Ok, so I managed to figure out the part number and got a replacement one. It was a used part however but it was cheap so worth a punt. I installed the replacement BPC valve and it turns out the one for the small turbo was the problem. Once the new one was installed the power was back. We took it for a spin down the motorway and it was great, with one exception. When accelerating hard in 5th or 6th gear he was getting the restricted performance message. I just put it down to the codes not being cleared so we did that once we stopped and I said to him to see how he gets on over the next few days.

Haven't seen a lot of each other since as he's a busy man, however he's away on holiday at the minute and he's left the car with me to look after. I took it out for a spin the other day and I noticed it's low on power again like it was before. With the new part being a used one I can appreciate that it might not be reliable and i'm happy to source another one. However before I throw more money at it I was wondering if there is something else that can cause these to fail?

If it helps, I also notice if you try and accelerate hard like for overtaking on the motorway the car tries to pull back on the power which is scary when trying to manoeuvre into fast moving traffic. You have to reduce the amount of throttle to try and gain some power back. Perhaps an over boosting issue?

 

I'm currently having a similar issue. Only started a few days ago, put my foot down to overtake and the 'limited performance' message appeared. Significant loss of power and the turbo would only boost to about 20%.

Pulled over, switched engine off and back on and ran like normal until I got to about 2750 revs in 4th. Then went into limited performance again.

When I got home, I found code p0234-5b which is a code where there is less boost than expected in the system I believe. From what I read about this there's a few possible causes. People advise it could be the maf sensor, map sensor, egr valve clogged, clogged or split hoses, leak from the intercooler or (dread the thought) mechanical failure of the turbo.

I Checked for split hoses, changed both boost solenoids (with scrappy replacements) and cleaned map sensor but problem persisted. Egr was cleaned about 10 months ago so I'm not too concerned about it but may check that soon if I don't get anywhere. I was fearing a new turbo or intercooler was needed but today I have checked the hoses again and found a large split in the intercooler to throttle hose, no idea how I missed that! I've taped it up and now have full power from the turbos. Unfortunately the tape I have is just not strong enough for me to give it a long drive to test thoroughly so I am waiting on a new hose to see if that will nail it. Fingers crossed!

If you remove the thicker vacuum pipe from the boost solenoids and suck on them, you can check that the two diaphragms on the turbos are moving the control arms OK and can also confirm that the vacuum pipes themselves are not split or blocked. If you have a tech2 you can check that the solenoids themselves are working by opening and closing these with the engine running.

Make sure you've no split pipes between the air filter, intercooler and throttle body. I'd then recommend removing and carefully clean the map sensor (or replace) and clean the egr valve.

Next step would possibly be testing the pipework and intercooler for leaks with a pressure testing kit.

If that doesn't show any issues then it may be worth replacing the maf sensor before biting the bullet and accepting that there may actually be a fault with the twin turbo unit 😬

 

Hi I am newby to the Saabscene - my 93 Areo TTid (2008) is having a similar problem in that car on gives 50% boost. You mention the Boost valves but I can only see one which appears to be at the front of the engine. But seen others talking about 2 valves. Could someone advise as to where the second one is located as I am wondering if I am going mad and not seeing the obvious. Any advice would be appreciated as don't wont my beloved car to go to the Saab cemetery.

 

The WIS information shows them side by side however on mine they are back to back.

If you check behind the boost solenoid that you can see, there should be another one there hidden above the radiator. There's 2 bolts on the panel above which you can remove and, if like mine, they will be bolted back to back on a metal plate.

 

The ones I looked at new were on ebay for about £50 each but I managed to find a 1.9 ttid in the scrap yard and got 2 of them with the boost hoses for £6. It appears to be the exact same boost valve on all the saab 9-3 1.9 tid's (though they only use 1 boost solenoid) and all the late model vauxhall 1.9 tid vectras also use it (but will also only have 1 fitted). Try searching ebay for 'Z19dth boost solenoid', it will show you some options for a new one.

I swapped both, and tried varying combinations in case one of the 2nd hand ones was also knackered, none of them made a difference or performed differently - turns out they were all working and I've now confirmed that an air leak (split hose) between the intercooler and the throttle body was the problem.

Hopefully a new boost solenoid helps you, I've not come across an issue where I'm only getting 50% boost. On limited performance Im normally restricted to about 20% boost. There was also a time i had 100% boost until 3000 revs then there would be no boost - that was caused by me accidentally knocking off the vacuum pipe for the larger turbo boost solenoid.

 

Ebay - Pressure converter,turbocharger for VAUXHALL,OPEL INSIGNIA PIERBURG 7.03652.01.0 | eBay

Neo Brothers have them (as a recycled/2nd hand item) for £36. I've always been happy with my parts from neo brothers.

 

Saab part number is 55573732

 

I have the same problem on an 08 ttid i just bought! Went well, but not a lot low down. Noticed the vacuum pipe to the engine side solenoid was off, and if connected it pulled the actuator right in and kept itere, even if revved. Also if connected the car goes like a snail, no power atall. Disconnecting the pipe leaves the car driveable, but obviously only on the big turbo! Goes like a tid then! Does anybody know how to check the electrical side of the valve, without a Tech2?