Engine breather: what is it, where is it located and how does it work?

What is an engine breather and why is it needed?

Everyone knows that the internal combustion engine, the same one that is installed under the hood of your car, does not run on gasoline, diesel or gas, but on their mixture with air.
Moreover, it is air, which costs nothing (unlike fuel, for which we regularly pay a tidy sum at the gas station), that is required many times more. But in addition to the influx of clean air and the removal of exhaust gases through the exhaust pipe, parasitic gases are formed during the operation of the internal combustion engine. A breather is nothing more than a breathing valve that constantly relieves excess pressure that forms inside the engine during operation. The need for this simple, relatively inexpensive part is difficult to overestimate.

Purpose

The task of the breather in a car design is to connect the engine sub-piston space with the atmosphere. Additionally, the breather is installed in the valve cover of the block head.

During operation of the power plant, the movement of components, mechanisms, and lubricant leads to an increase in pressure inside the crankcase and under the cover. In addition, crankcase gases accumulate in the sub-piston space, which also increases the pressure.

Piston rings are not able to ensure complete tightness of the combustion chamber, so some of the working gases break through and enter the sub-piston space.

The operation of the motor is accompanied by temperature changes, which causes condensation to form inside. The accumulation of moisture inside the motor is unacceptable, since it is the main cause of corrosion.

A mixture of working gases that have broken into the crankcase, moisture, and oil particles that are mixed in contact with the lubricant are called crankcase gases. An increase in pressure inside the crankcase is usually accompanied by a deterioration in engine performance, since gases create additional resistance to components and mechanisms.

If gases accumulate in large quantities in the sub-piston space, then they break through leaks and “weak” components - oil seals, dipstick, seals, etc.

Therefore, it is important to equalize pressure and gas removal. And this is done by the breather, which is essentially an air valve. Note that this element is used not only on the engine, it is also used in gearboxes and rear axles.

In addition to maintaining pressure in the cylinder block, many car enthusiasts use the breather to diagnose the engine. It helps determine the degree of wear of the cylinder-piston group and the position of the rings.

When engine components wear out or piston rings become coked, a large amount of gases enters the sub-piston space. And thanks to the breather, this is clearly noticeable by the smokiness of the crankcase gases escaping. If the CPG is in good condition, there is practically no smoke in the crankcase gases.

Design features

Previously, the breather was a regular fitting with a hose attached to it and directed downwards. This design ensured the removal of crankcase gases to the atmosphere. To prevent oil from escaping, an oil separator was installed in front of the breather. This element changed the trajectories of gas movement, while the oil, due to inertia, settled on the walls of the oil separator and flowed into the pan.

Crankcase ventilation system of VAZ 2111: 1. Engine crankcase. 2. Breather. 3. Hose from the breather to the valve cover pipe. 4. Oil separator under the valve cover. 5. A thin hose from the valve cover to the fitting with the throttle body nozzle. 6. Fitting with a jet on the throttle valve block. 7. Thick hose from the valve cover to the inlet pipe.

In modern cars, to improve environmental friendliness, a whole system for removing these gases is used. Thanks to it, they are not released into the atmosphere, but are fed into the cylinders, where they burn.

This system includes:

1. Breather.
2. Oil separators.
3. Pipes.

It is noteworthy that the crankcase gas exhaust system uses several oil separators - labyrinth, centrifugal, and mesh.

The breather is located in various places in the lower part of the engine block. It can be either a separate element or act as a housing for the probe.

The breather is a very simple element in design, but the performance of the engine depends on it. If you turn it off, then within a few minutes the increased pressure will squeeze out the oil. If the oil comes out through the dipstick, then you just need to restore the lubricant level and wipe the engine compartment. But if the oil presses through the crankshaft oil seals, then replacing them is impossible.

There are no moving parts in the breather, so there is nothing to break in it. But it still requires maintenance. The oil separator is not able to catch all the oil and oil particles remain in the gases. Some of them settle on the inner walls of the breather along with soot and pollutants. Gradually, the diameter of the tubes decreases, which impairs crankcase ventilation. In winter, frozen water is added to the dirt on the walls.

