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Discussion Starter · #1 ·
Hello,
Please excuse me if these questions have been asked before, but I'm new to this good forum!

My '93 9000 turbo has developed a strange boost problem. Accelerating hard in 2nd/3rd you can hear the boost being bled off every second or so - ptsch - ptsch - ptsch - ptsch - ptsch.. etc! Does anyone have any idea what's going on?

Some background, the car developed a problem with it's wastegate actuator and the main dealer ended up replacing a load of vacuum hoses and fitting a bleed valve from Abbott. Also the car sat idle with a flat battery for a few weeks just prior to the problem developing - I've just fitted a new battery and driven it to find this problem.

On a separate note, there is a loud tapping noise coming from the cam followers which has been getting worse recently. Is it possible to get new cam followers & cams (preferrably standard) as I understand I can't just fit new followers to the old camshaft. And if so does anyone know where from or a rough price for them? Or can the followers be refreshed in any way?

Sorry for all the questions!

Cheers,
Tim.
 

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Hi Tim,

Welcome to Saabscene .

I've got a '93 model and during fairly hard acceleration (say 2/3 throttle) you can sometimes hear the boost being bled off continuously as the car goes through the mid-range, perhaps this is the same type of event you are describing?
Are you unhappy with the cars performance since this noise started or is it just a noise that worries you?

Nick.
 

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hi tim it could be a weak or duff dump valve.pull off to hose at that sensor thingy on the passenger wing(its got three hoses on it),that goes to the dump valve(the middle lower one IIRC)and suck on it.it should hold a vacuum if you stick your tongue over the end of the hose.if not its a new dump valve required.also check over all hoses for splits etc
simon.
 

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Discussion Starter · #4 ·
Thanks for the replies. It's a new thing which is why I was concerned about it. It's definitely not a continuous bleeding off, but repeated short bursts - you can feel a slight reduction in acceleration each time it bleeds off.
Have also discovered the boost gauge isn't working - not sure if that's related or not?

On the plus side I think it's stopped hitting the APC "brick wall" which it used to do frequently under hard acceleration.. It seems odd to me that the only thing that's changed is the battery, and the car is completely different to drive!

I'll check the dump valve tomorrow - unless that is the bit thats now been replaced by the Abbott bleed valve? I'm sorry I'm not very clued up on turbo engines!
 

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Welcome to Saabscene!
In answer to your question about cam followers, firstly are you sure it IS them and not the chain?
If the rattle is at the belt end of the engine, suspect the chain.
Secondly, is the noise still there when the engine heats up? Most Saab cam followers are noisy when cold.
Thirdly, is it ALL of them or just one or two?

To the best of my knowledge, you can replace them either individually or as a set, relatively easily. Last time I looked, they were about £13 each at Eurocarparts. And you don't need to replace the camshaft.

It might be worth using a flushing oil in the engine first, in case they are just gunged up with cheap oil.

You may be able to remove them and soak them in flushing oil or something, to clean them, I don't know - anybody?
 

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Discussion Starter · #6 ·
Thanks
Erm, it makes a real racket when you first start it from cold - noise gets quieter eventually as it warms up (over minutes, not seconds IYSWIM). It is the chain end of the engine - car is due a service soonish so I'll get them to check chain and tensioner then.
Flushing oil sounds a good plan too..

I thought that followers "wore in" with the camshafts, and you couldn't replace one without the other. That's my experience on other engines anyway - anyone know if Saabs are different?
 

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Discussion Starter · #7 ·
PS. Boost related problems all solved - turns out the front part of the exhaust was blowing. A new front section (the section with the flexy part in) and all is back to normal.

Boost gauge had stopped working cos the vacuum hose had come adrift
..
Thanks for all your replies & help.
 

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timid - another potential reason for the boost issue: Changing the battery resets the ECU. When you floor the car it will relearn and you get the cyclic whooshing noise as it calibrates. It should not do this for long though.
If this has not been done for a while, chances are that the car will run better for it.
 

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timd, to get back to your cam follower problem, you can replace them individually or as a set, without any problem.
They don't "match" the lobes on the cam as such.
Type "cam follower problems" in the 9000 search facility, there's some good advice/experience there.
 

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Discussion Starter · #13 ·
Originally posted by DaveS:
[qb]timd, to get back to your cam follower problem, you can replace them individually or as a set, without any problem.
They don't "match" the lobes on the cam as such.
Type "cam follower problems" in the 9000 search facility, there's some good advice/experience there. [/qb][/b]
Thanks, search was interesting, looks like it might be worth whipping the cam cover off and giving them a clean at least.
 

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Discussion Starter · #15 ·
Originally posted by faero:
[qb]timid - another potential reason for the boost issue: Changing the battery resets the ECU.  When you floor the car it will relearn and you get the cyclic whooshing noise as it calibrates.  It should not do this for long though.
If this has not been done for a while, chances are that the car will run better for it. [/qb][/b]
Yup, thanks. I tried to do the "learning" thing for the ECU, but so far haven't found a road long enough to complete the run properly.
It seems 100% better now though with the new front exhaust section - I think that was just confusing the poor car.
 

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IMOA do note use flushing oils, it can cause more problems. The cam followers are constantly fed with an oil supply which is sealed in when the engine stops. These will hold whatever flushing fluid you have used and will contaminate the fresh oil which you will then need to change again. I was amazed how much oil all the followers hold when I stripped my engine down.
From your description it sounds like a chain problem though.
You can remove the followers and clean out of the engine, safest way to do it.
 

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Discussion Starter · #17 ·
Originally posted by Mark in Ireland:
[qb]IMOA do note use flushing oils, it can cause more problems.  The cam followers are constantly fed with an oil supply which is sealed in when the engine stops.  These will hold whatever flushing fluid you have used and will contaminate the fresh oil which you will then need to change again.  I was amazed how much oil all the followers hold when I stripped my engine down.
From your description it sounds like a chain problem though.
You can remove the followers and clean out of the engine, safest way to do it. [/qb][/b]
Ok, thanks for the tip. What is the procedure for cleaning out a follower out of the engine so that it won't hold whatever it's cleaned with?

Cheers,
Tim.
 

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Remove cams, get a valve lapping stick with rubber sucker on end to pull out the cam follower. You will see a recessed groove with a couple of holes in on the side and a plug/piston thingy in the bottom, this is what is pressed again the valve stem when oil pressure is pumped through the holes in the sides. I washed them in petrol and kept pushing the piston in to remove all old oil etc. Easy to show than explain but once the follower is out it becomes clear.
 
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