Replace thermostat, this will cure the overcooling problem (and prevent overheating if it fails shut, too!).

Replace the fan shroud and re-install the sound encapsulation panel -- both these items are important to provide proper cooling air flow in hot conditions. the fan shroud is designed so that the fan will pull air over the entire radiator and exhaust it. Without the shroud, air will circulate from behind the fan around the to front and back again, rather than through the radiator. You then risk overheating.

The bottom panel has a vent slot in it, aligned with the shroud and fan to exhaust the hot air out the bottom of the engine compartment rather than back over the engine and firewall. Helps keep both engine and passenger compartment cooler, and keeps water off the alternator and belt, too.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!