Modification of the crankcase ventilation system of the VAZ 2114 injector 8 valves

Refinement of the small circle of crankcase ventilation on the 8-valve

Not long ago I came across an interesting article on a website.
The essence of which is to change the path of crankcase gases through low crankcase ventilation. AvtoVAZ has always allowed a small ventilation of crankcase gases into the throttle assembly, both on 8 and 16-valve engines. But, with the release of the Lada Grant and the advent of the 126th engine, the circle of low ventilation has changed, now it does not enter the throttle, but directly into the receiver. And this is more correct.

After all, by increasing the amount of air behind the throttle valve, you can reduce jerks in transient modes. Roughly speaking, make the engine more elastic.

The advantages of this modernization should be the following: • Increases traction at low speeds; • The engine jerk disappears when the throttle is closed abruptly; • Cleaner throttle assembly; • Decrease in crankcase pressure;

So, without hesitation, I decided to do this on my 8-valve engine. The materials that I read said that there would be no special effect on an 8-valve engine; it would only be noticeable on 16-valve engines.

But even on the 8-valve engine in Grant the ventilation is made directly into the receiver, which means it’s better. It’s not for nothing that AvtoVAZ came to this decision years later.

This is what the ventilation picture looks like initially

We remove the low ventilation hose; it will no longer be needed. I wanted to take clamps from it, but they don’t tighten very well

To ventilate the receiver, you will need a hose of the same diameter, only twice as long. I still have a hose for HBO in my bins (from the ramp to the injectors). It fit perfectly

I plugged the hole in the throttle assembly using a small piece of hose and a bolt. For greater reliability, I tied the ends together with plastic ties.

The receiver has two rubber plugs that are pulled together with a little effort. I had a vacuum connected to one hole from the HBO reducer, and the second was free. It was in the second hole that I connected the small crankcase ventilation circle. The hose fit freely, so I tightened it with a clamp

Now the small ventilation circle looks like this:

The new hose does not interfere with anything. When the decorative engine cover is installed, the changes are not noticeable at all.

Now about impressions. On my first test ride, I didn’t feel much of a change in traction at low revs, but there was some effect. I would say that traction improved by 5%, no more. Or maybe this is just my own self-hypnosis. But I don’t have a 16-valve one, where it should be really noticeable.

But the nods when releasing the gas almost disappeared. Everyone is familiar with the situation when you are driving in 1st or 2nd gear at a speed of over 3 thousand and sharply release the gas pedal without squeezing the clutch, the car “nods” and a noticeable nod appears.

So, now these “nods” are barely noticeable. They remain, there is no longer the feeling that someone suddenly pressed the brake.

In general, I consider the revision extremely useful and can recommend it. Simple manipulations that will take no more than 10 minutes and will increase driving comfort.

Source

What is a PCV valve

Theoretically, without this valve, the forced ventilation system cannot work correctly a priori. After all, it is the PCV valve that doses the supply of crankcase gases to the most important area - the space behind the throttle valve, right in front of the combustion chamber.

The PCV valve is not a check valve at all, as many people think. Yes, it is not blown in the opposite direction, but it also does not simply have two positions, open and closed. Everything is much more complicated. Inside the PCV valve there is a plunger loaded with a spring, the force of which is calculated depending on the engine volume, or more precisely, on the vacuum created in the manifold.

PCV Valve Design

The valve has four operating positions:

1. The engine is switched off. The valve is completely closed, gases do not enter the manifold, and now they have nothing to do there.
2. The engine is running at idle speed. In this mode, the vacuum in the manifold is the highest, the valve is completely open (100%) to ensure the supply of gases (essentially air) into the throttle space. Moreover, the amount of gases is strictly regulated and clearly controlled by the ECU, and the ECU already controls the idle speed controller depending on the amount of air supplied and a number of other factors.
3. The engine operates in normal mode at medium speed and medium load. The PCV valve is approximately 50% open. The flow of crankcase gases is average, they burn efficiently in the cylinders.
4. Maximum load and high speed mode. The PCV valve is open by 20-25%, the maximum amount of crankcase gases is burned, thereby the pressure in the crankcase is not dangerous for oil seals and gaskets, since it is completely controlled due to the vacuum in the manifold.

