New to me E420, runs cold @60C
 

Hi guys, my new 1994 E420 runs alittle on the cold side, I did an hour long highway trip at 60 mph, and it runs at 60C the whole time. In stop and go driving i did see an 80, and before I had a fan shroud it got to 100. but now it just sits at 60. Is this normal behaviour.

My first thought was that my thermostat is bad, but wanted opinions first.

I've got a 300SE (W126) that runs around 60c also, and my tech says not to worry. It's been like that since I've had it which is 4 years and close to 60K miles.

Thermo is stuck open, but you will need the engine serial # b/c there was a mid-year change in thermo and they do not interchange.

E420 Thermostat
 

I had the same problem with my E420. Had a new thermostat installed and now it runs perfectly at 80C. Any temp cooler than that would encourage excessive carbon. At 100C the moisture generated in the crankcase starts to evaporate cutting down the formation of acids.
Anziani

300E 200K
E420 110K

I'd love to see the A/F mix ratio on that car...........

I think you need to speak with another tech.

What do you get for gas milage on that car?

jp