pilotknob1964

I've noticed that after my car sits for more than a few days, it makes a strange noise momentarily when I start it up. I'll try to explain what it sounds like. For those of you who have seen Dumb and Dumber, it sounds like a 1 second version of Jim Carrys' "most annoying sound ever". For those of you who haven't, it sounds similar to a dry bearing making a momentary howl. I had the belts replaced with the valve cover gaskets in November, but don't recall it making this noise before. Could it possibly be a bad idler pulley or that the belts are too tight? Any input would be greatly appreciated. Also, could the water pump/timing belt section cause this problem? They were replaced 88,000 miles ago(I know, they're due, but after 1100 in repairs in the last 6 mos. I'm taking a short break!) No other symptoms related to this except for the noise. Thanks!