While the engine is running, the color of the exhaust gases may be different, this is a kind of indicator in what condition your unit is. On revised engines, white smoke comes out for a short period of time when starting up. If the engine is faulty or in poor condition, it can smoke white, black, blue or bluish exhaust.

If the engine is running continuously white, black, blue or gray smoke, this is the reason for its verification.

Consider why black smoke appears when the engine is started, what blue smoke indicates, and why white smoke comes from the engine.

What does the exhaust of a car say?

Exhaust can be different color, sometimes noticing smoke that is not typical for your car, you should think and check the condition of the power unit.

A white exhaust color may appear after a long parking period. This is due to condensation that builds up in the exhaust system and starts to evaporate when the engine starts. Outside air temperature also affects the production of white smoke. The colder it is, the more and longer the smoke goes.

Therefore, in frosty weather, smoke can go constantly. Worse if white smoke comes out in warm weather. This may indicate that working fluid from the cooling system has entered the cylinder.

In this case, it is necessary to disassemble the engine, remove the cylinder head, change the cylinder head gasket, repair cracks, check the tightness of the head, and the like.

To check and confirm that the liquid has entered the cylinders, you need to perform a number of actions:

• Start the engine, open the cover of the expansion tank of the cooling system and check for fluid bubbling. If bubbling is present, therefore, gases erupt into the cooling system. When the engine is turned off, the coolant level decreases, as part of it goes into the engine cylinders.
• Attention should be paid to the color and condition of the liquid in the cooling system, the smell of burning, the presence of greasy spots on the surface, changes in color, density, etc. This may indicate microcracks and defects in the motor.
• It is necessary to check the oil level, there are often cases when it rises as a result of liquid entering it from the cooling system. As a result, the engine oil liquefies and becomes cloudy, and an emulsion appears in it.

Until the problem is eliminated, it is better not to use the engine, so as not to aggravate the situation. In the worst case, a water hammer can occur as a result of a large accumulation of fluid in the space above the piston, which will damage the power unit and lead to costly repairs.

The gasoline engine produces black exhaust from the muffler, as a rule, at startup, this occurs due to problems in the power system. In this case, a strong enrichment of the working mixture of fuel and air occurs, more fuel than necessary enters the combustion chamber. The signs of this situation are as follows:

• Engine start is difficult;
• The candles are filled with fuel;
• At startup, the power unit malfunctions, not stable;
• Loud noise in the operation of the muffler, pops;
• High fuel consumption;
• The motor does not deliver its former power;
• The on-board computer gives an error;
• Gasoline smell when the unit is running

When the engine is running, the color may vary from gray to jet black. This is due to the fact that in the process of work it accumulates a large number of soot and over time it is released into the atmosphere.

There are many reasons that lead to a disruption in the fuel supply. You need to start looking for problems with the fuel supply systems. On carburetor engines, it is necessary to check the metering device, fuel, air jets, float chamber.

It is necessary to check the ignition system, it happens that when an element fails, such as an ignition coil, high-voltage wires, candles, there is a failure in the engine as a whole.

Check the status air filter, if it gets dirty, the mixture entering the cylinder will contain a lot of fuel.

In engines with an injector, the electronic engine management system sometimes fails. By transmitting incorrect data to the control unit, the controller increases the fuel supply. Which in turn leads to an excess of the fuel mixture.

Also, injectors in the engine can lose their tightness and overflow fuel into the combustion chamber.

Filling the candles with fuel not only causes an oversupply, but also many other problems. For example, washing off the oil film from the cylinder walls, as a result, severe wear of the cylinders and the piston group. In addition, large amounts of fuel enter the crankcase, causing the oil to dilute.

In any case, the motor needs a complete check, adjustment and troubleshooting, otherwise the consequences will be very expensive.

Blue smoke when the engine is running, signals that engine oil enters the combustion chamber.

Increased oil consumption by the engine will indicate that oil has entered the cylinder. Reasons for oil ingress:

• Strong wear of parts of the piston group;
• Damage to the gas distribution mechanism

When parts wear out, the piston rings fail, defects appear on the piston and cylinder walls.

In the event of a breakdown of the gas distribution mechanism, there is no seal in the area of \u200b\u200bthe valve stem and the valve guide.

For repair, it will be necessary to replace the valve seals. Measure the compression in the engine. If the reduction in compression is insignificant, then as you work, the blue smoke disappears, since the gaps decrease during warming up. If the gaps are large and the smoke does not stop, it is necessary to carry out repairs.

Summing up

So, to eliminate black, white, blue smoke, sometimes it is enough to replace the filter and clean the injectors. Whereas in more serious cases it is necessary to repair the engine and its mechanisms.

It must be remembered that if the engine suddenly began to smoke black, the fuel must be replaced, since low-quality fuel, with a high content of additives and undesirable impurities, leads to a change in the color of the exhaust and difficulties in combustion of the mixture.

Do not forget that the timing belt must be installed according to the marks, the valves and valve timing are clearly adjusted, the valve thermal clearance is correctly set. Spark plugs, when diagnosing, will help assess the condition of the engine.

