Hi,
I'm new to the group so maybe this posting is better elsewhere. Please let me know if there is another forum for the topic.

I've got a 1978 450sl and at the last oil change the mechanic said that it was running a little hot for this cool/cold time of the year. It was about 200 degreees F and so he suggested 2 things. First, change out the thermostat or worse, R&I the radiator and recore it. As it turns out, the themostat was stuck and so he replaced it. Now he is OK with the 25 degree F reduction in temperature (at 175 degrees F). But, my question to the group is, what should be the normal winter/summer temperature of my car? If it is 175F during winter, won't I see 225F+ during 100F+ summer days?

At what point should I become concerned?

I've got a 74 450 SL and it runs around 175 degrees all the time.

I think that is what the manual says it should be at.

Hi Aaron,
Thanks for the input. It seems to be operating OK now. With a little experience on the temp I do not panic when it temporarily goes above the 175-185 range.