gas tank "thunking"? [Archive] - Forum


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10-19-2006, 04:11 PM
Same 96 GA SE - I've noticed intermittently now (owned the car less than 2 months) that after I park the car and its sitting cooling down, the gas tank seems to "thunk". No better way to explain it really....think of a pop can you dented slightly, and then manipuated it so it "thunked" back to shape...

I'm speculating there is a pressure release issue here - gas cap?? I get no lights on the dash and the car runs meticulously...



11-06-2006, 08:14 AM
Its probley just the gas moving back and forth in the tank if you fill your tank then try parking it shouldn't make the noise i wondered the same thiing about my 02 grand am gt and i asked my mechanic and thats what he told me

11-06-2006, 06:23 PM
Are you positive it's coming from the rear? I ask because upon cooling down, the cooling system can make some sounds too...when the pressure fluctuates.
I've honestly never heard of a gas tank doing that though.... Hopefully somebody can chime in with an explanation or ideas.

11-07-2006, 07:00 AM
It's just the gas sloshing around in the tank. Nothing to worry about.

11-07-2006, 08:04 AM
Yeah its just the gas. If it were something worse you would probably notice it while you were driving too.

Simple physics, the liquid has to move somewhere after its been at the back of the tank, then you stop, where you think its gonna go?

11-07-2006, 08:21 AM
Run it out of gas, see if it still makes that noise.

11-07-2006, 04:35 PM
" after I park the car and its sitting cooling down, the gas tank seems to "thunk". No better way to explain it really... "

Disregard my reply above. I was under the impression that you heard noises when the car was parked for some time.... meaning the car was parked for many minutes.
If it "thunks" immediately when you come to a stop, then of course it is sloshing, lol...
So if that is what you mean, then disregard my reply above.... One of us is misinterpreting your description... it's probably me though, lol...

11-07-2006, 07:22 PM
I don't think it's gas sloshing. I think the tank has a vacuum in it and the tank pops back into shape when the car is shut off.