Date: Wed, 29 Nov 2006 07:03:22 -0500 From: Fred W <Malt_Houndnospamm-me-not*yahoo.com> Subject: Re: Terrible Screaming Noise
Eeyore wrote: > > danielakers007nospamail.com wrote: > > >>I recently purchased a 1987 Saab 900, 4 door, normally aspirated. I >>shut it off coming home from work (it was a pretty cold night, but not >>below 30f I'd say) The next day I started it up and it made a >>incredibly loud screaming noise (one could say squealing as well). I >>checked the condition of the belts, they all apear fine, I didn't check >>the tension though... It seems the noise is coming from the front of >>the engine, which has me scared since all the moving parts up there are >>expensive. A few notes about the noise: it makes it wether in gear or >>not, makes it whether the clutch is engaged or not, and there seems to >>be no change in loudness or pitch of the noise in any change in the >>above conditions. >> >>PLEASE tell me it's just water on the belts, I live in Oregon, so it's >>VERY wet here. >>Any help would be greatly appreciated, as I am only well versed in the >>workings of the Chevy 350, which the SAAB is, obviously, very different. > > > It's belt tension. > > Rubber *expands* when it's cold so the belt loosens and slips a bit causing the > squealing. > I'm afraid not. Rubber has to follow the same rule as all other matter in the universe and *contracts* when cooled, expanding when heated. The obvious exception being when liquids change state and become a solid some do expand. I've always thought that the reason for the squealing is that the rubber is *harder* when cold and therefore has less grip on the pulleys. That and the alternator load is the highest right after starting the car, so more apt top slip then. -- -Fred W
