"SMS" > wrote in message
...
> Probably not the temperature sensor switch for the electric fan which
> appears to be doing its job. If the temperature sensor switch were faulty
> (turning on the fan at a higher temperature), then it would not be staying
> on to cool the engine down after the engine is shut off.
>
> When was the last time the thermostat was changed? Was it an OEM
> thermostat or after-market? Sometimes the after-market thermostats are not
> opening at the proper temperature and the normal operating temperature of
> the engine changes. You don't want to run either too hot or too cool, so
> putting in a lower temperature thermostat is not a good idea.

Most of the recent systems I've seen for controlling the cooling fan use the
Coolant Temperature Sensor (CTS). The ECU reads that and controls the
temperature gauge and cooling fan. If that's the case, don't think you have
two separate systems that agree.
I had an old Subaru where a temperature switch in the radiator directly
controlled the cooling fan. In that case, as the contacts wore with age
(from switching current), the car began running hotter. Changing the switch
was the fix.
Most thermostats by the way they are designed will tend to fail open
rather than closed. That's why I recommended a cooling system flush.

Good call from Hubops about tranny temp. Auto Trans have an oil cooler that
is part of the radiator. This can add to the coolant temperature in extreme
cases. Good idea to check the color and smell of the tranny fluid.