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9-3 Boost problem /solenoid valve?

Hi all,

I need your guess on a diagnosis:

Car is 1999 9-3 SE 200hp.

Acceleration is sluggish, turbo gauge indicates half way into yellow, at max throttle in 3rd, 4th, 5th, between 2000 and 5000 rpm (i.e. not reaching boundary between yellow and red at anytime, regardless of gear or revs).

Disconnected wastegate pipe from solenoid valve (the black thing with three hoses and electrical connector attached, known as "magnetventil" in Swedish) and floored the gas pedal, but boost does *not* shoot way up into the red, as it should. Reassembled.

Detached the circlip and wastegate arm to confirm that wastegate on turbo moves freely (it does). Reassembled, lots of copper grease. Took the whole thing to the repair shop and got following results:

Saab dealer confirmed base boost 0,24 bar, max boost 0,6 bar (should be

1,0 by the way).

But they note - no leaks in intercooler circuit, no engine error codes, exhaust pipe was disconnected to check turbine (they say it's OK), wastegate examined (OK as well). Hoses checked for leaks (none).

The only thing they could not do was check the solenoid valve, nor did they have a spare with which to test the car. So they could not reach a conclusion, but said they suspect the solenoid valve. Of course I ordered one and it will arrive on Tuesday (at EUR 40, it's a cheap test), and I will take 5 minutes to install it at home.

So until then, I am wondering whether all these symptoms really *do* point to a failed solenoid valve.

I'd thought that the *absence* of excessive boost upon disconnecting the wastegate pipe from the solenoid valve would have indicated a fault elsewhere.

What do you think?

TIA, Robert Gothenburg Sweden

Reply to
Robert Brown
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Hi Robert,

This should eliminate the solenoid valve as a possible failure, since you've effectively removed it from the control loop.

My money is on a leak - you didn't mention whether they checked the dump valve (turbo bypass valve, plastic thingy). This is a very common source of trouble. To check, locate the valve, follow the small tube to where it joins other tubes, disconnect it at that end, and suck on it. If you pull air, the valve diaphragm is holed.

I just can't see how it could be that, given how you've tested it.

Symptoms certainly could be bad soleboid valve, but your test says not.

Agree.

Reply to
Grunff

Hi all,

(I am responding to my original post; pls excuse this, if you're sensitive to this kind of thing. Grunff's initial reply omitted here 'cause I can't find the text to it)

After almost two months of having the car in and out of the Saab repair shop, I'm pleased to say we finally got the problem solved.

I'm posting this in case any of you out there get a similar problem, and need some ideas on how to diagnose. Here's a short version of the events:

  1. Got good advice from Grunff on how to test the dump valve. As a result, I was enable to eliminate this as a cause of the problem. Now onto the more expensive stuff ;-)

  1. Into the Saab workshop and tested a new solenoid valve. Gave no improvement. BTW the valve costs about EUR 200, not EUR 40 as previously advised.

  2. Into the Saab workshop again, since they claimed that water pump was making enough noise to trigger the knock sensor and thus reduce boost. Paid for new water pump and labour. Boost problem remained unresolved (water pump was probably OK after all)

  1. Saab in the meantime claimed that our aircon compressor was shot, so we booked the car in and got that replaced. That cost some money. AC doesn't work any better, so the old AC was probably OK too.

  2. Back to the boost problem. Sent the car to Saab workshop again since Saab claimed that worn out turbo was the cause of the lack of boost. Car returned after three days. Boost problem remained unresolved, so our old turbo was probably OK and didn't need to be replaced after all.

  1. Into workshop for final time (we hope). Replaced exhaust system. Got all boost back. Saab then asked us to pay for the new exhaust system(!) Of course we countered by demanding that they refund us the cost of the turbo change, whereupon the confessed to having botched the diagnosis job and "let us have" the exhaust pipes for free . . . :-|

At this point we were just too fed up to argue so we just took the car home and swore we'd never buy another Saab. The Saabs are very nice to drive (we've had Saabs since 1987), but just hope you never have to get one repaired in Sweden (if the next generation Saabs are indeed Subarus them maybe we'll get their Japanese service network, which is said to be excellent BTW)

Luckily our auto insurance has an engine failure clause (motorhaveri) that reduced our costs somewhat, but the dealer sure made a pretty penny on all this.

What's kind of frightening is that if Saab had made a *correct* diagnosis to begin with, we would've only have had to pay for a new exhaust pipe. Instead, we have all sorts of nice new expensive shiny bits bolted on to our engine that we really didn't need, and a perfectly good turbo unit sitting in our garage. Will make a good paperweight, it's as heavy as hell.

Anyhow* - excuse the sidetrack - the moral of the story is that a lack of boost can be due to a blocked exhaust system, so next time you suffer from lack of boost, and once all the obvious items have been checked (wastegate, solenoid valve, charged air system leaks, knock sensor, ask your mechanic to check the exhaust pipes.

BRgds, Robert

Reply to
Robert Brown

Glad it's sorted - but what was it blocked with? The only blocked exhausts I've ever come across have been collapsed catalytic convertors.

Reply to
Grunff

Yeah - that's what the workshop claimed - that the cat had fallen apart. But I always thought that the cat is the *first* box after the turbo. What's strange on this repair job is that this "first box" is the only one *not* replaced. Everything aft of the first box is completely new.

As I'm very wary of this repair shop, I'm beginning to wonder if they could have left the bad cat in, fished out the bad pieces through the back, then bolted on a new exhaust system. Result: flow re-established but no emissions control?

This theory fails, of course, if it is the second item after the turbo that is the cat (see separate posting this evening).

/Robert

Reply to
Robert Brown

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