Re: Dodgy Stat or Sender?
I just tried pulling off the temperature sensor connector. My engine management warning lamp came on. The car started fine but as you'd expect the dashboard display sat hard against the minimum stop at 50 deg C. The high speed fan came on after a couple of seconds and stayed on. The engine started fine.
There are two sensors in the unit I believe - one is for the dash gauge and the other is for the ECU? I guess the ECU one will bring on the warning lamp and turn the high speed fan on. The other one will show 50 deg on the dash display.
Your stat may have gone but even then I'd expect the display to sit about 70 deg.
I'd check the connection on the temp sensor first just to make sure it's seated and that it's clean.