my dodge intrepid was overheating and I replaced the thermostat. Now just one day out of the blue i started it and it idled up then back low like it was going to cut off. So I figured it might be the water pump well when I took the timing cover off I saw 4 ball-bearings sitting in there.Can anyone tell me where thses ball bearings come from is it thecrankshaft sprocket or something. please help

The best way to tell is remove the tension from the belt, and see where the slop is. How many miles, and has the belt been changed in the past? How about the water pump (timming belt driven)? Seeing that you are overheating, my first guess is the water pump went out on you.