Boost leak test, bad turbo seals? air coming out of dipstick?

[dragrush]

I did a boost leak test on my turbo inlet and I hear bubbling when I take the oil cap off. I then tested it at the licp, the bubbling stops but there still is air coming out of the oil cap and dipstick. I blocked off the pvc valve, and got same results. Compression test shows 170 171 172 171. I dont build boost while driving. No bubbles in the coolant. Im guessing the turbo seals are bad. Will the air coming out of the dipstick and oil cap be due to bad valve seals? What does this sound like it can be? Help appreciated

 

[dragrush]

ok im just updating this since i havent for awhile. i still yet to find the problem since i am replacing the rear main seal and decided to get a shep tranny while the trans was out, so it set me back a little. But my rear main seal has popped out and I was wondering if it is due to pressure in crank case. Could this be where my boost is going? If I have less than 10% leak down on a cold engine is it possible for boost to still be getting in the crank case enough to pop the rear main seal out? I also still hear hissing coming from the dipstick and oil cap when removed when doing a boost leak test. Is this normal for having less than 10% leak down? Only about 100 miles on engine so far (still breaking it in)

 

[Burg2DaWorld]

Not to bring up such a OLD post but I'm having similar problems currently. Did you ever find the problem

 

[DigORdieTSi]

When you boost leak test a car from the turbo, any intake valve that is open is going to allow those cylinders get pressurized. Even when piston rings are in good shape they allow some blow by into the crank case. That air is then escaping up through the oil drain backs in the head and out of the valve cover, where you can hear oil bubbling. Blocking off the PCV vent is a BAD idea. If you build too much crank case pressure you could push out oil seals in the engine and cause leaks.


but it was a decade ago