Valve cover breather bypass...will it cause an oil leak?

[monteperformanc]

Will removing the stock passenger side valve cover vent tube from the turbo inlet bell and replacing with a bypass kit (breather and plug) cause an increase in crankcase pressure and cause seals to leak oil?

Everyone says to install the bypass to eliminate oil in the intercooler, but I'm not sure what the intention of this system is in the first place.

My car somehow has no oil leaks and I don't want to cause one.

 

[tlap]

They are intended to keep the oil from coating the inside of the intercooler, which reduces the effiency of the IC.
I was getting an oil leak from the open filter in the end of the valve cover. The oil would blow back along the valve cover and block while driving, then drip down onto the exhaust crossover pipe.
Along with the leak I noticed the constant smell of oil vapor in the car at slow speeds.
Since I am not into full on performance, I opted to remove the mod.

 

[1KWIKSIX]

Or, install a catch can . Vent your lines in / out of a catch can , then back into your turbo inlet.
You'll prevent any oil from entering your turbo or intercooler.
Do a search, there's plenty of information on this modification.

 

[Front Mount]

Good idea. I was thinking of a one way check valve (like ones used on air pumps) with a filter on the end of that. It would allow air out on boost but not suck air in to mess with MAF reading at idle and cruise. How well do catch cans work on the oily air? The stocker had a foam pad to catch it, but most removed to prevent any oil from entering intercooler.

 

[1KWIKSIX]

If you purchase a proper catch can that was designed as such, they work well.....otherwise I'd buy an air/oil separator at the local hardware store.

 

[GNONYX]

Here is an example one of our board member Pronto who did an excellent job
http://www.turbobuick.com/forums/threads/installed-an-oil-catch-can-today.392886/

 

[monteperformanc]

Thank you for the info on the catch cans. That is a great idea. I also found this link in that thread that helped me understand what the factory system is designed to do. http://www.dsmtuners.com/forums/articles-engine-fuel/366890-4g63t-pcv-system.html

My plan is to get an aftermarket inlet bell and cut a hole and have a small pipe welded into it to mimick the factory inlet bell style.

 

[tlap]

The catch can is a great idea, however here in wonderfull california, that mod would be a smog violation.

 

[GNONYX]

No different in the great Apple of New York with it's own smog violation.
Move to SC, with no smog regulation or inspection, but if you drive a smokey car, bald tires, crack windshield, and etcs, you will be majorly fine.

 

[monteperformanc]

Over 26 years old in NY is a safety only inspection. Emissions exempt.

 

[87gninpa]

The stock passenger side rocker cover has a baffle in the front.. Been running an open breather there for almost 10 years and never get any oil leaking. Of course the filter media gets lightly coated in oil, but it never drips.

 

[Pronto]

You can make (or buy) a 90* fitting to raise the little filter up to the height of the valve cover. If your getting pressure in the block oil can get pushed out the vents (and oil pan, front cover, etc). Turning the vent straight up helps let the oil down. Some venders have valve cover vents that are angled to make the filter level, that does the same thing.

Adding the bypass relieves pressure in the block, not increase it. It really cuts down on oil in the intercooler and intake.

The oil catch can is helpful reducing getting sucked in the throttle body.