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function of breather-pcv valve 1995 VR6 12V AAA

hi all, This is regarding an infamously fragile piece at the top of the valve cover, tying the crankcase ventilation system together.

My question is whether someone can verify the function of this valve - in particular the reason for having the line from the charcoal canister to the throttle body tee-d into it. I have searched for hours online and still have not found two sources to say the same thing.

The part in question starts at the valve cover near the front of the engine and has a valve with unknown function and continues to a heating element and there on into the air intake hose prior to the throttle body and after the MAF.

The reason I am asking about this ( in addition to my own curiosity) is that the part is >$100 to replace because VW makes it only available as a large assembly containing the intake tube, heating element, valve and all the tubes. (no thanks, vW!).

I have the Bentley and they call this the "PCV breather valve". My problem is that I cannot determine whether this is the "PCV Valve" end if the circuit where the air leaves the crankcase or wether it is the Breather side of the circuit where the air enters the crankcase.

I also do not understand why it is coupled to the charcoal canister- throttle body line.

I am considering seperating the two and installing a simple PCV check valve between the valve cover and air intake, and plugging off the tee- hose that comes out of the charcoal-canister vent.

Reply to
Mark
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I am still trying to figure this out. I would like to ask a more simple question. Is this breather/pcv valve (at the top of the valve cover) the Inlet to the engine crankcase or is the Outlet or is it both? My understanding of a PCV system is that there should be an inlet under low negative pressure and an outlet under high negative pressure with air flowing through the crankcase. The air going in should be filtered and the air going out should go into the combustion air.

I have looked around the engine and I can only find this one location for air to move in or out? of the crankcase. what am I missing?

thanks!

Reply to
Mark

Reply to
Lost In Space/Woodchuck

Thanks for taking the time, Woodchuck. Unfortunately for me, if I always fixed my VW with 'the correct' parts I wouldn not be able to afford the car-literally!. I have to be careful what to spend money on. (I'll avoid going off on a rant about B4 VR6's for now) After further reading and searching I think I found that there is NOT a fresh air inlet for the Crankcase ventilation on this engine and the area in question (breather) is meant to evacuate the crankcase either through the big tube to the air intake hose or through the small hose into the throttle body. The particulars of operation under all conditions is hard to understand and does not seem to be common knowledge to people on the net.

Reply to
Mark

Yes, VW's are pricy to keep going and I don't like to spend money either, but sometimes you must to prevent problems down the road. And yes, VW uses a "closed" crankcase breather system which I think is the same with all other car/trucks. I'm sure it's a federal emission thing and has been for many years

Reply to
Lost In Space/Woodchuck

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