Bucking or jerking of vehicle and Blinking check engine light

[nine-fiver]

The turbo gauge would not normally actually go into the red. It should sit on the edge of it, just past the yellow.
If it does, it is overboosting but the Trionic 7 ECU management system will adapt over a 200km distance and recalibrate all the inputs to protect the engine. Clever system and almost foolproof. Unless someone has plugged one of the three lines to the boost controller with a bolt. A common trick.

What fuel are you running?

[handjammer]

Hi,

Interesting info about the boost controller, if I knew where it was I would check it out! Seems strange that immediately after the mechanic made the top turbo pipe fit snugly the gauge went into the red and the jolting started, it's almost as if the problem had existed undetected for ages.

As I'm in Germany the last few tankfuls have been 102 octane, partly because I can, and also I read somewhere that the higher octane burns more cleanly and more efficiently and so is better for the engine. I also read that the Trionic system will work out what fuel is in the tank and adjust things accordingly. All far too technical for me though!

Yesterday I ordered a new (Saab) DI and NGK plugs so let's see...

I'd just like to say a huge thank you to all of you who have taken the time not only to read, but also to comment and advise on my non-techically minded ramblings! I really do appreciate your help - thank you all.

[Audax]

While you change the DI and plugs pull out fuse 17 from the end of the dash board, this will reset the engine management system back to defaults so any bad settings it has adapted to will be lost. It might be necessary if it hasn't been running right for a while.

[handjammer]

Hi again,

I received a new DI cassette from Neo Bros the other day, and fitted it to the car. I left the old spark plugs in (they looked ok and have only covered around 3-4000 miles maximum since the other DIC was fitted, but will change them later).  I took the car out for a test drive and it was much smoother, both idling, at low speeds and under acceleration - no shuddering at all.  I'm really amazed at such an instantaneous improvement to be honest.

However, when I put my foot down hard, and the turbo reaches the same level as before, I still get the jolting happening. Any ideas?

I was really hoping the new DI would solve the whole issue!

[Audax]

Did you pull fuse 17? If not then I'd try that first and if that doesn't cure it then I'd expect an air leak somewhere in the system... or, well, possibly a dozen other things. It could be that it has managed to get an incredibly bad adaptation and can't reset itself from that, pulling fuse 17 (and leaving it out for about 5 or 10 minutes) will be enough to reset the system back to default.

[handjammer]

To be honest, I have no idea where fuse 17 is, but I disconnected the battery while I did the work, so it was probably disconnected for about 20 minutes - I work slowly, didn't want to make any mistakes!

Will this have had the same effect as pulling the fuse?

[Audax]

Will this have had the same effect as pulling the fuse?

Yes it will. The next thing to look for are any splits in any hoses and/or worn vacuum hoses or hoses that aren't connected.

[handjammer]

Aaaarrgghh, this sodding car!!  Driving home this afternoon, accelerating (not hard) down a straight, the engine started to shudder and the CEL was blinking. I backed off, and all returned to normal until I stopped at a junction and all power was lost, and the engine died. I managed to get it started again and limp it off the road.

I called ADAC, who I have to say were absolutely fantastic (3 phone calls to keep me updated of the situation), but unfortunately they were unable to do a roadside fix, so then I had to wait to be towed to a garage. More expense to follow no doubt.

The ADAC chap plugged the car into his laptop, and I watched as he perused the engine monitoring - really interesting stuff. I mentioned the new DIC which was fitted the other day, so he checked the cylinder readings ( I don't know what the figures mean) and he assured me that all was ok.  However, as he was revving the engine hard the turbo reading was barely moving, and he said it should be moving around far more than it was, indicating, in his view, a problem with the turbo itself (it'd better not be), or a sensor (better).

I've just about had enough now, there's always something, and it never seems to end, especially taking in to account all the money I've spent on it so far. I don't want to come across as though I'm grumbling but at the moment I'm pretty pee'd off with the expensive silver thing in the garage (either mine or someone else's).

I'm sure the garage will tell me tomorrow exactly what the problem is together with the requisite expense.

BTW Audax, I've checked all the hoses and can't find anything amiss. Hopefully it might be this turbo issue which is the root cause of all the problems.

I think I'll have a beer and calm down now...

