Dealer cannot fix noise or locate it in '07 328xi. Please help.
I'm a female owner of a '07 328xi. I do not know much about cars and would like to pick anyone's brain regarding a fix or similar experience I'm currently haunted with. When I bought my car in 2009, a metallic type sound (more similar to a dentist's drill) was coming from the driver's side door. At time of purchase the dealership agreed to resolve this. However, 2 years later and over 3 weeks total in labor, the dealership's maintenance dept. has not been able to solve this problem.
A side note: the noise occurs only when driving, at all speeds, and when driving on both smooth and rough pavement. The noise mimics the sound of a dentist's drill and will start and increase in strength in 30 seconds intervals (reminds me of playing through a music scale). My car is back at the dealer and they called me today asking if they can take apart my dash for the 3rd time (which is not under warranty). Each time they have worked on my car they write in the service reports that they test drove and noise fixed. Not the case. Help!
Here is what the dealership has done so far and none of their work has fixed the noise:
4/21/2010 - Road test. R/R lower left FT door panel and replace damaged retaining clips (clip with seal ring). Panel not held tight to door.
4/27/2010 - Incorrectly torqued instrument panel trim support cage. Test drove and confirmed rattle. Removed steering column trim, lower knee bolster, and air bag. Test drove. Problem still present. Removed light switch, driver vent, and cluster. Test drove with problem still present. Removed instrument panel trim (dash) and test drove. Rattle coming from dash support cage. Removed dash support cage, inspected and found no defects. Inspected with Shop Foreman. Reinstalled and retorqued instrument panel support cage and reassembled.
1/17/2011 - Scanned for faults front central locking faults A6D4 and A6D5. Performed SIB 51 19 07. Replaced central locking fuse and replaced both front door latches. Tested, no noise.
1/20/2012 - Wire harness and plastic clip came loose from metal frame in dash. Removed driver side trim panel on dash and resecured wire harness. Also removed instrument cluster and checked for anything making contact with metal frame. Nothing found.
Please let me know what you would advise me to do or if you have any fixes.