We change the thermostat on the VAZ 2107 with our own hands

The temperature of an internal combustion engine is a parameter that must be controlled particularly carefully. Any temperature deviation from the values ​​specified by the engine manufacturer will lead to problems. At best, the car simply won't start. At worst, the engine of the car will overheat and jam so that it will not be possible to do without an expensive overhaul. This rule applies to all domestic passenger cars, and the VAZ 2107 is no exception. The thermostat is responsible for maintaining the optimal temperature regime on the "seven". But it, like any other device in a car, can fail. Is it possible for the car owner to replace it on his own? Of course. Let's take a closer look at how this is done.

The main function and principle of operation of the thermostat on the VAZ 2107

The main task of the thermostat is to prevent the engine temperature from going beyond the specified limits. If the engine heats up above 90°C, the device switches to a special mode that helps cool the motor.

All thermostats on the VAZ 2107 are equipped with three pipes

If the temperature drops below 70 ° C, the device switches to the second operating mode, which contributes to the earliest possible warming up of the engine parts.

How does the thermostat work

The "seven" thermostat is a small cylinder, from which there are three branch pipes, to which tubes with antifreeze are connected. An inlet tube is connected to the bottom of the thermostat, through which antifreeze from the main radiator comes to the device. Antifreeze goes through a tube at the top of the device to the GXNUMX engine, into the cooling jacket.

The central element of the thermostat is the valve

When the driver starts the engine after a long period of inactivity of the car, the valve in the thermostat is in the closed position so that the antifreeze can only circulate in the engine jacket, but cannot enter the main radiator. This is necessary in order to warm up the engine as soon as possible. And the motor, in turn, will quickly heat up the antifreeze circulating in its jacket. When the antifreeze is heated to a temperature of 90 ° C, the thermostatic valve opens and the antifreeze begins to flow into the main radiator, where it cools and is sent back to the engine jacket. This is a large circle of antifreeze circulation. And the mode in which antifreeze does not enter the radiator is called a small circle of circulation.

Thermostat location

The thermostat on the "seven" is located under the hood, next to the car's battery. In order to get to the thermostat, the battery will have to be removed, since the shelf on which the battery is installed does not allow reaching the thermostat pipes. All this is shown in the picture below: the red arrow indicates the thermostat, the blue - the battery shelf.

The red arrow shows the thermostat attached to the nozzles. The blue arrow shows the battery shelf

Signs of a broken thermostat

Since the main main part of the thermostat is the bypass valve, the vast majority of breakdowns are associated with this part. Let's list the most common symptoms that should make the driver alert:

• the engine overheat indicator on the dashboard came on. This situation occurs when the central valve of the thermostat is stuck and is unable to open. As a result, the antifreeze cannot go into the radiator and cool down there, it continues to circulate in the engine jacket and eventually boils;
• after a long period of inactivity, the car is very difficult to start (especially in the cold season). The reason for this problem may be that the central thermostat valve only opens halfway. As a result, some of the antifreeze goes not into the engine jacket, but into the cold radiator. Starting and warming up the motor in such a situation is extremely difficult, since heating antifreeze to a standard temperature of 90 ° C can take a long time;
• damage to the main bypass valve. As you know, a valve in a thermostat is an element that is sensitive to temperature changes. Inside the valve is a special industrial wax that expands strongly when heated. The container with wax may lose its tightness and its contents will pour out into the thermostat. This usually happens as a result of strong vibration (for example, if the motor of the "seven" is constantly "troit"). After the wax flows out, the thermostat valve stops responding to the temperature, and the engine either overheats or does not start well (it all depends on which position the leaked valve is stuck in);
• the thermostat opens too early. The situation is still the same: the tightness of the central valve was broken, but the wax did not completely flow out of it, and the coolant took the place of the leaked wax. As a result, there is too much filler in the valve container and the valve opens at lower temperatures;
• damage to the O-ring. The thermostat has a rubber ring to ensure the tightness of this device. In some situations, the ring can break. Most often this happens if oil gets into the antifreeze due to some kind of breakdown. It begins to circulate in the engine cooling system, reaches the thermostat and gradually eats away at the rubber O-ring. As a result, antifreeze enters the thermostat housing and is constantly present there, regardless of the position of the central valve. This results in overheating of the engine.

Ways to check the health of the thermostat

If the driver detects one of the above malfunctions, he will have to check the thermostat for proper operation. At the same time, there are two ways to check this device: with removal from the car and without removal. Let's talk about each method in more detail.

Checking the device without removing it from the car

This is the easiest option that every car enthusiast can handle. The main thing is that the motor is completely cold before starting the test.

