Car in question is a 2010 Mazda 3 2.5L. 193,000kms.
My car's temperature starts to rise when idling or driving at low RPM. Before this problem started, the coolant temperature always stayed at 88C. Now when the car is idling or in stop and go traffic the temperature keeps rising unless I turn on the heater full blast. When driving on the highway, the temperature stays around 93C(5 degrees above normal), but does not rise above that.
However, on the highway on if I stay on a lower gear and keep the RPMs above 4,000, the temperature drops and stays at 88C as normal.
Also, the radiator fan does not seem to turn on when the temperature is rising. However, it does turn on when I turn the AC on.
What has been done already:
- Changed the thermostat.
- Drain the coolant and filled it with new coolant.
- Bleed the system of any air.
I'm trying to figure out and fix the cooling fan issue next. Do I also need to change the water pump because the overheating does not occur at high RPM?