5.14.1. Features of a design

Fig. 5.12. Cooling system: 1 – stopper of a broad tank; 2 – the bringing heater hose; 3 – the taking-away heater hose; 4 – distributor case; 5 – the bringing radiator hose; 6 – radiator; 7 – the taking-away radiator hose; 8 – steam discharge hose of a broad tank; 9 – water pump; 10 – liquid hose of a broad tank; 11 – broad tank

The cooling system of the engine (fig. 5.12) liquid (with compulsory circulation of liquid), tight, with a broad tank.
The system is filled with the liquid on the basis of ethylene glycol (antifreeze) which is not freezing at ambient temperature to –40 °C.

The replacement procedure of cooling liquid is described in the subsection "Replacement of Cooling Liquid".

It is not recommended to fill the cooling system with water as the anticorrosive and anti-making foam additives, and also additives interfering adjournment of a scum are a part of antifreeze.
Cooling liquid is toxic! Avoid inhalation of its vapors and hit on skin.
In due time eliminate violation of tightness of the cooling system to avoid hit of vapors of cooling liquid in interior of the car at its operation. Your health is more expensive, than a new branch pipe of the cooling system or a tube of sealant!

Except a radiator, the water pump, a broad tank and hoses, the shirt of cooling of the engine executed in casting surrounding walls of cylinders in the block, combustion chambers and gas channels in a block head and also a radiator of a heater of interior of the car log in.
The normal thermal mode of the engine is defined by temperature of cooling liquid which is maintained automatically by means of the thermostat in range of 90-100 °C.
Radiator with a horizontal stream of liquid, with a tubular and tape aluminum core and plastic tanks on each side. In the lower part of the left tank there is a drain crane. In tanks the bringing and taking away branch pipes of hoses to a water shirt of the engine are executed.
The broad tank serves for compensation of the changing volume of cooling liquid depending on its temperature. The tank is made of translucent plastic. Tags of "max" and "min" for control of level of cooling liquid are applied on its walls, the bulk mouth which is hermetically closed by a plastic stopper with two valves in it (inlet and final) assembled in the uniform block from above is located. The final valve opens with a pressure of 120-150 kPa (1,2–1,5 kgfs/cm2), providing temperature increase of the beginning of boiling of cooling liquid and preventing intensive steam formation. When cooling liquid its volume decreases and in system depression is created. The inlet valve in a stopper opens at depression about 3 kPa (0,03 kgfs/cm2) and passes air in a broad tank.

Serviceability of valves of a stopper is very important for normal operation of the cooling system, but often at emergence of problems (boiling of cooling liquid, etc.) motorists pay attention only to operation of the thermostat, forgetting to check valves. Leakage of the final valve leads to decrease in temperature of boiling of cooling liquid, and its jamming in the closed state — to emergency increase in pressure in system that can cause damage of a radiator and hoses.

The water pump of centrifugal type provides compulsory circulation of liquid in the cooling system, is installed on the forward plane of the block of cylinders and is given to rotation from a pulley of a bent shaft by a poliklinovy belt of the drive of auxiliary units. The closed bearings which are not needing lubricant replenishment are installed in the pump. The pump is not subject to repair therefore at refusal (a leak of liquid or damage of bearings) it is replaced assembled.
The thermostat with a firm thermosensitive element maintains the normal working temperature of cooling liquid and reduces time of warming up of the engine. It is established in a special nest on the side surface of the block of cylinders and pressed to it by the case. At a temperature of cooling liquid up to 87 °C the thermostat is completely closed and liquid circulates on a small contour, passing a radiator that accelerates warming up of the engine. At a temperature of 87 °C the thermostat begins to open, and at 102 °C opens completely, providing circulation of liquid through a radiator.
The electric fan with a plastic eight-bladed krylchatka provides a radiator purge with air at small speeds of the movement of the car generally in city conditions or on mountain roads when the counter flow of air is insufficient for cooling of a radiator.
The electronic block of a control system of the engine obtaining information from system sensors operates operation of the electric fan. The electronic block turns on the fan with a small speed of rotation at a temperature of cooling liquid of 93 °C, with high speed — at 97 °C, switches the fan from high speed on small at 94 °C, switches off it at 90 °C.
The cooling system by means of hoses included a radiator of a heater of salon.