ka-t rediculous blow by out of valve cover.

[sil80forme]

so i am almost positive that its bad but what is the cause and how do i fix it....

[sunnys14]

You blew your piston rings. Rebuild time.

[rappadan]

blow by is caused by excessive combustion pressures in the crankcase meaning combustion pressures are "blowing by" the rings into the oil pan. More than likely your rings are shot, my Sr had crazy blow by, filling up the catch can in like 20 minutes of hard driving. I had a broken ring on one cylinder.

[S14DB]

At idle or under boost?

At idle, dead rings.

Boost, bad PCV.

[89singlecamnoob]

You blew your piston rings. Rebuild time.

now me and the mad scientist gotta rip apart the block and replace the piston rings you fried

[Z U L8R]

typically the problem's not just the piston rings, especially on a ka...whoever owned it previously probably had the boost up too high and was eating away at the side of the piston till finally it cracked/melted a ring....that little sand in a tin can noise is called detonation lol.

good luck man,
Dave =]

[2_fast_240]

You shouldnt have anything coming out of your valve cover. Air is suppose to come in through the top, and out the bottom. When turboing a ka, the stock pcv system needs to go.
This probably isnt your main problem though. Just wanted to let you know. Go over to ka-t.org and search pcv and theres a big long thread about the proper way to run the pcv on a ka-t. Theres still no definate way of doing it however.

[Z U L8R]

ka's have an internal oil separator in the timing cover. the pcv valve screws into that, and gets vacuum from the intake manifold. the nipple on the valve cover runs to your turbo's "intake" snorkel/pipe that has the air filter on it. in order to keep oil/crap from being ingested by the turbo, you put an oil catch can in line , in between the valve cover and the intake. the motor relieves the positive crankcase pressure under vacuum via the pcv valve/intake manifold's suction, under boost the pcv valve closes, so under boost the suction created by the turbo via the intake snorkel is what relieves the crankcase pressure when ur boosting

in any case, we all know ka pistons are probably the first thing to go when u boost those suckers. however, before you do anything else. just do a compression test. if you got 3 cylinders getting ~150psi and one giving u 100psi then you know that cylinder is the one that took a shit. if you have even compression on all cylinders, then you may have some hope =]

Dave =]

[dftsilvia]

yah this happened to my ka-t too. it ran good then just didnt run lol ended up being cooked piston

[UNISA JECS]

You shouldnt have anything coming out of your valve cover. Air is suppose to come in through the top, and out the bottom. When turboing a ka, the stock pcv system needs to go.
This probably isnt your main problem though. Just wanted to let you know. Go over to ka-t.org and search pcv and theres a big long thread about the proper way to run the pcv on a ka-t. Theres still no definate way of doing it however.

Its possible to have air come out the valve cover during full throttle situations and even at cruise and idle if your sufferening from excessive blow by, and more so when you are turbo because you are more likely to get more blow by do to the fact of more air forced into each cylinder. But thats the stupidest thing I ever heard you dont eliminate the PCV system, you'll contaminent and sludge up your system more rapidly with no PCV system, not to mention do more damage to your seals in the engine, mainly the front and rear main seals. Instead make sure its working at 100% and rerouted correctly if you went turbo (this simple means extend the hose from teh VC to the turbo intake (between the MAF and Compressor housing).

ka's have an internal oil separator in the timing cover. the pcv valve screws into that, and gets vacuum from the intake manifold. the nipple on the valve cover runs to your turbo's "intake" snorkel/pipe that has the air filter on it. in order to keep oil/crap from being ingested by the turbo, you put an oil catch can in line , in between the valve cover and the intake. the motor relieves the positive crankcase pressure under vacuum via the pcv valve/intake manifold's suction, under boost the pcv valve closes, so under boost the suction created by the turbo via the intake snorkel is what relieves the crankcase pressure when ur boosting

in any case, we all know ka pistons are probably the first thing to go when u boost those suckers. however, before you do anything else. just do a compression test. if you got 3 cylinders getting ~150psi and one giving u 100psi then you know that cylinder is the one that took a shit. if you have even compression on all cylinders, then you may have some hope =]

Dave =]

Well said, that how the system should remain.

[e1_griego]

The valve cover breather draws in fresh air, it doesn't evacuate air (well, it's not supposed to).

A lot of ka-t setups bypass the pcv and run the oil separator to a vented catch can.

Alex

[UNISA JECS]

The valve cover breather draws in fresh air, it doesn't evacuate air (well, it's not supposed to).

A lot of ka-t setups bypass the pcv and run the oil separator to a vented catch can.

Alex

It does work that way, but not always heres a scenario which it will evacuate air from the VC via the sucktion provided by the turbos compressor intake (this is even true for NA at full throttle).

When boosting 7 psi (thats just a randon number) the PCV will close/shut not allow boosted air pressure to fill the crankcase.

Now why im against putting breather filters in the VC:

1) Simple, you disable the sucktion provided by the turbo to the VC to scavange blow-by gasses from the crankcase during full throttle situations when the PCV is disabled/not working.

[240sx_LE]

now me and the mad scientist gotta rip apart the block and replace the piston rings you fried
gotta have the f&f qoute on that one

[bizzyj83]

common mistake..
did you route your pcv to the pressurized air?

if so.. thats putting compression in the crankcase.

if not.. rings.

[S14DB]

common mistake..
did you route your pcv to the pressurized air?

if so.. thats putting compression in the crankcase.

if not.. rings.

That's what the PCV valve is for. To allow the crank case to vent but to seal it off from pressure(boost, backfire).

[UNISA JECS]

common mistake..
did you route your pcv to the pressurized air?

if so.. thats putting compression in the crankcase.

if not.. rings.


That's what the PCV valve is for. To allow the crank case to vent but to seal it off from pressure(boost, backfire).

I think what bizzyj83 was saying is that if this guy is boosted you have to reroute the VC hose to an area between the compressor and MAF. If you are boosted and you leave the hose connecting just before the TB like it was when you were stock NA you well infact pressurize teh crankcase = NO GOOD.

[sil80forme]

wow. thanx u guys definitly helped out a lot. I won't know exactly what's up till I do a comp test. but to be honest. even with the oil comin out of the valve cover she is still very stong. if I had felt a loss of power I would of first thouht rings with all the blow by.. I am hopin it just has to do with thw pcv. I will keep u vguys informed

[rappadan]

i had a broken piston ring and still had plenty of power, didnt notice a power loss at all. So it could still be rings

[nismo tuned s14]

this is how i blew my engine.

i noticed oil was coming out of my valve cover.
i replaced my pcv valve. it didnt fix it.
i bought an oil catch can. i went to test it to see if it worked.
i filled up the catch can after about 15 seconds of flooring it.

so i was doing 100mph+ w/o oil. im pretty sure i blew a ring. after doing a compression test one of the cylinders read 0 compression.

[sil80forme]

this is how i blew my engine.

i noticed oil was coming out of my valve cover.
i replaced my pcv valve. it didnt fix it.
i bought an oil catch can. i went to test it to see if it worked.
i filled up the catch can after about 15 seconds of flooring it.

so i was doing 100mph+ w/o oil. im pretty sure i blew a ring. after doing a compression test one of the cylinders read 0 compression.

nice now i got something to look forward too