Significantly different from gasoline. But the problems with them are almost the same as with gasoline units. After reading automotive forums, you can see a lot of all sorts of topics where certain problems are discussed. But especially often you can see topics where motorists complain that black smoke from the exhaust periodically comes on diesel engines. Let's see what the problem is, why this phenomenon occurs. Let's also see how you can solve this problem.
Diagnose by exhaust colors
Diesel engines, like gasoline engines, can have different exhaust colors. More often it is white, gray, gray and black smoke.
Let's start with white. White is often referred to as bluish smoke. This happens when the turbine breaks down and grease goes straight into the intake tract. In such a situation, blue smoke comes out of the chimney. But an inexperienced car enthusiast will quite take it for white smoke. And if you also smell it, then it is immediately clear and understandable what the reason for its appearance is.
Many in the kitchen at least once, but burned vegetable or butter in a frying pan. The smell is about the same. Such smoke can also be confused with steam, which is more often observed in the winter months from the exhaust of not only diesel cars. It's all the fault of the water that appears as a result of combustion.
Later, after the engine has warmed up, the steam will not be noticeable, although this can be easily checked. You just need to put your palms to the exhaust. The palm will be slightly damp. This steam causes significant inconvenience when tuning the engine, especially in winter. For high-quality adjustment, you have to warm up the unit for a long time. And in cold weather, the setting may not work at all.
White smoke is a signal of a serious problem
If the smoke from your diesel is not steam, then it is definitely coolant that enters the combustion chambers. Typically, a cylinder that has been filled with refrigerant mixtures does not have the ability to run dry. Therefore, the motor can triple.
How does coolant enter the cylinders?
Coolant enters the cylinders due to the poor condition of the intake manifold gaskets. Also, the reason may be a burnt cylinder head gasket, and in diesel engines, most often it can be a cracked block head. In the crack in the cylinder head, the reservoir, often full of fluid, also completely goes into the pipe.
Repairs
If you find a crack in the cylinder head, then here you can only recommend replacing the head. However, prices ... Therefore, many motorists do not hesitate to contract details. These are used spare parts from Europe.
Cracked cylinder heads can be repaired, but we will not recommend this technology, because during such repairs, a hole is drilled that will hit the crack, and then a copper rod is pressed into the hole. There will be no gas breakthrough, but one of the cooling valves will be half-blocked. Such a head will have a significantly reduced resource.
Blue smoke
Those who were getting smoke from the diesel made them worry at the sight of blue smoke.
Blue, and on some engines it can be gray, on a working engine is often caused by late injection. About this problem has been said more than once, many motorists managed to discuss this topic up and down.
Experts say that blue smoke is not scary. In most cases, the problem of late injection is associated with the natural wear process of the injection pump, of course, if the pump has not been touched by anyone.
Causes of blue smoke
The fuel pump in our conditions works as follows. The set of parts in this unit is constantly rotating, working, rubbing. And the lubrication is provided by the pumped-over diesel engine. While the diesel is moderately fat, the pump can work in this mode for a very long time. But when cold weather sets in, winter diesel fuel is poured into diesel fuel tanks. Everything in it is excellent, but there are no lubricating fractions at all. Well, or almost none. All of its fat content, along with various paraffins, was removed at the refinery.
So, when winter comes, most diesel fuel injection pumps run without lubrication and are subject to severe wear. Due to this completely natural, but already too fast and increased wear, the injection lead is reduced. Diesel fuel stops heating and the cylinder stops working normally. The engine jerks, shakes. Fuel that does not have time to burn, as a result, turns into blue smoke. Some engines have black exhaust smoke. If the engine is warmed up, then it will stop smoking, or at least the amount of exhaust will decrease. In this case, the fuel has time to warm up and ignite.
If the power unit has poor compression characteristics, then the temperature in the combustion chambers is less than necessary. And the fuel will not ignite. If the unit is equipped with a pair of cylinders with good compression, the cylinder with the least compression will not work.
This picture often happens in parking lots. The cars are trying to start, and the site is filled with blue smoke. But sometimes the diesel blows out black smoke from the tailpipe. After warming up, the fumes will disappear. After all, the temperature in the engine rises, and the temperature rise even in worn-out cylinders will be enough to ignite.
