weird sound from 240sx rear

[JDM_Alex]

1991 240sx hatch: I noticed a weird sound that seems to be coming from the rear of the car. The best way I can describe the sound is similar to a buzz. You know that sound when someone has to "buzz you in" to a room or something...? It is the same sound as that "buzz-in" buzz. The sound comes occasionally and seems to disappear as I slow down. I've only noticed it to sound when I drive forward and straight...but I then brake to slow down and the sound goes away. I have no idea what it may be...possibly the fuel pump? I do drip a little power steering fluid but the sound just seems to be coming from the rear. Any help is appreciated. Thanks

[KingNub]

I have a couple of guessesstuff in the rear of your car vibrating ie between body panels insulation worn or missing they didnt weld all the body panels edges down so its stuck with like rubber cement or something similaryour speakers with inadequate grounding or intermittent grounding makes a buzzing (this is my guess on this one)

[JDM_Alex]

yeah I've gutted the rear interior so I'll take a look for loose objects. My high mount brake light won't work so mabey , if it is a ground, it's something related to that? I replaced the fuel filter yesterday and, so far, I haven't noticed the "buzz". The significance of that is, I read somewhere, that if you have a dirty/clogged fuel filter the fuel pump works harder and "whines". I don't know but thanks for your input.

[KingNub]

hmmm well yeah ive gutted my interior as well and the panels buzz a littlealso before i removed all my sound stuff it made this wierd buzzing noise as well as making a buzzing that would increase in frequency as my engine rev'd up hopefully replacing the fuel filter fixed it