Bought a certified used 04 Dodge ram 1500 3.7L v6 on 09 which only had 60k on it. In august of 10, started overheating. Truck would be fine on the freeway, but on streets or in stop and go traffic, would over heat to were the gauge was all the way in the red. Had to turn the heat on blast to remove some of the hot air. Replaced the raidator, themo., and engine at the time. Fast foward to the start of may, and the gauge is telling em once again that the engine is starting to over heat. Same problem. On freeways, gauge is right in the middle, on streets and in stop and go traffic, guage is 9/10 of the way towars the red. Have checked the radiator and its not leaking, top off the cooliant as well. Have noticed that water is leaking from the truck. Need advise. Is the a common problem, that would make the old raditor and engine overheat and a new raditor and engine to over heat? Could it be the water pump with the water leaking? And suggestions?