1990 300TE.
The TE runs at about 80 degrees c on the open road, but at idle in N, the engine temperature rises towards 100 degrees after 5 minutes and idling in D the engine pushes 110 degrees, but is very stinky with a scorched metal smell from the engine bay and exhaust.
There isn't any emulsion on the oil filler cap, the coolant is clean and the viscous fan turns, although the idle speed in D is just about 500rpm. The exhaust emissions at idle are 0.143% CO as set by the independent Merc garage. The car does not have a cat, a/c or electric fans as it is UK / Euro spec.
What temperature is the viscous fan supposed to cut in at? it is the bimetallic strip triggered version, not the magnetic triggered version.
Am I missing anything obvious?