Smoke came from the engine. A brief description of the symptoms accompanying the exit of smoke

ALEXANDER KHRULEV, candidate technical sciences, director of the company "AB-Engineering"

A familiar picture: they started the engine after a long stop and from exhaust pipe thick smoke poured out. It is possible that after warming up, it will decrease, and during the trip it will completely disappear. But more often it is different. The smoke continues and clearly shows that there are some problems in the motor. Long inaction served as a kind of impetus for their sharp manifestation.
Exhaust smoke can be white, black, or anything in between. Color is an important diagnostic feature. The operation of the engine with increased smoke is often accompanied by other deviations from the norm, although sometimes subtle. They must be caught and noted in order to more accurately assess the situation.
Usually, the appearance of smoke is associated with malfunctions of the following working parts of the engine: control systems (mainly fuel supply), cooling systems, mechanical parts (piston group, distribution mechanism, etc.). In accordance with this, smoke occurs either due to incomplete or "improper" combustion of fuel, or coolant entering the cylinders, or oil entering there. The presence of oil, coolant or excess fuel during combustion in the cylinders and gives the characteristic color to the exhaust gases.
If we analyze possible faults, it turns out that in many situations the smoke is the same in color, although it has a different nature. Another circumstance: often a malfunction of one system, which turns out to be a source of smoke, occurs due to malfunctions and defects in another. Here is a typical example: poor performance of the cooling system leads to engine overheating and, accordingly, burning piston rings. As a result, oil enters the cylinders and causes smoke, the cause of which is essentially secondary.
It is better to start the search for the cause of smoke by comparing all the recorded circumstances: the nature of the smoke itself, observed accompanying phenomena, and possible external influences.
We will talk about the characteristic combinations of these factors.

White smoke.
White smoke from the exhaust pipe is quite normal during cold engine warm-ups. It's not just smoke, it's steam. Water in the vapor state is a natural product of fuel combustion. In an unheated exhaust system, this vapor partially condenses and becomes visible, and water usually appears at the end of the exhaust pipe. As the system warms up, condensation decreases. The colder the environment, the denser and whiter the steam will be. At temperatures below -10°C, white steam is also formed on a well-heated engine, and at a frost of minus 20-25 degrees it acquires a thick white color with a bluish tint. Humidity also affects the color and saturation of steam: the higher it is, the thicker the steam. White smoke in warm weather and on a well-warmed engine is most often associated with coolant entering the cylinders (for example, through a leaky head gasket), The water contained in the coolant does not have time to completely evaporate during fuel combustion and forms a rather thick white smoke ( in fact, again, steam). Its shade depends on the composition of the coolant, the weather and the light outside. Sometimes it looks bluish, resembling "oily" smoke. Distinguishing water vapor is easy: it immediately dissipates, and after the "oily" smoke, a bluish fog remains in the air for a long time.
To make sure that the cooling system is at fault, a number of targeted checks will be required. It is easy to clarify that water is indeed emitted from the exhaust pipe, and not oil. To do this, on a well-heated engine, briefly cover the exhaust pipe opening with a sheet of paper. Drops of water from the leaf will gradually evaporate and will not leave obvious greasy marks, and they will not be greasy to the touch.
Further, the search must be coordinated with the design of the engine. Fluid can enter the cylinder due not only to gasket damage, but also to cracks in the cylinder head or block. All these defects during engine operation cause exhaust gases into the cooling system (sometimes a gas plug is even formed there), which serves as the basis for recognition.
By opening the cap of the radiator or expansion tank, it is easy to notice the smell of exhaust gases and an oil film on the surface of the coolant. Yes, and the liquid level will be reduced. It is characteristic that in such cases, after starting a cold engine, the pressure in the cooling system immediately rises (it is easy to feel it with your hand by squeezing the upper radiator hose), and the liquid level in the expansion tank also increases rapidly. Moreover, this level is unstable, and in the tank you can notice the release of gas bubbles, sometimes with periodic ejection of coolant from the tank.
If the engine is stopped, the picture will change. Fluid begins to flow into the cylinder. Gradually, it passes through the piston rings and enters the oil, into the oil pan. During the subsequent start-up, the oil mixes with the liquid, forms an emulsion and changes color - it becomes opaque and lighter. Circulating through the lubrication system, this emulsion leaves a characteristic light yellow-brown foam on the head cover and oil filler cap.
This is checked by taking out oil dipstick and opening the neck plug, but if the defect (crack, burnout) is small, then there may not be any changes (it happens that the oil remains clean, although foam forms on the plug). On the contrary, if the leakage in the cylinder is significant, then the liquid, accumulating above the piston, even prevents cranking crankshaft starter at the first moment of starting. In especially severe cases, a water hammer in the cylinder, deformation and breakage of the connecting rod are possible.
Sometimes it is possible to determine the location of the defect. Once in the cylinder, the coolant actively "cleans" everything it comes into contact with, so the spark plug will also look very fresh. the liquid level in the expansion tank will begin to rise (when checking, it is necessary to turn the crankshaft to a position in which both valves are closed, put the car on the brake and shift into gear).
Further checks are only possible with removed head block. Assess the condition of the gasket, the planes of the head and the block. Gasket burnout is often accompanied by deformation of the head plane, especially if the defect was preceded by engine overheating (for example, due to a malfunction of the thermostat, fan, and other reasons). Worse, if obvious defects are not found. Then it is necessary to check the head for tightness under pressure; it is most likely that a crack will be found on the wall of the combustion chamber (more often near the exhaust valve seat). You should also carefully inspect the cylinder, lowering the piston to bottom dead center. A crack in the cylinder is a rare defect, but if it exists, it is not difficult to detect it. The edges of the crack diverge (the walls "breathe") and often turn out to be polished piston rings. It also happens that coolant enters the cylinder through the intake system - for example, due to a gasket leak. intake manifold(if it simultaneously seals the collector heating channels with coolant). In such cases, the pressure in the cooling system does not increase, there is no smell of exhaust gases in it, but the oil turns into an emulsion, and the coolant level quickly decreases. These signs, as a rule, are enough to find a defect and not confuse it with the one described above, otherwise the block head will be removed in vain.
All problems associated with white smoke from the exhaust pipe require not only the elimination of direct causes. Since defects are usually caused by engine overheating, it is necessary to check and eliminate malfunctions in the cooling system - it is possible that the thermostat, switch-on sensor, clutch or fan itself are not working, the radiator, its plug, hoses or connections are leaking.
If white smoke and related defects are noticed, then the vehicle must not be operated. First, defects progress rapidly. And secondly, the operation of the engine on a water-oil emulsion sharply accelerates the wear of parts, and after several hundred kilometers, it is most likely impossible to do without a major overhaul.

