Car runs hot while idling changed thermostat cooling fan is working but temperature still goes up to 240 degs

Over heating the engine is a serious concern. With the hood raised you should hear the motorized fan turn on just behind the radiator as the engine requires additional cooling.. If you look in from the rear of the radiator you should see the fan blades.

This electric powered motor operates on a thermostat and when the engine temperature rises this fan should come on. I'm assuming from your description that when driving and air is flowing through the radiator as the car travels the engine is nor overheating.

Check fan motor thermostat, check fan motor and check wiring.

Wiring Diagrams related to the Honda Civic
http://www.wiringdiagrams21.com/category/automotive/honda-automotive/civic

Motor engine cooling fan only runs as engine temperature requires additional cooling.

check coolant level could be too low allowing air in the cooling system causing air pocket in engine around the engine coolant sensor.coolant sensor needs to be in hot coolant so it will cause the cooling fan to come on at a set temperature.make sure coolant correct level and the coolant level in the cooling overflow jug should be at full cold mark.the cooling overflow jug should never be empty,if you see empty cooling overflow jug air got in the cooling system so make sure when engine cold every time raise hood make sure cooling overflow jug coolant level at full cold mark.if jug stay empty you have cooling leak.so replace radiator cap,if coolant level all good,i would replace the engine coolant temperature and thermostat.when your car come to a long stop or driving along long line of slow moving traffic the engine coolant blower motor should running if not have vechicle code scan for faulty coolant fan motor control module.or ecm problems.

Did you controlled the cooling fluid? Maybe you have not enough.

The breather hose should run to the air cleaner housing or intake tube.
Check your radiator cooling fan. If it isn't working the car will run hot at slow speeds or idle then cool down after you get going faster. A quick check would be to turn the AC on and see if the fan comes on. If not try lightly tapping on the cooling fan motor with a wooden broom handle. If it comes on then you have a bad motor.
If the fan comes on with the AC then check to see if the fan comes on after the engine gets hot. If the engine temp doesn't kick it on then the temperature sensor might be bad.
If the fan is ok please post more info on your problem

Is the engine actually cooling off? If the temp switch isn't seeing a drop in temperature, it will keep the fan running.

Check first your coolant level. Start engine and turn on ac open hood see if cooling fans are running, if fans are running and coolant level is ok temperature should stay normal. If temperature rises squeeze coolant hose, it should be firm like you could feel pressure on the hose a sign that the water pump is good. Thermostat opens only when coolant reach normal operating temperature.

i believe the question was explained as fans work!! why all the fan inop answers?? anyway...you will need to check the water pump first...if you change it then make sure your cataltic converters are not plugged. from there its ussually a combustion leak from cracked or defective head gaskets due to the mileage. if it stays cool at idle its deff not a cooling fan problem..the fans only are used primary at idle. hope this helps

The electric radiator cooling fan isn't working, first check the fuse[s], then it's either the fan motor,or the sensor.

Hm. did you put a 50/50 solution of antifreeze in or pure antifreeze solution? If pure antifreeze is in there, then it won't cool properly and may overheat.

That's just one cause. Another cause is poor circulation in the block.

A flush may be indicated if you haven't done that.

Good luck on getting your car to not run so hot.

Also, the normal temp. can go up to 220 deg. F or 230 deg. F and still be normal in a GM car. Just don't want any leaks.

Hi and welcome to FixYa,

A couple of ideas you may want to explore:

• the engine overheating after a shutdown could perhaps be addressed by installing a time delay off on the relay of the radiator fan. The idea is after absence of Ignition B+12 (engine off), the fan/relay should still be energized for a number of minutes so as to cool the radiator;
• idling the engine for about 5 minutes before shutdown is a good practice. this enable the engine to cool slowly rather than an abrupt change in temperature of the external but the inside is still rather hot;
• the opening of the thermostat is triggered by the temperature of the water above it not below (where the spring is);
• in my country, where it is relatively always hot, some mechs remove the thermostat (of course not applicable in cold climates);
• a more helpful idea would be the installation of an electric water pump in lieu of the mechanical one. There are several after market models. Pls try here, here or here for a start;
  
• it is also possible to wire the electric water pump to still run for a minute or more similar to the proposed time delay for the radiator fan above.

Good luck and Thank you for using FixYa. Happy Holidays.