markc24

Ok, guys, let me first say that I completely realize that you cannot diagnose a sound over the internet...BUT im hoping that the symptoms of when the sound appears and what not could lead me to the problem.. I have looked through tons of searches and have followed some leads to no prevail. I recently was having loud tire noise..turns out my rears were cupped. I replaced them and got a 4 wheel alignment and thats when I decided to start listening for any noises for a few days on the way to work..at first nothing..but now Im having a new noise which is driving me crazy. Its definitely coming from the rear..at least behind where I sit..It sounds more like it could be towards the drivers rear but could possibly be coming from anywhere in the rear...the thing is is its a loud whine or harmonic whistling..its intermittent and the volume of it changes. It does not do it if you push in the clutch which makes me wander..its pretty much only when its in gear...if I just ever so slightly ease on the gas pedal the sound comes up..as soon as I let off the pedal or push the clutch in it goes away. It does not sound rotational I could be wrong..the main thing is if it was a diff would it not make sound regardless of whether it was in neutral or the clutch was in? Also why would barely pushing the gas pedal cause it to appear and letting off causes it to disappear? Any ideas would be greatly appreciated as it has me worried and the sound is driving me crazy! Thanks!

markc24

also I noticed if I keep it at one rpm and constant speed it gets louder and continues to make the noise until I let off..or clutch in..weird..

markc24

anyone have any suggestions?

learning03

Can you please do this quick test for me? Driving in first gear at around 2000rpms hold it constant and see if it whistles?Also you say the sound is coming from behind you but what your describing to me sounds like tranny whistle. In other words the pump in the transmission, cruising sounds is there you press clutch in theres no sound please let me know.

markc24

I would have to say its more of a humming sound..a metallic humming..it does it in any gear if I hold it constant if I put a slight pressure on the gas pedal and hold it constant it hums..when I push the clutch in its gone..if I let of the gas it goes away..cruising..if I punch the gas hard I dont hear it..either because it drowns out or its not there..but cruising its there..unless Im in neutral or the clutch is pushed in..

markc24

the loudness of it changes also..but there is no way this noise is normal..

markc24

it sounds like its coming from my side of the car slightly behind me..I guess it could possibly be right under me..but it doesnt sound like the same area from where the clutch buzz comes..its like if I do a light acceleration or stay constant at a speed with my foot on the gas its humming..as soon as I take my foot of the gas it stops but sounds like it could slightly still do it during decel just not as loud.. but it DEFINITELY does not do it with the clutch pushed in..so if it doesnt do it with the clutch pushed in then does that eliminate it being the diff? Also..can transmission make noises like that? It definitely doesnt do it in neutral either..

markc24

guess everyone else is as lost as I am on this..

learning03

So the transmission is eliminated as a culprit, have you ever heard a wheel bearing failing?But then it would make noise at all times right just not when a laod is on it? The diff is the only culprit left, did you change the fluid recently?

markc24

it kinda sounds like what I would think a wheel bearing would sound like..just a loud humming..but if it was the diff would it not do it regardless of whether the clutch was pushed in or if it was in neutral? i can just barely put pressure on the gas pedal and I hear the humming..no clunking or anything like that..changed the fluid about 7k or so miles ago..with the appropriate mobil 1. It doesnt change sound when Im turning and doesnt change by which direction im turning or if Im going straight..