On my recently purchased 2007 997 turbo, I was experiencing vibration noise/rattle when driving over certain rough roads. I narrowed the location/source to the front speaker grilles located on the upper dash at the windshield.

After inspecting the 2 outer grilles, it was obvious that they were "loose" and not firmly seated....resulting in "buzzing" in certain situations. When I removed them, it was clear that the oem "dust guard" made of approx 1/8" thick foam sheet had deteriorated to the point of disintegrating. The design of the grilles actually uses the foam to insulate the plastic grille from the dash.....but as it deteroriates the plastic grille can contact the dash surround, thus creating noise under some frequencies present when driven over rough roads.

I replaced the film with 1/8" speaker foam but this didn't totally isolate the grilles from contacting the dash surround. To completely eliminate the vibration/contact, used some rubber cement/glue and dabbed it on the underside of the removable plastic speaker grille at the corners and on long straight edges. Since the rubber cement/glue is not permanent and easily removable from any surface....acting primarily as a "standoff" and insolation medium, it provides an easily reverseable solution.

 

Very interesting!
My 2007 TT has the same issue.

I thought my entire dash needed to be removed to solve this, but speaker grilles is much easier.

 

I ended up also doing the center speaker grille too, but didn't need to replace foam...just added a few dabs of rubber cement/glue and fixed all of the grille(s) rattle.

 

Nice job. Gotta love fixes like this. While I don't have any rattles in the 997 (yet), I have employed felt tape, foam, tie wraps and anything else that would quiet some rattle or buzzing.

Great work!

Ed

 

I had this issue also.....very annoying.

I just popped off the grill and put some 3m double sided tape under it. took care of the noise