Pressure limiting valve, Pcv, pancake valve 034129101c

[Fastguy]

Wanting to cover all bases with the engine on the stand. Pulled the line on top of driver valve cover during vc work. Was going to put this "pancake" valve back on. Out of curiosity I blew through it and can blow with even pressure from top or bottom. Is this normal?

16205

[RSoverAll]

Found this on AZ. Same exact valve by part number. I can't find it in the Bentley manual right now...

http://www.audizine.com/forum/showthread.php/445236-Found-an-issue-with-the-pancake-valve

[hahnmgh63]

$98.21 from www.genuineaudiparts.com but try to clean it with some Brake cleaner. It should flow air both ways. Under a certain amount of Boost (pressure & volume) it will start to close off in order to maintain a certain amount of vacuum in the crankcase. So at ambient pressure you should be able to blow through it both directions. Don't know what the difference are between part revisions but the 'B' version on my tt is only about $25. There is a little hole you should see on the end and try to squirt a little bit of brake cleaner in there too. They do get a bit of Oil inside them and many times just get a little bit of sludge built up.
The valve has two ports inside, one is approximately 0.400 diameter and a smaller one that is approximately 0.180 inches. The larger port and the smaller port are open during low boost operation but when the turbo makes enough boost and flows enough air to produce a vacuum on the suction side of the turbo, the regulator valve diaphragm sucks closed and blocks off the larger port.

[s8prtotype]

Or maybe just delete all that crap and catch can it :revs: