View Full Version : WTF is this "pancake valve" thing.

01-12-2006, 04:09 PM
i pulled it off last night and it seems to be some sort of valve. its the circular thing above the n75 coming out of the air intake hose.
mine doesnt have any sort of resistance when i blow through it. its probobly something really obvious

01-12-2006, 04:45 PM
is it the pcv valve your talking about. does it have little traces of oil in it.

01-12-2006, 04:56 PM

01-12-2006, 05:08 PM
what does it do? is it supposed to be open like that? i could blow right through it and no resistance.

01-12-2006, 05:11 PM
I believe it's a one way valve you are talking about. Can you blow through it on the other end?

01-12-2006, 05:19 PM
I can blow through it on both ends.

01-12-2006, 05:19 PM
is the oil a bad thing?

01-12-2006, 05:25 PM
my friend at work said that the oil is normal, but he wasn't sure what it was for.

01-12-2006, 05:34 PM
found a good explaination on AW. heres a link for anyone interested.

01-12-2006, 05:35 PM
It basically is a breather valve for the crankcase i believe, if you look at it closly, the end that is not connected to the intake track has a small golf tee size hole on the middle shaft. The reason for this is to vent the crankcase, while still catching blow-by oil that can sometimes get in the intake track, hence the hollow surrounding. once in a while i wll take mine off and clean it out with a little carburator cleaner. a lot of times guys who do large turbbo upgrades elmintae that by using a catch-can or jsut a breather filter. Hope that helps

01-12-2006, 05:41 PM
ahhh, so its supposed to flow freely both ways? Im trying to diagnose why Im not getting full boost. thought this might be it.

01-12-2006, 05:59 PM
Yea your valve is fine, There should be no restrictions, and the oil in there is normal, Personally when i removed mine, i wiped the oil out completely then re-installed. I didnt have to do that because the oil is going to get back in there anyway. Like someone said it works as a breather type valve.

01-13-2006, 06:50 PM
No boost?

Are you getting zero boost or are you only boosting at 4 psi?

Check the line from the intake manifold to the DV that cracks and causes issues.

Also, if yo are getting erratic boost, it could be your MAF...