On some cars, the crankcase ventilation system provides for the supply of gas to the valve covers, where they additionally pass through an oil trap mesh before entering the cylinders. The honeycombs of this mesh are also clogged with dirt, so the throughput is reduced. This “results” in the pushing of the camshaft seals

Device

The breather is essentially a valve that bleeds air from the engine. As the pressure increases, it begins to allow a certain amount of gases to pass through it. The greater the pressure, the more air can pass through it. To prevent atmospheric air from entering inside, the valve is capable of flowing only in one direction. But on some cars this process is reciprocal. In such versions, a filter is installed in the valve to prevent dust from getting inside the motor.

Most often, the breather is located next to the oil filler neck. Much less often you can find options with its location on the side of the cylinder block. From the outlet pipe there is a hose connected to the air filter housing. This arrangement is typical for all cars. It may differ only in small nuances due to the characteristics of the body. Sometimes there are 2 pipes, in which case the second hose is connected to the injector.

The role of the oil separator

An oil separator, often called an oil sump, is designed to capture large and fine oil particles. Its role is extremely important for the proper operation of the mass air flow sensor (MAF). As oil mist settles on the walls of the intake tract, it quickly becomes covered with dust. Because of this, the operation of the flow meter’s sensitive element is disrupted. The engine control unit receives incorrect readings about the amount of air entering the intake tract. Therefore, forced crankcase ventilation of a modern engine may include several types of oil separators.

Labyrinth oil trap

When gases move through the labyrinth, large oil particles under the influence of inertial forces are pushed towards the walls of the oil separator. The oil flows by gravity through the separator plates into the pan. An oil trap similar in operating principle, consisting of a set of plates, is installed in the valve cover of VAZ injection engines.

Cyclic oil trap

Designed to capture fine particles of oil suspension. As crankcase gases pass around the circumference of the oil separator housing, oil droplets move outward, settling on the walls of the oil separator housing.

Oil separator with filter element

Filter paper or fiberglass filler is installed inside the housing. Passing through the filter, the oil is retained on the walls of the filter element, after which it flows into the pan.

Turbulence of exhaust gas flows moving through the crankcase ventilation hose impairs the uniform filling of the cylinders. Therefore, many cars have an additional sedation chamber installed. In addition to a gas flow retarder, the chamber also acts as an additional oil separator.

Where is the breather installed?

Breathers on a car are installed:

• in the engine itself;
• in the gearbox device;
• in the design of the front and rear axles;

Note that the functions of these devices are almost the same regardless of the installation location. It should be added that the valve also has an additional filter that prevents mechanical particles, dirt and moisture from entering the engine along with the outside air.

To put it differently, the breather allows those components to “breathe” from which the working fluid cannot leak out, as well as water and dirt from entering from the outside. During operation of the internal combustion engine, the engine oil in the crankcase heats up, which causes it to expand. The air in the crankcase also expands and pressure is created. If this pressure is not relieved, then the oil will begin to squeeze out through the seals, seals and gaskets of the engine. This statement is also true in relation to other components of the car (axles, transfer case, gearbox).

After stopping the engine and stopping the operation of other components, as well as when it gets into water (important for SUVs), cooling occurs. When cooling, the pressure in the container drops, a pressure difference arises again and outside air tries to break through through the gaskets, etc. To counteract these phenomena and safely equalize pressure on the engine, gearbox, etc. breathers are installed. It turns out that the valve prevents water and dirt from entering the power units when the pressure drops, and also does not allow the gaskets to be squeezed out and the working fluid (lubricant) to leak out when excess pressure occurs.

Breather in gearbox

The gearbox must convert the torque in the engine and also change the traction force. It often happens that the gearbox starts to work poorly due to the fact that the gearbox breather is clogged. To avoid any damage, you should clean not only the breather in the engine, but also all the others that are installed in different parts of the machine.

In the gearbox, the breather is located on the gearbox housing cover. Sand or dirt getting into the breather will cause the wheel mounted on the secondary shaft to jam. As a result, wear of bearings and synchronizers increases. It is necessary to wash the breather during each technical inspection, or even more often. If the valve is clogged, the pressure in the gearbox will increase, which will lead to oil leakage through the seals.

Bridge breathers

There is oil inside each axle that connects the wheels. The internal cavity must contact the external environment, and it does this through the breather. With the help of this valve, an increase in pressure inside the bridge itself is eliminated.

