why is the crankcase ventilator hose routed to manifold?

[supark]

While I was taking out my airbox and such in order to access the ICV to clean it - I noticed that there was a bit of oil in the junction between the airbox and the manifold. Following the path of one of the hoses - I noticed that it leads to the crankcase ventilator hose.

As far as I can remember - the ventilator hose on my other cars did not lead to the manifold - any ideas why it does on the 325? I'm not saying this is something wrong with my car - I'm just curious as to why it's routed this way - as it gets the butterfly valve and airbox a little dirty from builtup oil...

In fact I'm not really what the purpose of the crankcase ventilator hose is for the engine. Is to allow oil to escape if you overfill it? In that case, I guess it'd be a decent idea to just inject it into the combustion chamber - as it would just get burnt up the next time you run your car...

any ideas?

[Boondoggie]

It's that way on pretty much all cars for the last 20 years, unless they've been modified.

It's Positive Crankcase Ventilation. It uses engine vaccum, via the intake, to draw vapors out of the crankcase, and to keep the airspace in the crankcase at a sligth vaccum. (remove your oil cap, the engine should stumble for a sec. Put your palm over the hole, you should feel slight suction.)

[UKFan4Sure!]

It's that way on pretty much all cars for the last 20 years, unless they've been modified.

It's Positive Crankcase Ventilation. It uses engine vaccum, via the intake, to draw vapors out of the crankcase, and to keep the airspace in the crankcase at a sligth vaccum. (remove your oil cap, the engine should stumble for a sec. Put your palm over the hole, you should feel slight suction.)

It is also to put you engine vapors back into the combustion chamber (Via the Manifold) where they can be burned....The earliest form of pollution controls....

[supark]

interesting - I've just never had a car with so much oil and crap around the butterfly valve from the crankcase ventilation hose. I wonder what that could be a sign of... or if that's completely normal