Blue or gray smoke
The main reason for the appearance blue smoke- oil getting into the engine cylinders. "Oil" smoke can have different shades - from transparent blue to thick white-blue, which depends on the mode of operation of the engine, the degree of its warming up and the amount of oil entering the cylinders, as well as illumination and other factors. Characteristically, oil smoke, unlike steam, does not quickly dissipate in the air, and the paper test mentioned above gives greasy droplets flying out of the pipe along with the exhaust gases.
It is also clear that oil smoke is accompanied by increased oil consumption. So, at a flow rate of about 0.5 l / 100 km, blue smoke appears mainly in transient modes, and when it reaches 1.0 l / 100 km, it also appears in uniform motion modes. By the way, in the latter case, in transient conditions, the oil smoke becomes thick blue-white. True, the owners of the most modern cars should be aware of the possible presence of a converter that can clean the exhaust gases from oil even at fairly high costs.
Oil enters the cylinders (more precisely, into the combustion chambers) in two ways - either from below, through the piston rings, or from above, through the gaps between the valve stems and guide bushings.
Part wear cylinder-piston group is one of the most common causes of oil smoke. The upper compression rings show wear not only on the outer surface in contact with the cylinder, but also on the end planes that perceive the pressure of gases in the cylinder. The grooves of these rings in the pistons may also be worn out. Large gaps in the grooves create a pumping effect. Even oil scraper rings still normal, the oil still enters the cylinders, since the upper rings continuously "pump" it from the bottom up.
Cylinders wear out most of all in the stop zone of the upper ring when the piston is in the top dead point, and in the middle part often acquire an oval shape. The deviation of the cylinder shape from the circumference worsens the sealing properties of the rings. Gaps usually form in the zone of locks, but their appearance in other places of the circumference is not excluded. There are frequent cases when, with a relatively decent condition of the rings and pistons, the surface of the cylinder is damaged. This happens, for example, with poor oil filtration, when abrasive particles get between the piston skirt and the cylinder. Then there are scratches on the cylinder. A similar situation is real after a long parking of the car, when corrosion centers may appear on the surface of the cylinders and rings. It will take a considerable amount of time to smooth out these defects and to run the parts together (if they can run in at all). The same effect often occurs when the technology of engine repair is violated, if the surface of the repaired cylinder is too rough or the cylinder has an irregular shape, or poor-quality pistons and piston rings are used. In such cases, as a rule, one cannot count on normal running-in at all.
Wear of parts of the cylinder-piston group is often accompanied by a loss of compression and an increase in pressure. crankcase gases, which is determined by appropriate instruments (compressometer, leak tester, etc.). However, it should be remembered that a large amount of oil entering the cylinders seals the gaps in the mating parts well. If they are not too high, then the result of the compression evaluation may be quite normal, sometimes even closer to the upper limit. It is this circumstance that confuses the search for a specific cause of blue oil smoke.
One more note about characteristic circumstances. When there is no large wear of parts, then blue or blue white smoke is clearly observed only when the engine is warming up, gradually decreasing and even disappearing. The reason is simple: when heated, the parts take shape and take up space in which they better fit together. With excessive wear, the picture is reversed: the smoke on a warm engine will intensify, since it is easier for hot oil, which has a low viscosity, to enter the cylinder through worn parts.
It is always easier to identify a malfunction associated with more serious defects or even broken parts. So, detonation usually leads to breakage of the jumpers between the rings on the pistons, less often - to the breakage of the rings themselves. Severe overheating of the engine causes deformation of the piston skirts, forming big gap between piston and cylinder. The deformed piston warps, disrupting the operation of the rings. The same result is possible if the connecting rod is deformed, for example, due to water hammer when water enters the cylinder or after a belt breaks and the piston hits an unclosed valve. The use of low-quality oil can cause the rings to burn and lie in the piston grooves. And due to prolonged glow ignition, the rings can simply be rolled in grooves with a complete loss of mobility. The defects discussed above usually do not occur in all cylinders at once. It is not difficult to find a faulty cylinder by comparing the condition of the spark plugs and the compression value in different cylinders. Moreover, such defects are often accompanied by various kinds extraneous noise and knocks that change with engine speed, load and degree of engine warm-up, as well as unstable engine operation due to cylinder shutdown (especially during cold start).
A common group of faults that cause oil smoke and oil consumption is associated with wear of valve stems and guide bushings, as well as wear, mechanical defects and donation (loss of elasticity) of oil seals. These defects tend to produce a noticeable increase in engine smoke as the engine warms up, as diluted hot oil passes through gaps between worn parts much more easily. In addition, the ingress of oil into the cylinders increases at idle and during engine braking. In these modes, a large vacuum occurs in the intake manifold, and oil flows through the valve stems under the action of a pressure drop, accumulating on the walls of parts and in the exhaust system. Follow-up 01 throttle valve at the first moment sharply increases the density of blue oil smoke.
In turbocharged engines, oil consumption accompanied by blue smoke is possible due to a malfunction of the turbocharger, in particular, worn bearings and rotor seals. Seal wear front bearing compressor gives a picture similar to the failure valve stem seals(including oil soot on candles), but at the same time a puddle of oil collects in the compressor inlet pipe.
Turbine seal failure is difficult to determine because the oil enters directly into the exhaust system and burns out there.
In operation, blue smoke and oil consumption often appear when one of the cylinders is turned off due to an ignition malfunction or valve leaks. In the latter case, the smoke becomes white-blue, especially if the valve has a clear burnout. Such a defect is determined without difficulty - the compression in this cylinder is insignificant or absent at all, and an abundant black deposit appears on the candle, often in the form of growths.
There are also quite exotic defects that cause blue oil smoke. So, in automatic transmissions with a vacuum load cell, the regulator diaphragm may break. Since its cavity is connected by a hose to the intake manifold, the engine simply begins to suck oil out of the gearbox. As a rule, oil enters only those cylinders, near which a vacuum is taken in the manifold. In this case, spark plugs can be thrown and oil can splatter from the spark plug holes (recall that ATF oils usually have a red color).

