Your Fiat water pump performs one of the most essential functions of the engine.  It circulates the coolant throughout the heads, engine block and radiator.  The coolant absorbs the heat from the engine and releases it to the atmosphere through the radiator.  If the water pump fails, the coolant will sit and boil in the engine jacket.  This will cause over heating and result in engine failure.  The three main causes of water pump failure are: leaking shaft seals, noisy shaft seals, and impeller slippage on the water pump shaft.  Leaking shaft seals can be spotted by locating coolant stains around the vent area.  Normal oxidation of the lubricant and normal wear of the bearings will cause your bearings to fail.   This happens more often to remanufactured water pumps.  To avoid these three causes of water pump failure, it's important to replace your water pump every 100,000 to 150,000 miles.