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Discussion Starter #1
I have a turbo boost problem and a vibrating steering wheel.

I was checking for air leaks, the air filter box was split and the filter removed.

I started the car from cold, it went to 1100 - 1200 revs as it normally does and there was a loud shooshing through the air box, this sounds normal however it stopped whooshing dead for a few seconds then started again, it did this a few times before the revs dropped to 720 rpm.
Then I could hear it still doing this but quieter.

I took the engine back up to 1200 revs and the sound returned, it sounds like a flap/valve opening and shutting cutting off the air. Its hard to tell from inside the car as I need to give it some gas to get it to 1200 rpm.

The car seems to be hunting slightly and randomly.

I have checked for leaks and have found none.

Any ideas? Could a blocked cat cause this?

Symptoms are, no turbo boost, sometimes irregular turbo boost but never getting all the way there, vibrations at wheel on idle disappearing at 1200 revs but still feeling a harshness through the pedal (this symptom showed up at the same time as the turbo boost problem , then went away for 2 weeks then returned however during this period the turbo still had a boost fault), fuel economy might be down slightly, slight lumpy idle with random hunting.

Generally the car drives OK and has power apart from the turbo,

So far , I have checked the engine for air leaks and have not been able to find any, I have flushed the engine and replaced the oil and filter.

Known issues, spark plugs have not been changed in a long while, over a year. Air filter may be bad, needs replacing , SAI pump/valve failure.


Any help would be greatly appreciated.
 

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Discussion Starter #2
I just whipped the cat off at the turbo flange and took it for a small drive and the problem is still there, so I guess I can rule out the cat.

Saab main dealer has diagnosed a balance chain problem but everyone I have spoken to has said it shouldnt limit the turbo like this, so now I'm flumped.
 

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Discussion Starter #3
Just a thought, the crankcase is a closed vent system, when the engine is under no load a one way valve send the gasses to the manifold, when under a heavy load the gasses are sent to the turbo.

Is this valve internal , and if it were to malfunction would it cause the air through the air box to be cut off momenterally if the turbo was being fed from the crankcase instead?
 

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Discussion Starter #4 (Edited)
Guys, I put up some vids just to show what I mean regarding the engine breathing and the turbo boost, the air box vid you can just about hear the engine suck in air then stop for a moment then start again, it sounds like a diver breathing through a tank underwater.
Please note the cars engine does not sound as bad as it does in the vid, Its lumpy but fairly quiet.

In the other I floor it in third at around 14 seconds and you can see the needle try to get there but not quite, at this point it felt like something was holding the car back and a roughness felt through the pedals.

Any ideas chaps?

http://www.youtube.com/watch?v=j7pA50OSuPU&feature=youtu.be

http://www.youtube.com/watch?v=5cGmaYxkobQ&feature=youtu.be




Edit - just to note, when I separated the cat from the turbo it actually went like the clappers, just not reaching full boost, but quite impressive all the same.
 

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what do you mean by full boost?

Mine just dips into the red when under full load through the gears but not in 1st or second as they are limited.

I cannot get much from the vids really.

How long have you had the car, when did things change? was any work carried out around the time of the change or just prior, some history would help.

removing the airbox lid will cause changes within the induction system to mixture and airflow which is why you can hear changes in engine note - that's my theory.

roughness through the pedals, please explain, jerkiness, vibration, what exactly???

where i would be looking.
Sticking, weak wastegate/spring
pipework to wastegate actuator
plugs - right type and working OK, same for DI packs
Turbo, bearings ok, no noticeable play in shaft
fuel filter - change and fuel pump working ok
all vac hoses in tact and good condition
intercooler undamaged and holding pressure + all pipework and clips from i/c back.

reading your other post on the subject (which i will lock) the sai pump will not have any effect. mine has packed up and makes no difference whatsoever, it will be physically removed and software 'delete' when i get round to it.

if you remove the cat it will feel more lively, a turbo car doesn't require back pressure in the way a non turbo does, you just removed a large restriction by disconnecting from the cat back.
 

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Discussion Starter #6 (Edited)
Hi
Thankyou for the reply.
The problem started about a month ago. The car went to Cambridge with the missus then when it returned it was not reaching full boost and there was a vibrating/droning from the steering wheel at idle, as if the exhaust was in contact with the steering, from outside the car it sounded fine.

I took it to the garage who checked it over (quickly) and couldnt find anything wrong with it.