Algorithm of operation of the crankcase ventilation valve

On the Lada Vesta, the ventilation system is designed in such a way that in fact it always works the way a normal system works in the fourth mode. The flow of gases is limited only by a 1.7 mm jet built into the throttle pipe. In theory, the expectation was that the system would operate as a dual-circuit system.

This is how the ventilation scheme is implemented on 8 and 16-valve VAZ engines

The first circuit operates in the speed zone from idle to 1500 rpm. The pipe behind the throttle and the same 1.7 mm jet are involved here. The second circuit is connected to the ventilation already at high speeds, and gases begin to flow into the intake manifold up to the throttle through a hose with a diameter of 18 mm.

Design and principle of operation

As was said at the very beginning, the ventilation system removes crankcase gases from the VAZ 2114 back into the engine, preventing unburned fuel oil mixture from entering the atmosphere. It includes a pair of pipes through which gases are removed, and a filter that traps solid particles and clots.

The whole system functions as follows:

• the fuel mixture entering the engine burns and forms exhaust gases, most of which are discharged from the engine into the exhaust line;
• a small part of the gases leaks through the piston rings and enters the lower pipe of the ventilation system;
• From the lower pipe, gases enter the filter (made in the form of a multilayer mesh), after which, already purified, they return to the engine, where they burn out.

Breather oil: what to do and how to find the cause

Let's start with the fact that during engine operation, so-called crankcase gases accumulate in the crankcase. To prevent excess pressure from being created, there is a special valve for ventilation. This solution allows the closed crankcase to communicate with the atmosphere. This valve is the breather. In simple words, a breather on an internal combustion engine is actually needed to equalize the pressure inside the engine.

It should be noted that in the crankcase gases mix with oil mist. As a result, lubricant particles enter the breather. Although there is a special oil trap inside the device, a certain part of the oil may escape out. Given this information, minor contamination of the system is acceptable, which is normal. In cases where a lot of lubricant leaks, you should look separately for why oil is leaking from the breather.

On injection engines, traces of oil getting into the throttle area are noticeable, the power unit also loses its throttle response and power, and fuel consumption increases noticeably. It turns out that to check it is necessary not only to inspect the outer surfaces under the hood, but also to remove the air filter, throttle assembly, etc.

How often should cleaning be performed?

If the ventilation system is clogged and its filter is unable to clean the mixture passing through it, then not only unburned gases, but also oil particles and other pollutants will enter the engine. All this will ultimately have a negative impact on both the operation of the engine and its remaining service life.

The frequency with which the crankcase ventilation of the VAZ 2114 should be cleaned directly depends on the condition of the engine. So, if the car just recently came off the assembly line, and its engine has not clocked up 50,000 km, you shouldn’t even think about cleaning it, since the piston rings are still new, and there is practically no leakage of gases through them.

The first cleaning (as recommended by AvtoVAZ itself) should be performed after the car has covered 60,000 km. And all subsequent cleanings should also be performed after every 60,000 km.

Many owners of domestic cars with extensive experience say that 60,000 km is too much, and cleaning should be done at least every 30,000 km - this will help avoid many problems with the engine and extend its life. In this case, the first cleaning should be carried out after the first 60,000 km.

Why is cleaning necessary and its frequency?

When the ventilation system is clogged, an emulsion containing soot and oil residues settles inside the engine, resulting in the creation of excess pressure, leading to damage to the seals. This leads to loss of sealing and oil leaks, which can be seen during an external inspection of the engine block. Crankcase gases are gases from engine cylinders that are not discharged through the exhaust valve, but are squeezed out into the crankcase through the gaps of the pistons and piston rings when the engine is running. This process occurs especially intensively in worn-out engines with high mileage. For VAZ 2101-2107, these are mileages of 80-100 thousand km.

If the crankcase ventilation is not cleaned in a timely manner, the operation of the fuel supply system will be affected. In carburetor engines, the air filter and the carburetor itself become dirty; in injection engines, the throttle assembly, inlet pipe and sensors become dirty. All this leads to a decrease in power, problems with operation, and in some cases a complete stop of the engine. To avoid this, additional elements are introduced into the ventilation system to clean crankcase gases from emulsions containing oil.