Black smoke
Black smoke from the exhaust pipe indicates a re-enrichment of the fuel-air mixture, and, consequently, a malfunction of the fuel supply system. Such smoke is usually clearly visible against a light background behind the car and represents soot particles - products of incomplete combustion of fuel.
Black smoke is often accompanied by high fuel consumption, bad start, unstable engine operation, high toxicity of exhaust gases, and often loss of power due to non-optimal composition air-fuel mixture.
At carburetor engines Black smoke is usually caused by an overflow in the float chamber due to a defective needle valve or due to coking of the air jets. At gasoline engines with electronic fuel injection, the over-enrichment of the mixture appears, as a rule, in case of malfunction and failure of various sensors (oxygen, air flow, etc.), as well as in case of leakage of injectors. The latter case is dangerous due to water hammer in the cylinder at startup with all the consequences mentioned above. The bottom line is that through a faulty nozzle on idle engine a lot of fuel can flow into the cylinder, and it will not allow the piston to approach the top dead center. In diesel engines, black smoke sometimes appears not only when there is a malfunction in the pump high pressure, but also at high angle injection advance. A common feature of the operation modes of gasoline engines on a re-enriched mixture is increased wear and even scuffing of parts of the cylinder-piston group, since excess fuel washes oil from the cylinder walls and worsens lubrication. In addition, fuel enters the oil and dilutes it, worsening lubrication conditions in other related engine parts. In some cases, this dilution is so great that the oil level in the crankcase (more precisely, the oil-fuel mixture) rises significantly. Diluted oil acquires a distinct smell of gasoline.
It is obvious that the operation of an engine with such malfunctions is not only difficult, but also highly undesirable, since it quickly leads to new, much more serious troubles.

When you start the engine on a cold, thick smoke often comes out of the exhaust system. Smoke may have different shades from white to blue and even black. The smoke stops after the engine warms up, and may continue afterwards.

If a warm engine smokes, this means that the power unit has specific malfunctions. The color of the exhaust gases indicates the stage of development of the breakdown and its severity.

A brief description of the symptoms accompanying the exit of smoke

In some cases, smoking may be accompanied by the following symptoms:

• difficulty starting a cold engine;
• unstable operation of the motor both at idle and under load;
• inconstancy of tachometer readings (revs float);
• boost and engine oil;
• power loss of the power unit.

There are often situations in which engine smoke is the only alarm signal.

The device of the car is designed for a constant, unobtrusive release by the system of exhausting the atmosphere of exhaust gases in specified volumes. But if, when starting the engine, smoke comes out of the exhaust pipe in large quantities, it is urgent to look for the cause of the alarming symptom that has appeared.

The first thing you need to pay attention to is the color, shades and density of the smoke coming from the engine. The most common are the following colors of the emitted gases:

1. White.
2. Black.
3. Bluish gray.

Each of the listed smoke colors can have different shades, but it is this division into groups that is the main one.

Causes of engine smoke

Why, car owners are often interested in this. The main malfunctions that cause increased smoke output from the exhaust pipe:

• damage in the fuel supply system;
• wear of parts included in the cylinder-piston group;
• violations in the operation of the gas distribution mechanism;
• problems in the cooling system.

Smoke can appear when there is a violation of the quantitative air-fuel balance, uneven mixing and incomplete combustion of the air-fuel mixture, failures that occur when coolants or lubricants enter the combustion chambers.

Each of the reasons described can affect the shade of the ejected smoke cloud.

An experienced craftsman is able to take into account the impact of defects in one system on wrong work other components of the power unit. For example, malfunctions in the cooling system lead to overheating of engine components. Under the influence of ultra-high temperatures, the piston rings are destroyed, the tightness is broken, oil and coolant penetrate the cylinders, burn out, forming smoke of a certain color.

After the capital, as a rule, the smoking of the motor stops.

Clear smoke from the exhaust

The steam coming out of the engine can be mistaken for white smoke. Steam is generated by the evaporation of accumulated fluid in cooled engine systems. Most often, the accumulation of liquid at the end of the exhaust pipe and the release of steam are observed in the cold season after starting the engine.

Elements of the engine and exhaust system heat up, water evaporates intensively. After the engine and exhaust system are fully warmed up, the amount of steam is reduced to a minimum or disappears altogether.

The amount of steam that comes out depends on the humidity in the environment, the higher they are, the longer its traces will be visible. The release of steam is not a sign of a breakdown of engine parts and assemblies; if this effect occurs, repairs are not required.

Black smoke exit

The greatest damage to the environment is caused by puffs of black smoke coming out of the exhaust pipe of a car or directly from the power unit. The most likely causes of such smoke lie in the following violations:

• malfunctions of the engine management system;
• disorder of adjustments in the fuel equipment;
• decrease .

An imbalance between the amount of components of the air-fuel mixture in the direction of increasing fuel causes not only the formation of black smoke, but also significantly increases fuel consumption. Failure of the normal mixture formation process may be caused by a dirty air filter. The lack of air entails an excess of fuel in the preparation of the air-fuel mixture.

Compression loss may be caused by mechanical damage cylinders, which significantly reduces the power of the power unit and contributes to an increase in the concentration of fuel in the mixture.

For accelerated diagnostics, it is necessary to examine the condition of the spark plugs. A black coating indicates that it became necessary to replace the candles with new samples, followed by the repair of deformed elements and the regulation of power unit systems.

