I have a 2004 Pontiac Grandam GT 3.4L with 91,300 and for the past couple of months I have been having problems with it overheating. In the beginning the coolant light would come on, I would fill the reserve tank only to have to do so again later in the day. This would continue for a day or two and then it would be fine for a month before completing the cycle all over again. We did replace the radiator. However after a couple months the problem has restarted and much worse. For the past four days I have constantly had to fill the tank and when it heats past 230 you can hear a rattling noise from the driver side of the engine. My brother did discover a drip on this same side in the engine. Do you have any idea what this problem could be?