Humming sound

[gbleezy]

I have a 2008 Tahoe LTZ 4WD and yesterday when I started the engine, I started hearing a humming sound. The sound becomes more high pitch when I accelerate and the sound seems like its related to the acceleration and gear changes. Today I smelt a burning smell after I got to work. Any idea what it might be?

 

[HiHoeSilver]

I have a 2008 Tahoe LTZ 4WD and yesterday when I started the engine, I started hearing a humming sound. The sound becomes more high pitch when I accelerate and the sound seems like its related to the acceleration and gear changes. Today I smelt a burning smell after I got to work. Any idea what it might be?

When's the last time you serviced the differential(s)?

 

[gbleezy]

When's the last time you serviced the differential(s)?

I don't think I've ever serviced the differential.

 

[Doubeleive]

I would open the hood and take a look, is the A/C working? take a look at the belt and pulleys see if one is frozen or maybe something specific is making the noise that could be pinpointed from under the hood, does it make the sound with just the engine running and sitting parked or does it only do it when you are moving? in gear or not in gear?

 

[HiHoeSilver]

My earlier reply notwithstanding, I agree with @Doubeleive. Try to at least get a general idea of where the sound is coming from. Under the hood, under the rear seats, etc.

 

[avalonandl]

Alternator may be seizing.

Look for black dust around front of engine.

 

[massivespl]

Most likely it’s a pulley

 

[dmad1]

My '17 LT has a whine from the AC. Dealer replaced the compressor under warranty but did fix it. I can turn the AC off and it stops. Dealer said sense they replaced the compressor it couldn't possibly be that and don't know how to repair it. Said if GM came out with a fix, they would cover it even after the 36k warranty ran out. NOT! Was back in last week and was told they could not help me now that it is out of warranty. Called GM and they just referred me back to the dealership. No more GMs for me.

 

[Kraig]

Some good suggestions here. I’d start by pulling the serpentine belt off and start the truck and listen for the noise. If it’s still there i’d Pull the AC belt and do the same thing. If it’s gone, figure out which component is making the noise. Also, when you fix the problem and put it back together, you can use a pick or point of a razor blade and remove the seals for the idler and tensioner pulleys, including the AC, dab some grease in there, and snap the seals back in place. Last long time.

 

[14RamHemiSport]

low on power steering fluid?