cghelani

I've got a 99.5 V6 2.8L Quattro

I am hearing a wind rushing sound from the drivers seat. When I took the engine cover off, I noticed that the crankcase breather hose had broken up in a few parts. Its a brittle plastic hose...looks like some type of vaccum hose. I had duct-taped it a few years ago and now it simply gave way.

I have a couple of noobie questions:

1. What exactly does the crankcase breather hose do? And what is the impact of not having this hose connected?

2. I've heard that this hose has something to do with the oil leaks coming from the top of my engine? Is this true....why?

3. I'm thinking of home depot-ing a fix to the hose to save the $75 for a new one. Good idea?....or should I just spring for a new one?

4. The hose looked a little dirty on the inside...oily grit stuff...should I be checking the entire hose to see if its clogged anywhere?

5. What exactly does the PCV valve do?

Thanks for the education....still learning how this stuff works.

n0yxl

You have a world of info at your fingertips.

cghelani

Not entirely clear on the purpose of the crankcase breather hose. Why does the crankcase need to be ventilated?

I noticed a lot of posts talk about oil leaks due to the crankcase breather hose breaking...I dont see the connection between the oil pressure and the vacuum hose?

n0yxl

Meaning that some of the gasses make it past the piston rings and into the crankcase. The PCV(positive crankcase ventilation) system is put into play to relieve this pressure buildup in the case and re-route the gasses back into the intake system rather than just venting them into the atmosphere. The PCV valve just regulates the amount of crankcase suction, so that your engine doesn't run rough at idle due to too much vacuum loss.

The system also helps combat against sludge buildup; by quickly evacuating these gasses and oil residue(for lack of better words), out of the crankcase instead of it building up inside the engine.