Cooling liquid (Fiesta 4)

In the cooling system, a mixture of antifreeze and anticorrosive agent with water provides the necessary cooling of the Fiesta engine. That is why they talk about coolant. Ford fills the system at the factory with approximately 50% antifreeze (ESDM-97B49-A) and 50% water. This is enough to reliably protect the coolant from freezing to a temperature of -30°C. At a temperature of -38°C (freezing point), the coolant begins to crystallize. Most coolants lose their properties after four years of operation and must be replaced. Regular antifreezes available on the market are suitable for topping up, they just need to be mixed with water according to the manufacturers' instructions. Just as important as frost protection is corrosion protection, which prevents the formation of scale, rust and other products in the cooling system that are poor conductors of heat and impair cooling - the engine may overheat.



TECHNICAL DICTIONARY

Elements of the cooling system

Water pump.



Fig. 6.2. Elements of a water centrifugal pump: 1 – pump body; 2 – pump impeller; 3 – shaft; 4 – sealing ring; 5 – pulley



In all Fiesta engines, the coolant is forced through the cooling system by a centrifugal pump (Fig. 6.2). In OHV engines, the drive is carried out by a V-belt, in OHC engines - by a poly V-belt.

Radiator.

The radiator serves to cool the liquid by the air flow passing through the radiator core. The radiator is a tubular-plate type with plastic tanks located on the left and right sides of the radiator. The radiator core consists of aluminum tubes and aluminum cooling plates. To improve the efficiency of liquid cooling, the plates are stamped with a notch that provides turbulent air movement through the radiator. The Fiesta radiator is attached to the upper and lower crossbar.

Thermostat.

The thermostat maintains a constant temperature of the liquid in the engine cooling system, regardless of changes in the pressure in the cooling system. Depending on the engine versions, thermostats begin to open at a temperature of 85–90°C and are fully open at a temperature of 99–102°C with a tolerance of ±3°C. The opening and closing of the thermostat valve is carried out by a sleeve filled with special wax. When the coolant is heated, the wax melts, its volume increases and due to this, the valve opens. If the liquid cools, the spring presses on the valve plate and, accordingly, closes the valve.

Expansion tank.

Automatically limits the amount of circulating coolant in the cooling system. Excess pressure is reduced by a safety valve, and vacuum is compensated by an inlet valve in the expansion tank cap. The transparent plastic expansion tank is located in the engine compartment on the right side in the direction of travel of the vehicle.

The original article is available on the website [FordBook]