Unless it is a 190e it should have the viscous. Easiest way to determine if fan clutch is good, watch it when temp is 100, shut off your engine and see is it spins for a second, if it spins for 3 seconds or so then it might be the fan clutch or radiator is not hot enough( clogged radiator or thermostate problem) a flow problem. I have seen alot of good fan clutches get changed. Most of the time fan clutch is good . Expensive part to guess at.