How to replace the thermostat on a VAZ 21102 with your own hands - useful tips

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On a VAZ 2110 car, the thermostat is an integral element, which, despite its small dimensions, performs a huge function.

Photo of the thermostat for VAZ 2110

The thermostat protects the engine from overheating. You all understand what sad consequences overheating of the power unit can lead to, and what financial losses the car owner will suffer.

Design and tasks of the VAZ 2112 thermostat

On cars under the Volzhsky Automobile Plant brand with a carburetor, and even on injection cars, until 2002, a thermostat was installed in an all-metal housing (i.e., on 8-valve gasoline engines). The unit was secured using four pipes. People call the VAZ thermostat a 4-hole thermostat. The first terminal of the housing is connected to the engine, the second is connected to the radiator, the third goes to the heater and the cooling system pump, the fourth (the thinnest) is connected to the expansion tank.

Until 2002, a four-hole tremostat was installed on carburetor and injection internal combustion engines

Inside the case there was a heat-sensitive element - a thermostat. You can see it only after complete disassembly. The operating principle is based on changing the shape of a bimetallic plate when heated or cooled.

When the engine starts, antifreeze circulates in a cold circle. When the power unit warms up, the coolant also heats up. At +87 degrees Celsius, the thermostat opens slightly and some of the antifreeze begins to flow in a large circle. When 102 degrees is reached, the temperature-sensitive element opens completely. A radiator is connected to the engine cooling process.

A car thermostat regulates the flow of antifreeze in the cooling system

On injection VAZ 2112 since 2002 (the engine by this time had become 16-valve), a thermostat is installed in a collapsible housing with six outputs. One additional terminal is connected to the stove when antifreeze circulates in a small circle. The second pin is used to heat the throttle valve.

Since 2003, a new type of unit has been installed on the VAZ 2112, as well as on the Priora and Kalina. The housing has 6 pins and is attached to the power unit unit using 2 nuts

When using a housing that can be disassembled, there is no need to purchase an assembled unit. Since 2003, on the VAZ 2112, Priora and Kalina, in the event of a malfunction, only the temperature-sensitive element must be replaced.

Where is the thermostat installed on the VAZ-2112?

Regardless of the type of power unit, the thermostat is located in one place - below the air filter housing. There you can see the cover of the device, under which the required element is installed.

This simplifies the search and replacement of the thermostat on a VAZ 2112 of any modification.

The role of the thermostat in the engine cooling system

The engine cooling system is divided into two circuits: large and small. The small circuit encloses the internal elements of the engine and the heater radiator for heating the interior. The large circuit includes the small one, but in addition passes through the cooling radiator located in front of the engine. Thus, when the coolant temperature reaches a set level, the valve opens the flow into a large circuit and the antifreeze is cooled by oncoming air, entering the cooling radiator. If there is not enough oncoming air, the engine temperature sensor transmits a command to the control unit, which in turn turns on the cooling fan located in front of the radiator.

As soon as the air entering the radiator cools the liquid to a certain temperature, the valve closes and the antifreeze again flows through the small circuit. As a result, the engine temperature is maintained in operating condition.

Principle of operation

VAZ 2112 injector thermostat 16 valves

The operating principle of the thermostat is characterized by the following points:

• Inside the thermostat there is a valve filled with a special substance. This very substance, due to its chemical and physical properties, expands with changes in temperature. Thus, when the substance expands, it acts on the valve, which overcomes the force of the spring and opens the flow of fluid from the radiator to the outlet - the outlet pipe.
• In addition, the design of the thermostat implies the presence of a bypass valve located on the antifreeze path from the engine to the outlet pipe.
• It is noteworthy that at a time when the antifreeze temperature is low and the engine is running but not warmed up enough, the coolant circulates in the so-called “small circle”.

Note. A “small circle” of coolant passage implies the opening of the bypass valve, resulting in rapid warming up of the engine.

