EVAP capillary leak - BMW Forum

Hootie · 10-19-2005, 06:29 PM

OK experts, what is the EVAP? I've been having oxygen sensor adaptation errors recently and I'm wondering if the EVAP is short for "exhaust vacuum...[something something]". I somehow doubt it has anything to do with the A/C evaporator.

zibby · 10-19-2005, 07:45 PM

Evaporative emission(EVAP)
The EVAP system's task is simple. Store the vapor created in the vehicles fuel tank, and allow it to be burned in the combustion process when commanded to do so. Why? Again simple..fuel in the fuel tank, the vapors from the fuel is a form of vehicle emissions.Only cars equipped with an OBDII system are alsso equipped with EVAP.
Hope it helps. Z.

Hootie · 10-20-2005, 11:02 AM

OK, that clears up what the EVAP is, thanks Zibby. Next question would be what would cause an EVAP leak? Right now, the leak is listed as a "capillary leak" in my computer. I've read some comments that this is caused by the grand ol' gas-cap conundrum. Anything else I should check along the fuel lines that would cause such a small leak?

zibby · 10-20-2005, 02:58 PM

In my experience, I would look primary on a gas cap, even if it visually look normal sometime it cause trouble.My friend had simmilar problem on 2 years old ford taurus ! can you imagine ? only 2 years old car! and fuel cap went bad. He got a new cap and problem had gone. Everything get old with a time and after a while tend to brake (also gas caps!), so perhaps is good idea to buy new one , should not be expensive. Next, you have to investigate all fuel lines an its connections for any small leak as well as EVAP itself.I am tellin you , it can be a very difficult thing to localize, but everything is possible.Good luck! Z.