1999 S80 T6 coolant leak

[BodenM]

Hi all,
Got a 1999 S80 T6 with a coolant leak problem. Up until yesterday the car had been sitting in my garage for a week, bar being driven a few times, and had not leaked a drop of coolant. Yesterday, I drove it to uni, parked it up in the direct sun and went to class. Came back 3.5hrs later to a fat puddle of coolant on the ground, looked like it was originating from under the center of the aero tray, and a "CHECK COOLANT" warning on the dash, and sure as shit, the coolant tank is just about empty. Called RACQ (local AAA equivalent) who couldn't find the leak, they topped up the coolant with a bottle of demineralised water so I could move the car out of the carpark to load it onto a flatbed for towing, and since then, it hasn't leaked a drop of coolant. I've checked the expansion tank and its hose connections, and the radiator and radiator hoses, and none of those appear to be leaking, what other options are there that frequently are the cause of leaks on these cars?

[Cees Klumper]

Other sources of leaks could be the water pump or the thermostat housing and the hose from the thermostat housing to the expansion tank. Careful with taking the distribution cover off if you want to check the thermostat housing, there's a nipple on the thermostat housing that will break off at the slightest. Other possibility, although perhaps remote, could be the expansion tank cap? Good luck.