Mattlws6

Seems like every Evo I have looked at including my friends Evo's all puff air from the oil fill cap at idle. If you remove the cap to see if there is blow by to my understanding on ANY engine there should not be air puffing out a foot above the hole. In fact it is a pretty clear test on LS motors after a hard pass to see if you hurt a hole or not.

I know the difference between normal windage and compression entering the crankcase. This puffing I am referring to is pulsed with the engine. I have searched/ asked around and gotten mixed answers. Like I said to my understanding that means 1 or more cylinders are hurt or getting tired.

I guess the question should be does anyone else's car not puff air at idle when the fill cap is removed? This could just be what they do and I am too critical but I do not want to buy a car with a tired motor.

Thank you all.

evolve_VIII

iTrader: (11)

Is it a built motor?

Paul Walkin

iTrader: (6)

4G63's don't vent well in stock form, this issue is exacerbated with a built block.

I don't think you'll find mentionable blow by from the oil cap with the engine properly vented.

evolve_VIII

iTrader: (11)

https://www.evolutionm.net/forums/ev...eo-inside.html

mrfred

iTrader: (50)

I'd say that blowby at idle is normal for a built motor. I never checked my motor when it was stock.