[johnc]

I have a slight oil leak which appears to be coming from the filler cap, i had a volvo once and this spelt doom and gloom. But i read somewhere that theres a part failure which can cause this on 9000's but i can't find it. any ideas guys?

 

[Derek]

Oil leaking at the filler cap is usually indicative of worn pistons/rings/bore causing excessive crankcase pressure. However, first check that the various crankcase ventilation hoses are not blocked and,if I remember correctly, there is a valve in one of them which it is possible to fit the wrong way round.
Best also to check that the sealing washer in the filler cap is intact and that the cap is seating correctly.

 

[Julian]

As Derek says, check the breather hoses. The valve Derek refers to is the PCV valve, which is a one way valve fitted to turbo models that prevents boost pressure from pressurising the crank case. Failure of this valve often sends oil up the filler pipe with sometimes spectacular effects

The valve is located at the end of about 50mm of vacuum hose, on the twin outlet plastic fitting on the back left of the cam cover (when viewed from the front of the car). The other end is connected into the rear left of the inlet manifold with further vacuum hose. To test, remove the PCV valve and blow through it gently. You should be able to blow through it in the direction towards the inlet manifold, not so in reverse. Be careful when removing it as the plastic gets brittle with age. Replacements are only about £12 from Saab - a lot for a bit of plastic but not a lot for a Saab part

 

[johnc]

thanks, I think then, that this is an indication of something wrong futher up the line, I've been having problems with the turbo overboosting and cutting out, i'll start there at my local specialist. thanks again.