Just to add my three penny worth. My V6 had a new radiator a few months back and was running perfectly. A week or so ago I noticed that it suddenly started to lose coolant rather quickly (about half a pint on an eleven mile round trip to the station and back). First port of call was of course the V, where I noticed some liquid had accumulated. Using my hi-tech tool to identify it (a tightly rolled piece of kitchen roll inserted through the gaps in the manifold and dipped in the liquid. If it turns pink it's coolant. If it comes back brown it's probably mouse urine as a result of the little blighters once more nesting in the bonnet soundproofing). To my disappointment but without any real surprise it came back pink.
My first thought was, naturally enough, some part of the thermostat housing assembly. Quite annoying really as I'd been half way to it when swapping out my rattling inlet manifold chamber only a week or so earlier. The thought occurred to me that maybe I had knocked it while congratulating myself on getting the chamber off without detaching the throttle body.
I mentioned it to a mechanic friend who suggested I come round and let him have a look before I started taking it apart again. Once we got in there with a bright light and some mirrors it became apparent that the real culprit was a failed clip attaching the top hose to the thermostat housing. The coolant was leaking from the hose, down the back of the manifold and into the V, accumulating next to the thermostat housing.
A five minute fix after that.
Evidence once again of my favourite observation that water flows anywhere except in straight lines