After the mechanic looked over it he jacked it up to check underneath. Whilst on the jack (offside) he also pulled the turbo pipe from the air box out to check the turbo, he found no play. He asked me to start it up with the pipe off and I did, then he asked me to shut it off so I did.
He said the turbo was fine.
He put the pipe back on only this time when I started the car it hunted badly, it could barely idle. So out came the computer (not tech 11) and he reset the idle and ECU, the car returned to normal after a few mins sitting at idle only this time the vibrations in the steering were gone. The car was back to normal except it still had boost issues, not quite reaching full boost. I put this down to a leak somewhere and was going to have it pressure tested to find the leak.

Last week, about 10 days after the garage visit the fault returned, on idle the steering wheel vibrated at idle and sounded like an exhaust fault, only from inside the car.

This time I took it to a Saab main dealer, only after stripping out all the pipework to look for leaks. They diagnosed a balance chain problem and a 1200 quid repair bill. I was dubious about this because I'm not sure this would effect the turbo, my thoughts have been confirmed by a few different garages.
Thinking perhaps oil starvation I flushed the engine with Forte flush and replaced the oil and filter, no joy.

Yesterday I pulled all the hoses off again and tried the car with the cat separated from the turbo, this is where I am today.

The westgate spring, thats is interesting because when I checked it I disconnected the actuator and the westgate moved freely, however I dont remember feeling any resistence, are you sure there is a spring in there and its not the actuator that keeps the seal on the westgate?
I'm going now to pull the actuator arm off and try again.
If I can get confirmation that there is a spring in there and I should feel resistance then I think we may have nailed it.

TRhe harshness in the pedals at 2500 revs feels like the engine is dry from oil , my old landy does it when it needs an oil change, or air/fuel starvation, like a groaning kind of feel.
 

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Discussion Starter #7 (Edited)
I just pulled the westgate actuator arm off the westgate and it moves freely with no resistance, so no spring.
Is there supposed to be a spring on this?

Edit - intersting you should mention the fuel, sometimes when I start it (I always let it go through checks first) when the fuel pump starts I can hear it groan as if there is air in there, but this doesnt happen all the time and its been happening on and off for a good year now.
The car isnt throwing any fault codes apart from the sai fault.

edit again - when I say full boost I can feel the car pick up as if the turbo is kicking in and I can feel it picking up all the way to around 3000 revs, then it stops and lets back slightly so something seems to be preventing the turbo from reaching full pressure. This is when I can feel the harshness in the pedals. I know it is restricted in 1st and 2nd so the video is only really relevent at around 14 secs when I put the car into third.
 

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Hi - tried to read all your posts so forgive me if you've already changed the fuel filter, the DI packs are ok and you're not running crap fuel. Have you filled up with Vpower and checked some injector cleaner in. All sounds fuel/spark related to me now you know the hoses, turbo, cat etc are ok. Was the Saab main dealer Cambridge Saab and did they tech 2 it? Al
 

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Discussion Starter #9 (Edited)
Hi - tried to read all your posts so forgive me if you've already changed the fuel filter, the DI packs are ok and you're not running crap fuel. Have you filled up with Vpower and checked some injector cleaner in. All sounds fuel/spark related to me now you know the hoses, turbo, cat etc are ok. Was the Saab main dealer Cambridge Saab and did they tech 2 it? Al
Hi Al , thank you for the reply, the main dealer was Cox's in Ipswitch, they did tech 2 it but read no fault codes apart from the SAI fault. They did tell me that the balance chain runs one of the cams which made me dubious, they also said the balance chain if faulty would prevent the turbo from boosting and stop the car revving , ''it just doesnt want to rev'' he told me after taking it for a test drive, this also made me dubious.

On the turbo side, when at idle I can hear a knock from it, it is random. I put a screw driver to the turbo and to my ear and it sounded like a twanging from a spring. This corresponds to the air intake rush change when the air box is taken apart.
I have watched the actuator when it does this and it doesnt move so I am not sure if it is the westgate or not.

On the fuelling and spark side, the plugs have not been changed while I have had the car, I had my socket set nicked and dont have a socket to remove them, I need to get in there and have a look so I shall try and borrow one if I can.
The fuel filter also might be dodgy, when the car does its initial checks I can sometimes hear a groan from the tank somewhere and lately on start up I can smell a slight fuel smell from the back of the car, but it clears up very quickly so I just thought it was from the exhaust or EVAP.
I know it also could be doing with a new air filter but the problem remains even with the filter removed.

