GregWork

2004 GX 470 Mark Levinson with Nav.

Wife said she heard a 'pop' on the way home from work last night and thought she blew a tire or ran over something. Nothing in the road and tires fine so she continues home. Temperatures were near zero last night.

Upon start up today, the speakers were at full volume roar with the audio off.

Turning the audio on, only changed the pitch, not the level.

I tried cycle the audio on / off but no change. Restarted car, same thing.

Let the car sit a while and restarted it to check the system codes. Same noise for a few seconds, then a sort of 'pop' and the noise stops. Radio/ CD work fine now.

I checked the system and all shows OK.

Any ideas on what is going on? It is not drivable with the roar (if it comes back).

Thanks,

BlackCat81

Typically, feedback through speakers is an amp on the fritz or a bad ground somewhere. Did the pitch change with increased engine RPM?

GregWork

Unknown. This roar was in the garage the next morning and was too loud to drive with the noise.