VAZ 2109 coolant circulation

The engine cooling system is an important structural element of a car. Its malfunction leads to poor heating of the engine to the required temperature, which causes poor operation of the stove, loss of power and reduced service life of the power unit. On the other hand, the engine system may overheat, which causes breakdown of the cylinder-piston group.

cooling system vaz 21099 carburetor diagram

VAZ 2199 cooling system injector

1 – element in the form of a plug for the expansion tank; 2 – expansion tank; 3 – hose for draining liquid from the pipe; 4 – hose passing between the radiator and the expansion tank; 5 – hose leading from the radiator; 6 – tank to the left of the radiator; 7 – aluminum tube; 8 – plug systems; 9 – tank to the right of the radiator; 10 – drain plug; 11 – middle of the radiator; 12 – casing for electric fan; 13 – plastic wings of the electric fan; 14 – electric motor; 15 – toothed pump pulley; 16 – pump impeller; 17 – camshaft drive belt; 18 – engine block; 19 – pump pipe; 20 – radiator hose with supply function; 21 – heater radiator hose with drain function; 22 – hose supplying coolant to the throttle pipe; 23 – exhaust pipe; 24 – hose for refilling; 25 – heater radiator hose with supply function; 26 – thermostat; 27 – coolant temperature sensor; 28 – coolant level indicator sensor.

The cooling system of VAZ 21093,2109,21099 removes heat from engine parts subject to heating through forced circulation. And the injector doses the flow of fuel. Structurally, the VAZ injector cooling system consists of:

coolant pump,
monoblock thermostat,
electric radiator fan,
radiator with expansion tank,
pipelines, pipes, drain plugs.

How the cooling system of VAZ 21093,2109,21099 works

The cooling pump drive is driven by the timing belt. The total volume of the system, including the stove, is 7.8 liters. Temperature control is carried out using a sensor installed on the cylinder block jacket. The temperature indicator is displayed on the instrument panel.

During operation of the VAZ engine, liquid from the block jacket passes into the radiator (where heat is removed) or into the thermostat (short circuit - to warm up the engine). Next, the liquid is pumped into the cooling jacket of the VAZ injector power unit. The pipelines circulate and heat the fuel mixture in the intake manifold and throttle valve area.

The cooling system communicates through pipes with the radiator of the interior heater of VAZ 21093,2109,21099. The coolant pump is centrifugal. The system is equipped with a collapsible tubular plate radiator with plastic tanks.

The internal surface of the radiator is increased by using aluminum tubes and cooling plates; it does not have a filler hole; topping is done in the expansion tank. Which also has a sensor for turning on the electric fan. The tank has a filler plug with valves (inlet and outlet). To drain the cooling liquid from the system, unscrew the drain plugs of the tank, cylinder block, and radiator.

CO elements

The cooling system used on the VAZ 2109 operates at low pressure. After studying the components, you will learn about their functions and features.

Element

Peculiarities

It ensures efficient, stable operation of the system. The pump is used to pump cooling liquid, which facilitates its movement along a small or large circuit. The pump consists of a housing, an axle with a pulley located on it connecting to the timing belt, and a plastic impeller. The latter allows the coolant to move. A bearing lubricated with antifreeze is installed between the axle and the housing. Because of this, the presence of water in the system is unacceptable. Otherwise the bearing will collapse

Plays an important role, although in practice the CO can do without it. The system works in such a way that the engine first warms up to operating temperature (about 90 degrees Celsius), after which it is necessary to further cool the liquid. First, the coolant moves along a small circuit - through the jacket into the stove radiator, and then the excess is returned to the expansion tank. But when the operating temperature is reached, the thermostat begins to move the coolant flow into the radiator. A thermostat can be called a mechanical valve that automates the operation of the CO. Hot liquid acting on the bimetallic plate of the thermostat deforms it, which is why the coolant supply valve to the radiator can open or close

