Ok.. My 93' 300ce has been overheating. Highway speeds over 40mph it is fine. 95deg with outside temps to 93deg. In stop & go in town driving it vaires from 100 -115. Turning on the heater it goes back down fairly quickly. If I return to highway speeds it goes back down. I do not seem to have any or very little pressure at the cap. I am not loosing any coolant, oil looks clear and fine. Both of the aux fans work as they should.

I have repalced and done the following in the last month:

Coolent tank.( old one had a stress crack on the backside and was leaking)
Rad cap
upper/lower hose
Thermostate
Fan Clutch (from Pelican)
Coolant ( MB coolant with distilled water)
Serp belt
Spark plugs and boots

I question the new fan clutch as when I put it on it would only turn by hand pushing it 90 deg now a week later it will turn 180/240 deg. And I can stop it when running with one section of the paper rolled up.

The rad is clean I have blown out with air any grit and trash.

The car runs great with no other issues.

So suggestions!