When the engines were only carbureted, black exhaust from the muffler meant, in the overwhelming 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" on idling, 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 the 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 black exhaust from the engine is the only option. 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 washes away 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 the normal operation of the engine.

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 a carburetor engine) clogged air filter, which 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. No wonder in modern carsequipped with a diesel engine, a preheating system is always provided. 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 handle 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.

Intervention may also be required to troubleshoot a black exhaust from a muffler. fuel pump or a 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 preserve 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 coked fuel not only fly out of the muffler, but also get into piston group, becoming an abrasive and at an accelerated rate wears 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.

Black smoke from a muffler is a serious reason to seek help

Such a nuisance as black smoke from exhaust pipe can overtake every car owner, regardless of the car brand and engine type. The main reason for the appearance of black smoke, regardless of how it goes - intermittently or constantly - is one. This color of the exhaust signals an over-enriched mixture, that is, too much fuel gets into the combustion chambers and the mixture does not have time to be fully processed. Also, this symptom may be accompanied by unstable engine operation, triple action, etc. Black smoke can occur in different forms:

• constantly,
• on a cold engine,
• on a hot engine,
• periodically.

There are many reasons why black smoke comes from the exhaust pipe. In many respects, it depends on what kind of engine you have - carburetor, injection or diesel. The most common cause of black smoke is a malfunction. fuel system or sensors when the mixture is re-enriched with fuel. It is also a common problem that the car smokes black for a short time after starting. And this is permissible when low temperatures... But let's talk about everything in more detail.

Why is black smoke from the exhaust pipe

Needle valve malfunction on carburetor engines Is the most common cause of black smoke

If black smoke comes out of the exhaust pipe, an urgent need to determine the cause. The consequences of inaction in this situation can be very dire. The causes of black exhaust, as mentioned, differ depending on the type of engine, and the following table will help you navigate a situation when black smoke is blowing from the exhaust pipe.

If diesel car smokes black from the exhaust pipe, but the engine runs smoothly, then most likely the DPF should be checked

Black smoke when starting the engine?

If you notice black smoke coming out of the exhaust pipe when starting up and then it disappears, then know that in most cases this is normal. Especially if there is a deep minus behind. Quite simply, the computer gives the command to deliver a more enriched mixture to make it easier to start in cold weather. If this happens even with a "plus", then look at the diagnostics.

Black smoke can occur when the engine is started - this is the injectors delivering more gas for a richer mixture that makes starting easier

In any case, it will not be superfluous to turn to specialists for diagnostics, since in case of advanced cases with excessive fuel supply, the engine may receive a water hammer. And this means a complex and expensive repair, in some cases comparable to the cost of a car in the secondary market.

The consequences of a water hammer - it happens when the owner ignores the black smoke of their silencer for a long time

You can always contact our specialists, because we even take on other difficult-to-repair brands.