• The main valve opening begins at temperatures between 80.6 and 81.5 degrees. It is at this moment that the liquid begins to move in a large circle, implying circulation through the radiator.

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VAZ 2112 injector thermostat

• When the temperature reaches 94 degrees, the main valve opens to its maximum value, approximately 6 mm. In this case, the bypass valve closes completely, and the coolant moves only in a large circle and is automatically cooled as it passes.

Note. In most cases, failure of the thermostat implies jamming of the valve stem, which naturally leads to the circulation of coolant in either a small or large circle. If the movement of antifreeze in a large circle is not so dangerous, then the first case threatens to overheat the automobile unit. How to check the thermostat status

VAZ 2112 injector thermostat

The simple test below will help you do this:

• The engine warms up to operating temperature (the arrow should be vertical);
• We feel the lower thermostat pipe with our hand, which should be slightly warm and gradually warm up.

If the lower pipe is cold, then most likely the thermostat is not functioning normally and the liquid circulates only in a small circle. If the lower and upper pipes have similar temperatures, then the probability of the valve being open is one hundred percent.

Choice

You can buy a thermocouple separately, but it is better to buy an assembled thermostat. There is also a slight difference in the design of the thermostat housing depending on the year of the car. Below are the original articles; select analogues yourself.

• thermostat cover with thermoelement - 21082-1306020;
• thermostat assembly (with gasket) - 21082-1306010-82.

Symptoms of a problem

There are several main signs of a malfunction:

1. The engine takes a long time to reach operating temperature.
2. While driving, the engine overheats even on short trips.
3. The engine temperature drops while driving and rises if you stop and let the engine idle.
4. A few minutes after starting the engine (in warm seasons), the lower pipe is warm. This indicates that the thermostat is opening very early.
5. If the engine (coolant) temperature is close to boiling and the lower hose is cold, it is most likely a stuck thermostat valve.

When to think about replacement

If the device has stopped opening the valve that releases coolant to a large circle, or the valve is simply jammed and does not close on its own, then you need to think about replacing the Grant thermostat on the VAZ 2110. If you do not replace the device in time, negative consequences may occur.
If the fluid cannot circulate in a large circle, the car will overheat. This should not be allowed and, if possible, the thermostat from the Granta VAZ 2110 injector 16 valves should be replaced as soon as possible. Overheating can cause the cylinder head gasket to burn out. Moreover, the friction of the car itself will increase.

If the valve gets stuck in the open position, which is extremely rare, the motor will not be able to heat up. It is also advisable to replace the device.

Verification methods

There are several ways to check the VAZ 21102 thermostat, in particular:

1. check without removal;
2. checking a removed thermostat

To check without dismantling, start the engine and wait until it reaches operating temperature. Next, grab the lower pipe with your hand (it comes from the thermostat). At first, the pipe should be warm, and after a few minutes it should gain temperature. If the lower pipe is cold and the coolant temperature approaches 100-110 degrees, then the thermostat is not working and needs to be replaced.

There is also a simple and working way to check the thermostat removed from the engine. Heat the water to 80 degrees and lower the thermostat into it. Next, heat the water another 10 degrees and watch the thermostat; the valve stem should gradually come out.

It is not advisable to repair the VAZ 2112 thermostat due to the low cost of a new spare part.

Prices for VAZ-2110 components

One of the features of VAZ-2110 cars is that it is extremely rare to completely replace thermostats on it. If desired, you can only get by by replacing the starting element, which will be somewhat cheaper. The price of an assembled thermostat ranges around 1,000 rubles, while its trigger mechanism can be purchased for 400.

Please note: this VAZ model produces two types of components (new and old). VAZ 2114 thermostat (injector): malfunctions and replacement For novice motorists, driving courses will certainly focus attention on the catastrophic consequences of power overheating

Thermostat VAZ 2115 injector 8 valves. It’s not scary if your car previously had an old-style thermostat, and you purchased its updated version. In this case, you will need to cut off part of the pipe (leading from the pump) with a hacksaw and disconnect the piece from the old spare part. After this, it will be possible to install the unsuitable spare part into the vehicle's cooling system.

