View Single Post
Old 02-27-2018, 08:47 PM   #3
Qmulus
inveniam viam aut faciam
 
Join Date: Mar 2014
Location: Arvada, CO
Posts: 440
Pull the oil fill cap and see if the noise goes away. If it does, you may have a torn diaphragm on the AOS, that will create a lot of vacuum in the crankcase, sometimes to the point that it pulls in air past the rear main seal causing the squealing noise. I had that happen on an Audi years ago. It sounded terrible, but was an easy fix.

The tip off to me is that the noise changes when you give it a bit of throttle. Under that condition, there is less vacuum in the intake, and therefore less being transferred to the crankcase through the AOS diaphragm.
__________________
'03 S, manual, 18" Carrera wheels, PSM, PSE, Litronic, 996 Cluster, +

Last edited by Qmulus; 02-27-2018 at 08:50 PM.
Qmulus is offline   Reply With Quote