[powerdyne 5.0]

I decided to put a new 180* thremostat in and when I first put it in the car started leeking like crazy around the thermostat housing, so i put a new gasket in it the second time, started the car looked for leeks and i did not see any so I went for a test drive and then about 1-2 mins later i hear this high pichted noise so i went back home and I saw a hole in the water pump??? It looked like where a freeze plug went but then I was told that there is a hole there anyways???? Does any body know about this??? thanks