Had all the symptoms of a dead thermostat i.e.
Coolant temp gauge off the bottom of the scale while driving on fast road.So, I got one of the one of the ones that goes in the radiator top hose from the bloke who sells them with a hose clip for the 8v engines. Fitted the new thermostat and as it was cold, it was firmly shut.
Temp comes up to normal eventually [only] when stopped or driving slowly.
Took it out for a long drive today the symptoms had not changed AT ALL!
I am totally confused how the engine can massively over-cool with two thermostats fitted, one of which is brand new and was shut.
How can this happen?
Where is the coolant temp sensor, could it be being cooled by the air flow?