Appearance of white smoke

A smoking engine with white gas does not always release harmless water vapor. White smoke is distinguished from steam by the following features:

1. increased density of smoke;
2. long dispersion;
3. the presence of a persistent smell of burning;
4. does not disappear when the engine warms up.

White thick smoke coming out of the exhaust pipe of the car indicates a malfunction in the cooling system. Variety of shades white smoke depends on the type of coolants used, but in any case, with such emissions, it is necessary to urgently repair the engine cooling system.

Incorrect operation of the elements of the cooling system can lead to serious disruptions in the functioning of the power unit as a whole.

Causes of white smoke:

• cracks in the cylinder head (cylinder head);

• the ingress of coolant into the cavity of the engine cylinder;
• motor overheating;
• use of low quality coolant.

If the cylinder head is leaking, the coolant penetrates into the cylinders, into the crankcase of the engine sump. When lubricants are diluted with antifreeze or antifreeze, the viscosity of the oil decreases, which significantly affects its functions.

What to do if white dense smoke is detected

When disassembling the cylinders, it is necessary to analyze the condition of the candles. The formation of scale on candles indicates the ingress of water. After examining all cylinders and glow plugs located in them, it is necessary to repair or replace the cylinders and candles. These activities are recommended to be carried out with the help of qualified craftsmen at the nearest service station.

Often, low-quality coolants in contact with the working elements of the engine cause increased corrosion of the components and parts of the power unit. Cheap grades of antifreeze can literally corrode the internal parts of the engine in the event of leaks. After such an impact, it is not possible to repair damaged parts.

To make sure that coolant enters the combustion chamber, you must remove the cap from the expansion tank. A sharp smell of burning, a decrease in the level of antifreeze in the tank, a floating oil film indicate the identification of this defect.

Smoke with a bluish (gray) tint

If diesel or gasoline engine smokes strongly with blue gas, this means that machine oil seeps into one or more cylinders. During combustion, thick clouds of smoke are formed, which have a persistent smell of burnt oil and do not dissipate for a long time.

Depending on the type of engine oil used, temperature conditions environment the color of the smoke may have a different intensity of blueness. In order to give a more accurate assessment of the nature of the emitted smoke and to distinguish it from standard exhaust, it is necessary to produce regular check oil level. Excessive consumption of machine lubricant indicates the presence of leaks.

In addition to visual analysis of the color of the exhaust gases, a check is made using paper attached to the exhaust pipe. If distinct oily spots remain on the sheet, then the reason for the bluish smoke exiting the chimney becomes clear: the presence of oil in the combustion chamber.

Description of the causes of white smoke with a blue tint

Why does the engine smoke with white gas with a gray or blue tint? When studying the origin of a bluish or blue exhaust, the following reasons are most often called:

1. Damaged valve stem seals.
2. The occurrence of rings designed to remove residual oil from the cylinder walls.
3. Turbocharger failure.
4. The oil used is of poor quality.

The purpose of the caps is to hold the oil before it is dispensed. Poor quality and malfunction of these elements lead to loss of tightness, grease constantly leaks and accumulates in the cylinders. Worth starting cold motor after a long break, the accumulated oil will burn along with the fuel in the chamber, blue or blue smoke will escape from the exhaust pipe of the car in a huge cloud.

The wear and tear of the oil scraper rings leads to the ingress of an excess amount of lubricant into the engine cylinders and subsequent combustion. The use of the ring decarbonization method temporarily solves the problem, but at the same time the rings lose their elasticity, and the bedding can resume. To avoid serious damage to the power unit, it is necessary to constantly monitor the color of the exhaust gases.

With little wear of the engine elements, a short-term release of blue smoke is observed during cold operation. As the motor heats up, the parts expand as a result of an increase in their temperature, which favorably affects the gaps between the mating surfaces of the elements. The smoke output is reduced or completely disappears.

Turbocharger and causes of blue smoke

If the car is equipped with a turbocharger, then the output of thick bluish smoke may be due to its unsatisfactory condition. As a result of a malfunction of this unit, engine oil is leaking, designed to lubricate the bearings of the turbine. Lubricant penetrates into the starting system of the motor.

During the combustion of turbocharger oil, thick bluish smoke is formed, causing irreparable harm to the atmosphere.

To diagnose the turbine, you must perform the following steps:

1. Disconnect the turbine from the engine.
2. Check for oil accumulation inside the air duct.

The accumulation of a large amount of oil in the air duct and turbine is serious defect. If such a situation is detected, it is necessary to immediately seek qualified assistance from the service center.

The influence of the quality of the oil used on smoke generation

Engine oil must have certain characteristics. The quality of the lubricant used directly depends on its properties. If the car engine contains low-quality oil, the viscosity coefficient of which does not match the brand of the car, or when the temperature inside the engine rises, a sharp loss of the useful properties of the lubricant occurs, this leads to serious breakdowns elements and systems of the power unit. If blue smoke appears, check the oil for compliance and, if necessary, replace it completely.

The appearance of smoke can be caused by a number of other reasons - from the appearance of microcracks in the engine housing to the use of an inappropriate type of fuel intended for this brand of engine. Each specific situation always has a solution when seeking help from qualified specialists.

Greetings to my dear subscribers and readers! If you follow these lines, it means that you are not indifferent to the topic of efficient and proper functioning of the engine of your car. Every self-respecting car enthusiast cannot remain indifferent to the question of why the engine has oil. On the one hand, this is not just a matter of constantly topping it up, because the reasons can be much deeper and require prompt intervention. Let's try to understand these reasons.

It is believed that in the engine it is equal to plus or minus 10-15 thousand kilometers. The situation is normal if in this interval the engine “eats” no more than 1 liter. Much, of course, depends on the style of driving, and on the condition of the car. A new engine can consume completely different amounts of lubricant compared to a fairly worn one. If you are a supporter of an aggressive driving style, you should know that in this way the combustion chambers are cleaned. But not only carbon deposits are removed, but oil is also blown out.

