Oil in throttle/intake and air box?

[nando]

That tube doesn't connect to the intake in the least. You should be able to take that tube out, run the car and not see a drop of oil in your intake. Granted there will be oil all over the place under there.

What is probably happening is that your rings are dying or the bad tube caused the crank case to receive neutral pressure (not in vacuum like it should be) and frothed some oil into the vent tube that goes from the valve cover to the intake.

Basically, oily vapor is seeping into your intake via the crank case vent tube from the VC due to either bad sealing of the crank case or dying rings/valves.

"should" and what actually happens are two different things.

I'm telling you - my tube was slightly off and not sealed all the way. my car was going through huge amounts of oil, the intake, AFM and air filter were all soaked. I snapped the tube into place (without touching anything else), cleaned everything up and never lost a drop of oil in the last ~40,000 miles.

[guibo09]

what is the function of the tube anyway? is it to create a vacuum in the crank case or does it serve as a return for all the oil thats pumped into the head? where does the oil getting pumped into the head go in by anyway?

[shiboujin]

"should" and what actually happens are two different things.

I'm telling you - my tube was slightly off and not sealed all the way. my car was going through huge amounts of oil, the intake, AFM and air filter were all soaked. I snapped the tube into place (without touching anything else), cleaned everything up and never lost a drop of oil in the last ~40,000 miles.

I mean, how would oil get to the intake/afm? its a tube that goes down with gravity. There IS no pressure shooting it anywhere. The crank vent tube is in a perfect spot for all that oil to get into intake places.

what is the function of the tube anyway? is it to create a vacuum in the crank case or does it serve as a return for all the oil thats pumped into the head? where does the oil getting pumped into the head go in by anyway?

Its a main drain from the head to the oil pan for extra oil. It just happens to go through the intake.

[nando]

easy, vacuum pressure. it could be 10psi at idle, that's plenty enough to suck oil fumes into the intake.

[shiboujin]

You would have to refill your oil so often at that rate though. I mean like 1-2 quarts a week worth. The crank case vent tube is so much more likely of a culprit.

[nando]

well yeah, that's exactly what happens. I mean the air filter was litterally dripping with oil and it was brand new after a day or two of driving. I don't recall how much oil I lost as I figured it out pretty quickly

I'm not suggesting it sucks it up the tube, but the vacuum causes it to suck it from somewhere else, like the vent from the valve cover to the throttle body.

[delatlanta1281]

You guys do realize that if you compress the tube and turn it, it will stay compressed so it doesnt come shooting out at you right. Installation is the opposite of removal btw.

[Adrian_Visser]

a main drain from the head to the crank case? i don't think so buddy. it is a ventilation tube, crankcase ventilation is necessary to prevent blowby gases from building up in the crankcase, oil vapor also escapes through this tube, this tube and the one coming from the valve cover are the bmw pcv system.