Oil pressure rises when it heats up during forward gear operation. The breather also performs a protective function. It protects the bridge from water entering it when the car overcomes a water barrier. There is also a special hole in the middle of the bridge through which oil drains.

Particular attention should be paid to the rear axle crankcase breather. It is located on the rear axle boat, on the right side, at the top

As a result of this valve being clogged, oil may leak. To get rid of this problem, you need to clean the breathers from dirt. You also need to check the free movement of the breather cap. It should move in all directions.

After cleaning the breather, you should check it again after a short run of 20 km. If traces of oil are detected again, this will indicate a malfunction of the device that needs to be replaced. The rear axle breather must always be in good condition, because it plays an important role in the operation of the entire vehicle.

How does it work and why should you clean it?

The functions of the breather, regardless of its location, always remain unchanged. Typically, such a device has a filter that prevents dirt, dust and moisture particles from entering the motor. In more understandable terms, the device allows the structural units to breathe and prevents the possible leakage of working fluids. As for the operating principle of the breather, since the oil in the crankcase heats up during operation of the power unit, this leads to an increase in temperature. Then the air begins to expand and creates pressure. This pressure must be relieved, otherwise the oil liquid inside will begin to flow out through the seals and seals. But when cooling, quite the opposite, the pressure in the crankcase quickly drops and air begins to escape through all the holes. To somehow prevent this, it is necessary to equalize the pressure on the motor. And this is done by installing a breather. Over time, dust and dirt accumulate in it, causing it to stop working properly. Because of this, problems begin with pressure and this leads to oil leakage. If the breather is very dirty, it must be replaced with a new one. but before installation, it is definitely recommended to clean it and clean its installation location.

More information about what a breather is will be discussed in this video:

Source

Engine breather

Some novice drivers are stumped by the question “engine breather and what is it,” because recommendations for the operation and care of a vehicle often mention this important element of the engine.

In addition, the breather often helps diagnose important problems associated with the power unit: the fact is that problems with this element can subsequently cause engine problems, which can then lead to expensive repairs.

That is why the car owner simply needs to know all the aspects and characteristics of the device, as well as have an idea of ​​how to properly prevent disruptions in its operation, because the breather valve, which does not seem like a significant detail at first glance, is of great importance for the proper operation of the power unit.

What is its purpose?

To understand what a breather is, it is recommended to find out what it is for, since this is directly related to its operating principle.

The main task of this device is to reduce pressure in the engine crankcase.

While the car is running, a lot of gases accumulate in the crankcase, which over time create high pressure. If they are not released in time, the engine may stop working, since high pressure will support the pistons, and gas will begin to escape through any other hole. To prevent this from happening, this valve is installed.

Another significant function of the device is to reduce the temperature inside the engine and ventilate it.

Based on the operation of this unit, one can draw conclusions about problems in the operation of the motor.

In normal operating condition, a slightly transparent, barely noticeable smoke can be seen from the unit. There are situations where the engine constantly throws out oil through the breather. This is a common cause of not only valve clogging, but also other technical problems.

The breather valve is an important element that allows communication with the external environment of a closed container. It allows you to equalize the pressure inside the internal combustion engine: if it drops sharply, fresh air will enter through the valve, which will eliminate the difference between the external, atmospheric, and internal pressure created in the crankcase cavity.

The principle of operation of the breather in the engine

Today, a breather valve to reduce pressure is very often installed on SUVs. This is due to the fact that the device is suitable for off-road driving. Breathers prevent oil leakage. Heated engine oil expands, causing engine pressure to increase.

The pressure in engines or in other automotive devices must find a way out. This causes oil to leak out through various gaskets and gaps. To prevent oil leakage, breathers are installed.

All breathers in the car should be checked periodically. Due to the constant movement of oil, debris and dirt remain in it. Breathers must be properly removed and cleaned of contaminants. If it is too dirty, then it must be replaced with a new device. Before installing a new valve, be sure to thoroughly clean the installation area of ​​dirt and debris. This is done to prevent debris from getting into the new device.

Installation location

The breather valve in a car is usually located:

• directly in the engine;
• inside the rear and front axle structures;
• at the checkpoint.

