My 98 continues to have a belt squeak? Both belt tensioners have been replaced along with the belt? Even the dealer is perplexed? Even more odd...the squeak is only when cold...after about a minimum of 10-15 miles, the squeak goes away. Any ideas?

 

Clean your crank pulley with a wire brush and brake clean. Also clean any other grooved pulley, after cleaning try a good quality Gates or GM belt. Sometimes you get a build up on the pulleys and the squeak you here is the belt slipping. [8D]

 

Not sure if it would work for you.....but my belt was sqeaking on my 97 while I was on the track....and one of the guys that has been around vettes for a long time (nicknamed the "professor") went to his trailer, got a bar of soap out of his shaving kit and with the engine running (obviously) took the bar of soap and held it up against the under side of the belt and after a couple seconds, the squeak went away.....same concept, I would guess as mech259 is getting at.....cleaning.