Do-it-yourself replacement of the VAZ 2115 thermostat. If the engine operating temperature is more than 90 degrees or vice versa.

In this video I will tell you how to change the thermostat

for
VAZ
2114 with your own hands. Similar to Priors, Kalinas, and Grants.

When purchasing a new spare part directly from the store, check it for functionality. To do this, you will need to blow forcefully into the fitting. The air should remain inside the housing, which is evidence of the tightness of the small circuit.

Tips before starting the procedure

1. Before you begin removing the thermostat on a VAZ 2112, be sure to ensure that it has completely cooled down after operation.
2. The thermostat is removed when it is replaced due to unstable engine temperature conditions (overheating, insufficient heating). To carry out this procedure, completely draining the coolant is not necessary.
3. To check the condition of the thermostat, start the car engine and touch the lower radiator hose, at first it should remain cold, and only after the coolant temperature reaches about 90 degrees, the hose will begin to gradually heat up. If there is no such reaction to the manipulations performed, remove the thermostat from the car and check its functionality; if defects are detected, it must be replaced with a new one.

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Replacement process

Open the hood and move the air filter housing to the side.

Installation is carried out in reverse order:

1. We install and secure the thermostat.
2. We connect the pipes.
3. We tighten the coolant drain plug in the block and the faucet.
4. Install the air filter.
5. We fill in new coolant according to the level and the work is completed.

Replacing the thermostat on 8 and 16 valve engines is carried out similarly. Also, when performing such repairs, it is advisable to change the coolant, and, if necessary, the pipes.

How to replace a thermostat yourself

Replacing a faulty thermostat in a VAZ-2112 with 16 valves is a fairly simple matter, so even minor skills in car repair will help the car enthusiast to perform this operation on his own. The part is replaced in stages:

1. Start work only with a cold engine to avoid getting burns on your hands.
2. All liquid intended for cooling must be completely drained, since replacing the part involves disconnecting the pipe in which it accumulates. To avoid spilling liquid during this process, you should place a container of the appropriate size under the bottom of the car.
3. For ease of operation, it is recommended to remove the hardened air filter housing.
4. Using a screwdriver or wrench, unscrew the connectors that secure the hose to the thermostat. There should be two such hoses - one is for the radiator, the other is for the thermostat.
5. Using a hex wrench, unscrew the bolts, in triplicate, that prevent the element cover from moving when the car is running. After removing the fasteners, you should simply carefully remove the part from its permanent place.

If, upon inspection of the cover, any defects are revealed in the sealing ring, for example, cracks or deformation, this will indicate that the ring has also become unusable and needs to be replaced.

All car parts should be assembled in the reverse order that was used during disassembly.

The information described indicates that replacing a faulty VAZ-2112 16-valve thermostat is an easy operation, and if you approach the event responsibly and carry out the process step by step, then everyone will be able to correctly replace the faulty part on their car.

Removing and correctly installing the thermostat on a carburetor engine

1. Remove the plug from the expansion tank and unscrew the drain plug at the bottom of the radiator. Drain the liquid from there and screw the drain plug back on.

2. Disconnect the three hoses from the thermostat housing, having first loosened it. 3. Next, you will need to loosen the clamp and remove the device along with the hose. 4. After all the above steps, warm the water to 80 degrees and lower the thermostat into it. Just as with an engine with a fuel injection system, heat the water together with the thermostat, while constantly stirring it to 87–90 degrees. 5. At this temperature, the main thermostat valve will begin to open. If this opening does not occur, you will need to replace it. Installation occurs in the exact reverse order of removal.

