Engine fan on when standing still and low mpg 2002 yaris

[CTScott]

Originally Posted by andqe

Thanks for the reply Scott.
The engine fan isn't always on it turns on periodically. I don't think the sensor is bad as it turns on when the engine is hot and the engine seems to be (the front right headlight has faded from clear to almost yellow on the top part of it.). Unfortunately the yaris doesn't have an engine temp light. Does coolant always have to be flowing around the engine, how would I check this is ok? The fill level is slap bam in the middle and there is no leakage.

The water pump runs constantly to move water, by the thermostat regulates flow through the radiator.

Typically with the engine running, once it is warmed up, the fan will come on more when stationary than while moving, as the moving air has the same effect as the fan.