My 1989 300E overheats when I am at a stop and just idling. When I am driving the car the temp is just above 80 degrees but when I stop the temp rises past 100 to almost 120 degrees. My aux fan kicks in at 105 degrees and then the car starts to cool down.

In the past 6 months I changed the water pump, temp sensor, rad fluid flush, rad cap, thermostat and all the rad hoses. I have no idea what is causing the overheating.

Is there anything I should be looking for?

Thanks,
Fab

That's fairly normal... but you may have a bad viscious fan clutch.

When the temps get up over 100-110 pull over to a safe spoot, turn off the engine and pop the hood. If the fan between the rad and the engine block spins freely (it should have some resistance at that temp) your fan clutch may have leaked out the its hydraulic fluid. A partly plugged radiator or a missing fan shroud can also cause the fan clutch not to engage. It can be refurbished by a method described on this forum or replaced... but you are probably not harming the car driving it in this way, as long as the auxiliary fan kicks in before the temp gets into the red zone and brings it back down the system is working within the range it was designed for.

__________________
-Marty

1986 300E 220,000 miles+ transmission impossible
(Now waiting under a bridge in order to become one)

Reading your M103 duty cycle:
http://www.peachparts.com/shopforum/831799-post13.html
http://www.peachparts.com/shopforum/831807-post14.html

Does it do it with a/c OFF ????