Long story short my A4 has ahd a lot of weird problems. But last time I went to get gas I had something weird happen. Usually when I unscrew my gas cap I can hear a little air rush in as I unscrew it. I didn't think anything of it but this last time it sounded a lot louder. Like there was some serious vacuum on it, enough so that when I finally got the gas cap unscrewed the air still rushing in sent gas flying out of the tank and went about 5ft almost hitting the guy filling up across from me. About 8-10oz shot out. It was the weirdest thing. So i'm wondering if I have a fuel related issue now. Is the tank supposed to have that much vacuum/pressure on it? The only thing really different is it was one of the hottest days we have had so far, almost 100 degrees out. Is this supposed to happen? It's going to get hotter here I don't want this happening every time!

 

I've never heard of that happening before, and I'm not sure of what exactly could be the cause, but if I had to throw out a guess, I'd say something is plugged up that is supposed to release the pressure automatically. I'm not sure if we have this system or not, but I've heard of gas caps being engineered to release built up pressure automatically and other systems that have a computer monitor the pressure and release it accordingly to stay at a specific level so the fuel delivery isn't buggered up. So there's a chance that it could be something simple, or something very involved, but that is definitely not normal, it gets well above 100F here sometimes in the summer and I've never had anything close to that drastic happen or heard of anyone else here have it happen.