I've had the serpentine belt replaced on my 1997 Saturn within the last year and a half, and the Saturn dealer also replaced the idler pulley (whatever that is). Whenever it's very humid or has rained, the belt squeaks when I first start the car in the morning, but that soon goes away. Now, however, the belt seems to be making noise more often.
I've heard lots of opinions on this - put dressing on the belt, don't put dressing because it'll slop onto the engine, tighten it, replace it. Does it make sense to have to replace it this soon - after only a year and a half? Does it just need some sort of tightening? All opinions appreciated. P.S. What does the idler pulley do?