Loud squeal when starting in the cold (under 30F). 2010 V6 with supercharger, 100k miles. Video

This past winter, my Tacoma would squeal for a minute or so when starting it up in the cold. The colder it was, the louder the squeal. It has not been an issue if the outside air temperature is above 30F or if the truck is warm. The squeal is much louder than the video is able to pickup, can easily hear it 100 yards away

https://youtu.be/9WeH_dLMQko

Does anyone know what this sound is? Everything runs fine, I’m about to hit 100k miles and am wanting to do some preventative maintenance under the hood. I plan to replace all belts, but not sure what else is needed. I’m a bit of a novice compared to others on this forum, so any advice is greatly appreciated

 

I could be just imagining things, but that almost sounded like a power steering pump issue

 

Might be a idler pulley when the belts are replaced check the supercharger and engine ones

 

This seems likely to me, is there a way to identify which pulley could be responsible?

The previous owner swapped out the stock 3” SC pulley with the URD stealth 2.85” pulley, my initial assumption is that that is the culprit

 

No pulley size shouldn’t matter unless it’s slipping that’s usually at higher rpm. When the belts are removed spin them should be smooth and little to no noise

 

Did you ever pinpoint the source of this noise? Mine started doing the same thing about a month ago.

 

Belt or pulley; get a mechanic's stethoscope and track it down.

 

Sounds maybe like a bearing starting to go, by the pitch of it. Only fast-spinning bearings would make that pitch, so probably either one of the idler pulleys, or possibly one of the shaft bearings in something attached to these pulleys, like a power steering pump or alternator.

As for cold-sensitivity: colder = tighter serpentine belt = more side-load on spinning bearings. Usually the belt tensioner should adjust for that but maybe the tensioner itself isn't working right? Sound disappears as the belt starts to warm up, expand, and loosen a little bit.

I guess I would start by removing the belt & checking the play in the tensioner.

---

EDIT: I forgot till just now -- you have a SC, with more pulleys/bearings, + the internal bearings on the blower rotors. Possible additional sources for squeal at cold temps.