boost leak test problem

[turbo4awd]

So i performed another BLT since the first one i found my intake manifold was cracked.
So we pressurized the system and the bov flange was leaking fixed that.
The issue is when the system was pressurized and i pulled the coolant overflow lid you could hear air leaking in the resivor.
There is not coolant in oil no oil in coolant and leak down test was perfect. not sure if this is normal or not

 

[Calan]

Sounds like you could likely have a blown head gasket. Air is most likely leaking into the crankcase via the PCV valve or past the valves/rings, and then into the coolant passages in the block at the HG. It could also be leaking directly into the coolant from a break between the cylinders and coolant passages.

Do a leak down test to help isolate it.

http://www.dsmtuners.com/forums/articles-engine-fuel/336535-do-you-have-blown-head-gasket.html
http://www.dsmtuners.com/forums/articles-engine-fuel/338152-compression-leak-down-testing.html

Edit:

Doh! Totally missed the part about already doing the leak down test.

That should have found it...are you sure it was done properly? Are you sure you're really hearing air in the coolant tank and not from somewhere else nearby? Any bubbles?

 

[turbo4awd]

Leak Down test was perfect. Is there anyway air could go from the tbody coolant lines. Im not using any coolant, the car isnt smoking.
Man this crap is confusing

 

[Calan]

There is no way for air to get into the coolant, unless the coolant can get into where the air is coming from...at least not in the intake track. Even if boost was getting pushed into the coolant from somewhere in the intake, then logic says that coolant should also get sucked back into the intake under vacuum conditions.

This one has me stumped, unless I'm just missing something.

Did you do the leak down test per the instructions in that article I linked to? (just trying to eliminate possibilities).
What does a compression test show?

EDIT:

The more I think about this, the more it doesn't make sense. If you have a working radiator cap and the coolant system is hooked up properly...unless the engine is at operating temperature air shouldn't even be getting to the coolant overflow; into the radiator maybe, but not to the overflow. If you pull the radiator cap during the BLT or leak-down test, do you see air bubbles in the coolant sitting in the hose?

 

[turbo4awd]

im stumped aswell i just put a new mishimoto rad cap on. leak down was performed correctly. Im lost but deffiinatly can hear air leaking into the overflow bottle. Car runs perfect i couldnt ask for better, like i said before no smoke out the exhaust or anything.
I was saying from the tbody because there are the 2 coolant line coming off of it??? if my head gasket is out im pulling the entire motor to build it,

 

[Calan]

What does a compression test show?

 

[turbo4awd]

161 or 162 across

 

[Calan]

If you pull the radiator cap during the BLT or leak-down test, do you see air bubbles in the coolant sitting in the hose?

Pull the overflow hose (at the radiator cap) and see if you still hear air in the coolant reservoir.

 

[turbo4awd]

Ill retest it today sometime and ill pull the rad cap and watch for bubbles

 

[onefast2gdsm]

Mike the car was kind of hot when we tested it. Call me later and we will do another test tonight
After the cars cooled down

 

[turbo4awd]

good deal Maybe we can toss that shifter and kit in too

 

[Talipse96]

Put the guage on the coolant line and pressurize it a bit, then do a BLT, that should put pressure on the coolant lines if their is a leak, read the coolant pressure guage and see if there is any extra pressure.

 

[turbo4awd]

basically we were just going to pull the rad cap during the test to see if there were bubbles in the coolant.

 

[onefast2gdsm]

ok we pressurized the system to 22psi and nothing is coming out of the expansion tank. No bubbles from the radiator cap. There is air coming from the valve cover, and it bleeds down to 15psi in about a minute.

 

[turbo4awd]

Anyone know why there would be air sounds coming from in the valve cover. We did not set the engine at the proper timing marks before the test so it may be possible that a valve was not completely closed.

 

[Calan]

Anyone know why there would be air sounds coming from in the valve cover.

Air is leaking into the crankcase through a worn PCV valve or past the valves/rings, and...

We did not set the engine at the proper timing marks before the test so it may be possible that a valve was not completely closed.

You answered your own question.