sorry if this is a dumb question but ive never heard this before.

when i take off my gas cap alot of air comes out of the gas tank like its pressurized or something. i mean you can hear it for prolly 5 seconds. is this normal? it has a crappy yellow plastic gas cap.

 

actually that's how i think it's suppose to be...my corolla does that every time, esp if it's near empty. my 7 doesn't, so i was considering buying a new gas cap.

i remember reading somewhere a long time ago, that if theres no pressure, it may be the cause of bad gas millage. not sure tho...

 

are you freakin serious man!!!!!!! no **** its supposed to be pressurized wtf!!!!

 

lol all cars do that is cause of the fumes from the gas the lower your fuel level the more pressure there is.

 

It's not supposted to do that. Check the charcoal canister and I believe there is a check valve between the canister and the intake manifold.

 

sorry it its a dumb question dude but ive never had that happen in a car before.

 

Yes that is supposed to happen, in fact Ohio E-Check checks your gas cap to ensure it will hold that seal so that fumes don't leak out into enviroment, if it doesn't hold that seal it will also allow your fuel to evaporate at a much higher rate, in turn causing low gas mileage... well let me reprase i don't know if it is 'suppose' to happen but it is in fact suppose to hold a seal... dunno if the 7 has a pressure relife system

 

The gas tank is vented people, This is not supposted to happen and is dangerous. Flamable gases under pressure = a bomb.

 

Search Noob.

https://www.rx7club.com/showthread.p...=gas+tank+vent