Best regards, team of specialists

Black smoke from the exhaust pipe - causes, consequences You know, much to the relief, this does not mean a serious breakdown of the engine or auxiliary systems. But if this problem is not eliminated in time, then it is possible to bring the supply system, the fuel ignition system, as well as the engine itself to a deplorable state, because they are the causes of black smoke from the muffler. It appears: - in the form of a thick black exhaust from the muffler, especially when you press the gas pedal. Moreover, the car does not work stably, often the engine "troit", it starts poorly in the morning (especially in winter period time). Fuel consumption increases. Main Causes Black smoke indicates that the fuel-air mixture is too rich (over-enriched). A lot of fuel enters the cylinders, which does not have time to efficiently burn, so the exhaust is repainted black. It is much more toxic and more harmful than normal exhaust, because even a catalyst cannot burn excess fuel in the exhaust. The main reason for this is a malfunction of the fuel supply system, found in all types of engines. internal combustion (gasoline, diesel). The second reason may be a malfunction in the ignition system, the fuel is not ignited in the chamber, and therefore the raw mixture goes directly to the muffler, and the engine will mercilessly "troit". For carburetor ignition In the carburetor, everything is quite simple - if the exhaust is painted in gray-black tones, there is unstable operation, first of all you need to look at the carburetor itself. Most likely, there is an overflow in the float chamber here. This happens for two reasons: 1) The "needle" (needle valve) is faulty, it can stick or, on the contrary, let excess fuel pass. 2) The jets are clogged, coked (from our fuel). Small “nozzles” with precise dimensions. It is necessary to disassemble the carburetor, clean it, if it does not help, then you need to buy a repair kit and replace the "needle" and jets and correctly set the level of gasoline in the chamber. Injection option Here everything is a little more complicated on the one hand, and easier on the other. The injector does not have chambers with a float for needles, etc., it is a completely different system that supplies the air-fuel mixture electronically. Injection into the cylinders takes place using special devices - "injectors", hence the name. The main causes of black exhaust: 1) Often the injector itself is the cause, it simply clogs up and cannot supply fuel normally. There is an accumulation of pressure, and then a "strong" injection, often with excess. The engine operation will not be stable, then low revs, then high - in simple words will "float". In such a situation, you need to clean the injectors, there are many different ways, from removing the fuel rail, to special means which are added to gasoline - it's up to you, but after such manipulation, you can often get rid of the black smoke from the exhaust pipe. The efficiency is restored. Cleaning should be done at least once every 60 - 70,000 kilometers. 2) Since the system is automated, it monitors various cycles using sensors. So, if the sensor is not working properly, it will either not let the car start at all, or it will supply too much fuel. Here you yourself are unlikely to be able to diagnose a breakdown, you need to go to the service station. 3) Fuel pump. Usually, injectors have it in the tank, there have been cases when it supplied increased pressure. Which also led to overflow in the injection chambers. Again, it needs to be replaced. Diesel engine In general, the diesel engine holds the record for black exhaust emissions. The thing is that it has a slightly different fuel ignition system (from pressure), and it runs on a diesel engine (diesel fuel), and even in its normal state it gives a little blackish-blue exhaust. Remember at least our "KAMAZ". Recently, however, they have been struggling with such exhaust, because it is very toxic and poisonous, it contains a lot of lead. Therefore, now almost all diesel engines are equipped with a "PARTICULATE FILTER", for the sake of EURO 5 standards, it cleans the exhaust and prevents harmful substances from entering the air. Causes of black smoke: 1) This is a common failure particulate filter, it just needs to be replaced. However, the intensity of the smoke will not be as high. 2) The high pressure pump has broken. Excessive overflow in progress. You just need to change. 3) Incorrect ignition timing. Need to adjust. What can such smoke from the exhaust pipe lead to? If you do not take measures in time, you can run into decent malfunctions. For example, in injection vehicles, the catalyst quickly dies, but it is not very cheap to replace it (many even simply remove it). Also, if there is a large overflow through the "injector", this can almost lead to a water hammer, because sometimes the fuel is supplied in liquid form, and not in an air mixture. It is very dangerous, difficult breakdown. On a diesel engine with a large volume of fuel, it can break the block, because the pressure there is even greater than that of gasoline engines. As you can see, black smoke itself does not carry complex malfunctions, but if you do not react to it in time, it can result in big problems.

One of the most common signs of a car's malfunctioning certain breakdowns and smoke problems. The diagnosis of this problem is so wide that it takes into account the color, quantity, frequency of occurrence and other factors that can signal the appearance of problems. But not everyone knows what is the difference between constant white smoke and periodically appearing smoke of the same color. Or, what is affected by black smoke from the exhaust pipe. Blueish exhaust smoke also has its own unique causes. All these manifestations require detailed analysis and analysis. We present to your attention the first part devoted to the appearance of black smoke.

Before understanding the individual "pathological" conditions of exhaust smoke, you should understand what exhaust is in general, what it is for, and how it looks normal. As the name implies, the fumes coming from the machine through the muffler are a by-product of the processing that appears during the kinetic motion of the engine and its adjacent ones. In simple terms, this is a combination of steam from water, nitrogen and carbon dioxide that appears when the engine is running.

Normally, with serviceable systems in the engine compartment, as well as acceptable quality of consumables, this smoke is practically colorless, has a smell characteristic of exhaust, and a certain level of density. But as mentioned a little earlier, sometimes we witness the appearance of unusual smoke of a different color (most often white, blue and black smoke from the exhaust pipe), often simultaneously with the deterioration of the vehicle's resource (or without it). What is the reason for these diagnostic manifestations, we will try to understand in more detail by analyzing each of these types of fumes.

Black smoke from the exhaust pipe and its causes

This is probably the most "popular" question of all drivers with diesel, carburetor or injection engines... Owners of old, second-hand brands have encountered a similar manifestation many times. domestic production... But what is the reason for this uncharacteristic pungent evaporation, and why is black smoke coming from the exhaust pipe?

First, you need to calm down and ease the panic - the appearance of black smoke, as a rule, does not indicate serious breakdowns in engine compartment... However, counting on the problem not to cause damage later is a losing strategy. In fact, this is not a problem at all, but just one of the symptoms, the convenience of which is that it can be noticed without long delving into the components of the engine.

What does the appearance of black smoke from the exhaust pipe signal? Depending on the type of engine and the condition of the car, there may be several reasons, however, among all of them, the main and most probable is the oversaturation of the used fuel-air mixture. In practice, it looks like this: due to the oversaturated mixture, it cannot effectively burn out in the engine cylinders, due to which insufficiently processed exhaust, getting into the catalyst (and later into the open air), together with excess fuel, turns the smoke black.

