CX-30 Radiator cooling fan issue?

[gpdav]

My car's radiator cooling fan doesn't turn on unless the AC is on, even though the engine (G122, 2.0L, NA) is running hot: temperature gauge reads around 100°C on the dashboard and the engine surface temperature rises to 140-150°C (measured with a infrared thermometer). Is this normal?

 

[edmaz]

So the fans never run with the AC off, regardless of how long you let it idle when parked? In any case, you need to use an OBD live data reader in order to determine exactly what the coolant (ECT) temp is. Trying to rely on the dash gauge temp is not a good way to try diagnosing a potential issue with the fans.

 

[gpdav]

So the fans never run with the AC off, regardless of how long you let it idle when parked? In any case, you need to use an OBD live data reader in order to determine exactly what the coolant (ECT) temp is. Trying to rely on the dash gauge temp is not a good way to try diagnosing a potential issue with the fans.

Thanks! The coolant temperature via OBD live data reader varies between 88 and 95°C.

 

[edmaz]

Thanks! The coolant temperature via OBD live data reader varies between 88 and 95°C.

Those temps are below the trigger setpoint, so the fan not coming on is totally normal.

 

[gpdav]

Those temps are below the trigger setpoint, so the fan not coming on is totally normal.

Thanks! What would be the trigger setpoint? Above 100°C?

 

[edmaz]

Thanks! What would be the trigger setpoint? Above 100°C?

On my CX-5 the fan-on setpoint is 100°C, and it will shut off when ECT is back down to 91°C. Although your vehicle's engine is not the same as mine, I suspect the fan setpoints are either the same, or at least very close.