Faint whine/whirring sound under very light throttle

[MC2]

When i just barely tip in to the gas i can cause the sound, the moment i pass a certain threshold or release off the gas the sound stops.

Any ideas what it might be?

[jey]

Auto or manual transmission? Does it happen in any particular gear or all gears? Does it happen when in gear only or also when in neutral?

[ShadowGT]

Where is the sound? Front or back of the car. Left or right?
What transmission?

Is it only when you barely step on the gas pedal? What is the sound duration?

[MC2]

It's a 4EAT

Sound is definitely coming from the back. I can't tell if it's back right, left or center really. I can only hear it at lower speeds but i think it gets drowned out from the road noise when going faster.

Yup it only happens when i barely step on the gas pedal. The sound remains for as long as i hold that position in the pedal. The moment I give it more gas or let off the sound will go away.

[2.5GT]

Loose heat shields perhaps?

[jey]

It's a 4EAT

Sound is definitely coming from the back.

Then the first thing I would check is the rear diff fluid level.

[MC2]

Well i just had the tranny out to change the oil separator plate, still waiting for the final spring pin to put my front axles back together before i can take it out for spin. I changed all the fluids in the meantime so i'll report back and let you guys know if the sound still exists or not.

[decke48]

i wonder if its the axle seal cover on the axle rubbing on the tranny?. since you said you dont have the pin in.

[MC2]

i wonder if its the axle seal cover on the axle rubbing on the tranny?. since you said you dont have the pin in.

Oh no, the sound was happening before i pulled the tranny. I haven't driven it since since i still haven't gotten the new pin yet. I'll have it tomorrow and will have to try to drive it around and see if it makes the sound (hopefully i can fix my CELs too..)

[MC2]

Update:

So everything is back together now and i'm still getting the sound. I was wrong about only hearing it at low speeds, i can hear it at freeway speeds too. In the parking lot i noticed it only happens when i am going straight. The moment i turn the wheel the sound goes away.

The sound happens with what i am guessing to be .5-1" of pedal travel. Anything outside of that range will not cause the sound.

Any ideas? What does a bad or failing rear diff sound like?

[T_F_E]

does the whirring seem to go with the speed of the engine or with the speed of the wheels?

[MC2]

Hmm neither actually.

I can only determine that it's caused by a very light throttle application.

[MC2]

So i rode in the trunk while the fiance drove.

Sound is definitely coming from the right rear. Either from the wheel.. or i would almost think that it's coming from the fuel pump... ever heard of anything like that before from the fuel pump?