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Discussion Starter · #1 ·
First time Saab owner and don't know anything about them just picked up an 85 900 turbo and there is a knock in the motor/trans thought it might be a rod or valve but it only knocks while the clutch is let out meaning pedal is not depressed. Looking for some advice and possible prices. I'm loving this little car though and glad I bought it. Thanks
 

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First time Saab owner and don't know anything about them just picked up an 85 900 turbo and there is a knock in the motor/trans thought it might be a rod or valve but it only knocks while the clutch is let out meaning pedal is not depressed. Looking for some advice and possible prices. I'm loving this little car though and glad I bought it. Thanks
Welcome to the C900 world. You will find lots of help here.

Well, my first thought is that the noise is coming from the clutch or tranny and not the engine or primary drive since those both turn whether the clutch is engaged or not.

Can you tell us any more about the noise and any other sypmtoms?

Describe what you mean by knock.

You say the knock is only noticeable when the clutch is let out. Is that in nuetral or can you hear the noise while driving too?

Does the noise change with rpms / speed? If so how?
 

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Discussion Starter · #3 ·
Knock

Yes the noise sounds like a thrown piston rod or a loud detonation, only occurs while clutch is let out. I cannot hear it when I press in the clutch and give it throttle however when the clutch is out in nuetral the noise accelerates with the engine rpms. The noise is also present in first through fourth and also matches the engine rpms not sure about fifth for the fact I can't hear over road noise. There seems to be a sweet spot where the noise isn't there that's when I'm in gear driving and the trans isn't under load or decel kind of the slack between accel and decel
 

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Take a look at the primary chains...
 

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Take a look at the primary chains...
What was I thinking? ;oops: Of course the primary drive turns with clutch engaged.

Bob, do you have a Bentley's manual? It's an indispensble help, especially if you're new to Saab. Is your car an 8 valve? I think I might have a Bentley's that came with a car I no longer own. Send me a private message if you're interested since we can't do business here. I'll have to go look for it and won't spend the time unless you express interest.

The Primary drive is directly behind the radiator and in front of the clutch. Do you have an automotive stethoscope for listening to noises? If not you can use a piece of 3/8" hose about 2-3 ft long. Hold one end of the hose to your ear and move the other end around to where the sound seems to be coming from. Usually you can isolate it that way. There is a cover on the primary drive but I've never taken it off. Bentley's covers it or maybe someone else will offer help.
 

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Discussion Starter · #8 ·
I have a bentley and I'm gonna do some reading up today you guys rock and I'll get back to you when I figure what I'm going to do
 

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Discussion Starter · #9 ·
Decided to just do it and opened the primary cover and everything looked good noteven metal shards.the chains looked good and I flushed the gearbox and put new fluid now no knock at idlehavent drove yet but will repost after I go to schmuks for new taillights
 
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