I have a 2000 ford focus with a 2001 engine inside of it. when the car gets hot and i am sitting at idle in traffic or just at idle the temp goes all the way up in the red and sits there until i start moving and the engine start cooling from the outside air. so i let the car sit at idle one day and the engine went all the way to the red and then eventually the fan kicked on and bought the temp half way but the fan kicks on way too late the temp was at 240degrees or more i had a scan tool on it. Aready i changed the thermostat and thermostat housing. I am thinking about changing the coolant temp sensor any advice or have any body has had this problems before.