The stability, reliability and durability of the power unit directly depends on everything, and many other indicators.

When the engines were only carbureted, the black exhaust from the muffler meant, in the vast majority of cases, only one thing - worn out valve seals. Through which the oil seeped and burned along with gasoline, in the combustion chamber. However, even then, serious experts, "by eye", determined the difference between such a malfunction (now it is called a gray exhaust), and a situation in which the exhaust was really black.

Causes of black exhaust

When gasoline does not burn, but cokes

In fact, the exhaust is painted black by particles of unburned, charred fuel, which simply did not have enough oxygen to detonate, and which turned into flakes of coal under the influence of temperature. They then give the exhaust from the muffler black. Moreover, this process is usually accompanied by a malfunction of the engine, "tripping" at idle, a drop in thrust (quite noticeable, by the way). Well, this malfunction should be eliminated by adjusting the flow of oxygen into the combustion chamber.

When there is not enough air flow

In fact, everything is very simple. The process of fuel combustion in an engine begins with the fact that gasoline flows from the tank to the carburetor (or to the nozzle, if we are talking about a diesel engine), or to the injector. Here it is sprayed, mixing with the incoming air, turning into a combustible mixture, which detonates in the combustion chamber, alternately pushing the pistons. And if the air flow is not enough, then the black exhaust from the engine is the only possible variant... An over-enriched mixture is simply formed, which does not have time to completely burn out. After all, even in case of a strong fire, remember, first of all they try to block the access of air and oxygen to the fire site. And then there will be nothing to burn ...

In this case, you need to adjust the fuel level, clean the carburetor, jets, maybe even everything will cost just replacing the air filter, which, when clogged, does not allow enough air to pass through to create a mixture with the correct ratio of atomized fuel and oxygen.

Abrasive processes in the combustion chamber: what threatens black exhaust

Black exhaust always indicates increased fuel consumption when the engine is running, but this is a consumption that does not affect the increase in power. On the contrary, there is a drop in power, and a significant one. And now - the most important thing.

• The fact that black smoke is coming out of the muffler is not the worst thing.
• The fact that this black exhaust is accompanied by a drop in power (at which the car in fourth gear develops at least 100 - 120 kilometers per hour) is also not the worst thing.
• Even the fact that gasoline consumption doubles is not the worst consequence.

Black exhaust from muffler threatens serious engine problems due to the fact that coal particles are not only flying out of the muffler.

They also enter the combustion chamber and, without burning out, remaining there, in the space in which the pistons "move", adhere to the walls of the piston liners, acting as a kind of abrasive, undermining the walls, which, in theory, should be perfectly smooth and polished ... That's what the notorious black exhaust is. It is capable of reducing the engine life by an order of magnitude, at times, causing a complete repair (with grinding or replacement of liners).

Also, unburned excess fuel can enter the lubrication system, thinning the oil, making it unsuitable for lubrication. Sometimes this process is so intense that the oil level in the crankcase increases significantly. Which, of course, also does not contribute to the long-term operation of the engine. As well as the fact that gasoline that gets on the walls of pistons and cylinders simply flushes off the lubricant. As a result of all this, small scratches can form on the walls, and maybe even serious scuffs, which are by no means conducive to normal engine operation.

How to get rid of black exhaust

Carburetor faults ...

How to deal with it? How can a malfunction in the fuel supply system be eliminated and the process of creating an enriched combustible mixture in which air and atomized fuel would be contained in the proportions necessary for normal engine operation? In fact, you need to look for the true cause of the malfunction. As already mentioned, this may be (if we are talking about carburetor engine) a clogged air filter that does not allow enough air into the system. Black exhaust from the muffler may be the result of a clogged hole in the nozzle, through which air does not flow, or the reason may lie in the excessive supply of gasoline (if the float chamber is incorrectly adjusted and the fuel level in the carburetor goes off scale).

... injection and diesel ...

If we are dealing with injection injection, the black exhaust from the muffler may also indicate a malfunction of the fuel flow sensors (these units themselves are designed to regulate the amount of incoming air in accordance with a given rate). Or that the injectors are leaking, which, by the way, can be very relevant even in the case when black exhaust from the muffler is observed during diesel operation.

Although with a diesel engine, of course, there are certain nuances. During a cold start, black exhaust will be observed in any case. Moreover, a cold start for a diesel engine is a serious challenge. It is not for nothing that modern cars equipped with a diesel engine always have a preheating system. But even it does not save from exhaust in the initial stages of the engine running in a cold state.

The complexity of the repair: sometimes you can do it yourself, and sometimes you have to contact a specialist

It is important to simply navigate correctly and understand whether the exhaust has cleared up quickly enough, whether the engine is running idle, whether there is a drop in power and increased consumption. If there is at least one of the listed malfunctions, get ready for trouble. Either not quite large (adjustment), or rather serious. Up to replacing the rings of the piston group, or the group itself as a whole.

