2003 Yukon buzzing noise

I have a 2003 GMC Yukon, 5.3 engine with 4x4, and with flex fuel option. The vehicle is making a vibration type sound. The sound is almost like a buzzing type sound. It's not overly loud and it's a low vibration buzz. This sound is not continuous, but occurs when the accelerator is applied. It will last for several seconds and then go away. This happens between the speed of 0-40 mph, but only when the accelerator is pressed. The vehicle will not make any vibration sounds when coasting. At speeds of 45+mph, there is no noise even when the accelerator is applied.

I tried to pin point the sound, but it is very hard to locate. My best guess would be at the rear of vehicle. Maybe even where the fuel tank is located. This wouldn't be the fuel pump? I don't have any problems starting the vehicle or loss of power though.

Any thoughts will be appreciated. Thank you in advance.
Steve.

I suspect you have a broken/cracked heat shield on the muffler. Its welded onto the muffler. Take a look near where it connects to the muffler at the ends and look for cracks. You can purchase large clamps (look like huge hose clamps) that will go around the muffler and keep the shield from rattling.

I looked at the heat shield and it looks good. The noise that I hear is very conistent and almost sounds like it is being produced electronically.

Thanks for your input.

Steve

is this in 2wd?
fuel pump could make a buzz but I doubt you would hear it over the engine.

I would check the yolk on the drive shaft. and transfer case.