my wifes envoy has engine noise in the radio, it does not happen all the time but when it does the radio xm,fm,am is useless it also has the navi and single cd player. the noise in the radio corresponds to the revving of the engine. my wife is in the military so she is in California and I am in Alabama so it is hard to tell her what to try being so far away. I asked her to go out and see if the noise is there when the key is in the on position, thinking it could be the fuel pump or air bag compressor but there wasn't any noise even after she started it . So I'm just hoping someone else had this problem and knows the fix. The cars out of warranty and has 27,000 miles 5.3 liter engine. Thanks for any info===charlie