What could possibly go wrong? In a white 505 SR Auto at 488000kms.
One always wonders why the fan has been locked on in a pushrod 505. Usually a bad sign. . .
Overheating? Temperature sensitive cracked head? Head shaved so far it will ping at normal temperature? But no, the magnetic coupling had failed, and the electric fan wouldn’t run even when the thermo-switch leads were shorted.
Turned out that battery acid corrosion had got well into the plug leading to the fan. And the connections on the thermoswitch were loose from vibration, too.
Starting was never a really quick process either, and this was traced to a faulty alternator.
Uneven idling was fixed by tightening the very loose carby base bolts, and a bit of hot running seems to have helped, probably by burning carbon off the valves.