Engine breather: why is it needed, how does it work and where is it installed?

Not all motorists, especially beginners, know what an engine breather is for and what it is. This element is often mentioned in vehicle operating recommendations. This element helps diagnose important problems that are directly related to the car’s engine. Why? Yes, because often problems with this element can subsequently lead to problems with the power unit. And as a result, all this will result in expensive repairs. For this reason, every motorist should know everything about such a device and have at least the slightest idea of ​​how malfunctions in its operation can be prevented.

Troubleshooting

The first thing you need to pay attention to is the color of the exhaust, blue or black smoke, a sign of burnt valves or problems with rings. Next, you should check the compression in all cylinders. The value on gasoline internal combustion engines should be within 11-13 MPa. Disconnect the pipes from the valve covers, air intake and breather

Assess the degree of contamination. If the pipes are very dirty or clogged with oil deposits, use gasoline to clean them or a special carburetor cleaner. Check the condition of the oil separator. Unscrew the required bolts to get to this unit. Remove the oil separator and assess its condition. If necessary, clean or rinse followed by drying. Inspect and, if necessary, flush the breather valve. There are situations when the valve gets stuck, resulting in exhaust gases entering the crankcase and creating excess pressure. Remove the part and wash it; in most cases, this will resolve the issue of squeezing oil out of the breather.

Helpful advice! To distinguish stuck rings from a burnt-out valve, it is enough to perform several manipulations. After checking the compression in the cylinders, determine the cylinder with the lowest value. Then inspect the spark plug of this cylinder; if the rings are lodged in this cylinder, the spark plug will be covered with a thick oil layer. If the valve is burnt out, the spark plug will appear normal without any major abnormalities.

Signs of malfunction

1. Excessive oil fogging in places of rubber seals. It is pointless to change the cylinder head gasket, pan or oil seals without eliminating the cause of the increased pressure of crankcase gases. The reason may be either insufficient crankcase ventilation performance or critical wear of the cylinder-piston group (hereinafter referred to as the CPG). In the latter case, more crankcase gases leak into the pan than the crankcase ventilation system can pass through. On cars with a synthetic filter element, we first recommend checking the condition of the filter.
2. Excessive oil consumption. Increased pressure in the crankcase prevents the oil scraper rings from working effectively, causing oil to burn in the cylinders.
3. Floating idle speed. The reason is a leak in the system. Cracks in hoses, PCV valve body, loose clamps - all these factors lead to the leakage of unaccounted air.
4. Persistent smell of exhaust gases when driving at low speeds and while parked with the engine running. The closed crankcase ventilation system is leaky in the section up to the VCV valve, which is why gases break into the engine compartment, from where they are drawn inside the car by the cabin fan.
5. A large amount of oil in the intake manifold, pipes and even on the air filter. The reason is a faulty oil trap.

Why is there smoke coming from the breather?

There can be only one malfunction of the breather: it began to poorly pass accumulated gases, comparing the pressure inside the engine with atmospheric pressure. But the smoke coming from it can say a lot:

• The cylinder oil scraper rings were stuck or worn out. Simple decarbonization using traditional methods or special chemicals will not help here, so you will have to disassemble the engine.
• Likewise, if one/several exhaust valves burn out. A simple compression test will help determine this.
• Oil seals. Just replace them when it's time or they show signs of increased wear.
• The shaft seals, which allowed oil vapors to pass through, were worn out. Change them without hesitation, preferably without shelving them.
• The oil in the engine is old and needs replacing for a long time. No comments: as practice shows, repairing the “heart” of a car is tens of times more expensive than replacing it.
• White smoke on a hot engine - coolant enters the lubrication system. You'll have to look for where exactly the leak is.
• Oil overflow. In an internal combustion engine, it is just as dangerous as underfilling: engine wear/fuel consumption increases significantly, so check its level with a dipstick on a level surface when the engine is well warmed up. Then you will see how well the technicians at the service station (or you yourself) performed its replacement/topping up.
• The oil is of poor quality/not suitable for the car/counterfeit. There is only one way out - replace it. Likewise, if you filled up with fuel at an unknown gas station: just don’t do it again.
• Finally, the breather itself clogged from time to time, not working at 100%. Simple cleaning and preventive maintenance will eliminate this.

