'97 900 Turbo: noises?

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? Incidentally, the car is still very rapid, so doesn't seem to be suffering performance-wise. 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?

Thanks in advance for any help/ advice, Jim.

Reply to
Jim Walsh
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Thanks to Mohandes for the suggestion that it may be the timing chain, but I should have mentioned in my original post that the car has only done 50,000 miles, so it seems a little premature for it to be worn.

Regards, Jim

Reply to
Jim Walsh

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.

Could be anything. Once again, leave it until you have more definite symptoms to work with.

Reply to
Grunff

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