....from the engine bay. I know that's a little vague but any suggestions?! Obvious things to check? Engine was at idle when I noticed it.

Can you pinpoint where it is coming from?

Simon.

Well actually not easily. Maybe I'm hearing things again. It seems obvious when the bonnet is shut but you can't hear it above the engine noise very easily when you pop the bonnet. It seems loudest when the car is cold but I only noticed it yesterday so.... It seems to be coming from the front of the car but I can't say for sure.

I've just had my AC compressor fail on me 200 miles ago which was replaced under warranty by the garage and the timing chain was done at 107000 miles (May 2000) - I'm now creeping up on 133000. Surely it can't be the chains again?! It was serviced just last month (1000 miles ago) and I don't think the next major service is until 140,000 according to the service schedule booklet.

EDIT:

Just popped out and rechecked. It's a high pitch 'ringing' coming from the left hand side of the block. It's the damn chains isn't it....? :(

I does suggest a problem with the chain from what you say. However, my suspicion is that it is the tensioner that may be at fault. Was this changed when the chain was done? Sometimes the tensioners get stuck and may be worth trying to free it again. You might be able to 'fix' it by sticking the car in fourth gear and pushing the car backwards. This causes slack in the chain which hopefully should be taken up by the tensioner.

Tell us if it works.

Alanb

Thanks for the advice but my car's an Auto. Is there any other way of doing it?!

In the meantime I should be okay to drive the car though, right?

Did you change the balance shaft chains??

It was done by Swain and Jones, which is my local Saab Dealership, so I should think it was done properly.

It could just be the tappet noise you always get on 9000's before the oil works it's way into the top of the engine.

The noise is always louder when cold, though dies down after a few minutes. My old Carlsson wasn't particularly quiet when warm (as far as tappet noise went) though was told there was no problem.

Had this sort of noise on all 3 of my 9000's - none needed timing chain work - hope yours is just this!

More info on this thread:


http://www.saabscene.co.uk/ubb/ultimatebb.php?ubb=get_topic;f=2;t=001829

The other way to do it is to attach a socket to the crank and turn the engine in the opposite direction of rotation to normal. I have never tried getting a socket on a 9000 crank so I'm not sure how easy it is to attatch.

In my case, with my 900, doing this procedure sorted out the noise.

Another alternative is to remove the automatic tensioner device. On my 900 this was bolted on to the block (a 27mm bolt I think). I removed it, cleaned it, checked the spring worked and then put it back. I'm not sure whether the 9000 has the same bolt/tensioner design though...

Alanb

I believe the 9000 tensioner has a ratchet mechanism on it, so removing it will let it extend and you need to unlatch the ratchet to retract it again. Never having done this, I don't know how easy it is. I do know new ones come compressed and after installation you remove a retaining pin to allow it to extend.

Strangely the noise appears to have disappeared. I have no idea why.

The tensioner was replaced at the same time as the rest of the chain bits so hopefully it would be perfectly okay.

Yes, that sounds like the 900 tensioner device. I think it is a 27mm bolt that needs undoing to remove the spring and ratchet device. Before installing, the ratchet device should be fully compressed. Once installed, turn engine forwards for a turn or so and then turn it back the other way for, say, an eight of a turn.

Alanb

Go to this link to find out how to remove it:
http://216.78.172.244/engine_folder/incarchainpg3.htm

Alanb

While my car is off the road because of the snapped belt tensioner (see other threads!http://www.saabcentral.com/forums/viewtopic.php?t=6734) I'd like to take a look at the chain tensioner too. If I remove it and measure it/clean it can I just stick it back in again afterwards? Is it something you can clean with a bit of WD40?

That guide you posted Alan, specifically said 'don't change the position of the plunger after you remove it' but how do you clean it properly otherwise?

Matt,

I simply don't understand that advice. If you read elsewhere e.g. Haynes(?) then I think you find that you are fine. It's automatic so, take it out, check how far it extends (must be no more than 11mm), clean it, retract the arm and reinstall it.

Alanb

'don't change the position of the plunger after you remove it' but how do you clean it properly otherwise?

That means before you measure the distance that the pushrod extends.

As Alan says, just retract it before re-installing it, it will extend to the correct length automatically when re-installed.

Ah gotcha. Thanks chaps.