[wanyan]

Hi,

I have a 2011 E90 320i with 87km's I'm hoping someone may be able to identify this noise that started recently.

The sound is not happening all the time.
It can be heard in park, neutral, reverse and drive.
The tone can change as I bring the revs up, but the speed of the sound doesn't seem to speed up.

There are no interior fans/aircon on.

If I lift the hood and listen I can't hear it.

Link below:

http://foscars.com.au/BMW320i_noise.m4a

Thank you
Wanyan