the water pumps on these things are fairly easy to replace a few bolts holding it on. drain the fuild. A new gasket and your done. If your leaking fuild though I don't care what the temp gauge says stop driving it and get it fixed unless you want to spend a few thousand on new heads too. It definetly sounds like the water pump or its gasket let go. Now might be a good time to replace those upper lower ect. hoses too with that many miles if they havent already.
Don't Drive Fast, Just Fly low!!!
97 4.6 engine, 9" conical filter, 100mm Densecharger intake, 80mm L-MAF, Custom Chip, Optima Red top, J-Mod, Underdrive pulleys, Mk8 Aluminum drive shaft, no cats, 3" piping to Flowmaster 1 in 2 out 4" tips, crossdrilled rotors, shaved antenna Fuba on top, Clear corners, Gts solar wing. 99PI heads, JBA headers, Cobra R dual ram hood, Saleen whale tail spoiler w/3rd brake light, Eibach front/ Intrax rear springs.
Carbon fiber valve covers, 2800 stall converter.