Radio Reception Interference...What can it be?

Hi,

I have a 1995 Oldsmobile Eighty-Eight with radio reception problems. The bottom line is that if I shut the car off and just put the key back, I can get near perfect FM reception, but once the car is started I get nothing on FM. I've checked everything that I can think of and come up with nothing. What can be causing the interference?

Thanks

you are getting an EMI from somewhere, did you change the spark plug wires or have you checked them. Some type have a lot of EMI output, it can also be caused be a cracked one.

There was no reception when I bought the car, then I bought a new engine and had that installed, and still have nothing. I can't say for sure, but I think the plug wires in there now are the ones from the new engine, not the olds set. Anything I can try to check if this might be the problem?

ohhhh ... that's different.

Your radio antenna is most likely either not connected to the radio or broken somewhere

Check your Coax Cable at the antenna end too and see if it is plugged in there, some cables can be disconnected at the antenna end for easier replacement should the antenna get damaged.

I've checked all cables, the antenna is new, the cd/stereo is also new (a new to me factory replacement). Everything has been checked a million times. And until the car is started (key just turned back) there is perfect reception, but nothing once the engine is actually running. The problem was there before any of the above things were replaced or checked.

???

Sorry I know very little to nothing about OEM stuff. These are the problems I hate troubleshooting.