I just noticed a buzzing noise in my '04 UL. This is a freeway speeds and does not appear to engine-related. Letting off the throttle or stepping on it doesn't change the sound. The ptich never changes, but goes away at slower speeds. I hadn't noticed it before because I usually have the audio system on and yesterday it was turned off.

I can't think of what this might be, other than the car is in need of new brakes. Any ideas?

Thanks.
Gene

 

Might be the wheel bearings. I had this issue and had to have the bearings replaced on one of the tires.