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Forum nameTurbo/Nitrous Tech
Topic subjectPositive Crankcase Pressure, how to eliminate?
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=4563
4563, Positive Crankcase Pressure, how to eliminate?
Posted by DarkOne, May-03-01 09:12 AM
I'm getting some seriously positive crankcase pressure under boost, and i was wondering if anyone knew a way to eliminate it? The pressure has started to force a very small amount of oil past my valve cover gasket and i wonder if there is a way i can eliminate or at least lessen the pressure.
The PCV valve flows from the valvecover to the intake pipe, which is fine under vacuum, but once boost is built, with the pressure on both sides of the valve, it just builds up inside the crank case. What can i do? What are my options? Will it affect anything other than emissions if i vent it to atmosphere, or perhaps rig a boost activated switch that will vent it back into the intake pipe under vacuum, and to atmosphere under boost?

Tips, advice, suggestions ? ;-)

______________________________________
-Dino Yancey
I'm so bad, i should be in detention.


Get the Mitsubishi Technical Information manual for the 95-99 Eclipse HERE!
http://www.heavenz-not-0verflowing.com/files/dsmmanual.pdf
4564, RE: Positive Crankcase Pressure, how to eliminate?
Posted by Hoot, May-03-01 09:55 AM
two words...

catch can


4565, RE: Positive Crankcase Pressure, how to eliminate?
Posted by Greg, May-03-01 10:16 AM
Catch Can from the PVC valve?? I've never heard of that Hoot. I have one from the valve cover relief valve but not from the PCV.
4566, RE: Positive Crankcase Pressure, how to eliminate?
Posted by Jeff_99gs, May-03-01 02:26 PM
I have a good bit of oil coming out of my filter (through the crankcase). I ordered the catchcan/breather from RRE for $49 last night and it was shipped today. That will take care of that.
As for oil coming out of my valve cover seal....there is a slight line of oil sitting in the crevice between the valve cover and the engine block, but it isn't leaking...so I'm not worried about it. I haven't heard of oil coming from the PCV before though?

-Jeff
Now BOOSTED! HRC Super 16G

http://gs.dsmpower.com


4567, RE: Positive Crankcase Pressure, how to eliminate?
Posted by Armond30, May-03-01 05:01 PM
your pvc valve could be stuck open. A stuck pvc will cause that problem. best just to buy a new one. they are inexpensive.

Bring it on............


4568, RE: Positive Crankcase Pressure, how to eliminate?
Posted by sleepereclipse, May-03-01 05:22 PM
I found a ghetto catch can that is very inexpensive and works exactly live a market catch can. Its really simple. Its a sparkletts drinkinwater bottle. Its one of the small ones. I cut a small circular hole near the screw-on blue cap and that is where the hose is fed through. Does the job.
4569, RE: Positive Crankcase Pressure, how to eliminate?
Posted by phrenzy, May-04-01 05:00 AM
OK, let me make sure I've got this. PCV valve is the one to the left on the valve cover that runs into the intake mani, and the valve cover relief valve is the one that vents to the intake tube...correct?

What different purposes do these valves serve? I've see turbo 420A people with a little miniature air filter looking breather on the valve cover relief vavle, but it seems like there isn't any mods to the PCV valve. Do these valves function like P-traps, letting pressure out, but not in?

Just some random questions for ya...

Later-

'99 Eclipse GS
HRC Stage 2 on the way :7

http://www.rokitlabs.com/gsultra
4570, RE: Positive Crankcase Pressure, how to eliminate?
Posted by Jeff_99gs, May-04-01 06:34 AM
The "Valve Cover Release Valve" you are refering to is the Crankcase breather. the PCV valve shouldn't need any modifications.

The filter looking thing you are talking about is a catchcan/filter. That catches the oil that comes out of the crankcase and vents the air through the filter to the atmosphere.


-Jeff
Now BOOSTED! HRC Super 16G

http://gs.dsmpower.com


4571, basically....
Posted by Wyatt, May-04-01 08:29 AM
Our PCV systems SUCKS!
I thought I had some major blow by but it turns out it was my PCV valve. I replaced it twice and finally pur a HUGE check valve in line with it. No no more oil out the crankcase.
The PCV valve was letting pressure IN and there was no way for me to stop it.




Wyatt Leras
http://www.turbogs.com
98 Eclipse GS Star Stage 5,000 Turbo kit

4572, EXACTLY the answer i was looking for...
Posted by DarkOne, May-04-01 08:52 AM
I knew i could count on you, man.

Can you send me Some instructions on that ?? Where'd you get that bigass checkvalve???

______________________________________
-Dino Yancey
I'm so bad, i should be in detention.


Get the Mitsubishi Technical Information manual for the 95-99 Eclipse HERE!
http://www.heavenz-not-0verflowing.com/files/dsmmanual.pdf
4573, RE: EXACTLY the answer i was looking for...
Posted by 95ESi, May-07-01 03:39 AM
Hey darkone, what did you do with your crankcase breather? the tube that used to connect straigh to intake..


___________________________
l e o n
1995 Eagle Talon ESi-T
Star Stage 2
Boost is GOOOOOOOD!
4574, committed a sin...
Posted by DarkOne, May-07-01 05:31 AM
...and just left the thing hanging there.

______________________________________
-Dino Yancey
I'm so bad, i should be in detention.


Get the Mitsubishi Technical Information manual for the 95-99 Eclipse HERE!
http://www.heavenz-not-0verflowing.com/files/dsmmanual.pdf