As these cars age, the radiator tubes develop internal deposits, which reduces their heat exchange efficiency. Significant deposit buildup would be normal if the cooling system has been serviced with conventional green antifreeze.

If the car has only been serviced with MB antifreeze or Dexcool, deposit buildup will be less because these formulations either contain no inorganic salts (Dexcool) or a very minimum amount (MB brand). Though inorganic salt formulations can be effective in controlling corrosion, they precipitate out and clog the tubes.

The engine driven fan clutch should nearly lock at about 100C and you should hear fan roar above about 2000 revs. The electric fans should activate at high speed at about 110C. If fan operation is normal, the most likely culprit of consistent hot running is probably a loss of radiator efficiency due to deposit buildup.

Duke