One problem related to engine noise has been reported for the 2003 GMC Envoy. The most recently reported issues are listed below.
I own a 2003 Envoy sle. We have had repeated problems with this vehicle vibrating and making engine noise. I have taken the vehicle to two different service departments (repeated times). One finally recognized that the noise existed. After they drove two other Envoys they determined that the noise was inherent to the vehicle. The sound is like a bubbling metallic sound that cannot be good for the vehicle. Nothing has been done to correct the failure, I have been told to live with it.