[sfontain]

I'm not an expert on cooling systems, but here is my opinion: Your thermostat may be stuck open or is opening too early, or your cooling fan is staying on.

If you change your thermostat do so with a *Ford* part, not an aftermarket one. I suppose this is the first thing I would try. Unfortunately, this will mean draining your coolant.

If your radiator fan is staying on, you may have a bad coolant temperature sensor. But I doubt this; as I understand it, these sensors usually fail the opposite way, telling the PCM that the coolant is extremely cold, so your fan wouldn't come on at all and may cause an overheating condition. Anyway... In my car (2002), I can hear the fan spin down at idle after I've been driving for a while; additionally, there is a slight bump in the RPMs when it turns on or off. If you can hear it turning on/off properly, this obviously isn't the problem.

I would lean heavily toward a new thermostat. Instructions for replacement will be found in a Haynes or Chilton manual.

*edit* I've changed my mind. I completely believe you need a new thermostat. I think even if your fan were staying on, if the thermostat were staying closed when it was supposed to be closed, no coolant is entering your radiator to be cooled by the fan.