I have a 2000 GMC Savana 1500 Conversion Van, It's a 4.3 V6 automatic with 95,000 miles. The problem is the drivebelt is squealing. It squeals when it is idleing, and gets louder and faster when I accelerate. There is nothing leaking, and so far I have replaced the belt, the tensioner pulley(entire assembly), and the idler pulley. After all this I am drawing a blank. I am desperate to stop the annoying sound PLEASE!
Remove the belt and check the pulleys, make sure they are clean and turn easily, check for side play whiggle them to see if any are going bad. Check all pulleys including water pump pulley. Have seen a loose pulley make a belt slid causing it to squeel. Look at the pulleys to see if they line up properly.