After i get my car's temp up, there's suddenly a knocking sound coming directly from the water pump. Just wondering if the water pump's bad or if something somehow got in there.

 

When it's hot and making the noise, shut it off, take the fan belt off and start it back up while listening for the knock. Can't imagine the pump making this noise but could well be the lower pulley or damper, or something else there.

 

Just thought i'd say that i did go ahead and swap out my water pump for a new one, and the problem went away.

 

either a loose pulley, or the balancer on the car is comming apart.
never heard a water pump make any noise except a squeal.

 

What would have accounted for it only making a sound once it came up to 220*?