Gas Cap Question?

[PewterBird]

Should our gas caps make a PPPPPSSSSSSSHHHHHHH noise when we open it with a just a little gas left.
My 92 Camaro did
My g/f's 1996 firebird does
But my 99 firebird does not.

I know this will contribute to bad gas mileage, so what does yours do?

[Devilboy28]

The PSSSSHHHTT sound adds 5-8 RWHP. The PPPPPSSSSSSSHHHHHHH sound adds 10-13 RWHP. THATS the one ya want!

[TheV6Bird]

I don't know if it's good or bad, but my 3.4 makes that noise.

[navyblue2000]

it doesn't really matter...it's just pressure blowing out/off of the gas tank. does anyone have a non-stock gas cap? that could very well be it as well..

[chas]

your '92 probably didn't have an evap canister which is probably the difference.

[Loochy88]

mine does

[PewterBird]

All have stock gas caps. Does anyone know if it is good or bad?

[67-03 RIP]

What's the reasoning behind it giving you bad gas mileage???? I had an 84 that I put an old 350 in and it did that because I plugged the return line. Only did it when it was all most empty. Guess it could be tricking the computer. User manuals say that a loose (opposite of this) can throw an SES light, so I suppose it could be harming your gas mileage some, but it seems some pressure is good/normal (reason SES throws with NO pressure - cap off or loose).

<blockquote>quote:</font><hr> The PSSSSHHHTT sound adds 5-8 RWHP. The PPPPPSSSSSSSHHHHHHH sound adds 10-13 RWHP. THATS the one ya want! <hr></blockquote>

[img]graemlins/rofl.gif[/img] Is that dyno proven? I'll split it 50/50 with you and we'll sell it on Ebay. Should be as good as the $.95 resistor mod...

Ron

[ March 11, 2003: Message edited by: 67-03 RIP ]</p>

[TheV6Bird]

<blockquote>quote:</font><hr>Originally posted by navyblue2000:
does anyone have a non-stock gas cap? that could very well be it as well..<hr></blockquote>Yes, I have a locking gas cap that I bought at Pep Boys.

The stock cap and locking cap both make the same noises. No biggie.

[Colin]

<blockquote>quote:</font><hr>The PSSSSHHHTT sound adds 5-8 RWHP. The PPPPPSSSSSSSHHHHHHH sound adds 10-13 RWHP. THATS the one ya want! <hr></blockquote>Hey. . .I have a couple of stickers on my back glass that add about 2-3 hp. [img]graemlins/omg.gif[/img]

[PewterBird]

Should I assume everything is ok with my gas cap, if there is no release of pressure when I remove it, and that I don't get a ses light?

[Colin]

Nothin's wrong with it. Mine usually makes about a 3 to 4 second hiss, but it depends on several things, what kind of pressure your tank's under, if there's some pressure release mechanism or not, what the temp is outside, how hard you drive your car, etc. On the cap (OEM or aftermarket) it should say "Remove slowly, gas could explode" or somethin' neat like that (not a direct quote). If it does it, it's normal, if it doesn't it's normal too. [img]graemlins/thumbsup.gif[/img]

[LD]

<blockquote>quote:</font><hr>Originally posted by PewterBird:
Should our gas caps make a PPPPPSSSSSSSHHHHHHH noise when we open it with a just a little gas left.
My 92 Camaro did
My g/f's 1996 firebird does
But my 99 firebird does not.

I know this will contribute to bad gas mileage, so what does yours do?<hr></blockquote>

Hey when it does that, hold a lighter in front of it. :D [img]graemlins/rofl.gif[/img]
it's like a flamethrower

Disclaimer: don't really do that ;)