cat sound from engine

my 1997 transport when first started, sounds like a cat is stuck in the belts. I have new belts so it's not that. when the engine gets warm maybe 5 minutes later the sound goes away. T he sound always goes and comes back, maybe on a 20 minute drive it happens at first, then 10 minutes later. I think it's the water pump maybe or the a/c compressor but like my name i know nothing. Any suggestions.
Thanks.

If it was the water pump, it likely would be constantly. It's possible that it's the AC compressor, but that would only turn on if you had the AC or defroster turned on. How is your belt tension? Have you tried belt dressing to see if it still may be your belt?