If i fill my tank full of gas and drive for like half a tank or so, and then take the gas cap off, you can ALOT of air rushing in. This happens more when the fuel is low, im guessing because there is more air than fuel. Then the fuel gauge usually goes up a noticeable amount. My car also smells like gas sometimes. Its not really strong, like its leaking, but just slight. Does air need to get in the gas tank? My friend described it as if you are drinking water from a plastic bottle, and you seal your lips around it, when you are drinking it, the bottle collapses/crushes, and when you stop, and let air in, it takes shape again. This isnt happening to my gas tank, is it? I was also reading about how the PCV canister, takes away the gas smell, and creates vacuum pressure in your gas tank...could the PCV just be clogged or something? or do i just need a new gas cap?

Thanks for your help.

 

No man.......Your friend isn't mechanicly inclined. Your gas tank has a breather line so there is always gonna be air in it........The air rushing is normal.

 

That's air rushing OUT! Your fuel pump creates pressure inside the tank so that the fuel will flow to the front of the car. Also, the PCV system has absolutely nothing to do with fuel. It's a breather system for the gasses and pressure that builds up inside of your bottom-end (engine). Your friend doesn't know what he's talking about...

 

gas tanks usually have a vent in the cap to allow air in and to stop the tank from collapsing.Most tanks are vented three ways, as for the PCV canister, I think you mean charcoal canister.

 

ok thanks alot. so i should probably stop letting the air out every couple days? haha, good to know its normal.