High Crankcase Pressure

[Jcgonzal]

I posted this in my intro thread, but thought I’d make a separate post to try and figure this out. I found out I have pretty high crankcase pressure after chasing a bunch of oil leaks for months:

https://youtu.be/re0UeI7A2oc

So I took it to a shop in Iowa that is Saab specific, and they told me that the pressure was “completely normal” and that I shouldn’t believe everything I see on the internet. They just wanted to replace the head gasket to stop the leak there; though I’ve had no mixing of gas/oil and no overheating issues whatsoever. My thinking (correct me if I’m wrong) is that fixing the leak at the head gasket will just seal the engine up even tighter and the pressure will just wreak havoc elsewhere. Should I really not be concerned with that much positive crank pressure?

[Mjollnir81]

There is a check valve near the throttle body that fails and will cause oil leaks. About the size of an American quarter in diameter. I’d replace that and redo the valve cover gasket/cam seals (if needed)and you should be good to go.

[Jcgonzal]

There is a check valve near the throttle body that fails and will cause oil leaks. About the size of an American quarter in diameter. I’d replace that and redo the valve cover gasket/cam seals (if needed)and you should be good to go.

I’ve actually done all that. I replaced the entire PCV system, including that check valve. There’s a chance the valve was bad from the factory, but I’m not 100% sure how to check it because it’s apparently epoxied to the hard plastic hose that I replaced. I could completely disconnect the hose, just a bit of a pain since one end is connected to the oil trap on the back of the motor.

[Jcgonzal]

If someone could perform a similar test with their (healthy/non-leaking) car to either confirm or debunk the fact that it’s normal to have this much crank pressure, I would love that. Forgot to mention it’s a 2006 9-5 wagon with the 2.3T engine.

[Mjollnir81]

If it is a head gasket the leaks won’t get worse. Combustion pressure is pressurizing your crankcase if it is leaking.

Doing a compression test will verify that. You can buy a compression tester on amazon or HF and try it yourself. Just pull the fuel pump relay and crank the engine over.