I have a 97 C230 with 80k mi that, last night, I replaced my water pump. It was making noise from the front of the engine as you mention. To see if it is the water pump, you can disconnect the serpentine belt and turn/spin the water pump. Mine was so bad I could barely turn it by hand, probably got 6 HP by replacing. Also try to rattle the damper with the belt off. It is easy to put the belt back on so this shouldn't be hard. FYI-if you are replacing the water pump you may also want to replace the small "bypass hose" that goes to the t-stat (or other hoses and belt too). Why a water pump can't last a couple hundred thousand miles is beyond me, 80K is inexcusable.

good luck.