Hey guys,

I just wanted to drop in and tell you all about an issue I just experienced. A couple weeks ago my car started making a squealing noise. It started low and progressively got louder. It only occurred at operating temp. I initially thought it was a bad idler pulley and replaced them. $45 each at Autozone. I Warmed the car up in my garage and it seemed to be fixed. I put the car back together and went for a drive. Five minuted later it started again. I returned home and it was so loud it was almost unbearable. I removed the serpentine belt and cranked the engine to rule out any of the other pulleys. It continued to make the sound without the belt on. My next thought was some crazy exhaust leak. I actually found one on at the clamp before the passenger muffler. I fixed this and the noise continued. At this point I turned to google and found various possibilities from metal rubbing together due to a broken exhaust hanger to internal engine problems. The one that caught my eye was a post about a boxster squealing badly but it was a slightly different sound. In the post someone said to remove the oil filler cap and if the noise went away it was definitely the air oil separator. I did and it went away immediately. I replaced the AOS, that's a whole story in itself, and its just fine now.
So if you have an awful squealing sound save yourself some trouble and take your oil cap off first.

 

Good info, thanks for the post.

 

Thanks. I have it to but more of a hoot and very intermitten. Will try the cap butvdo think air oil separators go bad on these cars and need replacing.

 

YES, AOS is a known issue. And yes, it will need to be replaced if torn/leaking......just as EHGRay posted

In case you missed it, another thread that also covers AOS an much more: https://www.6speedonline.com/forums/...ring-more.html

 

The squealing noise is air being sucked into the engine past a seal, usually the front cranshaft seal.