The problem was not gradual, it went to Cambridge and was running fine (the missus) and came back broken.

It has had fuel from several different stations since the problem first occured.
 

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Discussion Starter #10
I have just pumped the engine, I blocked the intake between the air box and MAF sensor by removing the pipe and plugging it. I then removed the pipe from the pressure sensor on the inlet manifold intake pipe (the pipe from manifold to IC) and pumped it up with a hand pump, I could not hear any significant leaks, I put enough pressure in it to hear air coming out of the oil filler cap.
Nothing else was detected.

This time on start up white smoke belched out of the exhaust but it is clearing so I might have just blown oil or water into the intake.
 

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Discussion Starter #11
Now that is bazaar, it's fixed itself, again.

All I did was take the hose off the SAI none return valve and shove my finger in there, I dont know if I disturbed anything, and because I heard it ticking when the car is being revved I disconnected the pipe from the charge air solenoid valve on top of the wastegate actuator, the middle pipe (W) that leads to the wastgate actuator. Then I ran the car and it was almost fine but has now got better to fine and dandy.

The car now purrs like a kitten in comparison with just a slight hunt or miss.

So I connect everything back up and it still purrs like a kitten but still a slight hunt or miss.

The knocking noise in the turbo is still there, so I listened to everything with my screwdriver and it is definitely around the turbo/manifold area. I can also hear it through the wastegate valve with a screwdriver to my ear. It sounds like a spring being tapped with a screwdriver.

So, I pulled the pipe from the intake air sensor in the charge air pipe to the intake manifold to see if there was a decent vacuum and it was on and off, sometimes a vacuum and at other times not. One thing I did notice was when the turbo went 'twing' a gurgle came from this pipe and a swift pressure boost, like it chuffed.

Any ideas guys? This is starting to become a right PITA.
 

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Again apologies, I have seen the thread of uksaabs too, so dancing in the dark a bit... but how is the dump valve? Could be a split diaphram (sp?). That could give the car an iffy idle. Also, again i may have replied on uksaabs (under '9-3SEt'), but idle on these can be a little iffy. I understand there is a software update but if yours was ok before the Cambridge trip then prob not a route to go down. other idea, is boost control valve?

Al
 

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Discussion Starter #13 (Edited)
Those were my thoughts exactly. The wastegate actuator seems to hold pressure, the boost control valve (solenoid valve connected to the actuator via a small pipe, located ontop of the actuator?) makes a rapid ticking noise when the car is revved so I'm not so sure.

The car had a new CIM not too long ago so I assume it has the latest software.

I'm wondering if the car misses and that in turn causes the twang sound and the sudden chuff of pressure from the manifold?

Or if it has fluid in the IC?

Or indeed if there is another leak somewhere but I am sure I would have picked it up when I pressurised the engine during the leak test.

I have not test driven it yet so I am unsure if the turbo is now working correctly.

Edit - one strange thing, when I was listening for leaks around the engine I heard a faint ticking noise from the ECU ., or around the ECU area (is that the ecu on the side of the esp control module?), I cant remember if the ignition was switched to on but that has also gone.
 

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Discussion Starter #14
Just an update guys, timing cover came off and both timing and balance chains were cheese, two new kits have been put in.

Turbo guage still not reading right.

I learned that with the balance chain being defective it would trick the engine into thinking the knock count was high and thus retarding the ignition to compensate, this would mean the turbo performance would be limited.

However now even with the chain kits installed the turbo still isnt reaching full spec, On the dial the needle gets to two and a half bars below the red and sits there.

The car drives smoothly, idles smoothly and pulls well.

Have I missed something?
 

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Just an update guys, timing cover came off and both timing and balance chains were cheese, two new kits have been put in.

Turbo guage still not reading right.

I learned that with the balance chain being defective it would trick the engine into thinking the knock count was high and thus retarding the ignition to compensate, this would mean the turbo performance would be limited.

However now even with the chain kits installed the turbo still isnt reaching full spec, On the dial the needle gets to two and a half bars below the red and sits there.

The car drives smoothly, idles smoothly and pulls well.

Have I missed something?
Hi as far as I know the aero (and all turbo saabs ) will not go into the red but stop a mark or two down, if you have been hirsch upgraded then the needle will swing into the red, this is one way of making sure you have been upgraded, I have a 2004 aero that has the hirsch and it gives 252bph and according to the hirsch booklet about 150mph (260kmph)
 
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