To eliminate such a malfunction as black exhaust from the muffler, it may also be necessary to intervene in the operation of the fuel pump or turbocharger (up to replacement), because the exhaust can also mean a failure in the fuel supply system. When gasoline comes in too abundantly, and the system for creating a combustible mixture with such an amount simply cannot cope. You may also need to adjust the pressure in the injector nozzles. These are malfunctions that, perhaps, cannot be dealt with on your own. We'll have to contact a specialist.

To save engine life ...

Be that as it may, you should clearly know that black exhaust is dangerous not because it spoils the environment (soot flies out of the muffler, stinks of gasoline), but also violates normal work engine, leads to increased fuel consumption and lowers the efficiency of its work. It should always be remembered that particles of coking fuel not only fly out of the muffler, but also fall into the piston group, becoming an abrasive and at an accelerated pace wearing out the polished (ideally like a mirror) working surface of the liners, pistons and O-rings.

This can lead to a noticeable drop in the engine's operating life, and instead of, say, according to passport data, 500 thousand kilometers (modern cars are designed for approximately such a resource) before repair, the engine will work an order of magnitude less. This is why black exhaust from the engine muffler is dangerous in the first place.

In principle, many car owners do not pay much attention to exhaust smoke if it is the amount decreases after the machine has completely warmed up, and in the process of movement, the smoke disappears altogether. However, if the smoke does not stop while driving, this is a clear sign of more or less serious malfunctions in the car engine.

These malfunctions, as it were, are trying to attract the attention of the driver, aggravating when starting the engine and manifesting themselves in the form of various smoke. You should pay close attention to these alarms and identify the malfunction in time before complex and costly repairs are required.

The nature of car exhaust

The color and consistency of the smoke from the exhaust pipe can be figuratively compared with the freshness of human breath - a healthy organism (both biological and mechanical) exhales correspondingly cleaner vapors than a sick one. In a working car, when fuel burns, compounds of water and carbon dioxide are formed - as in the vapor from the breath of a healthy person. However, it must be taken into account that the combustion of fuel does not occur with pure oxygen, but with the help of ordinary air, for the most part consisting of nitrogen. That is why harmful nitrogen oxides (NOx) are formed in the smoke from the exhaust pipes of cars, which negatively affect the state of the atmosphere and even lead to the so-called acid rain. And the fuel does not oxidize and burn completely, even in engines newest brands, and because of this, there is an additional emission of carbon compounds - CO and CH. In addition to all this, when oil or coolant enters the combustion chamber, other, no less harmful, chemical "cocktails" arise and go into the air.

Of course, the exhaust system of modern engines is equipped with various converters and filters whenever possible. However, this is not enough - think of the dense smog clouds in the photographs of the largest cities. In addition, any filter systems will wear out over time, thereby increasing the toxicity of smoke coming out of a car's exhaust pipe. Although, as mentioned above, the color and toxicity of smoke depend not only on the inadequacy of self-regulation mechanisms, but also on many other malfunctions.

Comparative characteristics of exhaust gases of gasoline and diesel engines

Most often, more or less dense smoke from the exhaust pipe signals the car owner about a malfunction of the fuel supply and engine cooling systems, as well as about malfunctions of the distribution mechanism or piston group. Each of these cases has its own nuances: either the fuel burns out incompletely, or coolant, and sometimes oil, enters the cylinders. Strictly speaking, it is the excess fuel or the presence of foreign substances in the cylinders that give the exhaust gases different shades.

In general, the color of the smoke from the exhaust pipe is practically the same - the differences are only in the nuances, since sometimes the malfunctions of a certain system that cause smoke are directly related to the malfunction of other systems that cannot "make themselves known" with the help of smoke. For example, such a situation is not uncommon: the cooling system does not work well, which is why the engine overheats. Due to overheating, the piston rings burn, which entails the ingress of oil into the cylinders and, as a result, the appearance of smoke. Note that the root cause lies not in the piston rings at all, but in the cooling system. That is why, starting to look for the cause that caused the smoke from the exhaust pipe, you should be extremely careful - analyzing and comparing all the available factors.

The main causes of black diesel smoke

As the title of this subsection suggests, black exhaust smoke is most often due to fuel problems. The black color of the exhaust is due to the color of soot, which is formed as a result of, for example, incomplete combustion of fuel. Soot appears when there is a process of decomposition into elements of that part of the fuel, which did not have enough air for complete combustion. Modern cars are equipped with computer systems that control all processes occurring while driving - including the process of fuel combustion.

Under such "sensitive guidance" the risk of errors in the formation of a combustible mixture is significantly reduced - although, by and large, this applies only to gasoline engines, while a diesel engine, even the most modern, will still slightly smoke. This is due to the fact that in diesel engines the composition of the mixture differs from gasoline counterparts - its concentration in this case is heterogeneous and contains inclusions of high fuel density.

To make it homogeneous, the modern auto industry uses mechanisms of increased injection pressure - however, even this measure is not yet able to completely eradicate the problem, and therefore soot-colored smoke from the exhaust pipe of a diesel engine can be seen much more often than in gasoline cars. The black color of the exhaust smoke is due to the presence of soot. On latest brands Particle filters are used, which to some extent solves the issue (however, these filters must be periodically cleaned, and sooner or later changed to new ones). In addition to incomplete combustion, black smoke from the tailpipe can be caused by other factors, such as inadequate fuel quality.