The SO VAZ 2109 has a pair of radiators - a stove and a main one. Their design is the same regardless of whether you have a carburetor or an injector. At the same time, there is a noticeable difference between the main and stove radiators. The main one is larger in size, they perform different functions, plus the main one has holes for a sensor that turns off the fan. If the stove radiator can be connected to operation at any time by pressing a button, then the main radiator operates in automatic mode when certain operating parameters of the CO are achieved

Expansion tank with plug

A constant pressure is maintained inside the CO, which ensures efficient coolant circulation. On the VAZ 2109, the system is designed so that at high pressure the liquid does not boil when it reaches 100 degrees, but at higher parameters. This increases engine reliability. Pressure support is provided by an expansion tank with a cap and a pair of mechanical valves - inlet and outlet. The inlet valve is activated if the pressure drops to 0.13 atm. The second one comes into operation at the moment when the pressure is above 1.3 Atm.

Do not underestimate the role of pipes and clamps in the CO, since it is through them that the coolant is supplied to the required points. When replacing, under no circumstances use cuttings from other pipes that do not correspond to the parameters used previously. Plus, if at least one pipe is damaged, everything will have to be replaced as a set, and not separately

Looking at the radiator (main), below you will see a pair of wires and a yellow device twisted into the hole. This is the electric fan switch sensor. Another sensor is also located in the motor block - temperature. It transmits information to the electronic control unit or pointer

As a standard, the VAZ 2109 is equipped with fans equipped with 4 blades. But if you want to achieve greater efficiency, we recommend replacing it with a 6-blade electric fan. This will increase the air flow while maintaining the original power and rotation speed. Heat from the heater radiator begins to flow inside the cabin when the tap is opened. There is a fan under the hood connected via a rheostat. It regulates the rotation speed of the impeller. The switch is located under the audio system, near the heater damper control levers.

Thermostat

When planning to replace an electric fan, work should be done through the engine compartment. No need to dismantle the snail .

CO pump

Replacing the radiator

The radiator is replaced if there is a leak in it. In some cases, it can be repaired by soldering the leaks. To make sure that the device is repairable or needs to be replaced, it is better to first carry out a small check

Radiator location

We still advise you to immediately replace the faulty radiator rather than try to patch the old one.

Having gathered our strength, we carry out the replacement.

Disconnect the negative from the battery or remove the battery.
Drain all coolant completely.
If you have an injection car and not a carburetor, you will need to additionally remove the air filter.
Cut the clamp that holds the wire harness in place. Disconnect the electric fan wiring harness.
Remove the throttle linkage clamp. It is located on the fan shroud.
Disconnect the bleeder hose connected to the thermostat.
Disconnect the supply hose. It is connected to the jacket pipe.
Remove the steam exhaust hose.
Unscrew the nut that holds the radiator to the body at the top. The same bolt holds the fan shroud.
Tilt the radiator slightly towards the engine and remove it by lifting it up. Dismantling is carried out directly together with the electric fan.
Loosen the tension on the clamps and disconnect all hoses going to the radiator.
Unscrew all the fasteners holding the casing with the electric fan and the radiator itself.
Disconnect the radiator from the fan shroud.
Remove a pair of lower fixation pads from the radiator. Examine the condition of the pillows. If they are worn out or have lost their original elasticity, it is better to immediately replace them with new ones.
Moving in reverse order, install the new unit in place of the old one. Don't forget about the lower support pillows.
Fill the system with new coolant.

CO radiator
At this point, the replacement of the device can be considered complete. There are no particular difficulties in the SO VAZ 2109, which allows you to carry out maintenance, repair and replacement of its individual units yourself.

Features of the fan and thermostat VAZ 21093, 2109, 21099

The electric fan includes an electric motor and a four-blade impeller, the blades of which have a variable angle of inclination and pitch to reduce noise levels. To increase efficiency, the VAZ fan system is equipped with a casing attached to brackets.

The electric fan is mounted on rubber bushings. The fan is triggered by a signal from a sensor installed in the radiator tank. In this case, the contact closure temperature is approximately 99'C, and the fan shutdown temperature is 94'C.