1. The motor starts and idles for 20 minutes. During this time, the antifreeze will heat up properly, but it will not yet enter the radiator.
2. After 20 minutes, gently touch the top tube of the thermostat with your hand. If it is cold, then the antifreeze circulates in a small circle (that is, it enters only the cooling jacket of the motor and into the small furnace radiator). That is, the thermostat valve is still closed, and in the first 20 minutes of operation of a cold motor, this is normal.
   

   By touching the upper branch pipe with your hand, you can check the serviceability of the thermostat
3. If the upper tube is so hot that it is impossible to touch it, then the valve is most likely jammed. Or it has lost its tightness and has ceased to adequately respond to temperature changes.
4. If the upper thermostat tube heats up, but it happens very slowly, then this indicates an incomplete opening of the central valve. Most likely, it is jammed in a half-open position, which will further lead to difficult starting and a very long warm-up of the engine.

Checking the device with removal from the car

Sometimes it is not possible to check the serviceability of the thermostat using the above method. Then there is only one way out: remove the device and check it separately.

1. First you need to wait until the car's engine has completely cooled down. After that, all the antifreeze is drained from the machine (it is best to drain it into a small basin, after completely unscrewing the plug from the expansion tank).
2. The thermostat is held on three pipes, which are attached to it with steel clamps. These clamps are loosened with an ordinary flat screwdriver and the nozzles are removed manually. After that, the thermostat is removed from the engine compartment of the "seven".
   

   The thermostat without clamps is removed from the engine compartment
3. The thermostat removed from the machine is placed in a pot of water. There is also a thermometer. The pan is placed on a gas stove. The water gradually warms up.
   

   A small pot of water and a household thermometer will do to test the thermostat.
4. All this time you need to monitor the thermometer readings. When the water temperature reaches 90 ° C, the thermostat valve should open with a characteristic click. If this does not happen, the device is faulty and needs to be replaced (thermostats cannot be repaired).

Video: check the thermostat on the VAZ 2107

How to check the thermostat.

About choosing a thermostat for the VAZ 2107

When the standard thermostat on the "seven" fails, the car owner inevitably faces the problem of choosing a replacement thermostat. On the market today there are many companies, both domestic and Western, whose products can be used in the VAZ 2107. Let's list the most popular manufacturers.

Gates thermostats

Gates products have been presented on the domestic auto parts market for a long time. The main difference of this manufacturer is a wide range of manufactured thermostats.

The range of Gates thermostats is very wide

There are classic thermostats with industrial wax valves, and thermostats with electronic control systems designed for more modern machines. Relatively recently, the company began to produce body thermostats, that is, devices supplied complete with a proprietary body and a system of nozzles. The manufacturer claims that the efficiency of a motor equipped with their thermostat will be maximum. Judging by the consistently high demand for Gates thermostats, the manufacturer is telling the truth. But you will have to pay for high reliability and good quality. The price of Gates products starts from 700 rubles.

Luzar thermostats

Probably, it will be difficult to find the owner of the "seven" who has never heard of Luzar thermostats at least once. This is the second most popular manufacturer in the domestic auto parts market. The main distinguishing feature of Luzar products has always been the optimal price-quality ratio.

Luzar thermostats have an optimal quality / price ratio

Another characteristic difference is the versatility of the thermostats produced: a device suitable for the "seven" can be put on the "six", "penny" and even "Niva" without any problems. Finally, you can buy such a thermostat in almost any auto shop (unlike Gates thermostats, which can be found far from everywhere). All these moments made Luzar's thermostats incredibly popular with domestic motorists. The cost of the Luzar thermostat starts from 460 rubles.

Finord thermostats

Finord is a Finnish company specializing in automotive cooling systems. It produces not only various radiators, but also thermostats, which are highly reliable and very affordable. The company does not give any specific information about the production process of its thermostats, citing trade secrets.

The Finnish company Finord produces good thermostats at a reasonable price

All that can be found on the official website is assurances of the highest reliability and durability of Finord thermostats. Judging by the fact that the demand for these thermostats has remained consistently high for at least ten years, the Finns are telling the truth. The cost of Finord thermostats starts at 550 rubles.

Wahler thermostats

Wahler is a German manufacturer specializing in thermostats for cars and trucks. Like Gates, Wahler provides car owners with the widest range of models, from electronic thermostats to classic, industrial wax. All Wahler thermostats are carefully tested and are extremely reliable. There is only one problem with these devices: their price bites a lot. The simplest single-valve Wahler thermostat will cost the car owner 1200 rubles.

