I noticed this this year. After taking car out of storage... I noticed engine noise on Sony Explode FM only. Noise is gone when car is not running. Alternator is 3 years old...Maybe 3000 miles old. I pulled plug the the pack of alternator when running and noise still there. Radio has been in car for 7 years without a problem. CD and AM sound OK... I checked the wiring to the radio nothing seems obvious. Any ideas

 

Your antenna wire could be grounding to the body of the car that could cuase "noise" have u run any new sub or power wires? do u have an electic antenna?

 

No. no sub I pulled radio all the way out of the dash and checked antenna cable.
I had the same noise when holding it in my hand...sucks

And ...Doesn't your car talk to you... Maybe it was all the STUFF I did in The 70's and 80's...WHEW ...It sure is funny typing into this TV

 

was that w/ the wire plugged in or out? if it was in try un plugging it you may not get much reception but u should hear a difference w/ the car on or off if its not the cable or antenna