i can hear a blump noise comming from my gas tank. It is similar to the soud u get if u dented a bottle and blowed into it. Im sure its comming from the gas tank. Somtimes when i hear it i unscrew the gas cap just to see what happens, and it blumps a little bit more but not after the pressure is let out. Anyone else get this noise? whats wrong?

also my fuel level guage is crazy.....it reads anywhere from 1/4 to 3/4 when it is half full. also when i fill up my tank till it clicks, the guage reads waaay over filled. I dont know if that has anything to do with it, but i just thought i would mention it.

 

hmmm well that's interesting. The gas gauge on mine tends to vary as well, but only when I'm accelerating or parked up/down hill. My guess would be that there is something going on with the fuel pump. I don't know what else is in there though.

 

My gas tank does that to. Up hills, down hills, around corners. Parked on slopes. it all sways back and forth. Just gravity playing it's part in the game. What I always find funny is at the top of my hill ( I'm at 7500 feet ) my tank will read 1/4 tank and at the bottom of the hill ( 6500-6900 feet is what the City of Santa Fe sits at) it'll read 1/2 a tank. Which is the accurate reading. It's really odd.

As far as the whistling is concerned maybe your cap doesn't fit well enough.

 

I had the same problem with my 92, as if presssure would build up in the tank. After sitting for a while the tank would swell and then *POP*. But shortley after my gas cap took a toil and would actually lossen up due to the pressure. Someone suggested to me the evapertor canistor AKA Charcoal canister, could be the problem. Never got around to seeing about it or trying to fix it. Don't have to worry now my evap can. got crushed by the core support.

Maybe you should ask on the general tech or is it called engine tech, something like that not sure. They deal with generalized problems and should be able to help you with this.

As far as the guage, its a common thing for older cars really i think.

 

It's called oil canning. Never ever heard it from a gas tank tho. Check your vent and canister for correct operation. Something ain't right.

 

ok, thanks guys. Im more concerned about the gas tank popping than the fuel meter... where is the charcoal canister?....i dont see much near the tank and it should be around there...maybe im not looking hard enough

 

pop the hood, and if its a camaro it will be right by the drivers side headlights. Its a cylindrical object with lines running out of the top.

 

There is a vent for the tank right in front of it. Kinda the back of the drivers side rear passenger seat attached to the floor pan. It's white and will have a rubber hose attached to it. Under the car. Just in front of the rear end. Brake/gas lines right next to it.

The evap. canister will be in the front of the car on either side depending if it's a Camaro or Firebird. It is exactly where the battery would be on the opposite side. Black cylinder thing with about a half dozen vac. lines coming out of it.

 

it could be something as simple as the gas cap...what should the gas cap look like? Mine is grey and doesnt look stock. If it has the wrong gas cap, it might not be allowing air to enter the tank when gas is being taken out, creating a vacuum.
it has an "S" on the outside...sorry the pic is blurry

putfile doesnt allow direct linking so click here to see my gas cap
http://putfile.com/pic.php?pic=11/32412082815.jpg&s=x12

 

come on someone plz describe what the stock gas cap looks like

 

hey this is interesting,...one time me and my friend were in his 86 iroc. and we blew by a cop on route 6 in Connecticut. so we pulled behind a closed bar and shut the car off. as we sat there there was a sound coming from the gas tank like someone was tapping on it with a rubber mallet. the sound would come like every 3 or 4 seconds. and that car is long gone but to this day i can not figure out what that was.



BTW that gas cap you have IS stock,.... and there is supposed to be a vaccum in the tank. cuz mine is fine and everytime i fill her she hisses for like 3 seconds when i take the cap off.

 

the hissing you hear is the gas vapors leaving the tank, its supposed to hiss unless u have that special filler neck that are on some OBDII cars

i went to the chevy dealer and they said that cap didnt look stock...they didnt have any in stock so we couldnt compare them