Removing and checking the thermostat — only when the engine is cold (Mondeo 3)

An experienced car enthusiast is quite capable of carrying out such work. When you are ready to begin, you can first relieve the operating pressure in the cooling system and prepare the necessary spare parts. You will need a thermostat (for Duretec engines, completely with the housing), a cover gasket for the thermostat housing, and an elastic and heat-resistant sealant. If necessary, collect the drained coolant in a clean container; it can be used, without hesitation, after the repair.

However, if you want to check the functioning of the old thermostat, heat water in a special pan and check the water temperature with a household thermometer. Read the regulation temperature on the thermostat body and compare it with the actual water temperature. Naturally, we do not advise you to completely rely on an "unkempt" thermostat. Electrically heated Mondeo thermostats can also be checked with a multimeter: measure the resistance between the two contacts - a well-functioning regulator has a resistance of 15 ohms.

ORDER OF EXECUTION

Open the expansion tank to release the pressure in the system. Be careful with a hot engine: there is a risk of scalding. Therefore, "pack" the cap in a thick woolen cloth. Place a clean collecting container under the radiator and disconnect the lower radiator hose or remove the drain screw from the reservoir. Drain approximately three liters of coolant. Double-packed: In Duratec engines, the thermostat consists of a housing and a regulator. 1 — Thermostat/housing unit, 2 - Electrical plug connector, 3 — Thermostat valve spring, 4 — Valve, 5 - "Short circuit valve spring", 6 — Regulating element. Loosen the hose clamp on the thermostat housing and disconnect the hose. Unscrew the three thermostat housing mounting screws and remove the housing. If it is jammed, help it to come loose by lightly tapping it with a hammer (rubber or plastic). Thoroughly clean all sealing surfaces and screw the new housing with the engine block. Pre-lubricate the new gasket on both sides with an elastic and heat-resistant sealant. Reconnect the hose and secure with a hose clamp. Pour in the drained coolant and top up to the required level with weakly lime water. Warm up the engine at medium speed and check the mounting location for leaks. If necessary, add coolant and close the expansion tank.

If the engine is "cooked", the cooling system fan is to blame

Your Mondeo's cooling system copes with smooth, long idling runs as well as with strenuous mountain crossings. However, if the temperature rises to the boiling point, it may not be the fault of the "striking" fan. So don't tow the car straight away: let the engine cool down and then drive quickly to the nearest workshop. Idling and slow driving in high gears are, of course, best avoided if possible. Your supposed caution is unnecessary, as it will lead to the engine heating up, since the radiator is no longer "facing" the oncoming wind.

Note: when the engine is stopped and heated while driving, the fan may operate even when the ignition is off. Therefore, never work near a fan!

[The text was obtained in its entirety from the specified website FORDBOOK.ru]