I'm stumped and confused. Every diagram I have seen of the vacuum system shows the PCV valve (pancake) AND the little atmosphere vent under the intake manifold. On my car, I have the Pancake valve, but the "T" for the little atmosphere vent has been capped off with an aluminum bung. This is how the car was when I bought it in 2004, with about 35K on it. I presumed it was a factory mod.

Can anyone tell me definitively if I should be running the little PCV valve in ADDITION to the pancake valve. Mine is an AWM engine if that makes any difference.

This is the little PCV I'm rambling about

Audi B5 A4 Quattro 1.8T > Engine > Emissions > ES#257303 Pressure Control Valve (PCV) - (19mm) - 035103245A


Thanks

 

yes you need that otherwise your block would be pressurized and cause damage, lots of potential damage. id recommend the aluminum pcv valve from 034 for ten bucks more. the plastic ones are crap. maybe post pics so we know what youre talking about

 

Well I'll be damned. I'll try and take a pic tomorrow in the sun light. It pisses me off that someone would have capped it off for some reason. I swear to God that I presumed it was a factory delete because of it having a perfectly made aluminum bung and factory looking hose clamp.

Ive put over 130K miles on it since I bought it, so God only knows how much it's life span has been reduced.

 

Anyone know why someone would take off the pancake on the TIP? Nothing else was deleted besides this valve.

 

dont know why they would take it out unless it was bad and they didnt wanna waste the money on a new one. it doesnt really do that much anyways

 

oh, from what I am reading, I think that could be a lot of my problem. Especially since the hose was just half a** put into the inlet pipe, then clamped to another hose. There is no way that is not leaking air or working properly

 

thank you for responding. I can't get anyone to respond to my threads.

 

From what I've read about it, the pancake valve can be pretty important for cars with an intact PCV system. It limits the amount of flow into/out of the turbo inlet pipe from the PCV system. Without the pancake valve (when the rest of the PCV system is intact) you could potentially run into an issue where large enough amounts of unmetered air is flowing through the engine block and thus throws off the AFR for short periods of time.

 

from what i understand the pancake valve is simply a large check valve so it will not allow air back through the pcv system. obviously, air going out the tip would be a very rare instance, if it ever happens. of course you wouldnt want pressurized air going into the pcv system, especially the block, but then again the system is redundant because of the pcv valve coming out of the block.

 

^^That's pretty much how I understood it as well. OP, I have my pancake valve in my tool box if you want it, I ripped all that **** out a long time ago.