The "peeping" or, "chirping" or "squelching"??
Only makes this noise when warmed up, and running low rpms. Until recently that has meat only when off road, in low range, crawling about. However, about 2 months ago I was idling around the neighborhoods looking for a friends lost dog, and it did it then too.
Never does it daily driving.
At first I thought is was my power steering box, but, when I went hydro assist that saw swapped out, so, cannot be 2 boxes in a row making this unique noise.
Some say it's an accessory or idler pulley, but, is too inconsistent in my opinion, and, a shop looked at the pullies (belt off, spin/jiggle) and said they are fine.
first video the noise starts pretty much from go.
second video noise starts around 55seconds.

Anyone ever dealt with this/know what it likely is?

https://youtu.be/zxUlKbOaxO4
https://youtu.be/-ph4GeKE13U

 

I'm not familiar with that noise. Interesting. Subscribed to see what others might suggest.

 

So, on our local forum, a member suggested;
"Use a stethoscope and check control valves, sounds like one is oscillating too much, like the old PVC valves use to."
I do not experience fluctuating rpm at idle, but, if it's doing it's job, simply oscillating too much... hmmm...
I am aware there is an idle air bypass control valve... what others? Same member said he is is not familiar enough with new rigs to comment on how many/where control valves may be located... possibly charcoal canister purge?
Any help on control valves?