In the last few weeks i have had a sneaking suspicion that the defender was running hotter then normal. I did all the normal things full fluid flush, new thermo. Anyway I purchased a vdo temp gauge and drilled and tapped it into the top pipe near the thermostat as the defender has no switches like the disco for aircon and fan function. Anyway on a run the standard gauge reads normal, but the VDO reads 100 c. The radiator was rodded about 12months ago. I have not been bush bashing in that time so no mud or crud. Viscous hub to be changed but thinking maybe water pump is a worn. Any tests for it or just change it out.