rattle in gas tank

[black180sx]

The other day i noticed that whenever I brake suddenly I can hear something rolling around in the gas tank. The car behaves normally, i was just wondering what could be rolling around in there. Any ideas? btw- 1990 240sx hatchback

[Ni2s4s0aSnX]

Are you sure its coming from the gas tank? Or is it just something rolling around in the back seat, or under the spare tire.

[black180sx]

nope, it is not on the inside of the car, the rear is completely gutted except for the battery so its nothing in the spare tire well as it is empty for sure. It seriously sounds like it is in the gas tank. Just wondering if anyone else might know what it is.

[hek1620]

yeah, everytime i stop suddenly i hear stuff sloshing/scraping around in the gas tank. seems like the same with this guy. is it possible for something in there like the pick-up or something else that could break off but still allow everything to work?

[black180sx]

yes thats what mine does, a scraping sound like there is something rolling back and forth. Anyone know what this is?

[black180sx]

no one has an idea, nissan online mechanic guy?

[srpowered240sx]

i have the exact same problem, if i find out what it is, ill let you know.

[JDMSIL80]

I have rattling problem in the rear too, still trying to figure out what it is.It only happens around 2500K rpm.

[hamsterball]

bump. i have the same exact problem.

[2projects2many]

Same problem here. I am planning on pulling the pump and looking/feeling around in there one of these days I get a chance. I post what ever I find.

[Alfador]

Some areas have these dumb teenage gangs who think its funny to pull stupid pranks like throwing a couple marbles into someone's gas tank. Easiest solution is to remove the gas tank (I believe a service manual has how to do that), drain it, and then dump it out. Just make sure to follow proper combustible handling procedures like a static free environment.

Note: it could also be some odd component, in which case a garage magnet might work if you can keep it off the sides of the tank.

[donmega]

There's a metal plate with holes located in the gas tank. I think it's called the "baffle plate". I believe what that plate does is it dampens the swishing of the fuel in the gas tank as it runs low.

That plate most likely broke off inside the gas tank. It happened to my car a few month ago and to a friend's car a year ago. All you need to do is remove the fuel pump in the rear and look inside to see if the weld point for that baffle plate is broken. If it is, it's just floating along inside. you'll have to bend the baffle plate in a way that you can remove it from the hole where your fuel pump sits.

That's most likely the problem. At least it was for me. I had the same symptoms you guys were having and it turned out to be that metal plate. I'm running without that plate now.

[S14KoukiMonster]

I'd try a combo of "donmega" and "alfador"s posts. Remove the fuel pump and check to make sure it's in tact. Then check for the baffle. Then check for other objects with a telescoping magnet. I would't remove the tank since you wouldn't even have to jack the car up to remove the fuel pump. Dropping the tank would be a last resort for me though.