I replaced the Viscos fan for a electric Kenlow fan which worked well. I live in the south of France where temperatures are much higher than the UK. The electric fan would come on maybe two or three times a year. I also did a trip to Morocco with the Kenlow fan, no problems what so ever. However I found myself always watching the temperature gauge. I put the electric fan on as I read it saves on fuel etc etc. rubbish, made no difference what so ever. I also thought the engine might warm up quicker during the winter months and I might get some heat coming through the heater system. Also made no difference what so ever. I have recently gone back to the Viscos fan. If the Viscos is working as it should it does spin round on start up but then just ticks over when the engine is up to temperature. I feel I have piece of mind now as I am not constantly checking the engine temp gauge. If the Viscos fan was good enough for Land Rover to fit them, then its good enough for me. The Kenlow fan did work fine, its in the back of my garage somewhere.

Bobsticle said:

Daft question.
Is it hottest at the top hose or the bottom one.
I presumed the top one and put my temp sensors in this.

Click to expand...

the top hose, as that is next to thermostat. yu did right .

The viscous fan really needs the cowl on the radiator to be truly effective how many people still have that fitted.
Electric fan in front of rad if close to surface will force air through rad.
My series 3 came with a sherpa engine and no cowl fitted electric fan in front and removed viscous did not save fuel but have double heater matrix and got plenty of heat into cab when needed, now has 200DI fitted so no room for viscous fan heater still works well and the only time electric fan is needed is if I am fully loaded and driving tracks so slow speed. Fully loaded on roads is normally fine temp will sit at 88deg which is the 200 stat setting.

I have a digital thermometer with the sender on the top hose. I generally get a reading of about 75 degrees whilst driving but it goes up to 80 when stood in slow traffic. It did go to 100 when I had it idling on the drive and threw the coolant out. I think its just going to be trial and error to get it just right.