Whining sound with acceleration
 

I have a 99 with 170k miles. I'm hearing this whining sound that starts around 40 mph. It's faint and only happens when on the accelerator. Goes away when letting off the gas and comes back when on the gas. Its constant while cruising. Sounds like it is coming from the front but not sure. After taking it to 3 mechanics, diagnosis was trany pump was going out and i needed new transmission. Took it to have the trany rebuilt and there was nothing wrong with trany. So far I have replaced differential fluids in front and rear, front differential gear and bearing, pitman arm, trany diagnosed, U joints, front and rear brakes. Unfortunately after lots of money and mechanics, I still have no idea what is causing the noise. Anyone ever experience this before? Any information would be greatly appreciated.

Welcome to the forum.

Possibly differentials or wheel bearings.

could check the pullys to make sure they are all good. if you rev it up not moving is the noise still there?

I have the same issue, and have not found the a solution yet. I have check wear bearing and all that. Is it more of a whining or almost a whistle?

Are you sure it's from the front? I had a weird noise in mine, and it was the pinion bearing. Happened mostly when accelerating

is it possible to be a brake or power steering fluid leaking?i had this problem before,when step acc padel,it noise,they found there bubbles in fluid,they replace brake boost unit and it gone,do you note any difference on making turns or brake

everyone reply a over 1 year post:D

I see this is an old post, but there are new replies, so I'll take a chance here. I TOO have this whining sound on my new-to-me 2007 Sub LTZ.

Back in the old days, there was a common sound that was made by a bad power steering unit on any car. It was a whine which would increase in volume as you turned the wheel. Ok - got that sound in mind? That's how my car sounds as I accelerate off a stop. It's not louder than the exhaust note, but it is just below it. If I put the car in neutral and rev it, it makes the sound also.

My car has 73K miles. In all other respects it seems to run like a top.

I had a similar noise problem on my 2004 Blazer. It turned out to be the fan clutch.

Answered 2 years to the day :)