Date: Fri, 03 Oct 2003 14:29:01 +0100 From: Grunff <grunff232nopsam.com> Subject: Re: '97 900 Turbo: noises?
Jim Walsh wrote: > Hello all. The girlfriend has a 1997 Saab 900 Turbo Talladega and I've > noticed some peculiar noises that I wondered if you guys could help me > identify. The first one is engine related: Following a period of > acceleration, if the car is left in gear and the gas pedal released, > there is a rhythmic "shh shh shh shh" noise. It's not extremely loud, > but it is perfectly audible, even with the windows closed. I guess it > sounds like something turbo related. Is there a wastegate/ dump valve > on these cars that could account for the noise, or is it likely to be > a leak in the turbo plumbing? There is both a wastegate and a dump valve, but I don't think either is making the noise you describe. The dump valve makes one single "Pshh", which you hear when you release the throttle under high boost (e.g. when changing gear). Leaks in turbo plumbing tend to present themselves under boost, not on overrun. My short answer is don't worry about it. If something's going to break, you'll find out about it when it does. There's probably nothing wrong. > The other noise that the car has just started making is a "clunk" that > sounds similar to cars I've owned/driven where one or more rubber > bushes in the suspension have perished. The clunk occurs maybe once > every 2 miles or so, but I can't say for sure whether it's associated > with bumpy road surfaces. I also can't really identify where on the > car the noise is coming from, so can anyone tell me if a particular > bush (or bushes) are prone to going on these cars? Could be anything. Once again, leave it until you have more definite symptoms to work with. -- Grunff