If the crankcase ventilation system is not cleaned in a timely manner, the hoses crack due to excess pressure. This causes excess air to be sucked into the engine. Carburetor engines are not so sensitive to this problem, but in injection systems the quality of the mixture sharply deteriorates, the stability of the engine is disrupted and its power is reduced.

The best option is to clean the crankcase ventilation on a VAZ classic immediately before changing the oil. This frequency allows you to keep the system in order, change cracked hoses on time, extend the life of the engine, and reduce fuel consumption without loss of power.

How to clean

To begin work, you will need to prepare the necessary tools, namely:

The crankcase ventilation of a VAZ 2114 is cleaned as follows:

1. Loosen the fastening clamps of both pipes and then remove them.
2. Inspect the pipes for cracks or chips - if the latter are present, replace the pipes with new ones of the same diameter.
3. If the pipes are in good condition, clean them outside and inside with a damp cloth.
4. Disconnect the throttle cable from the sector.
5. Remove the pair of mounting bolts securing the throttle body to the receiver.
6. Remove the bracket along with the cable.
7. Unscrew the two bolts securing the cylinder head, and then remove the washers and rubber bushings located on them.
8. Remove the cylinder head cover itself.
9. Find the oil separator on the cylinder head cover and unscrew the mounting bolts that hold it.
10. Remove the housing cover, and then remove the oil separator itself.
11. Thoroughly rinse the filter mesh (oil separator) in gasoline (it is recommended to use highly purified gasoline for this) or kerosene.
12. Clean the cylinder head cover from oil and adhering dirt (this is best done using a rag soaked in kerosene).
13. Install the oil separator filter back into the cylinder head cover.
14. Reassemble in exactly the same order, but in reverse order.

To avoid possible injuries, all work on dismantling the cylinder head cover and cleaning the ventilation system should be carried out only with the engine completely cooled.

It should be noted that when performing operations to clean the ventilation system, it is worth paying attention to the condition of the rubber bushings that fasten the cylinder head, as well as the gasket. If they are worn out or covered with cracks, they should be replaced immediately, without waiting for serious damage.

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.

Cleaning the crankcase ventilation system on VAZ 2113, VAZ 2114, VAZ 2115

Welcome! Crankcase ventilation system - it is present in many gasoline cars, due to it the environment is not heavily polluted and all exhaust gases are sent back to the car engine for combustion; in old cars, people themselves modify this system in such a way that all the crankcase ventilation hoses go outside (And this is all due to the fact that the engine begins to release contaminated crankcase gases and if they fly back into the engine, they will simply choke it), because of this, the environment suffers, we immediately warn you, but the engine’s power increases and it It will be much easier to breathe.

Note! To clean the crankcase gas system, you will need: Screwdrivers, all kinds of wrenches and pliers!

Summary:

Where is the crankcase ventilation system located? This system consists of two hoses (Indicated by arrows) and a filter that passes all dirty air and oil particles through and thereby cleanses all the air of this rubbish, the filter itself is located in the valve cover (Location is indicated by a green arrow), in more detail if If you want to see it, look at the small photo, it is made in the form of a grid pack.

Note! The principle of operation of the ventilation system is this: when the engine is running, the mixture burns and for the most part everything goes into the exhaust pipe, but still, a little bit through the piston rings, vapors break through and in this case the ventilation comes into operation, due to it these vapors come out first along the lower ventilation pipe (Indicated by a blue arrow in the photo above), then they are cleaned by a filter and pass in purified form to the upper hose, the hose of the small ventilation branch (Indicated by a red arrow), and thus these unburnt vapors fly back into the car engine, to re-combustion, that’s how the ventilation system works!

When should you clean the crankcase ventilation system? When the filter becomes clogged with dirt, when the hoses become clogged, all this dirt begins to fly into the engine, so that the dirt does not fly, you need to periodically wash the filter and clean the hoses inside with a cloth, the frequency of this depends on how worn out the engine is, in new engines the first 50 thousand in general There’s no point in even getting into the crankcase ventilation system, because the rings on the pistons are intact and there’s not a lot of vapor breaking through them into the system. On used engines, we recommend it more often, since this operation is not long and there is no harm from it, only benefit ( The factory calls the figure 60,000 thousand kilometers, this is a lot, if you treat your car well, then clean the system much more often, once every 30,000 thousand kilometers approximately).

avtoexperts.ru

Among various auto systems, the crankcase ventilation system plays a significant role in the formation of the air-fuel mixture, stable and economical operation, full power delivery, protection of engine oil and extension of the life of the cylinder-piston group.

