Hmmm okay so then its the belt that goes from the alternator to the water pump. Same goes for the alternator. Its pivots back and fourth to tension the belt.

Check that one and come back. I'm still trying to figure out which belt your talking about. On a 4g63 there's 3... ps to water pump, alt to water pump and underdrive pulley (crank), AC to tensioner pulley to underdrive pulley (crank).