Loud Whining noise while idling

99 Venture has the above and it gets a little louder then almost silent once it shift gears up the first time. I thought it was the water pump but it's not that and now wondering if it's the serpentine belt. Anybody had this problem or got any good ideas. Thanks.

Sounds like the problem I had. Thought it was the power steering pump.
Ended up breaking the belt to find out the pulley on the belt tensioner was seized up. It cost $20 for just the pully and 10 minutes to change. YOu don't need to replace the whole tensioner assembly. If it fixes it great if not well it only cost $20.