[Rockyca]

My car is a 2006 BMW 323i. It has approx 70k miles on it. It started making a scraping noise, not too loud, from the rear, that sounds like a worn through brake pad rubbing on a caliper. The only thing that stumps me is that it only makes the noise when in gear. Which rules out the brakes. I changed the rear diff oil today and it made no difference. As soon as I touch the clutch the noise goes away. What gives? Any ideas or suggestions? Could this be a worn center diff bearing?

Btw, it is not a wheel bearing, sound does not change when going left or right. I also noticed a little bit of a clunk / click noisewhen transferring from decel to accel and back.

Tranny shifts smooth as a baby's bum as well

I have a lot of exp working on cars, Audi in specific, just not BMW

[Saintor]

Last week I was quoted 3200$ by the dealer to change the whole differential. 60000 miles. lol. I didn't ask about anything. In a test drive for a suspension issue, chief mechanic just heard an high pitch mechanical noise.

[Rockyca]

My noise isn't really high pitched. It isn't a whine or anything. It is like a rattling / scraping noise. I hope it's not the diff.

[uli007]

I think I have the same issue on my 2011 335i Coupe with just 6K miles. The noise is relatively faint -- you can hear it best in 4th or 5th gear at 1000 rpm or a little above (i.e., with not too much road noise), and it usually becomes quite faint when the car is warm. It does disappear when I step on the clutch.

Had my car in for service last week, and had played a recording to the service guy. Got the car back after waiting a few hours, with the noise reappearing after the car had cooled down for a few hours. :(

May give the service another try...

[Alpineweiss e90]

Maybe trans mounts?

[dassub]

Are you sure it's not the wheel bearing? I had loud scraping noises and they ended up changing the wheel bearing/wheel hub under warranty.

[mattws]

Originally Posted by Rockyca

My car is a 2006 BMW 323i. It has approx 70k miles on it. It started making a scraping noise, not too loud, from the rear, that sounds like a worn through brake pad rubbing on a caliper. The only thing that stumps me is that it only makes the noise when in gear. Which rules out the brakes. I changed the rear diff oil today and it made no difference. As soon as I touch the clutch the noise goes away. What gives? Any ideas or suggestions? Could this be a worn center diff bearing?

Btw, it is not a wheel bearing, sound does not change when going left or right. I also noticed a little bit of a clunk / click noisewhen transferring from decel to accel and back.

Tranny shifts smooth as a baby's bum as well

I have a lot of exp working on cars, Audi in specific, just not BMW

Hi There,

Did you find out what was causing the noise?
I have the exact same noise on my 2006 E90 323i. I am really looking for a solution to this. The car has got 130000km but it's been well looked after. It also makes the noise only in gear and moving. I can only hear it when the radio is off and the windows are up. It is the same noise you have described. I just hope it's not diff or gearbox.
I would find it hard to believe that the diff or gearbox is already failing, I had an e46 before and no issues like this.

[koches]

Did you recently take off your rear wheels? Maybe they are not flush when you put them back on. Happened to me

[BashShah]

Is your ebrake working properly.
How many clicks to lock rear wheels?

The only other option, take it to a shop that can run your car while on a hoist.

DN

[Rockyca]

Rear diff was toast. I have since sold and replaced the car though