Thermostat "Lacetti": functions, repair, replacement

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

The cooling system is an integral part of any car. It is she who allows you to maintain the normal temperature regime of the internal combustion engine. On almost all modern cars, this system is of a liquid type. Chevrolet Lacetti is no exception. In today's article, we will pay attention to one of the small, but very important details in the engine cooling system. It's a Chevrolet Lacetti thermostat. Where is it located, how is it arranged and how to replace it? All this - further.

Description

So, what is this element? The thermostat is a temperature-sensitive valve designed to regulate the flow of coolant in the system. The valve device includes a plate mounted on the body. The latter performs the function of a cylinder in which the rod is installed. One end of the rod rests against the upper frame of the thermostat, and the other end against the rubber cavity of the housing. The device also has a temperature-sensitive element, which consists of copper and granular wax.

Where is the thermostat in the Lacetti? This element is attached to the engine block. Located on the left side of the exhaust manifold.

Operation principle

This thermal valve works very simply. When the wax melts under the influence of hot coolant, it will begin to expand - its state will change from solid to liquid. When the wax ball melts and expands completely, pressure will be built up. Under the action of this pressure, a metal pin will be squeezed out of the metal case, which will open the valve, and thereby open access to antifreeze into the radiator. When the liquid in the radiator begins to cool, the wax will again take on a solid state, its usual shape, and the thermal valve will close - the coolant will again circulate in a small circle.

Due to the bypass valve, the liquid can only move along the line to the radiator. The outlet pipe of the pump is connected to the radiator pipe. The bypass valve is a disc and return spring design.

Thus, thanks to the thermostat, the car warms up faster, as the valve prevents the circulation of cold fluid in a large circle. Antifreeze does not get into the radiator and does not cool even more. And when the liquid is fully heated (up to +85 degrees Celsius or more), the valve begins to slowly open. Regularthe element opens at + 85-87 degrees. But they put on the Lacetti and the thermostat at 92 degrees. Usually they change the factory element to a non-standard one in order for the car to warm up faster. However, as practice shows, there is not much difference in this. If the factory valve is working properly, you should not change anything in the device of the cooling system.

What is the danger of a breakdown?

Where more dangerous is the situation when the valve is stuck and no longer opens. In this case, the liquid quickly overheats. Accordingly, the motor boils. In order not to harm the engine and preserve the geometry of the head of the block, it is urgent to replace the thermostat in the Chevrolet Lacetti. Note that the valve can jam in different positions. It may also be semi-open. In such a situation, the car does not heat up well, fuel consumption increases, the stove stops heating normally.

How to check the thermostat in a Chevrolet Lacetti

Unfortunately, there is only one correct, "old-fashioned" way to check this element. To do this, you need to dismantle the Lacetti thermostat and "weld". We need an empty container with a volume of at least one and a half liters. We fill the container with water and place our thermostat there. The water needs to boil. At this time, we observe the movement of the valve. The last one should open. If this does not happen, then the thermostat on the Lacetti is faulty. This part cannot be repaired, so it only needs to be changed.

Types and characteristics

Two types ofthermostats. This is a collapsible aluminum and non-collapsible plastic. The first one costs a little more and is sold complete with a regular thermal element. Which is better to choose? Reviews say that it is more reliable to put an aluminum hot thermostat on the Lacetti. Here are some characteristics of the thermostat:

• The diameter of the large pipe to the radiator is 35 millimeters.
• The angle between the nozzles is 60 degrees.
• Center-to-center distance between mounting holes - 75 millimeters.
• The diameter of the pipe that enters the head of the engine block (outer) is 39 millimeters.
• Length from end to flange - 18 millimeters.
• The diameter of the pipe going to the engine throttle heating is 10 millimeters.

Preparing for replacement

Before replacing the thermostat with the Lacetti, you need to make sure that the engine is completely cool. Since we will interfere with the cooling system, you can easily get burned. Therefore, if the motor has recently worked, we wait until it cools down. Next, we need a clean container to drain the antifreeze. We will not merge all, but only some part. Therefore, the volume of the container can be no more than three liters. We also need a one and a half meter hose with a diameter of 10 millimeters. For safety reasons, we cover the generator belt with plastic wrap or a bag. We cover the places near the hose with pieces of rags so that the antifreeze does not get where it is not needed.

What's next?

Need to open the cap of the expansion tank. So we will equalize the pressure in the system with atmospheric. Using pliers, press the antennae of the clamppipe of the engine cooling system, which removes antifreeze. It is the thinnest among the rest and is located on the right side of the engine in the direction of the car. You need to loosen it, but not completely remove it. Next, we prepare our one and a half meter hose. We quickly install it in place of this pipe, and lower the other end into the prepared container.

We are waiting for the liquid to drain from the engine block. We then do the same operation with a large pipe. Then we disconnect it completely. At the next stage, we take an L-shaped key for 12 (if this is not at hand, you can use a regular head) and unscrew the two bolts that attach the thermostat to the block. Be prepared that you will have to make some effort to unscrew it, as the fasteners may stick. Let's use a lever. It is important not to break the bolts themselves. If the O-ring is in good condition, it can be left. If there is damage, it is better to replace it with a new one. Also, a square seal is put on the new thermostat. The round one should go to the engine block.

After that, mount the thermostat in the reverse order. Do not overtighten the bolts. The thread is designed in such a way that when unscrewing the nuts go tighter. Therefore, we wrap them with a key with the effort of one hand, without an additional lever.

Next, fill the expansion tank with our liquid and start the engine. Do not be surprised that the level turned out to be highermaximum - an air lock could form in the system. It will resolve itself if the engine runs for a couple of minutes at idle with the expansion tank cap open. We turn off the engine and tighten the plug. Fluid level should equalize.

Conclusion

So, we have considered what a thermostat is and how to replace it. The thermostat is an essential element in the cooling system, if it malfunctions, you can easily lose the motor. Therefore, you should respond to warning signs in time, as well as control the coolant level itself.