It should be remembered that the use of low-quality fuel can lead to too fast process combustion - such combustion is also called detonation. Another factor affecting the intense formation of soot may be a malfunction of the notorious electronic system that monitors the efficiency of fuel combustion. For example, the failure of the oxygen sensor leads to the fact that the electronic unit is not able to control the completeness of combustion - and then it starts working at random, without maintaining a full-fledged "dialogue" with the oxygen sensor.

What to do to more accurately determine the cause?

This color of smoke signals that the power supply system of the engine is not working well and mixes the fuel with air incorrectly. Of course, the reason can be quite commonplace and lie in the quality of fuel, or rather in its poor quality. However, incorrect mixture formation is still the most common cause. This circumstance is due to excess fuel or insufficient air volume.

The reason for the lack of air may be a dirty air filter or ductwork. In addition, the air consumption sensor may not work properly. When on high revs the volume of smoke increases, then a fuel pressure check should be performed. When a vehicle that has a diesel engine is accompanied by black smoke, then it is necessary to inspect the performance of the high pressure pump. Perhaps the reason is precisely in him. Visual inspection of hoses, clamps, intercooler (look at oil leaks as a sign of leaks). The best test is to artificially create pressure in the channel using an external (for example, a bicycle) pump with the engine off.To do this, disconnect the hoses from the intake manifold and from the turbine, close them and build up pressure - observe / listen to the air coming out of leaks.

How to eliminate black smoke from diesel exhaust pipe?

- The air filter is dirty. It needs to be replaced.

- Malfunction of injectors - mainly associated with low-quality fuel. Black smoke appears in this case when hard pressing on gas or when driving with a load. The malfunction of the injector is also accompanied by the uneven operation of the diesel engine. It starts to shake (very noticeable at low revs). In such cases, repair is required for the faulty injector;

- Incorrectly set the injection timing. At an early injection angle, a significant delay in self-ignition occurs, the pressure in the cylinder increases, which leads to a hard operation of the diesel engine, and, in addition, a lot of soot is formed. If the setting of the injection pump angle is correct and the diesel fuel is of high quality, then the injection pump must be repaired together with the nozzles;

- Malfunction of the turbocharger. As a result, the turbocharger does not develop the required boost pressure, or it passes a lot of oil into the intake tract due to worn out labyrinth seals of the turbine shaft;

- Incorrect combustion conditions for the air-fuel mixture: low or high compression or lack of air.

At low compression, the engine is difficult to start, power is lost, and black smoke appears under load. At increased - the diesel engine works very noisy, knocking knocks are heard. This malfunction is very rare and is associated with errors in the assembly of the motor. The lack of air is associated with a malfunction of the turbine or with a leak in the intake tract. Under load, then black smoke appears and the diesel engine loses power.

- Operating a car with black smoke emitted does not damage the engine or its parts. But a long drive with an early injection angle or with faulty injectors will lead to burnout of the prechambers, destruction of jumpers and burning of pistons, which in the future will entail serious repair of diesel engines for any cars. e

The color of the exhaust gases during engine start and during its further operation is a kind of indicator of the state of the power unit and systems. Various malfunctions can lead to the fact that the engine smokes white, black, blue or gray exhaust. As a rule, on a serviceable engine, drivers briefly observe only white smoke when starting a diesel or gasoline engine.

Note that this phenomenon in some cases is not a malfunction, especially when the specified smoke generation after the internal combustion engine warms up becomes less intense or completely disappears. If, when starting the engine, blue smoke comes out or the driver notices black smoke when starting a cold engine, then this is a reason to check the power unit.

In this article, we will talk about the reasons why black smoke can appear when starting the engine in cold weather, what blue smoke indicates when starting a cold engine, and also why white smoke appears when starting the engine.

Read in this article

Smoke from the exhaust pipe when starting the engine: white, black, blue exhaust color

As already mentioned, when starting the engine, smoke from the exhaust system can be of different colors, and smoke does not always become a cause for concern. Let's start with the white exhaust.

The fact is that after parking, condensation accumulates. After starting, the condensate begins to evaporate, and the outside temperature and humidity of the air also affect the amount of smoke and its density (the colder and more humid, the thicker and longer the white smoke will remain). In cold weather, such smoke can be constant, that is, the installation smokes white, regardless of the degree of heating of the internal combustion engine.

The situation requires increased attention when it is warm outside, while after starting the engine from the exhaust pipes are coming thick cloud of white smoke. In this case, there is a high probability that the working fluid (antifreeze or antifreeze) gets from the cooling system directly into the cylinders.

This malfunction appears as a result of engine overheating, breakdown, or formation in those places where the channels of the engine cooling jacket pass.

In such a situation, you will need to remove the head, if necessary, grind the mating plane, change the cylinder head gasket, check the head for leaks, repair cracks, etc.

