Climate Control
Rear A/C Rattle
All three 928s I've owned so far have had an annoying rattle/noise from my rear AC under
certain road conditions. Finally, today I found out where it comes from. And it was
surprisingly easy to fix it. Took me about 30 minutes....
No, this rattle does NOT come from the vents - it comes from underneath! There is a mesh
over the evaporator, and it vibrates against the evaporator. I could easily simulate it by
banging on the rear AC console...
I took the rear AC cover off (see *** below), and found out that the mesh can easily pulled
out after removing a (temperature) probe that is stuck through it. I cut thin felt strips and stuck
them onto the underside of the mesh in order to keep it away from the evaporator.
Put things together again, banged against the rear AC console, no rattle anymore!
Jorg
'91 928 S4 V8 Auto
*** Warning: If you have not done this before, be careful when you remove the black cover at
the rear of the AC console. It has two screws towards the trunk, two clips on the sides, and
two weird "Z" shaped metal latches towards the front. If you pull too hard, these latches break
off. Make sure you have some really good Epoxy glue handy - just in case.