Sound system producing static at times

[schwim]

Hello there, everyone!


We've got a weird issue that I'd like to work on before it gets worse. It's only happened three times so far but if it continues, it will make the entire idrive/sound system unusable. Here's how it behaved when I witnessed it.


My wife got in the car to start it and the radio came on(satellite radio) and there was a layer of static making it impossible to hear the station. I had her switch it to FM and the static persisted. I hopped in and made a phone call at which time the static disappeared. When disconnecting the call, the static returned over the radio output. We removed the key and reinserted and the static was back. We did it a few more times and the radio returned without static.


Does this sound like the preamp/amp failing in the sound system? The fact that it persists through FM and Satellite when those two should use two different antennas but if that were true, I think the phone call should have had static as well.


Any suggestions would be most welcome, whether it's a fix, pointing me toward a replacement system to install, etc. I can't imagine the vehicle without being able to use that system at all.


Thanks for your time!

[crystalworks]

I'd first check for any water intrusion/corrosion at the electronics for the sound system. Driver's rear area in the trunk. Not as common on the E70 as it is with the E53, but it's worth a quick look.

The bluetooth calling is handled by the TCU so maybe the amp is at fault or the fiber optic (MOST) connection that carries the audio to/from the amp. Just thinking out loud.