Cooling liquid

In the cooling system, a mixture of antifreeze and anti-corrosion agent with water provides the necessary cooling for the Fiesta engine. Therefore, they talk about coolant. Ford puts in approximately 50% antifreeze at the factory (ESDM-97B49-A) and 50% water. This is sufficient for reliable protection against freezing of the coolant down to -30°C. At -38°С (freezing point) coolant starts to crystallize. Most coolants lose their properties after four years of use and must be replaced. Common commercially available antifreezes are suitable for topping up, they only need to be mixed with water according to the manufacturer's 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 heat conductors and impair cooling - the engine can overheat.



TECHNICAL DICTIONARY

Elements of the cooling system

Water pump.



Pic. 6.2. Elements of a water centrifugal pump: 1 - pump housing; 2 - pump impeller; 3 - shaft; 4 - sealing ring; 5 - pulley


In all Fiesta engines, the coolant is forcibly pumped through the cooling system by a centrifugal pump (pic. 6.2). In OHV engines, the drive is carried out by a V-belt, in ONS engines - by a V-ribbed belt.

Radiator.

The radiator serves to cool the liquid with an air stream passing through the core of the radiator. The radiator is tubular-lamellar 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 increase the efficiency of liquid cooling, the plates are stamped with a notch that provides turbulent air movement through the radiator. The Fiesta's radiator is attached to the upper and lower cross member.

Thermostat.

The thermostat maintains a constant temperature of the liquid in the engine cooling system, regardless of pressure changes in the cooling system. Depending on engine versions, thermostats begin to open at 85–90°C and are fully open at 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 disc and, accordingly, closes the valve.

Expansion tank.

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