But if your engine consumes more than 300 grams for every thousand runs, then this should be a reason to think. The bluish tint of the exhaust gases, to which they are due to the ingress of lubricant products into the combustion chambers, will help to determine this situation. What else could be the causes of increased oil consumption? Very often this is due to increased wear of the piston group cylinders, rings, as well as a number of elements of the gas distribution mechanism, for example, valve stem seals.

Another interesting point why the motor takes oil is related to the type of lubricant itself. It is believed that the use synthetic oils will definitely lead to higher costs. Say, their consumption is even calculated by the manufacturer in this way, and, in addition, the connecting seals are leaking due to high viscosity grease compared to its mineral counterpart. However, this is not at all the case, because it is synthetics that are able to maintain their viscosity stable, while mineral water liquefies when heated and freezes when the temperature drops.

How to calculate and evaluate the condition of the lubrication system

What to do if the engine still takes oil? First, it must be accepted as a fact that absolutely all engines internal combustion will spend it. This is the mechanism of their work, and we are not able to change anything here. The fact is that the lubricant is forced to constantly circulate through the system, so losses are inevitable.

The greatest losses are related to piston group, since it accounts for the maximum friction of the parts. If you do not provide it with lubrication, then the engine life will automatically decrease. But this is not the only reason. After all, this place is the hottest in the entire motor, which leads to the combustion of oil with the simultaneous formation of slag deposits on the valves and rings.

For modern cars there are established calculations for how much oil the power unit eats. This is due to fuel consumption, for example, if a car spends several liters of gasoline for every 100 kilometers traveled, then using 10 grams of oil will also be an acceptable norm. Therefore, they say that a liter of lubricant used for 10 thousand runs is quite normal. In fact, even a couple of liters will not be critical.

If this indicator is higher, then there are definitely some problems with the engine. Usually, the situation does not get out of hand suddenly, that is, the symptoms of oil eating begin to appear in advance. Most often, this looks like small leaks at the joints, and later develops into spots on the asphalt in the crankcase area.

The main causes of malfunctions and overruns

Go ahead. If the power unit is equipped with a turbine, then it by itself is capable of emptying the entire motor pan at once only due to wear on the rotor bushings. Therefore, it makes sense to start troubleshooting with a thorough diagnosis of the turbocharger.

Why can consumption be affected by failed valve stem seals that are installed on the valves of the gas distribution mechanism. How does this happen? Very simple - any overheating of the engine causes the cuff to harden several times at once. Therefore, the cap loses its sealing characteristics and oil can seep under the guide bushing. After that, the lubricant goes outside with the exhaust gases or burns out in the chamber along with the fuel-air mixture.

Another reason may be related to piston rings. In this case, the engine is said to be smoking, referring to the large amount of exhaust gases from the muffler. The oil scraper ring is located under the compression rings. They not only seal the gap, but are also lubricated with motor grease, which is evenly distributed over the cylinder walls. The rest of it goes to the edge of the oil scraper rings, the wear of which will determine how much lubricant the power unit will use up.

The role of piston rings and other parts of the crankshaft

During its further operation, it undergoes many heating cycles, and then cooling. Piston rings should not change their elasticity, as it was laid down at the stage of development and testing of the motor. However, it is enough for him to overheat, and their properties change dramatically. And in the future, you will have to change the piston rings.

But the rings themselves may not be the culprit. Much has to do with the quality of engine oil, even if it contains special additives. A poor-quality lubricant or a lubricant that has served its resource begins to burn out and oxidize, which leads to the formation of hard-to-remove deposits. Because of this, the rings boil on the piston and cease to fully fulfill their functions. Subsequently, this leads to a deterioration in compression in any of the cylinders or in all at once. Even if the car is operated without excessive loads, the cylinder walls are slowly deformed, gaps form between them and the pistons, in which grease begins to collect. With each subsequent cycle of work, it will burn out.

What can you wish for in the end. It is necessary not to miss replacement intervals, to evaluate the quality of the lubricant in a timely manner, as well as the condition of the power unit and exhaust gases. If there are signs of aging, it is necessary to change the oil, and, possibly, completely flush the engine. And it will also be useful to use only high-quality products and purchase them in trusted stores or outlets.

I hope that in today's review everyone was able to gather at least some valuable information for themselves. Or he confirmed his previous guesses, since the opinions of car owners are often opposite. We will definitely return to the issue of service lubrication system engines. See you in new posts!

Any car constantly sends exhaust gases into the atmosphere - and this is a normal situation. It's all about the amount of harmful emissions and their composition. With properly adjusted and working system gases from the muffler will be transparent and almost invisible (excluding frosty weather). But what if the engine smokes very strongly, throwing out dense exhausts of a black or bluish hue? This means that not everything is in order with your power plant and the color of the gases will help to understand the causes of the “illness” of the car.

Causes of engine smoke

The increased release of gases from the muffler may be the result of an incorrect balance between fuel and air, not simultaneous or incomplete combustion of the mixture, oil or antifreeze getting into the engine cylinders. The main reasons why a car smokes can be summarized below:

• the occurrence of malfunctions in the fuel system;
• wear of parts of the cylinder-piston group;
• cooling system problems;
• improper functioning of the gas distribution mechanism.

Experienced car mechanics can pinpoint exactly why a car smokes a lot by examining the hue of the exhaust. And if the cause is known, then it is much easier to deal with the problem. The appearance of a bluish, white or black exhaust is often accompanied by "passing" troubles:

• Difficulty starting a cold engine.
• Unstable operation of the power unit in idle mode and under load (the tachometer needle jumps).
• Increased consumption of oil and gasoline (diesel fuel).

Here it is worth making a small digression. The fact is that some cars have relatively high flow oil and fuel provided by the manufacturers. This applies to powerful and expensive machines. For example, a 4.7-liter Toyota 2UZ FE engine consumes 10 liters per 100 km on the highway, and all 16 in the city. At the same time, natural oil waste is 1 liter per 1000 km. Such parameters are especially striking after transplantation with economical cars middle class.