A case from one's life
The mechanics tell a story about this. The cylinder head gasket was replaced on the unit. After the motor was assembled, they found a strong shaking at idle. After a couple of kilometers, these vibrations stopped, and after a couple of minutes of work, the shaking appeared again at idle.
The mechanics analyzed this situation and found that the new gasket was slightly thicker. Until the diesel engine warmed up to operating temperature, it did not work exactly.
So, the main reason for blue fumes is late fuel injection and poor compression characteristics. Many modern engines have a device that injects a little earlier. Cars work harder, but the fuel in the cylinders heats up and burns without fumes, that is, at all. Further, the unit heats up, the coolant heats up the actuators, and they return the injection advance piston to its rightful place. The motor runs smoother and more pleasant.
How to remove blue smoke
If the engine shakes and emits black smoke from the exhaust pipe, or blue smoke, then you can safely turn the injection pump. But first you need to see if you have enough fuel. If the pump does not have enough fuel, then the pressure decreases, and this allows the spring to move the timer for the late injection. This will cause shaking.
Black smoke
Such smoke can be observed if the fuel is not completely burned. This happens if too much fuel is supplied or the wrong combustible mixture is supplied. If too little air is supplied to the motor, it will have the same effect as if too much fuel was supplied.
Why is there black smoke coming from the diesel exhaust pipe?
A large volume of supplied fuel is usually a signal of either incorrect adjustment of the high pressure pump, or wear of the injectors, or wear of the speed regulator in the pump.
Any fuel pump is equipped with a special adjusting screw. With the help of it, the volume of the supplied fuel is adjusted. This screw can only roughly adjust the volume. If this screw is tightened, then the volumes increase. And where there is an increase in volumes, there is also an increase in idle speed. But the turnover can be significantly reduced. Then you can increase the power. But the diesel will continue to drive black smoke from the exhaust pipe further. If the adjusting screw on the injection pump is screwed in even more than it should be, the unit will practically stop reducing the speed.
Nozzle wear
Here it can be assumed that the needle does not fit tightly enough into its seat. And the level of pressure that this needle should raise is reduced. This leads to the fact that excess fuel enters the combustion chambers. It is superfluous, if only because it is supplied not in spray form, but in drops. These drops take a long time to heat up and ignite. Hence the black smoke from the exhaust pipe, and the increased consumption (diesel) of fuel.
The saddest
One of the saddest breakdowns that lie in wait for diesel owners is the inevitable wear of the fuel pump. As already mentioned, the giblets inside the pump work without lubrication. If the diesel still lubricates something in the summer, then in the winter it does not. And domestic fuel is generally of poor quality. So the insides of the pump wear out.
When the gas pedal is pressed very sharply, for example, in order to quickly get under way, the injection pump lever is transferred to an increase in the volume of fuel supply. This arm will rest on the support. And the position of this very support has already been adjusted by the regulator. Therefore, it will not work to increase the volume too sharply. So, pressing the pedal, the driver only wants to give more fuel. And it's not at all a fact that this will lead to an increase in revs. It depends directly on how worn out the governor. If it is in good condition, then the car will move off with gray smoke. If the wear is big, then the diesel will spit black smoke from the exhaust pipe in a big club.
Lack of air
Also, dark gases from the pipe can sometimes be caused by a lack of air. But in this case, the exhaust will not be black, but rather gray or dark gray. At the same time, a decrease in power is observed.
A clogged air filter can cause this. This is by no means a rare case, and it happens to everyone from time to time. It has not been proven 10 or 100 times by bitter experience that only 15 minutes will be enough in a traffic jam in front of KamAZ, which has black smoke from the exhaust pipe. The diesel is on fire, and the new filter of the one in the back can now be thrown into a landfill. But this happens if KamAZ is incorrectly adjusted, although someone has it adjusted.
Also, a lack of air can be observed due to incorrect operation of the EGR and throttle valve, incorrect clearances in the timing valves. Also, among the reasons may be incorrectly set timing marks, turbine malfunctions.
When the car is equipped with a turbine and you see black smoke from the diesel-turbo exhaust pipe, it is worth checking the boost. Most likely, it is in him. It is also worth looking for cracks in the pipes of the fuel or air system.