• To confirm the diagnosis, unscrew the cover on the running motor. Bubbling and bubbles will clearly indicate gas escaping into the cooling system, and the coolant level may also rise. After stopping the internal combustion engine, the specified level in the reservoir decreases, part of the coolant enters the cylinders.
• Note that the liquid will not always boil, especially in the case of microdefects. In such a situation, you should be guided only by color, condition and coolant level.
• The smell of burning, the presence of oil stains on the surface, a decrease in the level in the tank for no apparent reason and a number of other indirect signs will indicate the ingress of liquid from the cooling system into the cylinders.
• Also, it will not be superfluous to get the oil dipstick and unscrew the oil filler cap. The fact is that with intensive penetration of coolant into the combustion chamber, leaks from the above-piston space through the internal combustion engine crankcase occur.

The result is the thinning and clouding of the engine oil, the appearance of a characteristic brownish emulsion. We add that with an intense accumulation of coolant in the space above the piston, an engine water hammer can occur. For these reasons, strong white smoke is an alarming symptom and requires immediate elimination. In other words, it is better to stop operating the internal combustion engine until the problem is eliminated.

Black smoke when starting the engine

The black color of the exhaust gases often occurs when there are problems with the power system and the quality of the fuel-air mixture.

Such smoke is formed as a result of the fact that there is a strong enrichment of the working mixture of fuel and air in relation to specific regime ICE operation.

Enrichment should be understood to mean a large amount of fuel in relation to the amount of air. In this case, the following additional symptoms may appear:

• the engine turns easily from the starter, but starts with difficulty;
• quite often, even new or serviceable;
• after starting the engine "troit", the operation of the internal combustion engine is unstable;
• in and clap strongly;
• the power unit loses power and uses up fuel;
• on the dashboard, maybe the BC gives an error;
• there is a clear smell of gasoline or diesel fuel in the exhaust;

The shade of the smoke can vary in various cases from gray to thick black. Blackening occurs from excess soot, which is formed as a result of inadequate combustion of the fuel charge.

The engine can smoke black both "cold" and after warming up, during gas re-gasings, etc. If permanent black exhaust is noted on a diesel engine, then another cause may be a failure or other malfunction of the particulate filter.

• The list of reasons that lead to violations of fuel supply, mixture formation and combustion of the mixture is quite wide. On engines with a carburetor, the check must begin with the metering device itself, the float chamber and the fuel level in it, as well as air and fuel jets.
• More attention should be paid to the idle system. At the same time, it is recommended to check the ignition system on the injection and carburetor engine, since failure individual elements (spark plugs, high voltage spark plug wires, coil, etc.) causes malfunctions in iCE operation and can lead to misfire.
• Another point during diagnostics is the intake system, since air filter contamination is a common cause of a too "rich" mixture.
• We add that on an internal combustion engine with an injector, sensor malfunctions lead to an excess of the supplied fuel. Invalid data is fed to, after which the controller initiates an increased fuel supply.
• In this case, check the throttle assembly, oxygen sensor and other elements. It is relatively rare, but it is also possible that the electronic engine control unit itself fails.
• With regard to the fuel system, the injectors themselves may leak and overflow fuel into the cylinders. This problem is common to both gasoline and diesel engines.

This can be due to heavy pollution, wear or other defects in the injectors. On gasoline engines also check the fuel rail and pressure regulator.

The danger of this situation is that with a strong overflow of fuel, not only the consumption increases, fills the candles and other problems arise, but the oil film is washed off the cylinder walls with the fuel. As a result, overall wear increases during startup. If a lot of fuel enters the cylinder, which does not burn, then the fuel can also drain in excess into the engine crankcase.

To check, it will be enough to remove the oil dipstick and smell the engine oil, assess its condition. Strong liquefaction and a distinct fuel odor will indicate significant overflow. In such a situation, the engine needs in-depth diagnostics, it may be necessary to clean, adjust or even replace the fuel injectors.

Blue smoke after starting the engine

A blue exhaust gas or a bluish tint is a sign that engine oil is actively entering the combustion chamber. This smoke is bluish, oily and thick. Oil ingress is easy to identify in a simple way.

It is enough to start the engine and lean a blank sheet of paper against the exhaust pipe. Greasy stains that will not dry will indicate lubricant particles in the exhaust system. An additional sign can be considered an increased oil consumption, which significantly exceeds the permissible indicator for this type of internal combustion engine. Oil enters the combustion chamber for the following reasons:

1. Significant wear of the CPG elements.
2. Malfunctions.

In the first case, we are talking about the wear of the piston rings, the appearance of defects in the piston itself or in the cylinder walls (seizure, ellipse, etc.). In the second case, the oil is leaking because there is no proper seal in the area of \u200b\u200bthe valve stem and the valve guide.

At the initial stage, for repair, it may be enough to replace the valve seals (valve stem seals). The status of the CPG helps determine the compression measurement in the engine.

If the decrease in compression in the cylinders is insignificant, then the engine may have a gray or blue exhaust only after starting and until the moment it warms up. The fact is that after warming up, the gaps between the parts decrease, oil stops getting into the combustion chamber.

