Metronet

This might have been asked before but I searched the forum and can't seem to find the answer. I've got a question about gas tank "whoosh" sound when you open the cap.

There is one time I open the tank and I could hear constant whoosh sound for about 30 seconds. I've never heard it going for so long before and strangely enough, ever since than it made no "whoosh" sound when I go fill up the tank... like absolutely no sound and I've filled up the tank at least 10 times already.

There is no codes and car drives fine. Fuel filer was recently replaced. Is this normal? Should I just ignore it and keeps driving, and maybe one day the whoosh sound would come back? Thanks.

GTA_Driver

What exactly is the problem you're experiencing?

Metronet

Thanks GTA_Driver.

There is no problem that I am experiencing really. I am just kind of worried if there is something wrong and if so is there anything I could do to check proactively? Is it normal to have no sound/pressure relief when opening the cap?

ECS Tuning-Audi

Doesn't sound like an issue at all. It's pretty normal for a gas take to vent when you open it, especially if the fuel is low.

Audi's usually vent slow. My B6 A4 will vent slowly when I get really low on fuel and go to fill up.

If you are having filling issues then it might be something with the charcoal canister or purge valve.

Jason

Huskerbob

30 seconds is a long long time. The vapor recovery system can pressurize to some extent but I have not noticed it on my Audis. I did get a short whoosh on one of my Hondas but it was 2 or 3 seconds tops.

Not sure it means anything if you are having no other problems.

Metronet

Thanks guys.

In the past it always has 1-2 second whoosh when I fill up. Until this really long whoosh sound it made lol

And now when I go to fill up the tank, it's almost like the gas cap is loose or something, no sound at all. Would it throw a CEL if the cap is loose or bad? Is it common for the cap to fail?

Huskerbob

If I recall correctly a loose gas cap will eventually throw a code P0455 along with the CEL. Major purge or recovery system leak. New gas caps are available from several outlets and not too expensive. Make sure you get the correct one for your vehicle.

Airbag

mine usually lasts 1-2 seconds .. if it lasted 30 seconds id be thrilled .. oh wait .. what were we talking about again ?

Anders1984

Mine sounds for 8-10 seconds...

haha

tester123

The worrying problems are the most expensive to get rid of on this car. You'd have to ask the dealer for a quote on replacing the entire fuel system all the way up to the engine. Just kidding.. oh man, I am knee deep in work on my car and needed to take my mind away from "fixing those problems".

It is normal and the "EVAP Purge Valve" will dump these fuel vapors into engine's intake directly. It's all part of the car's normal operation. Check for codes on engine with VAG-COM. If you have issues with EVAP, you'll see it.