I hear this weird Humming Sound when i start my truck

[s1m0n]

2004 Yukon

Frequently when i start it up, it makes a wierd sound when accellerating
in order to get it to stop i have to mash the gas a little a bit and then it stops

it happens maybe once or twice a day


its definitley coming from under the engine bay
i say a humming sound but i cant really describe the sound

 

[Sepiroth]

Hard to diagnose over the web. But here's a helpful hint. You know it's coming from the engine bay, that being typed, grab a wood broom handle. Using it as a stethoscope, with the engine running, touch non rotating assy's that are being belt driven. What you will be listening for is a resonates more through the handle to your ear.

Chances are you will find a bearing on a pulley going south.