Engine sounds like crickets at very specific RPM

Load on the pulleys changes with throttle.

Not saying it 'is' a pulley, but unless you have eliminated them via stethoscope or belt removal I don't think you can say 'it's not'.

 

But it sounds like a chirping version of a turbo and when you let off the gas it winds down in that sort of fashion

 

Would it matter what gear the truck was in?

 

Rockauto has idler pulleys for less $40 a piece. Might as well get one and swap out the pulley you think is bad. Do two if you're feeling preventative.

 

Oddly enough, I developed a similar thing this week. Almost like a screech/high pitched chirp at 1500-2000 rpms. Very annoying.

 

Does it go away when you let off the gas?

 

yep. Seems to sound worse while in gear. I haven't tested in neutral in the driveway yet with the hood open. But it doesn’t really “wind” down. The sound is the same, but is just more constant at 1500-2000 rpms

 

Do belt and idler pulleys first, then start ticking off other boxes if that doesn't fix the problem.

 

yeah that’s my plan. I’m coming up on 100k with the original belt anyway.

 

The noise still has not returned, but the power steering sounds louder and it feels like the car is not accelerating as hard as it normally does, but that could also be me being hyper sensitive about any noise or “lack of power”. I’ll be taking it to the shop next week before I head back to Mississippi.

 

Change the pulley already. Jeez.

 

Yep, doing it tomorrow, had to wait for it to come in. Also replacing tensioner because it’s movable by hand, this should fix my problems.

 

Fixed! Replacing the tensioner and pulley with a new belt fixed all of the symptoms

 

Thanks for reporting back! It's nice that it wasn't something more serious.