Hi All.
'Durite' temperature gauge arrived this morning and now fitted and surprise , surprise, the temperature is running at a steady 70. Took it up some serious hills, and temperature reached a maximum of just over 85 degree
Thanks for all your comments and particularly steve2286w who sent over the Gentlemans -guide- to- smiths-gauges.
I am now 99% sure as the the problem was the gauge especially since the gauge went to the nearly normal mark within a minute of switching on the engine.
For your information, I did the following checks which may be of help to others.
1) the voltage stabiliser is an electronic one and was giving out a constant 10.15V on tick over and under load
2) the earth was checked on the stabiliser and a separate earth added to ensure a good ground.
3) New series 3 temperature sensor was fitted.
4) No PTFE was used on the sensor thread and adapter. Sensor body was checked using a meter first from the brass body to a engine earth. Zero resistance.
5) Voltage checked to the sensor was 10.15V as per output from stabiliser
6) Disconnected wire to temperature sensor and shorted to earth on the engine block and needle shot off the scale past red and half way across the H.
7) Thermostat checked. Opening and closing correctly
8) Checked all readings with fuel level sensor disconnected. All were as expected
So I can only think it was the gauge.
Will let you all know if the problem comes back
