Has anyone experienced this noise,... it,s hard to describe really, but when under upshift of the gears (5speed box) I sometimes get this loudish shrill whistling noise,...... seems to be coming from drivers side front of engine, (US passenger side),..

The noise is still there (occasionally) even since replacing Cambelt/waterpump and tensioner, as it was before the change.

Iv,e checked the fan/alternator/ belts etc with no positive outcome,.. it also seems if you let off the gas pedal the noise decreases and eventually goes away,.... untill the next time.

Any advice much appreciated

Ken 1980 928S manual
United Kingdom

 

Does the noise rise up and down with engine rpms? I have heard noisey airpumps that sound really weird....

 

Just prior to spinning my first rod bearing, I heard a shrill noise. At first I thought it was a vacuum leak, so ignored it. Of course my car is strictly track and definitely a candidate for rod bearing failure.

I hope this isn't your issue...

 

Fan belt tensioner pulley bearings?

 

Clutch throwout or pilot bearings would be my guess. One bearing usually squalls with clutch engaged, the other when the clutch is disengaged. Not sure which is which. Do a search and you will find it.

 

Do you have the original short belly pan? A combination of shot motor mounts and too-high belly pan can cause the AC pulley to rub on the pan. I had a similar problem where it would rub at *ahem* very high RPM in 5th gear due to air pressure against the pan. Manifested as a shrill scrape/whine at about 130mph(closed course, not on a public road ) which left severe pucker marks in the driver's seat....

 

,....Thank,s guy,s for taking the time to answer my query,... will defo check them out,......incidentally my car which iv,e owned for 16 years stands around a lot ie winter hibernation etc, and never really gets a good thrashing,.....so the points you all raise are particularly relevent.

Best wishes to all

Ken 80 928s Manual
United Kingdom

 

I had a weak vacume line that caused an intermittent whistling noise. Once the rubber was heated up by engine bay temperatures, the wall would colapse on the vacume line causing a whistle.

 

I have the same issue on my '81 auto. Mine sounds like a bird whistle, or a woman on helium laughing.

 

Spot on SharkSkin,.... removed short belly-pan and found a very highly polished section on it directly below AC pulley ,.... I neatly cut a section out of the curve, so that it is,nt fouling anymore,.........Thanks

 

That can't be right, within 6 posts someone gets the right answer (well done Dave A). Surely it should take at least 3 pages before anybody gets close to the correct diagnosis. I don't know this place ain't so much fun anymore.

 

The first part of Dave's post refers to the MMs being shot, how are yours?

Jon, if you like, I can postulate some really obscure ideas for him to chase and also refute the fact that it's fixed now or that it's fixed correctly if that will help you feel more at home.

 

Fix it 'til it's broke!

j/k Congrats on the fix. Rennlist is a great place.

 

,......when you look under at the mounts, I can see approximately 2inch,es + of the steel rod showing,.. is this ok

 

Glad you found it! BTW, cutting it may not have been necessary -- With mine, I just loosened the fasteners and shifted it around so it would bow downward a bit more.