As I said, it functions completely normally unless I push it very hard up a steep grade. It warms up normally, tops out a little over 80 C in normal driving, etc. Nothing is different except how it acts on grades (when the thermostat should be wide open anyway!). It isn't too cool in normal driving and has no problem warming up in the morning...

__________________
'81 300TD Wagon 355k (Miss Diesel)
'83 300SD 180k
'84 500SEL 190k (Parting it out)