I am doing a boost leak test to diagnose a slightly high idle.

I put about 8psi connected to my turbo and there is air coming out of my valve cover on the driver side nipple that normally connects to the turbo inlet pipe (I have a breather filter on that nipple.)

If I pull the dipstick out, there is also air coming out of the dipstick tube.

Whats going on here? PCV issue?

 

update - I just removed the vacuum line that runs from the intake manifold to the valve cover on the back passenger side of the valve cover. There is still air coming out of the dipstick and both nipple's on the valve cover.

It's not lots of air but is it even supposed to be there?

 

blow by from shot rings?

 

I suppose so but I am really not sure.

I have done boost leak tests before this and I have never noticed this.

I recently installed a ported TB and IM, I also remove the EVAP solenoid and EGR system at the same time.

I think it is more likely that it is related to this than blown rings.

What else could it be?

 

that's not blow by...but i dont know what the hell that is....i can tell you one think top level did a boost leak test on my car and the air came out of the bottom right hole on the valve cover.....they sealed it up .........for me

 

do a compression test.

 

I will have to find some one with a compression gauge and do a test.

Man this sucks.

Please keep the idea's coming.

 

ya cant hurt^^^^^good luck dont stress it's proably nothing......

 

The car runs fine, aside from a slightly high idle. Would it still do that with bad rings?

 

yes,stock blow off valve?

 

There are only two vent lines that go into the crank case volume; the hose between the intake mani and the valve cover, and the hose between the intake tube and the valve cover. If neither of those lines are pressurized, then the only other choice is past the rings.

I've never done a leakdown test, but I wouldn't expect the rings to seal perfectly even on a tight motor.

 

Just remembered that it could also result from blowby past the valve guides.

 

mrfred is right, It's probably getting past the valve guides. I did a leak ckeck on mine and had the same problem. However, according to the AEM, when the car was on the Dyno it held boost across the powerband to redline and never dropped. With c16 we went to 32lbs and it still held the boost with no problem. When the car is off the valve guides don't seal all the way and the pressure vents through the valve cover and dip stick, at least that is what happened in my case.

 

yea that is what I was thinking was the problem. That or either the seals in the turbo are allowing air to get into the oil and up to the valve cover. The car drives fine so I don't think there is anything wrong with the rings.

 

I guess that could make sense... but if it was the rings it's not going to drive funny either so you can't rule that out based on driving.