Rear end death wine?
 

I gutted my back seat and trunk yesterday to take it to an auto x, on the way there on the highway around 70mph only under acceleration it seemed like the rear end had "death wine". but whenever I coasted or was off the gas, it made no noise. Has anyone else had this problem? It wasnt very loud but was definetly noticable. Didnt happen at low speeds or anything just between 70-80 mph.

Ive tried a search with no luck. Ill pull the cover off tonight.

are you running an exhaust with no cats?

Yes sir.

stock or after-market fuel pump?

Stock, it will only make noise at those speeds with everything gutted, and only under acceleration. Its not the Tcase most definetly coming from trunk area

Is it possible that it is a exhast leak, ive never heard an exhaust leak make a "whine" before

do you have an aftermarket fuel pump or the stocker?

definitely the fuel pump, when the car is off before you hit the ignition you can hear it also.

This happened in my miata I know exactly what your talking about it only makes the noise at certain times.....on my miata the rear differential was all messed up and it needed a new one

+1 for fuel pump, the rear seat insulates the sound very well and with it off you hear lots of new noises.

fuel pump is more likely than not your issue

when you remove the rear seat they become very noisey and do to your circumstances aka partial throttle and off throttle lack of noise I would venture to guess that you are just hearing your fuel pump

the amount of gas you have in your car will also impact the noise of the pump

i think your issue is that you are not used to driving your car without seats and whatever else you took out carpets and what not,, all these items help to insulate noise,, so now that you have take all this out noise amplifies,, have you ever been in a gutted evo its loud you hear everything

It is the fuel pump. The different pitches it makes are when it is on either high flow or low flow settings. It is very high pitched and not too loud eh? Put the bottom cover back on the rear seats and see if you hear it.

Does the tone change if you go slightly faster or slower around those speeds? If so I would say rear end, if not I vote fuel pump.