Breather Filter or Rubber Hose..??
 

Hey guys,

So, I am curious as to everyones opinion on this.. Do you know how on most cars, that there is a small rubber hose that connects from the intake tubing to the block and is referred to as a breather tube..? It has something to do with "crankcase breathing / ventilation" or something like that.. Well, some people use a breather filter instead of the rubber tube.. The breather filter, being a small (looks like a very small CAI type cone filter) cone filter, being clamped onto the tap on the block, and then the tap coming off of the intake being blocked off.. I've heard some people say this is perfectly fine, if not better for the car, while others say it is dangerous for the car.. Any idea..? I have this set-up on my car right now, and everything seems fine, but I just figured I would check.. I can post a picture if you're unsure as to what I mean..

Thanks!

its not gonna hurt anything. most people block it off because they are getting oil recirculated along with the fumes. that hose is just part of the PCV and relieves pressure by routing it back intake the intake. but sometimes oil will work its way into the intake. i would prefer a catch can over removing it all complete. that way i can stop the oil from getting back into the intake yet still relieve a good about of pressure

Honestly I never had any problem with any of that, I was just told it was better to have it freely ventilated rather than work it off of the intake.. lol

there are several reasons people do this, what is the point of having a cold air intake, if your going to muck it up with hot air from the crank case?

and why would you want oil going into your throttle body, sure its not all the time, but why? sure catch can is a solution and looks nice under the hood, but with as little oil as it is, i'd rather just vent it off to the atmosphere, and clean the filter every once in awhile.

will it hurt the car either way? no.

also the intake sucking air from the crank case creates a negetive atmosphere in the block why would you want that? stupid imo.

So, with a stock airbox, the hose is fine, but with an aftermarket intake I'm best just having the breather filter?

i didn't even do it with my factory intake was the first mod i did was removing that hose and filtering the crank case side and plugging the intake side.

Hmm. Good to know it's not a problem. Thanks!

the only reason it isnt vented to the atmosphere from the factory is it would be releasing a lot of oil fumes into the atmosphere. The manufacturer ties it into the intake so these oil fumes can be burned and eliminated. Removing it will cause you to fail emissions, and have a cleaner TB

I run it open woth a breather filter and pass emissions no problem.. At a dealership..

then your dealership has downs syndrome...lol
that should be an instant fail during the visual inspection alone.

i have a catch can setup on mine now

so just keep the hose and put it on for emissions tests.......i didnt realize that this had such a negative effect on the CAI........im thinking i should go get a breather filter right now to replace that hose........but dumb question how did you guys block off the hole in the CAI for the hose once you took it off?

thanks for the advice in advanced

Sucking in unmetered air from the atmosphere into the intake manifold on a MAF car is stupid.

Put the tube back on.

because, you know, they just put random hoses on cars nowadays, they put it there for a reason.

pics?

For me, its really varied on each car I owned.

On my RX-7 I had a Cork Sport intake tube and a Bonez street comp intake (MAF adapter/filter), and I ran a Bonez breather filter with that setup.

https://www.cobaltss.net/gallery/fil.../3/6/3/rx7.jpg

But on my Cobalt I just have the small silicon hose that runs between the block and the intake tube, which was included with my AEM CAI.

https://www.cobaltss.net/gallery/fil.../3/engine1.jpg

And no, my motor isn't that dirty any more, and yes, I removed that gayyyy ass oil cap spacer shortly, so no worries :lol:

to pass emissions standards while creating a release for the pressure at the same time. so for those of us who don't have inspections..... why not

Boosting the intake manifold makes power....the crankcase..not so much. :lol:

i breathe

massive pressure in the crank case makes one hell of a show though
:)

so whats the verdict.........leave it alone or put on a breather filter?

Leave it alone, theres no legit reason to vent the crankcase to atmosphere. All you do is create an induction leak through the head to the intake manifold and lose crankcase vacuum.

I personally say leave it alone.

its not robbing you of HP and it is designed to be there.