Crankcase tube question

[hakop_e30]

Hey guys so my tuner for my turbo m20 said to weld the crankcase vent shut so boost doesn’t go in the oil pan and blow a seal or something
Any thoughts on this?

[ak-]

Welding the crank case shut will do exactly that - blow every seal and damage internals of the engine.

What you have to do is leave it open and disconnected from the throttle body side of piping.
We're talking about the port on the valve cover here.

[hakop_e30]

Welding the crank case shut will do exactly that - blow every seal and damage internals of the engine.

What you have to do is leave it open and disconnected from the throttle body side of piping.
We're talking about the port on the valve cover here.

Im talking about the tube that connect to the intake manifold to the block

[ak-]

That tube is connected to your head for the oil to drain back into the block/pan.

From outside, it looks like it's connected to your intake manifold, but then it 90 degrees into the head. Tuner is just mistaken or not familiar with M20's.

Leave it, you're fine.

[hakop_e30]

Thanks bro i told him the same thing
I just wanted to double check

[varg]

Find a new tuner.

Sincerely,
A Tuner

[ForcedFirebird]

Find a new tuner.

Sincerely,
A Tuner

Let's get your m20 on the dyno! Did 2 on Thursday. ;)

[varg]

After finals.

[downforce22]

Find a new tuner.

Sincerely,
A Tuner

[LowR3V'in]

Tell your buddy he's a dumb muther fucker and stop listening to his ricer hogwash.


WE, r3vlimited are your new tuners for now or find an actual tuner. Not ur buddy that says he knows about cars.

[e30davie]

My understandig is the m20 crank case is part of the vacuum system. Does one need to put 1 way valves in anywhere when one does turbo their engine? Or do most people just run a catch can and remove the crank case from the vacuum system? Maybe this is what the tuner was attempting to get at and doesnt quite understand.

[digger]

The crankcase and valve cover is under little vacuum as the hose from valve cover goes to intake pre throttle butterfly.

[cro_xt]

Heres my experience, and please if I am wrong about something, let me know or share your opinion. Im here to learn also.

My turbo could not make any pressure at beginning so I did leak test of the whole turbo piping system. So I tried to eliminate where the leak was... I saw some leak at valve cover gasket so I have deleted the valve cover vent, put it to breathe to atmosphere...No fix, but I let it be like that.
Then I had welded that crankcase vent tube shut. It didnt fix the problem.But it did not do any harm to me, I ran 0.5 bar most of time (around 10 days total experience), also at one day 1 bar boost. The only reason I left it shut was because when I tested the system for a leak, after I welded that tube shut, the volume of turbo piping decreased a lot... I did pressure test with garage compressor and the time needed to fill the system went more then half less once i welded it.

When I think about it (does not mean its true), building too much pressure in crankcase does not sound good... you can blow your seals out. Having it shut isnt good either, all the compression leak at rings go straight into crankcase and even some fuel may come down and thin your oil over some time.
Heres how my oil went thin after 400km at most!

https://www.youtube.com/watch?v=FOTdA38epME

This was castrol 5w40 FS
I had serious compression leak somewhere and my car died and would not start... Anyway I believe if crankcase vent was open, or at NA engine was connected to intake manifold as it was before, vacuum would have take some of that back into intake manifold and back into engine. Maybe it would even save that oil I had from thinning out...

Anyway thats just my opinion and my experience... thats where catch cans come in place also, dont they?
As I said before, please let me know if I got something wrong, im here to learn beside sharing my experience and maybe even wrong info...
BTW I had badly adjusted wastegate actuator. Thats why beside leak, it did not make any pressure.
cheers

[digger]

Blocking the crankcase vent tube only blocks some of the vents, the oil drain holes can still vent. Diluted oil is a fuel problem that might just be a tune issue but leaking injectors etc can do it to