heater and my door panel where you put the windows up and down, the winshield wiper in the back works when it wants my speed ometer is stuck on 40 even when its off and my check engine light is on and I bought this truck less than 2 years ago!.