[Peter Rawlinson]

Been reading around a little on dump valves and was wondering if ther was a way to check if the original Bosch item on my car was working properly.

Currently experiencing some "underpower", possibly due to a need for new air filter and is due a oil & filter change and general check on plugs, etc.

Also, when doing the exhaust mainfold gasket I noticed a small amount of partly dried oil in the bottom of the intake side of the turbo. Should this be a big worry? car is 2.0 LPT with only 56k miles on clock & FSH.

If any other common causes of a general (not sudden) lack of power above 3krpm, then I would be glad of a few pointers on what to look for (e.g should I get a pressure gauge on inlet manifold to check boost, etc).

TIA,

Pete

 

[Andy M]

hey efcbluepete
Sounds like you and I are in the same boat my 2.olpt was reacting that way too, but my fuel economy has plumetted too its just had a full service. As for the dump valve mine arrives on friday with any luck so I'll post and let you know if its done the trick!!

Good luck on your quest for power

Oh and if this car is design like my last turbo you'll find that they're designed to burn some oil to keep the turbo lubricated and cooler, helps them last longer.

 

[Andy M]

fitted the dump valve today although they supplied the incorrect pressure spring(waiting on correct lower pressure spring to be sent on monday) And it did work even though the spring was so strong I got no noise. It made the car much smoother to drive and it felt stronger from low in the revs to redline.

Glad I got one now

As for checking your original can't really advise you on that but make sure all pressure hoses related to the actuator/dump valve and apc are all ok no cracks leaks etc.
A friend told me he removed the lower hose from the dump valve but not for long that way it could be heard better to check for leakage and to check it was opening etc. Not 100% sure I'd advise this but it did the trick for him but he didn't drive anywhere with it off just light throttle while stood running...

Hope this helps in some way

 

[Peter Rawlinson]

Cheers Andy, will try to have a look one lunchtime this week.

See yours is same era as mine so will have same plumbing.

What dump valve did you get, forge, bailey..., atmospheric or recirc?

Pete

 

[Andy M]

Cars may be same sort of age but yours will have an intercooler as mine does'nt(yet).
The dump valve is forge atmospheric fmdv004 with blanking plug(supplied) but as its an LPT you will need to call and specify a green spring as I was supplied with a blue and it wouldn't release the pressure it was to strong.

http://www.forgemotorsport.co.uk/saab.asp?...product=FMDV004

I actually called directly and got a small discount cost about 90quid


good luck