Update / still looking for suggestions on 1.8 MX5 Westfield overheating issue.
Replaced rad, thermostat and both temp sensors.
Reading the housing, stat opens at 88 degrees, fan kicks in at 97 and off again around 90.
Temp gauge reads zero when unplugged, but rises off the scale when the housing that the sensor is into is around 80 degrees as measured with IR thermometer.
So basically I don't think it's overheating, if it was the fan would be on permanently.
Could it be the gauge in the dash or a bad earth?