air leaking during boost test

[baxsom]

is it normal for air to come out of the large pipe in the valve cover
if i close it off and do a boost test
i get no leaks

if i open it and do the test air pours out of it
right now there is a small air filter coming off of a hose on the nipple
should i cap it off

here is a pic showing where i am talking about

 

[siueclipse]

i dont have a very good answer for that. im interested to see what the answer is. massive air flow shouldn't be coming out of that.

 

[baxsom]

yeah without taking the red air filter pictured off and capping the nipple
it wont even hold pressure

it holds boost and vacuum when running but if you put finger over the hole and pressurize the system it holds the air in
then if you take your finger off
whoosh all the air comes out

 

[TimG]

I don't know what that is on the 420a motor but it looks like the crankcase vent intake. Umm... nothing should be rushing out of there. A bit is ok, but the less the better. It means air is leaking out of your combustion chamber via valve guides or pistons. If you do a compression test, you should be able to see what I'm talking about. Either your engine is somewhat on it's way out or your PCV valve is broken.

 

[GotSome-Turbo]

Could it be emissions related?(not sure if this could cause it but it is fesible)
Also any check engine lights/codes?
Not really sure on but TimG's post sounded the most likely(and unfortunately the most expensice to fix)

 

[baxsom]

no engine codes
and if it is piston rings i am going to be pissed
i put too much cash into rebuilding the engine less than a year ago
i will put a new pcv valve on and try that

 

[siueclipse]

If you have a lot of oil vapor coming out of that hole, then more than likely your rings are ####ered. Good luck,

 

[TimG]

no engine codes
and if it is piston rings i am going to be pissed
i put too much cash into rebuilding the engine less than a year ago
i will put a new pcv valve on and try that

To test the PCV valve, take out the thing out and clean it. Put your lips on the vacuum line end (not the side that screws into the valve cover). Suck in. If air is sucked in, that is normal. Now try blowing into it. If it doesn't allow you to pass air through it, then the PCV valve is fine.

 

[baxsom]

i tried the air thing

pvc was bad
it allowed air in just fine from the VC to the intake
and even though the check ball would close when i blew from the intake to the valve cover end air would still get through
so i replaced it

i also checked the air filter coming off of the valve cover vent and there was no oil in it
it has been on for a year now so i think the rings are ok

i would hope so
the engine was built less than a year ago