Could the rattle be my water pump???

[ikessky]

Okay, so here's the reason I'm thinking this now. I originally thought that it was coming from my AC compressor, but now I'm thinking it is the water pump. Because I was leaking some coolant (not very much at all), I decided to try the old mechanic-in-a-can trick. I got some cooling system sealer that contained water pump conditioners. Now after driving for a while, the rattle has significantly decreased. Could it be that the WP bearings are wiped out or nearly there and it's rattling with the AC turned of because of the decreased load?

[3100 MPFI]

try taking the belt off, and seeing if the pulley for the waterpump feels loose, or if you can make it rattle.