I have a coolant leak somewhere.
Tried looking where from but all I can see/feel is it being sprayed up by the viscous fan.
I remove the coolant filler cap and see water coming in from somewhere.

Hi mate. That little jet of water is from small pipe coming from the top of the rad. That is normal.
Are you getting puddles of coolant under the fatty after being parked up?
There are lots of hoses behind the fan..it's very possible that one is leaking from a split or where the plastic connection becomes brittle.
If possible, remove the fan and shroud (have a look on YouTube) then get in there with a torch.
Good luck
Jake 2003 Range Rover Vogue 4.4 on Gas
1961 88" 2.25 diesel - George
Gone - 1997 3.9 V8i Discovery - Burt

Engine type would help

Can i run the engine with the fan removed to look for the leak? 2003 4.4 V8 Vogue

Thought it was in my sig. Its a 4.4 v8 2003 4.4 V8 Vogue

Having just rebuilt a 4.4 m62 which was killed by coolant leaks in the first place get your self some flouro dye in the coolant there on the bay and come with a uv light.
Poor it in and run around in it for a day then park it up and leave it..........go out when its dark pop the bonnet and start looking using the uv light its much easier at night in the dark the uv dye will glow much better under the uv torch.

Common water leaks on the m62 are
Hoses
Water pump
Radiator
Thermostat electrical connection
Rear of the engine coolant hoses
Front to rear coolant pipe O rings
And just for luck if your rearlly unlucky the valley pan gasket which leaks out from the bottom of the gearbox bell housing inspection cover