Bl**dy mystery.
Finished working about 7pm. Arranged for a lift back thinking I would take the viscous fan and water-pump off the scrapper. Figured I may as well test the viscous fan before setting off as it was going to be a few hours round trip so plenty of time to cool down. Viscous shredded the newspaper so no issues there. Decided to try to make it home armed with lots of water and my friend following. Damn thing performed perfectly. Got home, left the engine running while I unloaded my tools but needle only just to the right of 12 o'clock. Switched it off.
So, what was it? Is it possible the stat stuck closed? Did the water pump seize and then free itself off again? I swapped to the metal pump soon after getting the car 10 years or so ago.
I dunno. It is messing with my mind.