Just wondering why I get a loud pressure release sound when I open the gas cap on my 92' VE every time, but never had it in my 93' VG? Did they change something in the later models that made that stop, because a few have told me it's pretty normal since the system is pressurized. Thanks in advance.

 

seei have it in my 90 vg and didn't have it in my 94 ve. Its all about the cap I think. My vg has a much nicer gasket on the cap so it seals in better. But yeah its totally normal.

 

EDIT: accidental double post

 

Oh okay, so it most likely has to do with the cap. Im gonna swap the GXE cap into the SE, see what happens. I'll chime in later with the results.

 

The fuel systems are pressurized on maximas ....If it don't make that noise then the cap is probably bad....

 

If it doesn't hold pressure there could be a small leak almost anywhere, not just the cap. The filler hose could be suspect also.

 

the filler vent tube is also prone to leaking on these cars. it's the ~1/2" hose running next to the large filler tube.if that thing is leaking, then the system won't build pressure.

and yes, it's completely normal for the system to build pressure... one of the many reasons is that it keeps oxygen out of the gas tank to prevent explosions in severe accidents. no oxygen= no fire

If the system won't vent pressure, you have a leak somewhere- either a bad gas cap or hose is leaking.

 

Thanks for all the help guys.. Thankfully my current car(SE) is the one that actually releases pressure when the gas cap is opened. The time beltless GXE is the one that never made any noise which most likely had some leak. Interestingly enough though, the car had amazing fuel economy. Then it was probably the cap.

 

In Texas, we need to have state inspection once per year and the last time I was at one of the places that perform the inspection they did not pass a car which does not have the gas tank presurelized. They told the lady to go buy a new gas cap and come back latter.

 

yup.. they actually pull the cap off and test it on the machine. it's part of the zillion stupid parts of the emissions test.

 

You must be passin pretty well, with all your mods.

 

Everyone on the freeway too....

 

No doubt about it!

 

I was re-reading this thread and got a bit confused. I assume that most cars around do have pressurized fuel systems. From the many cars I have driven and filled up, I have never heard this pressue release sound from any car when the cap is opened. So there is most likely a leak goin on in all cars or they have a bad gas cap is what I understood from this thread. Cause some of these cars are actually new. Thats why Im a little out there on the subject. Any ideas?

 

bingo thats a part everyone left out.

 

I got plenty of gas today, gonna go open it. See what happens....

Edit: Even the new gas caps are bad? Some of my friends have got fairly new cars, and they never get these sounds.

 

some cars don't run the same pressures that we do, or the fill tubes are different, etc etc etc... some simply don't make the sound when you pull the cap off.

I know my chevy truck doesn't, but if you put your hand over the fill tube, you can feel the fumes coming out.
my altima, 240, and both maximas all use the same gas cap and all make the same whooshing sound when I open them.

 

If you have a VG maxima and you don't have a hissing sound when you open the cap than you should!

My 89 vg maxima did not I had a new gas cap and it still didn't hiss when I opened the gas cap!
I then noticed a few dips of gas on the pavment directly uder my left rear wheel suspension, so I thought I had the rusted through gas filler neck but when I go the car home and got under it I saw that the filler neck was intact and infact it was the one foot long 1 inch wide gas vent line that was dripping gas. If gas dripped out of the hose then certinly a pressurized gas could find its way out of the leaking hose.
So I went to the store a got some hose and after lots of swearing got the hose back on and in place and tightend down. Then I poured more gas back into my tank to verify I had stoped the leak and once I saw I had stoped the leak I started the car let it run for a min or two and then I shut it of and removed my gas cap and the hisssssssssssss whooooosssssssss it made the pressure release sound!!!!!!!

Thats most likley most third gens problems!!!!!!!

 

my 94 & 97 both hiss. the rubber hose and the cap are both good possibilities but also check the filler pipe itself. there is a recall on the 3rd gens for the filler neck rusting out that you guys in the snow belt need to be aware of.

 

my 1991 never does that and i just passed inspection in beginning of august (new jersey inspection stations are rediculous)

 

You would pass inspection regardless. You got pressure escaping from somewhere.

 

i have it too...and its totally normal...probly a good thing if the pressure release happens like that. dont forget nissan has recall on fuel filler necks being crappy or something. i cant remember exactly what the recall states but i know its there

 

yeah, i know abouyt the filelr neck.....only behind my seats are a little rusted.....not near the filler neck or in the trunk..

 

ok my gas cap not hissing anymore so i buy new one (non nissan)...now it seems work fine.. the hissing come again but with strange fuel gauge...after driving sometime, the fuel gauge drop half strip. So i try open the fuel cap, theres a lot of hissing and the fuel gauge going up again half strip...any advise whats wrong here?

 

Maybe something wonky with your fuel gauge sender unit. My cap doesn't make the hissing sound anymore like it did last yr. Not sure if it's because the breather pipe & hose is disconnected all the way to the carbon canister. I know you guys commented on the vent hoses or neck near the filler, but not sure about that other vent hose.

 

When you open the gas cap with engine running, it will not hiss. But with engine off, it will hiss. Maybe with engine running, the vacuum system (EVAP, PCV, etc) is dealing with extra pressure in the gas tank. Correct me if i`m wrong

 

It necessarily HAS to hiss? Does performance suffer if your losing pressure?