I have a cracked evo viii valve cover that I want to replace.

The only decent priced one I can source does not use the pcv valve I am currently using.
It uses the USDM one (the left one on the attached image)

My questions are,
Is it okay to use the usdm pcv valve if I get a valve cover that fits it?
and what are the differences between the two (apart from how they look)?
and why would mitsubishi use two different pcv valves for the jdm and usdm models?

thanks in advance

 

I am not sure why they would use two different PCV valves for different markets. Probably something to do with emissions. They are both just check valves. They both function the same, so there should be no issue with interchanging them.

 

Some (stock and metal) PCV valves, you can blow through both ways.
No good for a turbo.

The proper ones only flow one way.
The parts shops won't have a clue.

Easy to test........if you don't bother........you'll never know.

 

Mine blows both ways.. any suggestions on what to do?

 

Replace.

The purpose of the valve is so you don't pressurize the head under boost. Think about what that is actually doing and you can see why it's not good.

 

a brand new one would only blow one way right? (Away from the valve cover only)
so that means mine is broken?

 

Yes, a working PCV valve for the Evo should only allow air to flow away from the valve cover.
Any air coming through the PCV under boost is essentially a boost leak. That air is not going into the combustion chamber, it's going into the head and pressurizing the head does not help with power delivery. Or anything, really.

 

never mind,
I was testing it wrong. I was blowing and then pulling.
Instead of chucking it and blowing one side
thanks anyways man. Atleast im sure I have a working pcv valve.

but i still got a ton of blow by for some reason. Need to do a compression test soon.