[Grease23]

2013 328i convertible

I've got this sound and it is hard to describe. Sort of a scaping sound, but I'd also call it a ringing sound. (There is a definite note in there too.) I can hear it starting around 10 mph and up. Regardless of speed, the sound doesn't change in pitch. It seems to get slightly louder around 40 mph but I think it is there on the highway, but just masked by other noises. At 40 mph it is louder than engine or tire noise.

If the car is rolling (regardless of engine speed) I can hear it. Braking has no effect on it. It is hard to be sure (you know how hard that can be sometimes) but I think it is coming from the back, maybe more from the right rear wheel.

I jacked up the car, thinking I'd identify the problem by spinning the wheels by hand. But no noise and they turn just fine. I did notice shiny arcs worn on the bottoms of both backing plates. But with the wheels and tires in place they aren't anywhere close to rubbing. Stock tire sizes on original 8 inch wide wheels.

The sound is close to, but a little different from, a known sound in my experience. If I drive my MGB roadster with the battery cover removed I can clearly hear the shoes dragging slightly against the drums. The sound is similar, but not quite the same, with my 328i.

There is a somewhat similar prior thread suggesting parking brake issues. Most of what's there doesn't fit this. My parking brake is working fine and the dealer (a Chevrolet dealer, I might add...) changed pads and adjusted the parking brake before I bought it about six weeks ago.

Thanks for any well-intended suggestions. I appreciate it.

[Grease23]

And let me add that when lifting the parking brake lever, I can feel resistance at the second click. As I said, with the hand brake off, the rear wheels turned freely, but of course I could not manually simulate the equivalent rotation of 20 mph, which is when the sound starts.