Wahler thermostats - high quality and high price

Here it is necessary to mention the fakes of this brand. Now they are more and more common. Fortunately, the fakes are made very clumsily, and they are betrayed primarily by the poor quality of packaging, printing, and the suspiciously low price of 500-600 rubles per device. The driver, who saw the "German" thermostat, sold at such a more than modest price, must remember: good things have always been expensive.

So what kind of thermostat should a motorist choose for his "seven"?

The answer is simple: the choice depends only on the thickness of the car owner's wallet. A person who is not constrained in funds and wants to replace the thermostat and forget about this device for many years can opt for Wahler products. If you don’t have much money, but you want to install a high-quality device and at the same time have time to look for it, you can choose Gates or Finord. Finally, if money is tight, you can just get a Luzar thermostat from your local auto shop. As they say - cheap and cheerful.

Replacing the thermostat on a VAZ 2107

Thermostats on the VAZ 2107 cannot be repaired. In fact, problems in these devices are only with the valve, and it is simply impossible to restore a leaky valve in a garage. The average driver does not have the tools or special wax to do this. So the only reasonable option is to buy a new thermostat. In order to replace the thermostat on the "seven", we first need to select the necessary consumables and tools. We will need the following things:

• coolant, 5 liters;
• a basin for draining old antifreeze;
• flat screwdriver;
• wrenches.

Sequence of operations

Before replacing the thermostat, we will have to drain all the coolant from the car. Without this preparatory operation, it will not be possible to replace the thermostat.

1. The car is installed above the viewing hole. It is necessary to wait until the engine has completely cooled down so that the antifreeze in the cooling system also cools down. Complete cooling of the motor can take up to 40 minutes (the time depends on the ambient temperature, in winter the motor cools down in 15 minutes);
2. Now you need to open the cab, and move the lever to the right, which is responsible for supplying hot air to the cab.
   

   The lever indicated by the red arrow moves to the extreme right position
3. After that, the plugs are unscrewed from the expansion tank and from the upper neck of the main radiator.
   

   The plug from the radiator neck must be unscrewed before draining the antifreeze
4. Finally, on the right side of the cylinder block, you should find a hole for draining the antifreeze, and unscrew the plug from it (after substituting a basin under it to drain the waste).
   

   The drain hole is located on the right side of the cylinder block
5. When the antifreeze from the cylinder block stops flowing, it is necessary to move the basin under the main radiator. There is also a drain hole at the bottom of the radiator, the plug on which is unscrewed manually.
   

   The lamb on the radiator drain can be unscrewed manually
6. After all the antifreeze has flowed out of the radiator, it is necessary to unfasten the expansion tank fastening belt. The tank should be slightly raised along with the hose and wait for the rest of the antifreeze in the hose to flow out through the radiator drain. After that, the preparatory stage can be considered completed.
   

   The tank is held by a belt that can be removed by hand.
7. The thermostat is held on three tubes, which are attached to it with steel clamps. The location of these clamps is shown by arrows. You can loosen these clamps with a regular flat screwdriver. After that, the tubes are carefully pulled off the thermostat by hand and the thermostat is removed.
   

   The red arrows show the location of the mounting clamps on the thermostat pipes
8. The old thermostat is replaced with a new one, after which the car's cooling system is reassembled and a new portion of antifreeze is poured into the expansion tank.

Video: changing the thermostat on a classic

How to replace a thermostat on a VAZ 21099 and signs of its malfunction.

important points

In the matter of replacing the thermostat, there are a couple of important nuances that cannot be ignored. Here they are:

• on the latest models of the "sevens" (cars of 2010 and older), the clamps on the thermostat are not worm, but tape. This means that you won’t be able to remove them with a conventional flat screwdriver, and to remove them you will have to use a special clamp wrench, which not every car owner can find in the garage. If the car owner is a “happy” owner of a thermostat with band clamps, then there is only one way out: go to the store for a tool. A clamp wrench costs about 300 rubles;
  

  A special wrench is required to remove the band clamps.
• even after draining the antifreeze from the system, personal protective equipment must not be neglected. It should be remembered: it is impossible to completely drain the coolant from the machine. Some of this fluid will still remain in the thermostat pipes and in the thermostat itself. Given the fact that many motorists prefer to remove thermostats from below without leaving the inspection hole, antifreeze can easily get into the driver's eyes. This, in turn, can lead to severe eye irritation and even blindness. Therefore, changing the thermostat should only be done with goggles and gloves.

So, changing the thermostat to the "seven" is a simple task. Preparatory procedures take much more time: cooling the engine and completely draining the antifreeze from the system. Nevertheless, even a novice car owner can cope with these procedures. The main thing is not to rush and follow the recommendations above exactly.