In the case of greatly increased gaps, oil diluted from heating will still get into the working chamber. If the car is equipped with a turbocharger, then blue smoke after starting the engine or during its operation may be the result of malfunctions of this element.

If the turbine bearings and the rotor seals are worn out, oil will enter the exhaust system through the turbocharger and burn there. As a result, bluish smoke with grease particles is emitted from the exhaust pipe.

Smoke from under the hood when starting the engine

This phenomenon can most often be found in the event that there is an oil leak in some place (oil seals, gaskets). Lubricant falls on the exhaust manifold and begins to burn out as the internal combustion engine warms up, and the driver sees smoke from the engine compartment.

Also, one should not exclude the possibility of foreign objects entering the heated elements of the internal combustion engine or the exhaust system. A similar effect can be caused by a fuel leak, which occurs due to the loss of tightness of certain elements of the fuel supply and fuel injection system.

In both cases, the problem must be addressed immediately, since the risk of fire and fire in engine compartment... Parallel leaks in exhaust system or problems with turbocharging can also be the reason that smoke appears from under the hood when the engine is started or smokes constantly during its operation.

For example, a curvature of the intake pipe flange or burnout of the gasket will cause smoke to appear in engine compartment... You should also pay attention to whether the car is equipped with a liquid preheatingatel interior and engine.

The appearance of smoke from under the hood in this case is more characteristic of diesel units, since pre-heating is more in demand on this type of engine. To put it simply, a heater on a particular car may be.

Since the device internally burns fuel, an air supply is required for the combustion of a portion of fuel, and a system must also be implemented for removing gases after combustion. With unqualified self installation or for other reasons, the system for exhausting gases from the heater can be removed so that the exhaust pipe goes into the engine compartment.

Normally, prestarting liquid heaters practically do not smoke, and combustion products are removed in the area of \u200b\u200bthe front wing (behind the wheel). In this case, certain malfunctions may well lead to the fact that smoke appears from under the hood. In this case installed system should be checked separately.

As you can see, in some cases, replacing filters and cleaning the injector may be enough to eliminate the cause of black, white or blue exhaust. At the same time, for other engines, the only way out would be to replace worn-out elements of the CPG, timing or even overhaul engine.

We add that if the engine suddenly began to smoke with black exhaust when starting for no apparent reason, then it is recommended to change the fuel at the very beginning. Refueling with low-quality fuel or fuel with a high content of additives and impurities often leads to difficulties in igniting the mixture and discoloration of the exhaust gases.

It should not be forgotten that the stability of the unit's operation and the usefulness of the combustion of the fuel-air mixture directly depend on the valve timing, the quality of the valve adjustment and the normally set ignition. The timing belt (if any) must be aligned strictly according to the marks, the thermal clearance of the valves must be carefully adjusted.

Note that during the initial diagnostics it is possible, the color of carbon deposits on the electrodes and the threaded part. For example, wet candles or black oily soot will further indicate the cause and severity of the problem. Finally, we add that in order to quickly find a malfunction of an injection gasoline or diesel engine, it is recommended to immediately carry out a full computer diagnostics of the engine.

Taking into account the low cost of this operation at the service station, it is possible to identify malfunctions and malfunctions in the operation of individual ECM sensors. You can also check the internal combustion engine for errors yourself using the diagnostic adapter c.

Read also

Black color of the diesel engine exhaust. Soot from a diesel exhaust pipe, causes of incomplete fuel combustion. Determination of basic faults.

On the roads, you can often find cars smoking black soot. Heavy trucks are usually smoked. But often they are subject to carsequipped with a diesel engine. Black smoke from a diesel exhaust pipe does not bode well for the owner. But if you react in time, you can save the motor from serious consequences. Let's find out what are the causes of soot from the pipe and how to eliminate defects. The emergence of smoke should be treated with care and faults should be corrected in time to avoid costly repairs.

On the nature of exhaust gases

The color and density of exhaust gases can be compared to human breathing. When the body is healthy, it breathes out pure vapors. If the vehicle is in good working order, the combustion of fuel produces water and carbon dioxide.

But it must be borne in mind that the fuel mixture does not burn with oxygen, but in air, which mostly consists of nitrogen. Therefore, the smoke from the exhaust pipe most often contains harmful nitrogen compounds. In addition, even in modern engines, the fuel does not burn completely.

Typical Causes of Diesel ICE Smoke

If a diesel power unit smokes with thick black smoke, then this indicates a malfunction, which is often associated with fuel consumption. Don't ignore the problem. If black smoke comes from the exhaust pipe of a diesel engine, then this is necessarily accompanied by significant fuel consumption, unstable behavior of the engine in the entire range of its revolutions, and a significant loss of power.

This blackness can be seen especially well in the winter on white snow. Smoke often rises with sudden acceleration.

