Squealing Noise

[RED C5]

I have a '96 4.0L with 100K. Anytime I start it up when the temperature is below 25°F, it will start a loud squealing a few minutes later.
This noise is continuous (not at any periodic cycle) and reminds me of a rubber like sound. I will stop after about 5 minutes. This has been going on
for about 3 years now. I've tied opening the hood to hear where it might be coming from, but it's so loud I can't tell. Any thoughts or suggestions on what it might be?

 

[Big Jim M]

Most times that would be the belt tightner or the belt idler. Both have roller skate bearings in them that go away. Prolly on cold mornings the grease that is left in those bearings, if any, is not lubrecating.. There is the first place to look.
Big JIm

 

[wiesket]

Had that problem on my truck a few months ago. It was the tensioner pulley. Got so hot that the plastic pulley melted . Replaced it with a metal pulley with a good bearing and all is good. Had the idler pulley go bad a number of years ago, same thing, bearing went south. I'd check both of them real good.