Eliminating the b*tch tube.??

[20gmr]

I apoligize if this has been covered, but has anyone ever deleted the pcv tube? On my car right now I have the valve cover vented to atmosphere with the port on throttlebody capped. The reason I wanna get rid if this thing is because pcv air is nasty, its more susceptible too detenation as well as gums up injectors and carbon deposit. I was thinking of using two freeze plugs to cap it off. Ideally I'd like to add a breather on the other end of the valve cover and run them too a vented catch can. Any info ideas is appreciated

[KenC]

Just put an air filter on the valve cover vent.

[20gmr]

That's essentially what I have right now. But valve cover vented or not the pcv tube is still routing blow by back Into the intake side

[CorvallisBMW]

Are you talking about the tube that goes from the block to the underside of the manifold, or the hose that runs from the valve cover to the side of the throttle body?

AFAIK, both could be plugged/deleted without any ill-effect. Their whole purpose was to stop evaporative and crankcase emissions from escaping in the the atmosphere in order to satisfy emissions regulations. Just be sure to put some kind of filter over the valve cover vent or it will suck in debris. Also note you can't 'plug' that one completely, the crankcase needs to breath. Like KenC said, buy one of those tiny air filters on eBay or Summit or whatever.

[20gmr]

Am I speaking English? No offense but I said I currently have the valve cover breather vented to atmosphere. And as to what I was referring too I am referring too the TUBE from the IM to the crank case. Not trying to be a dick I just get annoyed when ppl take the time to offer advice but dont take the time to read the thread.

[NigelStu]

Can you read English?

J/K - take a deep breath, have some chocolate.


Now before you get annoyed some more, take a look at the Bentley. And your car.

That tube from the crank case (which does need to vent as Corvallis indicated - otherwise you might pop your dipstick - pressure needs to go somewhere), routes into the head, through the intake manifold. It does not route INTO the intake. So, that dirty crank-case air isn't getting into the clean intake air that way. For that air to get to mix with the clean air, it needs to go through the valve-cover -> throttle body tube that you already eliminated. You'll be fine.

So, like Ken suggested, just add a filter to the valve cover (you did say 'vented to atmosphere', which could be interpreted as 'no filter'). Or better yet, run a line from the valve cover into a filtered catch-can as you mentioned.

[CorvallisBMW]

OP, chill out. I found your post less than clear, hence why I asked for clarification. You switched between talking about the 2 different hoses/tubes a few times within the paragraph and I wanted to make sure I knew which one you were referring to so I could help you with your problem. If you can't handle that I suggest a different forum (or some Xanax)

Ben is correct. The 'b*tch tube' does not route any crankcase vapors in to your intake air stream. It goes in to a separate port on the IM which leads in to the head, not the intake valves.

[20gmr]

Haha I relaxed some, so my apologies. And thank you I was under the impression that where the tube entered the IM it was being reburned I now see what you were saying with the port into the head. It seams silly that they would bother adding this tube because crankcase gasses can already flow between the head and block via the oil drains in the head. It will be deleted next time I remove the manifold

[DaveSmed]

The reason I wanna get rid if this thing is because pcv air is nasty, its more susceptible too detenation as well as gums up injectors and carbon deposit.

This is a false statement.

[StereoInstaller1]

as to what I was referring too I am referring too the TUBE from the IM to the crank case.

Why would you even bother? How often do you remove the IM?

[20gmr]

Not often. But I did just powdercoat a spare

[jlevie]

That tube is more for oil return than for venting the crankcase. Plugging it would be a bad idea.

[DmcL]

why do people call it the bitch tube? its easy peasy to remove/install?

im going to try a sort of breather filter setup i peiced together for the rocker cover and plug the fitting on the side of the TB to see what the car runs like that way. i used a 135 degree elbow, a peice of metal pipe to add some rigidity to one end of the elbow hose and put a bike air filter in the end, actually thought the filter would have been smaller but hard to judge on ebay pics, its huge for a breather but what the hey.. didnt want one of those stupid shiny bling bling looking breather filters and couldnt find one in the neck size i wanted so i looked into bike/scooter/pitbike filters and found something that would work.

here it is on my spare rocker cover for size reference on the filter.. would have liked the filter to be a little smaller but what can u do. hopefully the 135 degree elbow is short enough to not foul on the fuel rail, if its not ill just shorten the straight part that goes onto the rocker cover, i could take a little under 2 inches off it there before i run into the bend.

[StereoInstaller1]

why do people call it the bitch tube? its easy peasy to remove/install?

You aren't catching on. The tube called the "bitch tube" is the one on the underside of the intake manifold that runs down to the crankcase.

[jlevie]

You can get away with just a filter attached to the valve cover on a freshly rebuilt engine if you don't frequently take the engine above about 4500rpm. But if the engine has significant mileage on it (over about 60k) or it will see the upper end of the rpm band you need a catch can rather than a filter.