I have a 2001 ML270 (early version) automatic. The coolant temperature gauge was sitting at just belowthe middle, i.e. <80°C (176°F) when I bought it 3 years ago. It's coming down in time and is now sitting at about 60°C (i.e. 1/4). The temperature rises up to 80°C when stuck at traffic. The usual suspect is the thermostat open up at a lower temperature then design which I believe is 88°C. Theoutdoor temperature is normally below 10°C (50°F). The fan works well in summer time whenoutdoor temperature isattheupper 20s.Any other suggestions?