Help! Odd sound and cannot locate

My ‘07 started making an odd whining/squealing sound coming from under the hood recently I haven’t been able for the life of me to figure out what it is, replaced the belt, spun all the pulleys and the upper idler pulley sounded off so i went ahead and replaced it but still the same noise, it’s not constant and at idle it won’t always make the noise if the engine was just ran but if i start to accelerate or start the engine when it hasn’t been driven for ahwile the squeel is there, I’ll try to get a video of it and post it, any thoughts would be appreciated

 

Manual or auto?

 

Auto

 

Power steering pump?

 

Not sure doesn’t make any sound while turning, just gets louder on acceleration, is it possible the belts to loose?

 

Try running your truck with the serpentine belt removed .This eliminates all things that spin on the front of the engine
You have a 4 minute window for diagnostic purposes .

 

A puppy in the drivetrain? That’s a weird, intermittent sound.

 

Update: pulled the belt and spun all the pulleys again, i must have missed another idler pulley making a noise the no2 on the left next to the power steering pump, i recently had to replace my valve cover gasket and there is a good bit of gunked up oil from that around that area and behind where the pulley mounts, heading to O reillys soon to get some degreaser and a new idler pulley