ALLWiTE2JZ

I notice almost everytime I go to fill up my gas tank in my SC, that when I go to unscrew the gas cap, it ALWAYS hisses and is like ready to shoot off lol. It feels like there is a ton of pressure in there when I am unscrewing it, I was just seeing if this is normal and if anyone else ever had it happen to them? I've never owned a car that has done that, but it does sound pretty cool as you're unscrewing it lol. Maybe it has something to do with premium fuel only?

plex

iTrader: (11)

Mine does that too for the last year but never did it before. Mine's pretty loud lol...

ALLWiTE2JZ

Yeah man, its crazy lol sometimes it can be pretty loud for me too.

turbodremz

iTrader: (18)

every single car I have ever owned does this, and its normal.

ALLWiTE2JZ

Really? Cause this is the first car that has ever done it to me lol.

HeisLegend

This happens when I'm low on fuel w/ my SC4.

It also happens to other cars as well. No worries.

aEO 37

iTrader: (2)

Happens to me all the time when my tank is almost empty. Usually never happens when I still have a half tank and refill though. It should normal though

tuterz

iTrader: (11)

its very normal.. it even says so on the cap itself.. something along the lines of.. remove cap carefully .. maybe under pressure or something..

wickedsc3

iTrader: (3)

That is the sound of u saving money!!!! Keep in mind that when u fill up the gas is below the surface of the ground keeping it colder more dense. Once it is in ur tank and through out the day the temp of the gas rises it should expand a little. So when u take ur cap off and hear that hissing sound it just means that ur gas tank is air tight. Some where there is a study of how much gas we actually lose due to evaportaion. So that sound just means u are not losing any vapors through out the day. Its a good thing.

YeA 2jZ

iTrader: (15)

x2 ..... I also run on E for a long time so i am sure that helps

FuMoFFuTT

iTrader: (2)

Air tight is a good way to put it, there are some cars that have the engine light turn on because the gas cap is not tight enough?

6SOARER

iTrader: (20)

What Wicked said, its fuel vapors that build up. Here in CA, if you dont have a sealed EVAP system your vehicle fails for an emission test..

mitsuguy

iTrader: (2)

there is a slight amount of pressure that builds up from fuel vapor...

the bigger reason this happens is that the car is checking for leaks itself... depending on make and model, they either pressurize the tank or pull a vacuum on the tank to determine if there are leaks in the evaporative emissions system... there is a valve on the evap line from the fuel tank that closes when the test is being run, but opens when it is time to let the fumes be ingested by the engine...

abounly

iTrader: (27)

Mine does that sometimes too, sometimes it goes crazy and it shot itself off one time, I think it happen when your running low on gas. I drive on E for a long time haha!

Kira X

iTrader: (24)

My SC300 does that too whenever I fill it up. My Saturn and Chrysler 300 never make any noise when I unscrew the cap. I don't think I've seen any cars beside the SC do that to be honest...