Fig. 169. The scheme of system of cooling: 1 — a heater radiator; 2 — the engine; 3 — the thermostat; 4 — a radiator with ветилятором; 5 — the pump of a cooling liquid; 6 — a broad tank
The cooling system is intended for maintenance of the necessary worker of temperature of the engine. Into cooling system enter: a radiator, the radiator fan, the thermostat, a broad tank. Pipelines of system of cooling and hoses are its components on which the liquid circulates. On what way the cooling liquid circulates, depends on engine temperature (fig. 169
After start-up of the cold engine the 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 quantity of the cooling liquid circulating on a small circle, less, therefore the engine faster reaches the working temperature. As soon as the cooling liquid will reach the working temperature, the thermostat opens also a hot cooling liquid starts to circulate through a radiator from top to down. In a radiator as a result of it обдува by a counter stream of air warmly from the engine it is taken away in atmosphere. The thermostat regulates temperature of a cooling liquid, protecting the engine from an overheat and cooling.
At normal working temperature of the engine the cooling liquid circulates on the 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 a cooling liquid comes back back through 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 a cooling liquid falls below necessary level, the thermostat is closed, while the liquid again will not heat up.
The cooling system at the working motor is under certain pressure. Therefore the boiling point rises from 100 to 120 ° S.Esli at the hot engine pressure in cooling system becomes above 85—120 кПа (depending on engine type), opens редукционный the valve on a cover of a broad tank and pressure is dumped in atmosphere. If at liquid cooling there is a vacuum it is levelled by the second, so-called vacuum, the valve which allows external air to get to a broad tank. At trips on a city or faltering trips often happens that the cooling passer of a stream of air does not suffice, that the engine has not overheated. For this purpose all cars Focus are provided by the fan with the electric drive (Zetec-E — two fans) which is established behind a radiator. The radiator joins at temperature of a cooling liquid 120 ° With and is switched off, when the temperature again reaches a normal amount.
If in extreme working conditions with the big loadings or because of any malfunctions the engine temperature suddenly rises above norm the management block will be connected to work (РСМ). At the first stage the program fixes position of the index of temperature of a cooling liquid in position of a red zone on a scale of a combination of devices. If this signal is passed also temperature rises further, the control lamp «lights up check up the engine» on a combination of devices. In this case you should muffle necessarily the engine, leave it to be cooled and on a tow to reach to the service centre. In this time the management block has written down a code of malfunction which is read out in Ford's workshops by means of diagnostic device FDS2000.
If nevertheless you have not noticed the control llama and temperature indications on a scale, the protection program passes to the second level, block RSM disconnects work of two cylinders and reduces turns of the engine to 3000 mines-1. The alarm llama of a control system of the engine (MIL) simultaneously lights up. She in due time warns engine damage. For increase of effective cooling of the engine the cylinders switched off from work start to tighten in the meantime pure air. Cylinders are alternately switched off to provide uniform cooling of all block of cylinders.
If all previous actions have appeared inefficient, the third stage starts to operate. A control lamp «check up the engine» starts to blink to show that at you is 30 more with that hands to roll away the car on a roadside. At this time the engine is completely muffled to avoid considerable damages or jamming.