The system thermostat provides priority warming up of the engine and regulates the thermal regime. The optimal coolant temperature is within 90-98'C. The thermostat includes a body and a cover, rolled together with the valve.

Features of the VAZ injector cooling system

Cooling in cars 21093,2109,21099 is liquid, but you need to understand that the radiator is cooled by the flow of incoming air and a fan, which increases the cooling intensity. Also, part of the heat is removed by the car's interior heater radiator at low temperatures.

The expansion tank is designed to compensate for the volume of liquid when heating, to top up and control the level of antifreeze.

The thermostat system provides temperature control, preheating of the VAZ engine, initial heating of the interior in winter, and only then ensures the inclusion of a large cooling circuit.

The temperature sensor provides control of the cooling system, allows you to monitor the engine temperature and regulate the operation of the fan.

The entire operating cycle of the cooling system is controlled using a power unit control system that takes into account all temperature parameters. It determines the optimal switching conditions and operating time of the structural elements of the system.

Diagnostics of the engine cooling system of VAZ 21093, 2109, 21099 and identification of faults

If problems arise with the engine cooling system, the causes should be determined, starting with the most probable and simple ones:

If there is a coolant leak, first check the fluid level in the system. In cars 21093,2109,21099 this is done using the level indicator or when inspecting the expansion tank.
If the level has changed, inspect the engine compartment for leaks. As a rule, the main reasons are: worn pipes and clamps, damaged engine cooling radiator or heater.
In case of jet changes in the tank at 3000 rpm. It is necessary to check the fluid circulation. To do this, open the cap of the expansion tank and determine the uniformity of antifreeze flow. The causes of poor circulation may be a clogged system or a malfunction of the circulation pump.

Malfunctions in the system

In a domestic car VAZ-2109, you can independently identify problems in the cooling system.

For example, system overheating occurs if:

lack of coolant - check, add if necessary;
the pump belt is torn or worn - replace it;
the radiator is clogged with dirt - flush or replace;
The fan may be broken.

There are also a number of other malfunctions:

Coolant leak. Hoses may be damaged or parts may crack. If fluid is lost, the system is overfilled.
Corrosion can occur if the water is contaminated or the antifreeze solution is not formulated correctly.
Air locks (warm up the engine properly, then let the car sit, remove the hose and start the engine again - this will help expel the air).

Causes of VAZ engine overheating

A faulty thermostat can cause the engine to overheat. If on a warm engine the upper pipe is hot and the lower pipe is cold, the thermostat is jammed and the antifreeze flows only in a small circle. Or the thermostat will only turn on a large circle, which will not allow the VAZ engine to warm up to the required operating temperature. In this case, the thermostat should be replaced.
Another reason for excessive engine heating may be airing of the cooling system; in this case, the system must be pressed and air removed from all cavities.
At high temperatures, the fan does not turn on - there is a problem with the temperature sensor, fan relay or the wiring harness to it.
Sometimes the radiator honeycombs become clogged, which sharply reduces the intensity of heat transfer. It is necessary to thoroughly clean the radiator; it must be done carefully to avoid damage to the cells.

These are the main reasons that affect the quality operation of the VAZ 21093,2109,21099 engine cooling system; with their help, you can identify and eliminate malfunctions, ensuring reliable and durable operation of the engine.

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When parts need to be replaced

When is it necessary to replace the VAZ 2109 coolant and cooling system elements? The fluid must be changed regularly after a certain period of use. Parts are not changed periodically, but only after a breakdown. One of the causes of breakdowns is overheating due to a malfunction of some element in the cooling system. The following signs of engine overheating can be observed:

the coolant temperature is higher than normal and can exceed 120ºС, this is indicated by a special sensor;
there is a sharp drop in engine power;
the sound of the engine changes, a ringing metallic knock appears;
oil consumption increases;
Coolant consumption increases significantly.

As a result of overheating, after you open the hood, you will see deformed parts - bent cylinder head, gasket edging, burnout of some parts. Repairing deformed parts does not make sense; they need to be replaced.