My 90 Eunos used to run with the temperature gauge well below the half way point. Recently this has gone up to the half way point and slightly beyond. I have put a new fan temperature switch in, flushed the system and bought an OEM rad cap. The fan switches on OK .but going by the gauge, the engine is still running hot.
What should I look at next?
Is the thermostat working properly?
The radiators on these tend to block up with age. Certainly worth checking the rad with a flow test. Drain coolant, disconnect top and bottom hoses from radiator and run a hose through the top port. Water should flow freely from the bottom port. If weak flow, rad is likely blocked and requires replacing.
Aggree with rhinno666.
Forget to say that I have also fitted a new thermostat and back flushed the radiator and run “Radflush” through the system.