[Audax]

Hmmn, depends... the turbo won't boost if the car is stationary....

[Steve440]

Could the electric turbo control valve be faulty?

The symptoms you are desribing is how my 9000 Aero used to behave if I had the turbo manual control valve wound it to much. If I backed it off a bit it would boost properly.

I ended up fitting it as the electrics that control the 9000's turbo often fail.

The jolting was a fail safe to stop the car over boosting and blowing itself up.

Steve
 

[andcro]

Hi guys,

I'm curious to find out what the fix was here?

I've just replaced my turbo on my 2002 2.3lpt auto - on start up it was fine, on test drive it was over boosting. It then went in to limp home mode.

I called the turbo supplier who asked my to remove the rubber pipe from the waste gate actuator and drive it to see if it still over boosted. Well it did - the gauge went straight in to the red, the fuel system shut down and the car coasted to a halt.

I restarted the car - it ran really rough - so I shut it off and refitted the pipe. Well - it barely runs - I can hold the revs at 1500 - 2000rpm but when I gently drop the revs it gets lumpy, the boost gauge goes in to the red and the engine stalls. This is an auto so it is undriveable.

Prior to removing the pipe I could drive it but had to be very careful how much I accelerated to keep the boost gauge out of the red. It was very peaky indeed!

Any suggestions?

As part of the turbo work I fitted the latest breather kit and replaced all the small rubber hoses with new silicon ones. I've checked they are all in the right places - which they are - I've also checked the pipes on the APC - they are all correct as well.

I'm thinking this is something to do with an air leak somewhere but I can't find it. The only thing I can think of is perhaps a damaged pipe in the wing - the bottom 2 brackets are broken off the airbox so by coincidence I suppose it could have moved and perhaps a pipe broke?

Any suggestions are extremely welcome!

Andy

[handjammer]

Hi guys,

An update on the situation with my Aero.

After breaking down just before Christmas and being towed to the garage, I have only just got my car back. I appreciate that the time of year didn't help much, what with holidays and that - still, it's here.

The garage called me to say that they had found a hole in the intercooler, and that the turbo boost control valve was also faulty, together with labour over 500 euros.

I found a secondhand I/C from the 'bay which reduced my bill hugely. Anyway, the upshot of all this is that my car works, and drives better than it ever has (well, for me, at least.)  It boosts just into the red, and now I can drive it properly without the peakiness and over-carefulness I was having to use with the boost / jolting horrors.

They showed me the two parts - the boost valve just looked tatty really, but the I/C was buckled and warped on one side.

I am hopeful now that the car is sorted, and can at last enjoy the car I wanted. That doesn't mean to say though that I don't anticipate more "challenges!"

Cheers chaps, thank you all once again for all of your help. This site is absolutely brilliant!

[andcro]

Thanks for the update Handjammer.

You've given me something to think about now. Since the last problem I'm beginning to wonder if my intercooler could be a problem - maybe a hole from the massive over boost?

Everybody I've spoken to so far thinks it is a vacuum leak somewhere - this would certainly fall in to that category as the hole would be after the MASS unit.

I don't have a Saab specialist near me so am planning on getting in taken to one thats been recommended - but its over 100 miles away so its going to be interesting!

Will keep you all posted.

[phoenix]

Have you reset the limp home mode- it won't run right until you have.

Here's how:

http://www.youtube.com/watch?v=wr_CmGp20mk

The only thing to add is pull fuse 17 before you start and then replace it after ~15 mins to clear the stored fault code. Might also be worth checking you have the APC valve pipes connected properly. From top to bottom the pipes are

R: Return to the intake system
W: Wastegate actuator
C: Compressor (turbo)

They have R, W, and C embossed on them

[andcro]

I've checked the APC pipe connections and they are definitely on there correctly.

One pipe has my curiosity, on the pipe to the intake system from the APC there is a "T" piece, this connects to a pipe from the inlet manifold, which has some one way valves in it. This pipe is part rigid and runs along the inside of the inner wing - on the left hand side when looking at the engine bay from the front of the car. I've taken this pipe off and can't suck or blow from either end - so I'm wondering if this might at least be part of my problem.

Does anybody know what this pipe does and what the effect of a faulty valve or blockage could potentially be?

Thanks

Andy