Chevrolet Repair: engine noise in raido, chevy blazer, electromagnetic interference

Question
I have developed engine noise in my car radio. I have a 2002 Chevy Blazer. The satalite raido campany said it was in my engine. Can you help to narrow down the possible cause?  

Answer
Hi Donna,

Electromagnetic interference is caused by a high voltage electrical source putting its radio waves into the path of your radio antenna.  This is invisible, but all electricity has this interference.  Your car should have a way of filtering this interference out.  

In the old days, it was the loss of the condensor at the distributor that caused this.  On todays cars it can be caused by bad plugs, bad wires, or some other electromagnetic interference near the radio.  


Does is change when you adjust the blower fan speed?  If so, that is the culpret.  Does it change with the reving up of the motor?  If so, it is the alternator, the plugs or wires.  

This is unusual on today's cars.  You have something going on to cause it.  It is not dangerous, just annoying on the speakers.  Good luck.

C J S