PCV Valve

[$lacker]

Is there any reason not to make the PCV valve stay open all the time and just run it into a catch can?
What's the point of having it automatically close under boost?

 

[steve]

Since the one side of the PVC valve is connected to the intake manifold, what do you think will happen if it's open all the time?

Steve

 

[allwheelTSI]

unplug it from your intake,plug the hole and run the hose to a catch can or to the ground,if you just took the hose off,your car would be idling rough and the left side of your engine bay would begin to get real greasy.

 

[racer]

it is good to have the breater there since the engine actually suck air from that hose.If u don't have filter it may suck some dust and durt and all that shit will go on ur camshavt and springs and make ur oil durty.U do not want that.Catch can best solution.Plugin just breater still good but U'll have to change the breater more often cuz it'll get soak with oil,and dont worry that oil wont leak out trough the filter.I just replaced mine that was very olied but I have no oil over the engine bay.

 

[Coldandafraid]

The pcv is not the same at the hole we stick a breather filter on... The breather/catchcan is on the passengerside. The PCV is on the top. The pcv is the positive crankcase ventilation, where it lets out the excess air pressure from in the crankcase, but doesnt let any back in. If it was clogged closed you would have oil consumption problems, if it were clogged open... I guess you would get extra air in there or something...

 

[clownface]

if it was left open you would prolly get way high pressure in the crankcase because of all the air coming in when the car is at good boost i would think, and that would prolly make the engine not last as long, make stuff wear out faster, break stuff and be bad all around, i would think.

 

[Defiant]

Originally posted by $lacker
Is there any reason not to make the PCV valve stay open all the time and just run it into a catch can?
What's the point of having it automatically close under boost?

I'm not sure what your issue is with it in the first place. It just opens under vacuum to draw out vapor from the crankcase. The small amount of oil you may get into the combustion chambers aren't enough to be concerned about unless the engine's about to shit itself anyway. Under boost, when your real power is being produced, it'll close and have no effect.