An impressive list of different situations. And there is no doubt that if your car’s breather is smoking, you have definitely found your case among them.

Oil is squeezed out through the breather: how to fix the problem

There are situations when oil leaks through the breather on a car. The liquid is squeezed out, and streaks on the unit become noticeable. This sign indicates the need to perform diagnostic procedures on the engine. Let's try to figure out the problem in the garage. If necessary, the technical fluids needed for replacement can be picked up in Tikamis and ordered there if you live in the service area of ​​this company.

When operating a car, crankcase gases accumulate in the crankcase. Without maintaining excess pressure, we use a special ventilation valve. This way we will cover the crankcase from interaction with the atmosphere. This valve is called the breather.

In the installation, gases are mixed with a mist of oil composition, so the particles penetrate into the element in question. As a result, some of the liquid flows out. This means that we can allow minor contamination of the device.

If leaks occur from the breather, the channels immediately become clogged and soot appears. The remaining substance flows into the crankcase, and the system “cokes.” Parts under load are practically not lubricated, the “engine” wears out. By the way, traces of the composition are not always visible from the outside.

Let's find out the causes of this disease. Oil appears due to worn piston rings. Gases flow from the seal into the crankcase, where overpressure is created. If the level is excessive, oil will leak out from the breather. The oil deflector drains may become clogged.

Why you need to clean the breather

Operating under the conditions described above means that the breather may become clogged. The release of oil through the valve is accompanied by the subsequent accumulation of dust, which clogs the valve passage. As a result, when heating, excess pressure is created or insufficient pressure when cooling, which leads to oil leakage through the oil seals and gaskets of the engine and other units.

To troubleshoot the problem, the breather must be removed for cleaning or replacement. It is recommended to replace the engine or gearbox breather with a new one if it is very dirty. Before installing a new breather, it is necessary to thoroughly clean the installation site. This will avoid its rapid re-contamination.

Transmission breather: what is it for and how it works

A car uses a large number of components and assemblies, inside of which there are technical fluids and lubricants. During operation, such liquids heat up, that is, they increase in volume and the pressure inside increases.

Taking into account the fact that the systems and units themselves are sealed, closed (there is no direct communication with the atmosphere), pressure differences occur inside relative to atmospheric pressure. This difference must be equalized to prevent depressurization, leaks and damage.

For this reason, the engine cooling system has a special valve, which on modern cars is located in the cap of the expansion tank. As for the internal combustion engine or gearbox, a similar function is performed by the engine breather and the breather on the gearbox. Next, we will look in detail at what a gearbox breather is, why it is needed, and how this element is designed and works.

Breather in the gearbox: operating principle and features

So, in order to understand what a breather is in a car, it should be noted that in fact it is a valve that allows you to reduce the pressure in the crankcase of a sealed unit (engine, gearbox, etc.) A breather, breather or breathing valve is a device through which the container communicates with the atmosphere, and even taking into account the temperature difference in the container, it is possible to maintain atmospheric pressure.

On the one hand, such a valve allows you to relieve excess pressure (equalize the pressure during heating and cooling), and on the other hand, it does not allow oil to leak out of the unit or unit. Also, when cooling, dirt, moisture and dust are not drawn into the unit or assembly. For this reason, engine breather or gearbox breather is actively used in various vehicles.

As you know, the gearbox performs the task of converting torque from the engine, after which torque is transmitted to the drive wheels. The box itself is filled with transmission oil, which tends to heat up during operation of the gearbox, expanding in volume. The result is an increase in pressure that needs to be relieved. If this is not done, the pressure in the gearbox will be increased, which will cause oil to leak from the gearbox through the seals, seals and gaskets.

It is not difficult to guess that oil leaks from the gearbox will lead to the lubrication level dropping, the box will begin to work poorly, and will also wear out quickly and actively. First, the driver experiences difficulties and discomfort (gears engage worse), then extraneous noise appears (hum, vibration of the box), then synchronizers, bearings, gears and other gearbox elements fail. In the gearbox, the breather is installed on the gearbox housing cover.

