excessive crankcase pressure

[sc430blue]

I've had a C2 procharger on my 3uzfe for about 2500 miles. When it was first installed I noticed a fitting on the passenger side valve cover that they left open. I was told it was ok to leave it open. I've never had a problem with that fitting until now. It now spews crankcase gases into the engine bay. At first it was just a little bit now it seems to have greater velocity. I tried to hook up a oil catch can but that just pressurized and spewed oil all over the engine. Any thoughts?

 

[Lextreme II]

http://www.lextreme.com/pcv.html
http://www.lextreme.com/pcv-fi.html

If your crankcase pressure increase now but not before. It might be your rings are bad.

 

[sc430blue]

I was thinking it was the rings as well. I just may have to buy the lextreme piston and rod setup.

 

[Lextreme II]

Many psi were you pushing? You might want to try the passenger PCV setup i mention on the second link.

 

[sc430blue]

Only pushing 6 lbs. I put a pcv valve on the passenger side and tee'd into the drivers side vacuum source. Blew a bunch of smoke out the back. Pulled the vacuum source off the pcv and the valve blew off! The engine rebuild was part of my winter project, just didnt want to start it this soon.

 

[Lextreme II]

6 psi should be ok. I think its possible that your crankvent is not properly routed.

 

[cribbj]

Pulled the vacuum source off the pcv and the valve blew off!

Check to see if the PCV is not opening, or could it be installed backwards? No way there should have been a pressure buildup behind it.

For a quick ring check, do a "dry" compression check with the motor warm, then repeat it, with a squirt of oil in each cylinder before testing it. A leakdown check would also be worthwhile while the plugs are out.

 

[chrisman]

im not sure if its the same on the late cars,,but on the throttle body of the early v8s is the inlet for the crank vapors-- it allows the vapors to pas thru the motor and get burned alond with air and fuel..WELL, in a forced induction aplication, you may be pressurizing the crank case because there is no "check valve- one way valve" it sounds like it already may be blocked off and the breather-vent was left open.. there should be no reason,, once you block of this inlet, to pressurize the crankcase except for normal engine crankcase vapors clooecting..

man,, i dont think im being clear.. but in any case,, you can re route the crank vapor hose to before the turbo--but then again,, this introduces "dirty" air--not a great idea from a performance view..
i may have a pic of the throttle body around,, il take a pic and post if i can.. it may make what i tried to say --clear..

 

[chrisman]

heres a few pics of the inlet on the throttle body.. if your going FI,, i highly recomend plugging this up.. i think i remember using a pipe plug.. it went in a litlle tight,, but fit well.. if this isnt plugged, or a one way valve put in,, it allows boost to get into the crancase..
thread the pipe plug in the outer steel pipe-not the aluminum of the throttle body.. mke sre it doesnt leak--use a sealer..
remember that my throttle body also has the taction control throttle--thats the one visible in the pics..

 

[Lextreme II]

Chris,

I think you are referring to my second link......

 

[chrisman]

hi david,, yes, i just checked the link.. that is exactly right..

 

[sc430blue]

I see a similar fitting on my engine that leads to the drivers side pcv. I've read threads of the boost backwashing thur there. If I seal that off what about the pcv. How about the passenger side valve cover fitting. Do I just put a filter on it?
Thanks for the help....

 

[Lextreme II]

Passenger side: you need to plug up the vent in the throttle body (1uzfe) and i am not sure where is the vent in the 3uzfe, but u need to plug that up. You can put in a breather filter if you like on the passenger side valve cover. However, please read my second link. I put in a pcv valve within the tube it self. This will only allow one way vent into the intake. At boost the pcv is closed and no pressure going to the crankcase. At idle or cruising the crankcase can vent into the intake. I find this to be very effective and great boost response. If you did the crankvent wrong you might not see boost at all and excessive blowby. However in your case would be little different. You stated not much blowby initially, but now its has increase. In your case might be rings.....

 

[Lextreme II]

Another thing you might want to check is the supercharger bypass valve. At idle is supposely open but at boost it should be closed. However, if you bypass valve is stuck closed, then you might have excessive blowby. Double check that along with a leak down test. If leakdown test is negative then you have either pcv or bypass valve problem. If your bypass is ok, then u have pcv problem.