I had some problems with the S3 fixed an engine mount that was causing loads of noise.
But was left with a problem that sounded like rear caliper sticking despite fitting new brakes. Took it to the garage who confirmed it was something to do with the 4wd transmission system.
I tried the handbrake on and it still made the noise.
I pulled fuse 31 for haldex controller and the noise went. As soon as I put fuse in the noise comes back.
This leads me to think its the controller.
However I thought if the controller went I would have only 2wd?
I had constant 4wd.
Cheers for any help