Tank vent valve boost leak???

[Bmwfixerguy1]

So we are all running higher and higher boost these days. Hell a couple years ago 21psi was a lot!! Not 30 seems to be more and more normal...

So the questions and the reason for the question...

Has anyone tested the failure point of the failure point of the factory tank vent valve and it's one way valve! You figure it was designed to hold 8pai or so and we are throwing considerably more at them right?!?!

The reason for the question is that I set a 2a15 today and u set boost could smell fuel.. which made me think the diaphragm may be compromised and I'm pressurizing the fuel tank causing the fuel smell..

I have not investigated yet but think I'm on to something. It's hard to smell the fuel under boost but my nose picked up on it lol. It would really be something if we have all had a minor boost leak and never really noticed it because wgdc compared to all cars was pretty normal, but if no one is fixing it than it will be normal compares to all other cars. Please discuss I've never messed with one on the n54 and curious if others have played around a little with them

 

[gmagnus7]

Sorry if this sounds ignorant, but what the hell is a factory tank vent valve? Do you mean fuel pressure regulator or? I'm confused as to what exactly your're proposing.

 

[GreyNBlueE92]

Sorry if this sounds ignorant, but what the hell is a factory tank vent valve? Do you mean fuel pressure regulator or? I'm confused as to what exactly your're proposing.

The flapper that routes fuel fumes back through the intake. Under or behind the intake manifold i believe. Usually throws gas cap/evap codes iirc.

 

[WOT808]

There's a one way valve between the throttle body and the Vent valve. The vent valve should never see any boost.

 

[Bmwfixerguy1]

There's a one way valve between the throttle body and the Vent valve. The vent valve should never see any boost.

Yea I'm aware of that my question was how much boost can the one way valve handle. The tank vent valve itself I'd assume can't handle any at all. So I'm curious what the one way valve is capable of handling before failure

 

[hardparker]

I've got a spare vent line I could test. I replaced it when I suspected it of being a boost leak culprit. If you've ever done an N55 boost leak test, you'll have noticed the OEM boost leak through the hard line back to the intake.

 

[Bmwfixerguy1]

I've got a spare vent line I could test. I replaced it when I suspected it of being a boost leak culprit. If you've ever done an N55 boost leak test, you'll have noticed the OEM boost leak through the hard line back to the intake.

Yea n55 is a little different it has a roll over valve in it I believe