Among the typical reasons, several of the most common for diesel engines... So, the first reason is associated with injectors. They pour fuel into the combustion chambers. Smoke also rises due to improper adjustment or fuel pump malfunctions, incorrect setting of the injection advance angle of the high-pressure pump. In the case of turbocharged engines, black smoke may indicate a compressor malfunction. The air filter may be clogged, or oil is leaking due to leaking connections. Also among the reasons are low compression, an incorrectly installed timing belt or a clogged particulate filter. The latter performs the same function as a catalyst on gasoline cars.

Another reason for black smoke from a diesel exhaust pipe is poor quality fuel. Nowadays it is common at many gas stations. Poor quality fuel not only produces black smoke, but also poses a serious threat to the engine. It is because of low-quality fuel that important units fail. Mostly injectors, high pressure pump, filters are affected.

Experts believe that a small amount of black smoke at the time of a sharp increase in speed and an increase in the load on the engine is quite acceptable, since at this moment the portion of the mixture increases significantly. But if the shade of the smoke is gray, then this indicates a malfunction.

Another typical reason is a clogged intercooler, a faulty catalyst or a mass air flow sensor.

Smoke and low compression

In a gasoline engine, a mixture of fuel and air is ignited by a spark generated by a spark plug. In diesel engines, the ignition process is carried out by creating a high pressure in the cylinder. If the compression force is insufficient, the engine will not start well. But that's not all. If the pressure is insufficient, the fuel will not burn completely. From this, black exhaust is formed. Most often, puffs of smoke can be seen with a sharp acceleration, as well as a strong press on the accelerator pedal.

Low compression causes a lot of problems in the winter. It is practically impossible to start such an engine, which is "near death", even at temperatures around zero degrees without the use of additional heating devices.

If the engine has low compression, then the temperature at the end of the compression stroke in the cylinders will be less than it should be. The combustible mixture, even if supplied on time, will not ignite. If the engine has at least two cylinders where the compression is normal and the engine has been started, the low compression cylinder may still not function. After warming up, the temperature in the engine will rise and during the compression cycle it will already be sufficient for the mixture to ignite.

Increased smoke due to turbine problems

When the turbine, for some reason, does not pump the required amount of air, at which the fuel mixture could burn completely, black smoke appears from the exhaust pipe. Turbo diesels suffer from this too. The smoke is clearly visible during gas movements. If oil gets into the turbine, then you can see the gray exhaust.

If the tightness of the intake tract is broken, then due to air leakage, the ratio of the amount of fuel and oxygen is disturbed. The motor starts to run intermittently. Among the reasons for air leakage, it is worth highlighting damaged pipes, damage to the clamps and their insufficient tightening.

Smoke and lack of air

The power unit smokes and consumes great amount fuel due to re-enriched mixture. There may be two options. The problem is related to overflow nozzles or insufficient air volume.

Why is the motor running out of air? The engine often lacks oxygen due to a clogged air filter. During the operation of the car, these elements become clogged with dust and dirt. But it also happens that the intake manifold channels are clogged. Insufficient air problems are also caused by:

• Abnormal operating modes of the EGR valve and the throttle valve.
• Incorrect timing valve clearances.
• Incorrectly set marks in the gas distribution systems.

It is very easy to diagnose the air filter - you just need to remove it from the case. It is worth noting that the filter elements should be changed according to the regulations of the car manufacturer. Often it is 10-30 thousand kilometers (by cars and trucks, respectively).

Particulate filter

Another fairly popular cause of black diesel smoke is a clogged particulate filter. Now this part is installed not only on large motors for trucks, but also on modern diesel internal combustion engines for passenger cars.

If this element gets clogged, then it starts automatic process regeneration of exhaust gases. However, if the engine has to run on poor quality fuel, the particulate filters must be removed. The electronic engine control unit is also flashed. It is very easy to find out about particulate filter malfunctions - an advisory indicator on the dashboard will light up, which will indicate a malfunction of the fuel system. Also, the machine will work intermittently.

The cost of a new particulate filter is quite high - from 60 thousand rubles. Most car owners prefer not to change, but to remove this element of the exhaust system. However, if you physically remove the particulate filter, the ECU will generate an error. In the workshop, when the filter is removed, the electronic system is also flashed. Often, removing the filter will help completely solve the problem of black smoke from a diesel exhaust pipe.

Problems in the fuel equipment

As the practice of repairing diesel engines shows, the main reasons why the internal combustion engine does not work correctly and smokes are injectors, as well as high-pressure fuel pumps. Among the popular malfunctions of nozzles, one can single out their clogging. Due to low quality fuel, the spray torch is disrupted and the nozzle no longer sprays, but pours diesel fuel.

In addition, it may not completely burn out due to an incorrectly set injection angle. This is especially detrimental to the motor when the angle is too early. If you operate the machine for a long time with such an early angle, then the elements of the cylinder-piston group may fail. In this case, they have to work under conditions of too high loads.

An equally popular reason when black smoke comes from the exhaust pipe of a diesel engine is an uneven supply of the combustible mixture to the combustion chambers due to worn plunger pairs in the high pressure fuel pump. Due to the late injection angles, the engine will emit plumes of black smoke.

