230E (W123) overheating

Can anyone advise how to test the fan please - it does not seem to be driven even when the engine temp. goes over 100. What temperature
should it cut in at?
Water and oil seem to be keeping themselves to themseves, and I can't see any bubbles in the collant, but the temperature just rises steadily until it gets "too hot"!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.