FWIW - I have had a bad temp sensor in the '82. It read +20-25C from the actual temp at all times. Verified inaccuracy with IR temp gun.

Put in new sensor and all is well.

__________________
-------------------------------
'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car