Replacing the thermostat on a VAZ-2112 with an injection 8-valve engine

To replace thermostats on an 8-valve VAZ-2112 engine (injector), proceed as follows:

1. Prepare your instrument. You will need a tee with tubes with a cross-section of 1.9 cm (not necessary to redo the connection diagram), a half-meter hose, a container (a plastic bottle will do), several clamps 2.5 cm in diameter (two or three pieces), a key to “ eight", screwdriver, hex wrench 5.
2. Purchase the necessary materials - gasket for the case, silicone-based sealant, thermostat, rags, antifreeze.

3. Unscrew the bolts holding the filter shell.

4. Loosen the clamps on the throttle pipe and crankcase ventilation hoses, and then tighten the throttle cable fixing bolt.
5. Separate the electrical connector.

6. Remove the rubber cushion from the hole in the housing bracket, and then remove the air filter.

7. Tighten the bolts on the clutch housing and cylinder block, and then remove the ignition module. The described action is necessary to gain access to the coolant drain plug.

8. Unscrew the drain plug on the radiator and cooling system block, and then drain the coolant.

9. Loosen the clamps on the thermostat pipes, remove the device and twist the temperature control sensor. Here, remove the controller connector.
10. If the design allows you to replace the main valve, then use a hex wrench to disassemble the thermostat and replace it.

11. Install the new device and connect the pipes to the same places. If possible, replace the hose with a longer one.

    
    Wipe the pipes and housing terminals with a rag, change the gasket between the housing and the motor and tighten the clamps. Add antifreeze and check the system for leaks. After 10-20 kilometers, inspect the joints again.

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How to change the thermostat on a VAZ-2112 with an injection 16-valve engine?

When replacing a faulty device with a 2112 with a 16-valve engine, the required tool and algorithm of actions remain virtually unchanged:

1. Drain the coolant from the system;
2. Remove the air filter;

3. Loosen the fixation of the water pipes (inlet and outlet) connected to the thermostat;

4. Tighten the bolts holding the device to the block.

5. Remove the cover (if necessary);
6. Remove the main valve from the casing;

7. Return everything to its place in reverse order. Be sure to change the rubber used to seal the case.

Installation

On the VAZ 2112 you can easily install a thermostat from the injection VAZ 2111. The advantages of such an upgrade:

• You will have to use one less hose and only two clamps, which minimizes the possibility of leakage;
• Smaller dimensions;
• Compact monoblock design;
• Large circulation through the stove due to the reduced cross-section of the small circuit;
• Placing the expansion tank in a convenient place, which allows you not to heat the engine until the thermostat opens;
• Relatively simple procedure for replacing a new thermostat.

What you need for installation

• Coolant sensor or plug bolt of the appropriate type;
• Long hairpin on M8;
• New thermostat;
• Gaskets and two clamps.

Thermostat operating principle

Functionally, the thermostat is a copper or brass cylinder, inside of which there is a pin and a piece of wax. As the engine heats up, the wax begins to melt and expands significantly, thereby squeezing out the pin that is responsible for opening the cooling system valve. When the power unit stops working and cools down, the wax turns into a solid consistency again and the valve closes. Such a simple device, the operation of which is based on the laws of physics and the chemical properties of wax, plays a colossal role in the cooling system.

The fairly simple structure makes the thermostat highly reliable. There is essentially nothing to break there, since the number of parts is minimal. The main reasons for its failure are oxidation and corrosion. The device constantly operates in a liquid environment, and even under the influence of high temperatures. Repeated heating and cooling cycles wear out the thermostat quite quickly. In general, the service life of the device, depending on operating conditions, is 1.5-3 years. Leading car manufacturers recommend changing it every 2 years.

Replacing the VAZ 2110 thermostat should be done quite often. The changeable Russian weather negatively affects all vehicle systems. Therefore, the service life of many parts in domestic conditions is reduced. This requires drivers to monitor their vehicles more carefully in order to identify problems in a timely manner. Diagnosing the problem at an early stage will help avoid serious consequences.