One of the first questions asked by the guy who is leading our group in Morocco this year was; "What type of fan have you got fitted?"
When I told him I had a factory standard viscous, he said; "Good, you've got the best item for the job. Anything else on the 300tdi's has proved to be a pain in the arse in the past."
Given he's been leading groups over there several times a year since 1982, I pretty much valued this opinion over anything else I've ever read on the subject.
I did a coolant flush and change just before Christmas, as that's when I tend to do a full check of levels as I also check the level of antifreeze etc ready for the cooler months.
But reckon my rad is on its way out, as had a better look at it, and its not looking at its best to say the least.....