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4d56 blow by but good compression
Posted: Thu Aug 02, 2012 10:36 pm
by wildplumdx
so my 4d56 has massive blow by as much as the dipstick pops up and if you take the oil cap off it sounds almost like a car exhaust spiting oil etc, but i have 420psi over all cylinders at 10 cranks? and the factory specs i could find say 384psi but not sure what cranks...
i have more compression than i should
Re: 4d56 blow by but good compression
Posted: Fri Aug 03, 2012 9:47 am
by Swamped
No idea about the mitsi motors (least thats what I think I remember this is
)
but...
Have you got a blocked crank case breather? Wouldn't take much to lift the dipstick out if thats the case. And I've not run a motor without the oil cap on haha. makes a mess but you could be hearing poor valve clearances or similar with the lid off? Could see what a top tune did for it?
If you can't figure it out a leak down test may give you more info.