I had an issue with the cooling system - when the aircon was on and the air temperature was above 17 deg C the viscous fan roared its head off - after a quick look under the bonnet coolant was low topped it up and a week later here we go again. Pressure tested the cooling system and it was leaking from not one but 4 hoses the hoses were fine but the retaining clips were no longer retaining so replace these and yep when I re tested others started to leak so now going round checking hoses and replacing clips.
Also found an odd one on the viscous fan that was very noisy one of the blades was missing a large chunk no other damage anywhere so new one on order.