WTH is this whining noise w/ my 2000 Tacoma 6 cyl?

I just dashed to the convenience store this morning — 7:30 am, lots of moisture in the air — left it idling while I was briefly in the store. Came out; and it was making this noise:

https://youtube.com/shorts/KsByCukuQ3o?si=LmBT5-kqa-joe5LI

My iPhone has a helluva’ microphone on it. It’s not QUITE as loud as my video here — but it’s a new development, just this morning. :-|

Yesterday, I had an odd thing happen as well when I first cranked it up. It was missing pretty badly, runnin’ rough — but it cleared up before I could swing by my mechanic (just 4.5 miles away). Same weather conditions. He ran a diagnostic on it … and nothin’, aside from a slight gallop in the idle. I’m now scheduled for a tuneup 10 days from now. Definitely gonna’ our new plugs on it. But I know this noise is not plug nor idle related.

Please don’t tell me my water pump is going out. :’-(

 

I won't tell you your water pump is going out. I would check the 3 belts to be sure they are not loose though. You could also remove one belt at a time and see if the noise goes away, but that's kind of a hassle.

 

Lots of possibilities,
Get a engine s Stethoscope to narrow it down, too many possibilities,
Water pump,
Power steering pump,
Alternator ,
Fan bracket pulley,
Ac idler pulley,
Ac unit,
Timing pulleys
Etc

 

That sounds very much like another low-hanging A/C idle pulley bearing starting to sing. With all the deep mud/high water I routinely wheel thru, I kill that bearing on a very regular basis. It literally gets changed every time the skid plate is removed to change the engine oil.

 

That’s actually good to know as I end up replacing mine at least once or twice a year and I thought maybe the quality of the bearings had gone south.
I was thinking of a way to make a shield or cover for that bearing.
I’m sure the winter Sodium Chloride salt is eating up my AC idler bearings