I noticed in the last few days that on my '90 300SE, the temp gauge goes from 83 to 98 in a matter of a minute or two. Like if you are waiting for a light to change.

Waiting in a line, like a drive through, 5-10 minutes, it will go up to 105 or 110. As soon as the aux fan comes on,(about 110) or as soon as you start moving, the temp drops quickly back to 83.

The outside temp has been around 75. with the really warm weather coming, I want to be sure I'm prepared. What do you think?

Thanks

Got enough coolant? What's the condition of the coolant (and the interior of the radiator)? When is the last time the system was thoroughly flushed? Is the aux fan kicking in?

On mine the temp was starting to climb in traffic. I had the radiator boiled for PM and put new upper/lower hoses and 50/50 mix in (MB coolant) and Water Wetter. Temp now sits nicely just a shade above 175. Should do fine when I run it to Las Vegas at the end of the month.

I would start by checking all of the above first. Possibly even change the T-stat for GP.

Typo?
 

You said; "Temp now sits nicely just a shade above 175".

You didn't mean that, did you? :confused:

I believe Mike meant 175F which is nice. Translates to about 80C. :)

Yeppers,

I omitted an F, meant to say 175F as my guages aren't metric.