Vacuum Whistle !!!! Arrgh!!! 02-D2 V8

[ozscott]

Gday all. I have an 02 D2 V8 with 100,000 miles on the clock. Had it since new. The problem is that it has developed what sounds like a vacuum leak - rev it and it holds onto the revs as they fall. Part throttle and above and its not there. However whilst it sounds like it comes from the front of the motor, near the plenum and accessories like the air con compressor and alternator, I can see anything obvious and the plumbing makes it very difficult to do much. Spraying aerostart does not pick the culprit. My 95 D1 at nearly 200,000 miles got a loud whistle also - same symptoms. Both vehicles on do it when warm which makes me think it must be valley cover gastket or similar. Its driving me mad!

Anyone got any ideas.

Cheers

 

[squirt]

Are you sure it's vacuum noise and not bearing/pulley noise? Idler pulleys tend to give the sypmtoms you describe.

 

[rev.fletcher]

pully bearings are a common problem, look there as well. I have seen lines that collapse too.

 

[ozscott]

Thanks fellas. I had the same though so 2 days ago I replaced the tensioner and all idler pulleys with brand spankers...noise still identical. I wonder though if it is the air con compressor or alternator - it does sound like that area and that might follow the engine revs like this too...further at below about 800rpm idle speed the sound goes away completely....a mystery.

Chees