Went out earlier to find the battery was flat as a pancake in my Iveco, the cooling fan doesn't work so I have to bypass it when towing to stop the engine overheating. Doesn't run the fan, just engages an electromagnetic clutch. Anyway, forgot to unplug it last week!

Jump started it from the Mondeo, took about 10 minutes to get enough juice in the battery to get the Iveco started, held the car at about 2,000 rpm for those 10 minutes (not revving the balls off it). Van started, girlfriend parked car and I noticed coolant pouring out from under the engine! I just spent the weekend cleaning the thing ready to sell it!

Plain coincidence? Or could the car have got a bit hotter than normal and a thermostat has opened to allow more water to circulate to the radiator and revealed a previously unnoticed leak? Obviously water must circulate to the radiator whilst its being driven but maybe it can increase the flow or something when required? The expansion tank is near enough empty. Or could the extra strain on the auxillary belt affect the water pump? Each attempt to start the van pulled the Mondeo's revs down quite a lot so the alternator must have been working hard.

I would say coincidence personally, the thermostat should open pretty much whenever it is used, normally by the time the temperature gauge starts showing the temp going up the thermostat wont be far away from opening and if there was a problem the vehicle would overheat pretty quickly.
Sounds like water pump gone to me. Sometimes when you leave a car for a length of time the water pump shaft gets stuck on the seals and then rips the seal out when the vehicle starts.

Just a PITA and something lke that always happens when you want to sell something….

Looks like I'll have to try and get it on axle stands and have a root around. (easier said than done as there is only 4 jacking points…so once on the jack there is no where to put the axle stands!)

Hopefully not water pump as the car is in use daily so seals shouldn't be stuck. Started leaking in the minute between the van starting and moving the car.