In the design of a car, the crankcase ventilation system is the “lungs” of the engine, necessary for its normal functioning. The system is called PCV (Positive Crankcase Ventilation). However, it is the one that is undeservedly given a minimum of attention and maintenance, and many car owners do not even know about its existence. In this article we will try to understand why this system is needed, how it works, its inherent faults and methods for checking its performance.

What are “crankcase gases”?

During combustion, the fuel-air mixture sharply increases in volume, creating enormous pressure inside the combustion chamber. The expanding gases from combustion force the piston to bottom dead center, causing the engine crankshaft to rotate. Some of the gases penetrate through the leaks between the rings and the cylinder mirror into the oil pan, where, mixing with oil vapor, they create pressure that aggressively affects the crankshaft seals and the pan gasket, and the oil dipstick channel.

The expansion stroke is repeated in each cylinder, constantly pumping the next portion of gases into the sump, and if the crankcase ventilation does not work, the gases will either squeeze out the crankshaft oil seals, or “knock out” the oil dipstick and expel the oil from the crankcase, with all that follows.

In addition, particles of unburned fuel, small fragments of soot, and moisture vapor are transferred to the sump along with the gas, which are mixed with the engine oil located in the engine sump. This, in turn, leads to oxidation of the oil, clogging it with wear products, reducing its performance properties and reducing its service life.

System design

In order to minimize the impact of gas pressure, the engine design provides crankcase ventilation systems. Modern cars use a closed ventilation system, which is necessary to comply with environmental standards.

Despite the differences in systems on different brands of cars, they all have three common components, such as:

• Air pipes for removing gases from the crankcase;

• Ventilation valve, responsible for regulating the gas pressure;

• An oil separator that cuts off oil vapors as gases exit the engine sump.

The valve opens when excess pressure appears and closes when there is a vacuum, that is, the principle of its operation is based on the difference in pressure behind and in front of it.

The separation of oil particles is carried out by the passage of gases through a system of labyrinths, vortices and grids in oil separators. The separated oil then flows back into the engine sump. This not only saves oil, but also protects engine parts from carbon deposits. In this case, oil separators can be located inside the valve covers, built into the engine, or made as a separate unit.

Principle of operation

The system works as follows. The ventilation pipe is connected to the intake manifold, where immediately after starting the engine, a vacuum is created, due to which crankcase gases are “pulled” from the pan and passing through the oil separator enter the intake, where, mixing with the incoming air, they enter the combustion chamber and burn out.

Advantages of the ventilation system

The use of crankcase ventilation allows you to reduce the percentage of harmful emissions into the atmosphere, reduce engine oil waste, and maintain stable engine speeds when warming up, since the intake air mixes with crankcase gases and heats up, which generally has a beneficial effect on the operation of the power plant.

Flaws

Despite the presence of an oil separator, the air ducts and intake elements become dirty from the passage of crankcase gases, causing frequent failures of the devices during operation. So, on gasoline car models, the throttle valve assembly and idle speed control become coated, since they have special channels that perform an exhaust function. This can also be observed on carburetor models, for example, with a Solex carburetor equipped with a fitting for crankcase ventilation.

The throttle valve assembly and gas exhaust valve on carburetors are the so-called small branch and are activated when the vacuum in the air filter is insufficient.

Symptoms of a PCV Problem

• The appearance of traces of oil in the air filter;

• Fogging of oil seals and the joint of the engine valve cover;

• Smoke from the exhaust due to oil particles and gases entering the combustion chamber;

• Traces of oil around the filler cap and on the valve covers.

Necessary tool

To clean the breather on a VAZ engine, check and replace the hoses, you don’t need any special skills or specialized equipment; a standard kit is enough. To complete the work you will need:

• set of keys No. 7-13;
• flat and Phillips screwdrivers;
• washing liquid, kerosene will do;
• container where washing will take place;
• rags;
• breather gasket;
• heat-resistant silicone-based sealant;
• if necessary, a set of new hoses will be required - separately for the carburetor and injector.

This tool can be found in any garage, so there are no problems with its selection. It is better to take rags that do not separate into individual elements, since during washing they can get into the engine.