Do we have baffles in our gas tanks?

[Couz]

And if we do how effective are they?

I just took my car to Nissan because everytime I fill up the car to full I get a sort of light thump from where the gas tank is located when i take off from a stop or stop with momentum, not always but here and there.

I've heard it for over a month and at first though it was something moving in the trunk, but my trunk is empty, than I thought it was something in the spare tire area, nope, solid.

Than over the month I noticed that it wasn't happening when my tank got to 3/4 full and less.

I told that to the tech and he suspects its a thump related to sloshing and that he too hears it on occasion on his Altima.

He says he's not 100% sure if the baffles are flexible or what etc...

Its not suspension related either as its a 4000km brand new car and the suspension sounds excellent over bumps and the brakes do to.


Modified by Couz at 1:42 PM 6/25/2009

[philipa_240sx]

I believe most modern gas tanks have baffles to prevent the fuel from sloshing excessively and to ensure the fuel pump/pickup remains submerged.

[Couz]

The tech says that he thinks the baffles don't go high enough so when the tank is really full sometimes the gas goes above the baffles and you can get a bit of noise from gas shiffting around with momentum.

Its not anything that bad just sounded like somerthing was shifting around in the trunk and or moving around but it was just the fuel.

I hear this is not unusual, I asked my buddy and he said he had a Camry that thumped when the tank was full because the gas was sloshing around.

No real fix for this issue