• Loss of traction power of the vehicle.

It also happens that the smoke from the muffler pipe is the only sign of a malfunction of any part of the machine. You can more accurately diagnose a malfunction by the color of the exhaust.

transparent smoke

Inexperienced car owners sometimes take the steam coming out of the muffler for smoke and start to panic. However, this is quite normal. Fluid condenses on the exhaust pipe when low temperatures and after the start of the engine, the water begins to actively evaporate, turning into steam. When the motor warms up to operating temperature, the "phenomenon" will stop. The amount of steam released is related to the humidity of the surrounding air: the higher it is, the longer the white "smoke". It is not a sign of a breakdown of the power unit, and no action is required in this case. To finally make sure that the engine is working properly and steam is coming out of the pipe, attach a clean piece of paper to the muffler pipe for a few seconds: the water will dry and leave no traces. If so, then everything is in order.

Black smoke exit

This trouble causes the most serious damage to the environmental situation and indicates serious problems in the power plant. At the same time, there is a strong smell of burnt oil or metal, sometimes it stinks of heated plastic in the cabin. Why is this happening? Probable causes when the engine smokes in this "mode":

• fuel system malfunctions: the composition of the air-fuel system is seriously unbalanced - an excessively enriched mixture enters the cylinders (a lot of gasoline or diesel fuel and little air);
• failures in electronic unit engine management (correct injection is broken);
• loss of injectors (they overflow) tightness in the injection engine;
• a drop in compression in the cylinders of the power unit: the cause is the wear of the rings, pistons as a result long-term operation or poor repair.

These malfunctions lead to increased fuel consumption, next to the car there will be a smell of gasoline or diesel fuel. For a quick check, remove the spark plugs and evaluate them: a black coating confirms a malfunction in the ignition or fuel supply system.

Blue smoke

If it appears in a diesel or gasoline-powered car, then this indicates the penetration of oil into the cylinders. As a result lubricant composition burns, forming gray clouds of smoke, which is poorly dissipated. The blue tint can have a different intensity, which is associated with the brand of oil used, the ambient temperature. You can make sure that the lubricant is overused by measuring its level with a dipstick. A regular decrease in the amount of oil indicates its combustion or leakage. Another test is carried out using a sheet of clean paper attached to the muffler pipe with the engine running. Oily spots will only confirm the presence of a lubricant in the combustion chamber. Reasons why the engine smokes:

• breakage, wear or low quality of valve stem seals: when starting the engine on a “cold” after a long stop, the lubricant composition will burn out along with the fuel, which will immediately show smoke formation;
• occurrence of piston rings;
• - the use of a lubricant that does not meet the requirements of the manufacturer.

Blue smoke can also form with slight engine wear. After warming up, the elements of the power unit begin to expand, and the blue exhaust gradually becomes less strong, and then may disappear altogether.

White dense smoke

It differs from steam not only in its increased density. If the car smokes white smoke, then the latter will dissipate for a long time. At the same time, a burning smell is felt, which does not disappear after the engine reaches operating temperature. When starting the engine on a "hot" problem is also not solved. White smoke indicates serious problems in the cooling system: antifreeze getting into the oil. Exhaust shades depend on the type of antifreeze (coolant). Reasons for this problem:

• violation of the tightness of the cylinder head: the formation of cracks, severe deformation or burnout of the gasket;
• the use of low-quality coolant and: poor antifreeze can literally “eat through” the metal, sharply increasing corrosion, which can lead to the impossibility of restoring some parts of the cooling system.

When mixing antifreeze and oil, the latter loses its qualities and becomes less viscous, which adversely affects the normal functioning of all systems power plant and leads to a decrease in its operational life.

What to do if white dense smoke appears

First, carefully inspect the candles: if they have scale, this indicates water has entered the cylinders. Then open the cap of the expansion tank of the cooling system: a low level of antifreeze, an oil film, a burning smell indicate a violation of the tightness of the cooling system. Next, you need to dismantle the head and check the integrity of its gasket, the presence of cracks. All restoration work must be carried out in a specialized car workshop.

Actions in the event of blue smoke

Into the cooking chamber air-fuel mixture, oil penetrates through a valve that has lost its tightness or “thanks to” worn piston rings and. Then you need to bore and honing the cylinders, move on to the next repair size. Sometimes (but not for long) it helps to replace the piston rings. The first option, when the amount of oil entering the cylinders exceeds all limits, implies either valves.

Sometimes whitish blue smoke is formed due to leakage of the lubricant and its contact with the exhaust manifold. Then check and, if necessary, install new gaskets and (or) the crankshaft oil seal.

Malfunctions of the engine with a turbocharger

If the machine is equipped with this unit, then the appearance of a white exhaust with a bluish tint may be due to an oil leak, which, instead of lubricating the turbine bearings, goes into the starting system. To check this, remove the turbine from the diesel or gasoline engine and see if there is oil in the air duct. If this is the case, then it is better to visit a car repair shop. When black smoke comes out of the pipe, test the tightness of the intake system. The exit of dark exhaust during regassing is especially noticeable.

Everyone who knows how to reason technically, the owner of a car, sooner or later asks himself the question - “why does the engine smoke?”.

There is an opinion among motorists that the color of the smoke from the exhaust pipe can determine what kind of engine malfunction is caused. There is no doubt that when a car smokes about its owner, an unfavorable opinion is formed.

Let us first consider this question in in general terms, and then we will analyze each specific case in more detail.

In general terms, the question of why the car smokes can be answered as follows:

1) Clear steam (whitish) from the exhaust pipe when the engine is running cold or when running in the cold season is normal.

The oxidation of any carbon fuel ideally yields CO2 and H2O. If CO2 exits the engine in the form of a transparent gas, then H2O exits as superheated vapor and, as it cools, turns into a liquid state. It is the condensed water vapor that we observe in the form of smoke from the exhaust pipe.

The fact that water vapor is always present in the exhaust (even when they are transparent and we cannot see them) is quite easy to verify by simple experience: cool the saucepan (or any other utensil) and place it under the exhaust pipe of a running engine.