Modern diesel engines equipped with various electronic systems, which control the operation of all units, including the fuel system. Often it is electronics that provoke black smoke from the exhaust pipe of a diesel engine. This is due to incorrect settings in the control unit, which generates commands for excessively large portions of the combustible mixture. Another reason may be in the sensors.

Injection pump

As you know, black diesel indicates a re-enriched fuel mixture. Such a mixture is supplied to the cylinders due to incorrect adjustment of the fuel supply to the injection pump, with worn out injectors, and also due to a worn out speed regulator in the pump.

Any high pressure pump has a special screw, with which you can adjust the amount of fuel supplied. More fine tuning is performed by the driver when pressing the gas. When the screw is tightened, the fuel flow is increased. Along with this, idle speed also grows. However, a large idle speed can be compensated for with the appropriate adjustment screw. This will increase the power of the motor. But black smoke will also appear. If you turn the coarse adjustment screw more than necessary, then the engine will not slow down, and black smoke will pour out of the diesel exhaust pipe.

During vehicle operation, the injection pump wears out. Inside the pump, all parts experience friction, while there are simply no good lubricants there. Diesel fuel acts as a lubricant, and domestic diesel fuel has practically no lubricating properties. If you sharply press on the gas, then a lever moves inside the injection pump, increasing the supply of the mixture. This lever rests on a special support. Its position is set by an all-mode speed controller. Therefore, it will not work to quickly raise the amount of fuel. By pressing the gas, the driver only expresses his wish, and the regulator is responsible for the increase in speed. How sharply the revs rise depends on how worn out this regulator is.

With minimal wear, gray smoke will be barely noticeable during a sharp start. When worn, the engine will emit a thick black smoke.

Soot and cold start

Many owners diesel cars complain that the engine smokes cold. Some experts argue that the problem is in the injection pump. But it is not so. Some people believe that cold smoke is normal. The cylinders are fed rich mixture... Don't worry about this.

Black smoke and ignition

The reason for the appearance may be atypical. So, reliable motor suddenly began to smoke. When investigating why the smoke started to form, it turned out that the problem lies in the ignition system. Some motors have a system for adjusting its angle with a solenoid valve. This valve can often turn sour.

If everything is in order with the sensor, it will crack. If smoke is detected, the sensor is removed. If the motor no longer smokes and the motor starts to run smoothly, then the sensor needs to be replaced.

Blue smoke and late injection

It is not uncommon to see blue smoke from the chimney. The reason is the late injection. It is believed that this is not scary and does not harm the engine. This is often due to the high wear of the high pressure fuel pump.

Diesel engine and white smoke

This type of soot is also called gray or blue. White exhaust appears due to a destroyed turbine. The oil flows directly into the intake tract. Smoke will come from the chimney, which many people often mistake for white. However, the smell of this exhaust immediately clarifies its origin.

This soot can be compared to the smoke from burning sunflower oil. The smell will be the same. Also, white clubs are often confused with the steam seen in winter. This is nothing more than condensation.

The most serious cause of white exhaust is the coolant that enters the internal combustion engine cylinders. Usually one cylinder jams. This combustion chamber may not idle. Coolant enters the combustion chambers due to destroyed gaskets in the intake manifolds, due to burnout cylinder head gaskets and, which is most often found on diesel engines, due to a crack in the cylinder head. If there is a crack on the head, this can be diagnosed by high coolant consumption and its rusty color due to constant engine overheating.

"Common Rail"

Smoke problems are also observed here. Most owners complain about the black exhaust.

It is believed that this is due to the quality of the fuel or the injectors. Fuel is not sprayed - the nozzle is pouring. Hence the black soot. After warming up, the motor runs normally again.

How to identify increased soot?

Car owners can find out the reason why black smoke is pouring from the exhaust pipe of a diesel engine on their own.

As we noted earlier, experts recommend checking the condition of the air filter - the element is removed and its condition is visually assessed. On engines equipped with a turbocharger, the pipes leading to the turbine are dismantled - this way you can assess the state of the turbocharger.

To check the elements of the fuel system on diesel units, it is recommended to contact a professional. Modern fuel equipment practically defies self-repair... The fact is that it is possible to check the condition of diesel injectors and their performance only on special stands.

Also, only experienced specialists can correctly configure the fuel system. The nozzles often need to be cleaned. Ultrasonic cleaning is most effective. Also, at the service station, you can correctly adjust the injection pump.

To assess smokiness, apply special equipment - opacimeter. If the vehicle is equipped with an electronic control unit, computer diagnostics are performed.

Conclusion

So, we found out all the popular reasons for the appearance of soot. different colors... It is normal if the engine starts cold and emits smoke. And other problems can be easily solved with your own hands. But the difficulty is that the black smoke from the exhaust pipe of a diesel engine (Ford Transit is no exception) can indicate completely different breakdowns - from a clogged filter to plunger pairs. Therefore, if the car smokes, the engine jerks or troit, it is better to contact a professional for diagnostics.

In this case, you can operate the car without any special consequences. But it is impossible to drive for a long time with early injection or incorrectly working injectors: the prechambers can burn out, the bridges can also be destroyed and the pistons burned. And this is a serious and expensive engine repair.