When everything is in spec these cars can run like MB designed them to when new.

Despite my radiator being 20 years old, the car ran incredibly well on the hottest day on record here in Sydney. Temperature reached 46.4 degrees Celsius (115.5 Fahrenheit) and that was the official temp.

Regular coolant changes/flushes must have helped along with an almost new viscous fan coupling, thermostat, top/bottom hose and rad cap.

For the most part of my 80km drive, the car sounded like the under workings of a diesel electric train! That mechanical fan absolutely raws when engaged.
Temp gauge stated 100C at most times (usually around 85-90C) and only went to 105C whilst stuck at a long red traffic light in which the electric fans came on.

Admittedly I was anxious for some parts of the trip but confident to take it out on hot days now.

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1995 E300 Diesel