And you will be able to observe how steam from the exhaust gases will condense on the cold walls.

At the beginning of the engine, until both it and the exhaust system have warmed up, you can even observe how it drips from the muffler. In this case, the exhaust system itself plays the role of cold dishes.

It should be noted that water vapor after exiting the exhaust pipe dissipates rather quickly and does not smell of anything.

2) Black smoke from the exhaust pipe - similar to what is spewed from their bowels by loaded old trucks going uphill (I think this picture is familiar to everyone) is the brainchild of soot.

It is this smoke coming out of the mufflers of the tractor that you can see in the photo in the header of the page.

IN cars Black smoke from the exhaust pipe appears mainly during a sharp increase in load, or when driving with a high load. Even logically, it can be determined that the reason for it is poor carburetion (over-fueled mixture). Like any deviation in mixture formation, this leads to excessive fuel consumption. Well, it needs to be repaired accordingly. fuel equipment or engine management system.

3) Bluish smoke from the exhaust pipe. Here you can draw an analogy with two-stroke motorcycles - everyone has seen what happens when a motorcyclist adds an extra amount of oil to the fuel (whoever has not seen a motorcycle can remember a chainsaw, or other device with a two-stroke engine), the exhaust in this case smells burnt oil. Thick clouds of bluish engine smoke flying out of the exhaust pipe, and dissipating for quite some time. The same is true in a car, in the cylinders of which, for some reason, excess oil enters. Of course, the density and amount of smoke strongly depends on the operating mode of the engine, as well as on the degree of warming up, downtime and other factors.

The degree of bluishness of this smoke, it should be noted, is quite weak, it is somewhat similar to an ordinary park, but the smell, traces on white paper and oil consumption should help you orient yourself.

In this case, you need to look at the engine hardware itself.

4) White smoke similar to the case described in the first paragraph, but thicker and does not disappear completely when the engine warms up in the warm season.

In addition to oil, coolant can also enter the engine cylinders. It is she who, condensing, turns into white vapor, which dissipates relatively quickly in the air. But there is a small but: liquids of various properties and structure are used as a cooling liquid. For this reason, steam may differ from pure white and thus mislead the wearer. For greater certainty, you need to pay attention to the flow of coolant. The hardware of the engine and the cooling system are subject to repair.

If we consider the essence of this problem in more detail, it turns out that in real life, not everything is so simple. Usually, an engine malfunction is complex, and it is all the more frivolous to start a repair based only on the color of the smoke from the exhaust pipe without checking your assumptions with additional methods.

For a fairly accurate diagnosis of the condition of the engine, you will have to roll up your sleeves and conduct a more complex diagnosis:

1) Transparent steam.

It does not require explanations and repairs, it is only worth noting - be careful when you put the car on automatic winding in winter due to temperature - it can simply clog the exhaust pipe with ice and the car will not start.

As a rule, soaring appears either in the cold season or in wet weather. The dynamics are as follows: when you start the engine, you can see a barely noticeable soaring, as it warms up, soaring intensifies. When driving with a cold engine, droplets of liquid may drip from the exhaust pipe. As a rule, by the time the engine is fully warmed up, the soaring either completely disappears or decreases. It should be borne in mind that not only working temperature engine matters, but so does the temperature of the entire exhaust system.

2) Black smoke from the exhaust,

As a rule, it is the cause of a lack of air (or an excess of fuel). Accordingly, the solution to the problem based on this:

The most shameful case - scored air filter(especially detrimental to carburetor, gas and diesel engines).

Next, you need to look at the compression - with “leaky” cylinders, the combustion process deviates from the calculated one and does not bring the proper result (the required power), as a result of which the ECU can re-enrich the mixture, despite its full serviceability.

We look at the fuel pressure and fuel correction - a situation is possible when a contaminated fuel system and the fuel pressure is low, which leads to a long and not timely injection of fuel into the cylinders. Or a variant is possible when the nozzles do not close completely and “pour” which leads to very poor low flow fuel, reduced power, and sometimes even water hammer (fuel accumulated in the manifold flows into the cylinder and leads to breakdown).

Sensors for monitoring the operation of the engine can also give erroneous readings, resulting in the operation of the ECU “blindly”. As a rule, in this case, the check engine light comes on ( check engine) . However, in some models, this light does not always light up if there is a malfunction of any engine. You can read more about engine management systems here.

All the cases described are accompanied by the formation of black soot on spark plugs, increased consumption fuel, reduced engine performance, increased CPG wear(gasoline washes away the oil film from the cylinders), shots in the muffler are possible and often there is a smell of gasoline from the smoke from the exhaust pipe.

Spark plugs can help diagnose the problem. With black smoke from the exhaust pipe, as a rule, candles have a soot-black coating.

That is, when analyzing smoke from the exhaust pipe, it is desirable to analyze the condition of the candles.

In any case, driving this way is not only not environmentally friendly, but also expensive, measures must be taken.

3) Bluish smoke from the exhaust pipe.

As already mentioned earlier, the reason is a large amount of oil that has entered the cylinders or the exhaust tract. The reasons may be as follows:

A) Worn or hardened valve stem seals. The malfunction is gradually increasing and manifests itself in the form of a large emission of smoke at the first moment after cranking, then gradually the intensity of the smoke decreases (as it warms up). This is due to the softening of the caps as they warm up. Accelerated wear of the caps may be an increased clearance in the valve bushings, poor quality of the caps or a large amount of crankcase gases (due to wear of the CPG).

Of great importance is the quality of the valve stem seals themselves. Unfortunately, this is what I came across:

The photo shows two different caps working in the same conditions. And if the left cap is already hardened (the car was shamelessly smoking and eating about a liter of oil per 1000 km), then the right one looks like new after 50k. work. The name of the good one is RoadSafe, and the name of the bad one is incognito, because most likely it is counterfeit and cast a shadow on brand Mitsubishi I do not want.

