Gas tank problems I have a 92 Chevy ½ ton that I has a New motor and Transmission with in the last year. Now the gas tank is building up A LOT of pressure in it. When I go to open the tank to put gas in it makes a loud swoosh noise. Its a lot!! It is almost enough to pull your arm off!! Now that this is starting to happen the motor is starting to run bad. I figure it has something to do with all the pressure building up in the fuel tank. I think there is so much pressure the fuel pump is not able to pump gas. I need to ask if anyone would know why this is going on and what can I do to stop it? Any help would be great.