Ford Focus>> Cooling system>> Specifications




Fig. 169. Scheme of system of cooling: 1 — a heater radiator; 2 — the engine; 3 — the thermostat; 4 — a radiator with a vetilyator; 5 — the pump of cooling liquid; 6 — a broad tank



The system of cooling is intended for maintenance of the necessary worker of temperature of the engine. Into system of cooling enter: radiator, radiator fan, thermostat, broad tank. Pipelines of system of cooling and hoses are its components on which liquid circulates. On what way cooling liquid circulates, (fig. 169) depends on engine temperature .
After start-up of the cold engine cooling liquid circulates on a small circle which is limited to a water shirt of cooling of the engine and a heater radiator. The thermostat remains closed while the engine will not reach the working temperature.
The amount of the cooling liquid circulating on a small circle, less, therefore the engine quicker reaches the working temperature. As soon as cooling liquid will reach the working temperature, the thermostat opens and hot cooling liquid starts to circulate through a radiator from top to down. In a radiator as a result of it обдува heat from the engine is taken away by a counter flow of air in the atmosphere. The thermostat regulates temperature of cooling liquid, protecting the engine from an overheat and cooling.
At normal working temperature of the engine cooling liquid circulates on a big circle from the right tank of a radiator to the water pump and further arrives in the block of cylinders and a block head. The most part of cooling liquid comes back back via the open thermostat to the left tank of a radiator while the remained quantity passes through a heater radiator. If during a trip the temperature of cooling liquid falls below necessary level, the thermostat is closed, while liquid again will not heat up.
The cooling system at the working motor is under a certain pressure. Therefore the boiling point rises from 100 to 120 ° S.Esli at the hot engine pressure in system of cooling 85 — 120 kPas become higher (depending on engine type), the reduktsionny valve on a cover of a broad tank opens and pressure is dumped in the atmosphere. If when cooling liquid there is a vacuum, it is leveled by the second, so-called vacuum, the valve which allows external air to get to a broad tank. At trips on the city or faltering trips often happens that the cooling counter flow of air does not suffice, in order that the engine did not overheat. For this purpose all Focus cars are provided with the fan with the electric drive (Zetec-E — two fans) which is established behind a radiator. The radiator joins at temperature of cooling liquid 120 ° With and is switched off, when the temperature again reaches a normal amount.
If in extreme working conditions with big loadings or because of any malfunctions the engine temperature suddenly rises above norm, the control unit (RSM) will be connected to work. At the first stage the program fixes the provision of the index of temperature of cooling liquid in the provision of a red zone on a scale of a combination of devices. If this signal is passed and the temperature rises further, the control lamp «lights up check the engine» on a combination of devices. In this case you should muffle surely the engine, to leave it to be cooled and on a tow to reach to the service center. During this time the control unit wrote down a code of malfunction which is read out in Ford's workshops by means of the diagnostic FDS2000 device.
If nevertheless you did not notice a control lama and temperature indications on a scale, the program of protection passes to the second level, the RSM block disconnects operation of two cylinders and reduces engine turns to 3000 mines-1. The alarm lama of a control system of the engine (MIL) at the same time lights up. She in due time prevents engine damage. For increase of effective cooling of the engine the cylinders switched off from work start to tighten meanwhile clean air. Cylinders are alternately switched off to provide uniform cooling of all block of cylinders.
If all previous actions appeared inefficient, the third stage starts to operate. A control lamp «check the engine» starts to blink to show that at you is 30 more with that hands to roll away the car on the roadside. At this time the engine is completely muffled to avoid considerable damages or jamming.