To Doug 41
I wouldn't worry about the oil pressure guage at idle. I'm pretty sure all Mercedes do this. As long as that needle spikes reight back up to 3 when you give it gas (usually by 1000rpm its up to 3 and will stay there. I'm not sure about the car running as hot as 100 though. I have recently changed my coolant (previous owner used a non-mercedes coolant) ad if anything they car is running cooler. I have been considering changing my thermostat too, just as preventative maintainance. How much did it cost to change yours? Did you do it yourself? I will try to have my changed by New Year's and I will email you with the results. I do think these cars are supposed to run just a hair about 80 degrees C. Did you get it done at a dealer? If not maybe they gave you a thermostat that opens too hot. If you can't wait for my answer give MBUSA or your local dealer a call. Ask to speak with a service advisor and see if that is acceptable engine temp.
I'll let you know how mine goes. Happy Holidays and Happy New Year
1995 E420 - retired
1986 420SEL - retired