This may be a dumb question, but since i'm not sure I am going to ask. I am working on a 1984 944 series one Porsche.. I assume the water pump is bad because the car overheats, coolant is overflowing from the fill reserviour and the inlet on the intake is completly dry. I back flushed the radiator and it ran clear. However, now that I have the front timing cover open, I noticed the belt for the cam to water pump and crank is loose. When spining the water pump, I feel no obstruction and the shaft has no play. Could this be simply that I have to replace (or tighten the belt? By the way, I did replace the thermostat (even though the old one did open when boiled in water. Any help with this would be apreciated.