07 ford explorer sounds like a ups track (howling sound when accelerate)

[Kibeere]

For moment i thought I had a semi track behind me until I realized the sound was coming from under my hood. The sound comes and goes after I stop and hit the gas. Please advice.

 

[Tike]

im guessing it sounds very loud in the engine bay, is what you are trying to get at.
Had a problem like that in my GMC envoy turned out to be my clutch fan. try opening the hood, then start the car and see if its coming from the fan, might need someone to rev the engine for you.

for my envoy it did not need to be fixed, but it did get annoying sometimes.