First i pulled the thermostat for Summer use during semi-annual radiator flush - mainling the flow - this brings operating temp down about 15 degrees.

Then i was messing with the auxiliary electric radiator fan..... trying to set it up with manual toggle switch from dashboard bypassing whatever sensor is supposed to make it run. Bench tested the fan to the battery and it was blown..... so I hurled the damned thing into the bushes so at least it wont block air flow to the radiator.

My plan is to add a fan clutch (which the 240D has never had) so the fan can spin faster than crankshaft speed. Am also prowling junkyards for suitable auxiliary radiator cooling fan from *any* car that will fit. One day I'd even like to find a larger capacity radiator to replace the silly plastic unit that plagued 123's.

The car has never overheated, yet hits 200 degrees in heavy traffic without yanking the thermostat. And throwing out the dead auxiliary fan also helps stabilize it at 185* for long haul runs.