Soo.... Understanding Vacuum, PCV Options

[6G94celica]

Alright so tried to research this in depth but want to make sure I totally understand the PCV or lack there of on the 2nd gen 3sgte. Please read my findings and fill me in if im incorrect.

As I understand it now, this engine does not actually have a Positive crankcase ventilator valve but merely a baffle to stop flameup/liquid oil from getting into the pipe. However the crankcase, by way of the valve cover, needs to have a vacuum source on it. This vacuum source can be from either the intake manifold, post AFM intake piping, or both. Is this correct?

The reason for digging into this is I believe I have been doing an injustice to my engine. Vac lines were connected from the intake manifold directly to the valve cover and the breather pipe off the driver side of the valve cover was covered with a small air filter instead of connecting to the air intake. Now that I know more about the system this seems as if it would be allowing unmetered air into the valve and thus into the intake. Also is there any way that running it like this could hurt the engine, or be the culprit for piston ring expansion and loss of compression?

Should a catch can be installed and rerouted to the intake? Also can the breather pipe be removed and replaced with AN fittings or anything similar?

This post has been edited by 6G94celica: Jul 1, 2015 - 5:39 PM

[6G94celica]

Anyone have any pointers, or was the message written poorly?

[Smaay]

you are right, there is no PCV and there should be. in my GF all-trac, i was getting serious blow by. I took off the small vacuum line from the intake manifold to the top of the valve cover. Im going to add a PCV like on the 3rd gen.

the PCV has a check valve in it. it allows for the vacuum in the intake manifold to suck engine vapors. the crank ventilation hard pipe is the intake and the PCV is the output. when you go under boost the check valve closes and prevent pressurizing the crankcase