ShapeGSX

The PCV valve only opens when the intake manifold is in vacuum, or if for some reason your crank case pressure is higher than the intake manifold pressure under boost.

The crankcase vent should vent extra pressure when under boost, though.

And when not under boost, air will flow from the crankcase vent, through the PCV valve into the intake manifold. If you have a filter on the crank vent, you will let unmetered air into the intake manifold.

Incidentally, I just zip tie the dipstick to some nearby piece so it doesn't blow out. It just happens once in a while. It is a 4G63, it is supposed to happen.

ogvw

iTrader: (4)

Truer words have never been spoken........ good post Josh

Smogrunner

iTrader: (5)

It turns out that this malady is more common than I thought. One of the the OTC evos (not Shiv's) blew their dipstick out and actually caused a car to skid off the track!

mikesevo8

I had always thought that the valve cover tube should remain connected to the intake even
when you put in a catch can.
The reason is that it is desirable to have a negative crankcase pressure if possible.
Positive pressure would be bad, yes ???
In the perfect scenario, the rotating mass will have the least resistance spinning in a vacuum.
So pulling out pressure is a good thing.

n00dle

iTrader: (4)

I've had no adverse effects with venting to atmosphere. Connecting the hose back to the intake would induce "sucking" more oil than usual with help from the turbo. This is with the breather hose on the valve cover. I didn't bother with the PCV. Not worth the trouble for that one IMO.

stimpy

iTrader: (3)

Now if the opposite problem occurred, where the PCV was stuck open, the pressure from the intake manifold could pressurize the crank case and create a similar effect?

-Jon

boostedwrx

iTrader: (27)

lol thread from the dead

hks-evo

iTrader: (2)

samething happened to me on the dyno sucks but i learned from this

Liberoz

Resurrecting the dead again lol

I've had same issue but oil through oil cap when under high boost on the circuit, & dip stick was fine, Solution = looking at a hollow bolt into balancer shaft alignment hole in the block with thick i/d vacuum hose and then T into just before catch can, whilst leaving stock rocker breather as is.

Seemed fine once 3psi was removed of boost setting but the aim is to run that extra 3psi and more if possible.

Well see how it works! if its sufficient to relieve the pressure enough and let rocker head oil return into the sump whilst maintaining high boost constantly for around 8minutes solid, the time it takes to run 5 timed laps at our local track.