• Let us add that breathers are also installed on the engine (engine breather), on the transfer case, gearboxes, and axles. As for the internal combustion engine, the pressure in the unit grows quite actively, as strong heating occurs, some of the exhaust gases inevitably break into the crankcase, etc. To avoid oil leaks as a result of increased pressure, said pressure is “released” through the breather.

Also in the car design you can find breathers on bridges. The fact is that oil is also filled inside the car axle. In this case, as in the case of gearboxes and internal combustion engines, the internal cavity must have communication with the atmosphere in order to avoid an increase in pressure inside the unit.

Another important function of the box or axle breather, as well as the engine, is protection from dust, dirt, water, etc. This is especially true for car axles, since the bridge is an open element (for example, on an SUV) and can be submerged in water or mud when driving through difficult areas.

Useful tips

As a general rule, you should check all existing breathers on a particular vehicle (engine breather, transmission breather, axle breather, etc.). The fact is that oil particles can be squeezed out through the breather during its operation, which leads to active contamination.

In practice, breathers need to be dismantled and cleaned of dirt and oil residues. If cleaning does not produce results (in the case when oil “presses” out of the gearbox, motor or axle precisely because of a faulty breather), the device must be completely changed.

Also, before cleaning, you need to know how to remove the breather. On many cars, it is enough to remove the rubber cap on top and then clean the valve. Some other models may not have a rubber breather cap, and the breather is located in the 5th gear cover. In this case, cleaning is also carried out using improvised means.

• Let us also add that before removing the breather for cleaning or replacing it, you should thoroughly clean the seat from dirt (so that the device does not become dirty again or the new breather does not fail after a short period of time).

Please note that when checking both old devices and new breathers, you must separately make sure that the breather cover moves freely in all directions.

At the same time, we would like to add that the rear axle crankcase breather deserves special attention (on many cars it is installed in the upper part of the rear axle crankcase, closer to the right side). This valve is subject to active contamination. If the breather becomes dirty or stops working for other reasons, oil leaks from the axle due to increased pressure.

In this case, you should start with cleaning. After cleaning, it is recommended to drive 20-30 km. If the leak continues, and there are no other obvious reasons, the rear axle breather needs to be replaced. If oil drips still appear, you should look for a fault not related to the breather.

Let's sum it up

Taking into account the above information, it becomes clear that even with its apparent simplicity, the breather of a gearbox, engine or axle performs a rather important function. This means that the condition and proper operation of this element must be monitored.

This is especially true for SUVs, trucks and special equipment, where in addition to gearboxes and internal combustion engines, breathers are installed on bridges. Such machines are often operated in harsh conditions, as a result of which the gearbox or axle pressure reduction valve may become dirty or fail more often (especially the rear axle breather).

We also recommend reading the article about why oil leaks from the gearbox. From this article you will learn about the reasons why oil leaks from the gearbox, as well as how to identify and fix the problem. Finally, we note that if the owner notices oil leaks from the engine, gearbox, axles, and other components and assemblies through gaskets and seals, this may indicate problems with the breather. If the valve is clogged or faulty, pressure increases in the closed cavity, which causes lubricant leakage.

Also, the unit or assembly itself may stop working normally, which subsequently leads to serious damage. For this reason, it is necessary to clean the breathers installed on different units and elements of the car at every service. If the car was driven off-road, it is recommended that after such trips you immediately wash the breathers to remove dirt and sand.

Source: https://KrutiMotor.ru/sapun-korobki-peredach-ustrojstvo-printsip-raboty/

Preventative work

Some motorists are wondering: why clean the breather? This is done in order to avoid problems with the operation of car components; it is necessary to clean the breather in a timely manner. Such actions will allow you to maintain the permissible pressure level, and as a result, stable and trouble-free operation of the car. It is recommended to carry out cleaning at every technical inspection (MOT), and in some cases even more often. The cleaning process itself looks like this:

• removal of pipes and hose. All pipes and hoses coming from the “breathing valve” are removed; in some models you will also need to remove the air filter housing;
• removing the breather cover;
• cleaning work. Now you can begin cleaning the valve cap and tube.
• installation work. Assembly is carried out in reverse order.

This is how cleaning is done. The procedure is quite simple, and you can do it yourself with your own hands, without the need to visit a service center.