I've had a couple of MB Gassers, C280 and C43. Once these cars are warmed up, I've never seen the temp gauge below 80C. And with C43, 90C was common. On my E300, I do see up to 95C when it's hot. But when running on the highway in cooler weather, sometimes the gauge drops as low as 70C. Do the TDs get a different thermostat that gives them more range on temp? And do Diesels in general run better that cool?

__________________
Barker

Diesel ideal operating temp. is ~87-95*C. Thermostat on diesels should open at 87*C. With a good thermostat, once warmed up, should not be below that unless stuck.

__________________
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

Bad thermostat, replace it.

I'm going to have to do the one on the 280, didn't replace it when I did the water pump (duh!), so have to drain the coolant again.....going to fix the heater valves at the same time , too.

A bad thermostat not closing will cause low operating temp (much lower than it is now) when it cools off more, and will usually cause overheating in hot weather in traffic because it won't open all the way, either.

The 280 has 75C thermostat, but the temp won't get up to 175F unless I drive for 15 min or so, and then goes up to 212F or higher if I let it idle for a while. Bad thermostat.

Peter

__________________
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!

Ditto on the bad thermostat. I was told that when these fail they tend to fail open so the engine runs too cool. You will want to get it fixed before the snow flies or you may have a very rough running engine.

__________________
LRG
1987 300D Turbo 175K
2006 Toyota Prius, efficent but no soul
1985 300 TDT(130K miles of trouble free motoring)now sold

I had one that went bad, and it was stuck open. My car never heated up in the winter, and the heater didn't work that well either.