B) Wear or occurrence of oil scraper rings. In this case, the oil film is not removed by specially designed rings and oil enters the cylinders in an excessive volume. Perhaps this is the reason why the engine can eat the largest number oils. At the first stage, decarbonization of the rings can help. But after that, it is necessary to increase attention to the engine, because. this may mean the loss of spring properties of the rings and a quick re-occurrence. The method of checking piston rings is described on the page on measuring compression in the engine, so I will not repeat it.

I will only add that the diagnosis is difficult if only the oil scraper (lower) rings are stuck. compression is nominal at the same time, and decarbonization does not help due to good condition top rings. Similar option in the photo below:

C) Turbine failure. Cars equipped with turbochargers in a deplorable state of the latter can smoke due to oil being thrown by the turbine. In this case, the oil used to lubricate the turbine bearings, through faulty seals (usually turbine shaft seals), is thrown into the intake tract:

This is pretty easy to diagnose. It is enough to remove the air duct going from the turbine to the engine at the lowest point and look to see if there is oil inside. Or (in the early stages) a white light fabric is stretched into the nozzle in front of the throttle, then the nozzle is placed. Then we gas and remove our tissue. Traces of oil will indicate an emerging turbine malfunction.

d) Clogged crankcase gas recirculation system.

Car engines are built in such a way that a small vacuum must be maintained inside the engine. This vacuum is created either by vacuum in the throttle area, or by special vacuum pumps(much less often). In any case, the exhausted crankcase gases are discharged into the intake manifold. But there are no pure gases in the crankcase, but there is oil mist. Because of what, these gases must be separated from them before being discharged into the intake manifold. This is exactly what the crankcase gas recirculation system does. When it fails, crankcase gases throw oil droplets into the intake, which can also cause the engine to smoke with a characteristic "oily" smoke.

e) Depreciation of the CPG. A special case of point "d" is the wear of the cylinder-piston group (or the occurrence of rings, including compression ones). If the oil scraper rings are not stuck, but simply there is increased wear in the friction pairs.

This will result in an increased amount of exhaust gases entering the crankcase. Those. the amount of gas passing through the recirculation system will significantly exceed the calculated one. Of course, there will be a slip of oil drops into the intake and the result will be the same as in paragraph "d". A malfunction can be detected by opening the oil filler neck with the engine idling. With a working CPG and a crankcase gas recirculation system, air will be sucked into the neck (you can check with a piece of paper), or slightly out of it. If crankcase gases are knocked out of the neck with tangible force, it is worth thinking about serious repairs. It is also worth paying attention to the color of the gases coming out of the oil filler neck - ideally they are colorless.

e) Bad oil. Do not discount bad oil. And here there are several options. Firstly, you could simply buy counterfeit goods. In this case, the properties of the oil alone .... are known. And how this oil will be separated in the crankcase gas recirculation system and how it will resist high temperatures in the cylinder is not known:

Secondly - you could just overheat the oil. The fact is that engine oil, when exceeded allowable temperature loses its properties. Athletes know about this and install engine oil temperature sensors, additional oil coolers, etc. There is nothing like this in a normal car. And the car itself is not designed for extreme loads. And the pistons from the bottom are cooled just engine oil! In normal life, the stock is enough. But imagine on a hot summer day you are going to rest: you have loaded your family, things (i.e., full load by weight), you have engine protection (interfering normal cooling oil in the crankcase) - where in Russia without it. Plus, there was a long climb on the way and ... voila, the oil is overheated. Should be changed without question.
g) The birthmark of many 16 valve engines are deep candle wells.
In these wells, there are several joints of mating parts. One for oil, the other for air. The result of a certain combination of circumstances will be the ingress of oil from the well to the engine suction:

Well, engine smoke as the end result. It is not difficult to check this - take out the candle tips and if they are in oil, then the gasket of the candle wells can no longer cope with official duties. If this is added to the lack of tightness of the intake manifold, the situation described above will turn out.

H) Original. In addition to the described malfunctions that cause engine smoke, there are a number of rather exotic and even curious ones. For example: engine smoke (oil smoke) can be caused by a microcrack in the engine (quite difficult to determine) through which oil enters the intake or directly into the cylinder, or oil leaks and gets on the exhaust system elements.

Curious cases include cases when the owner of a car accidentally fills the tank with fuel intended for two-stroke engines(mixed with oil) and then in a panic looking for the cause of the engine smoking.

4) Engine smoking with clouds of steam.

Here the reason is quite unambiguous - water enters the cylinders. The place of its deployment is unambiguous - the engine cooling system. This means that it is quite simple to determine this by reducing the level of antifreeze. In addition, for a more accurate diagnosis, it is necessary to examine the candles. In a cylinder where water is present, the spark plugs will have scale deposits on the electrode that are fairly easy to spot. Try to clean such a candle with a needle file and you will be able to see a coating similar to the coating inside a kitchen kettle.

In this case, there are two main reasons - the head gasket has pierced, or a microcrack in the cylinder. Again, the reason for this is either incorrect assembly, or poor-quality spare parts, or OVERHEATING of the engine (there are, of course, others, but these are the main ones). In any case, the repair is not delayed.

Sometimes the cause of fluid entering the cylinders can be corrosion of the engine from the inside (through!). Here is a picture I had the misfortune to see on one of my cars:

Not high-quality antifreeze literally ate the floor of the block from the inside. Corrosion products (simply rust) even filled expansion tank. Outcome - junk. Restoring such an engine is more expensive.

In a bad combination of circumstances, coolant can get not only into the cylinders, but also into the oil! This is easy to determine by looking at the oil level dipstick.

You will not confuse the emulsion with anything. It's not worth the hassle here. In this case, before repair, I would advise flushing the engine from the inside with diesel fuel. This will help save time and nerves during repairs, in addition to clean engine it will be easier to find the fault.

Good luck to you and all the best.

P.S. After warming, the article will be supplemented with a video with various defective exhausts.

Keywords: Why the engine smokes, the engine smokes with black smoke, the engine smokes with white smoke, the engine smokes gray smoke, water from the exhaust.