The appearance of such smoke is not affected by the type of fuel, be it gasoline or diesel fuel, since the cause of the problem indicates a breakdown in the fuel supply system. In addition, sometimes black smoke appears from the exhaust pipe at start-up, and later the smoke corresponds to its normal appearance and density. This is due to the fact that the fuel is not ignited in the chamber, and due to its dampness, it enters the muffler in an unprocessed form (as a rule, such an engine is strongly "troit" at the start).

Elimination methods, as well as types of breakdowns

A reasonable question arises "How to eliminate black smoke from the exhaust pipe?" For each type of engine, the answer will be different. The malfunction, as is usually the case, is hidden in the cause of its occurrence. Have carburetor type ignition the cause of black smoke is overflow in the float chamber, which means that for repair it will be necessary to clean the disassembled carburetor, change the nozzles, and set the indicator of the measured gasoline inside the combustion chamber.

Due to the absence of a float in a system with injector, their causes and elimination will be radically different. Here, electronics, or rather "injectors", are responsible for the supply. It is they who tend to clog and disrupt the fuel supply. You can clean them by hand or using cleaning additives in gasoline. Sometimes the black smoke from the exhaust pipe is "to blame" for the malfunctioning of the fuel pump (increased pressure is supplied). Unfortunately, the only way to eliminate this type of breakdown is to fully replace it.

What is the reason for the breakdown in diesel engines , because they are the biggest culprits and leaders in the emission of black smoke into the air. To begin with, it should be said that the products of diesel fuel burnout will a priori produce a darker color than gasoline counterparts. But to eliminate this toxic threat and reduce the amount of lead in smoke, diesel vehicles are fitted with a "particulate filter". Due to its malfunction, the smoke can become darker, thicker, and contain amounts of toxins that are dangerous for the environment. Replacing the particulate filter will usually return these readings to normal.

Consequences of faults

As in any other business, letting things go by themselves can bring a lot of problems in the future. Very often, smoke noticed in time becomes the first and last warning before a serious breakdown. For example, in gasoline cars such a malfunction leads to a complete replacement of the catalyst. We wrote about in our material not so long ago. However, in any case, replacing such a device will not cost cheap.

It is even more fraught with ignoring such a problem in diesel cars... Since the pressure in a chamber using this type of fuel is even higher than that of gasoline ones, oversaturation of the volume can cause a rupture of the feed unit, the repair of which will cost a considerable amount.

What do you think? This is a question about the color of the smoke from the tailpipe. On numerous forums on the Internet every day great amount people are looking for reasons that may have led to the formation of strong smoke in the exhaust system. proposes detailed instructions, which will help you to identify the reasons for the formation of excessive smoke by the color of the exhaust.

See also: Most expensive car breakdowns

Usually we do not think about how everything works in the car, and do not go into details about the device. vehicle... But this happens exactly until the moment when our car starts to show, which start to scare us. After that, many of us, instead of contacting a car service, spend sleepless nights looking for answers on the Internet to questions that arise about the car.

The most common is the appearance of excess smoke from exhaust system.

Unfortunately, the information on the web is contradictory and can confuse anyone. We offer you detailed instructions, infographics, which will help you to find out the possible cause of a car malfunction by the color of the exhaust.

For those who don't know. On all modern cars in which the engines are warmed up to working temperature (90 degrees), and all systems are working properly, the smoke from the exhaust system should not be visible.

Important to know: Five types of fluids to check in a car

There are three types of smoke that can come out of the chimney. It is white, gray (white with a bluish tinge) and black.

Here are the main reasons why smoke of a certain color is formed:

White smoke is formed by the evaporation of water, which mixes with the exhaust gases formed during the combustion cycle in the engine

Blue smoke * (blue, light blue) is formed from the mixing of fuel residues that enter the exhaust system, mixing with the gases coming from the combustion chamber

Black smoke indicates that there is an excess of fuel in the combustion chamber during the operation cycle.

* Attention! Unfortunately, many owners confuse gray smoke with other shades of colors. In order for you to know exactly what blue-gray smoke looks like (blue, blue, gray-blue, etc.) below, we give as a sample all possible shades of gray smoke. (Yandex color palette)

Below you can see three block diagrams (infographics) that will help you find out separately for each exhaust color. possible reasons smoke formation. Our instructions will allow you to save a lot of money, which you will spend for diagnostics in a technical center. After making simple diagnostics with the help of our circuit modules, you can find out how serious the problem with the appearance of smoke is. Of course, keep in mind that our three diagrams are not exhaustive and do not cover all possible options malfunctions. But, nevertheless, our instructions will help to give an idea of \u200b\u200bthe scale of the problem of smoke from the exhaust system of the vehicle. Also, our infographic will tell you exactly where to look for the malfunction that led to excessive visible smoke from the exhaust pipe.