Squeaky belts?

My 2003 Tribute has started squeaking. Seems to come from the main belt on the left side of the engine. Faint at idle, but gets somewhat louder as the rpms go up. Advice appreciated. What is the accepted protocol for dealing with this? How do I understand if the belt needs replacing, or if something is out of alignment? BTW, as best as I can see/feel it, the belt itself is in OK shape. Is there some kind of lube? (Though it’s a smooth belt, so that might not be smart …)

You can no longer look at a serpentine belt to determine if it’s worn or not. That’s why Gates is giving this away for free. http://www.gates.com/australia/brochure.cfm?brochure=12178&location_id=11309

If that’s the orginal serpentine belt, it probably requires replacement.

Tester

Cracks in the belt? Shiny? It’s old enough that you probably need a new belt. Especially if it has never been replaced.

Good advice. Thanks. I take it that ten years at 103K miles in a hot climate is a probably prescription for a new belt, especially if it’s not EDPM.

Ive been told cracks in belt is considered "acceptable"
It may not be a belt. You have a number of pulleys the belt turns that could have a bad bearing

Both an old belt
and
one of the components having some trouble turning.

Start with a new belt
AND
while the old belt is off test spin all the pulleys you can to check for noise and resistance ( you probably can’t spin the p/s pump )

Rubber components get hard and compressed with age and heat.
a good LOOKING belt can be sufficiently skinnier that it was and have lost much of its grab.

THIS is why MY truck completely threw off the belt a few months ago…and I’m a ‘‘car guy’’ and had viewed the belt last oil change.
Due to age hardess and compression, the belt jumped a groove or two one time the compressor kicked on. That groove misalignment chewed through the belt and the loose portion got caught in the pulleys under the remaining belt causing all of the belt to come shreading off the pulleys in massive turmoil. With warning lights ablaze, no power steering, and temperature rising, I pull over to assess the damage under the hood not believing that I, of all people, had lost a belt we thought was good enough a month ago.
The only collateral damage was one small wire harness to the fan clutch that I repaired as i put on a new belt. But a flailing, shreading belt can take out many other harnesses and hoses. plus the overheating that is the reason you stop immediately.

The belt started squeaking on my 2006 Matrix after 5½ years and 27K miles, so consider yourself a little luckier than average.