One of the car owners poured cleaning for the fuel system into the car. Having traveled a little, at high revs when driving uphill, the car puffed with black smoke. But after panting a little, the smoke disappeared and has not appeared since then. At the same time, he checked all the above reasons. He thinks the additive helped. The car did not smoke anymore. So, perhaps, the cause of the smoke in this case may simply be soot from the fuel system, especially if the diesel is equipped with a neutralizer. Sometimes the filter needs to be cleaned from time to time.
Another reason for black smoke from a diesel exhaust pipe
One of the owners of a diesel car suddenly started to smoke. During the autopsy, nothing intelligible was found. But after reading all kinds of forums, communicating with other diesel owners, it turned out that the problem was in the ignition.
After reopening, a control valve was found on the ignition unit. He was advised to hit the adjusting bolt. After that, the car stopped smoking. It turned out to be the ignition angle.
When the ignition is turned on, a serviceable sensor crackles. What to do if black smoke appears from the exhaust pipe (diesel)? With whatever ignition it appears, the sensor should be removed. If the motor has stopped smoking, and the machine is running smoothly, then it's time to change this element.
Black smoke and cold start
A study of the forums showed that many complain about smoke from a diesel engine. Some people say that this is a high-pressure fuel pump, but more experienced motorists say that this is not the case.
It is believed that this phenomenon is quite normal. It is usually short-lived. This can be explained by the fact that a re-enriched mixture is fed into the cylinders during a cold start. Hence the black smoke from the tailpipe. Diesel "cold" often does this. Therefore, do not panic about this.
The situation with the "Kia Sorento"
Let's give a concrete example. One of the owners of this car has thick, black smoke when pressing the accelerator pedal. In motion, the car is very reluctant to gain momentum.
A scan was performed for possible errors in the electronic system, however no errors were found. The analysis of the work parameters also did not give the desired result. At first glance, there is simply no defect. The balance of the injectors is in a normal state, no serious deviations were noticed, the turbine produces a normal pressure level, but at the same time the black smoke from the exhaust pipe of the Kia Sorento diesel engine was still giving out. When measuring the readings, we thought about the USR. This is the valve that regulates the exhaust gases.
After examining it, they found serious soot deposits behind the throttle valve. After removing the exhaust pipe, soot and oil were also found in the intake tract. In the end, everything was filmed and cleaned up. But a closer inspection of the valve itself revealed damage to its seat. As a result, the valve was replaced.
As a result, there is no smoke, and the car goes much better.
Coommon Rail System
Problems of the same kind are also visible here. Many people complain about black smoke from the tailpipe - the Comon Rail diesel engine successfully achieves this result when cold starts. Car enthusiasts say that this may be due to poor quality fuel or problem injectors. So, the fuel is not sprayed, but poured. Therefore, black soot. And when the engine warms up, the injectors pump fuel normally.
As a conclusion
We have found out the common and popular causes of fumes. Also, when starting "cold" a little black smoke for a diesel engine is the norm. Most problems can be easily corrected on your own. However, the problem is that all symptoms are suitable under black smoke, and it is not clear what to treat. Therefore, if you have black smoke coming from the exhaust pipe, the diesel engine troit and twitches, it is better not to tempt fate. In this case, you should give the car for diagnostics to experienced specialists.
So, we found out why black smoke is pouring from the exhaust pipe. Diesel is a complicated thing, so such cars need constant care.
When accelerating or starting a diesel engine, black smoke comes out of the exhaust pipe. It indicates a problem with the engine or fuel system. Let's deal with the source of black exhaust + video how to fix it.
When inspecting a smoking engine, first check that the smoke does not stop after the engine reaches operating temperature.
Main reasons
- Clogged air filter or air intake path ()
- Low compression ()
- Faulty boost pressure control system
- Clogged exhaust system
- Incorrectly set valve timing or start of injection
- Glow plug leaking (if equipped)
- Fuel injection pressure too low due to injector actuation or incorrect injector type installed
- Defective high pressure fuel pump (high pressure fuel pump) or wrong type fuel pump
- Motor overload (during acceleration)
Some of the points listed in the description of the causes of malfunctions can be discarded if you carefully examine the very soot from the exhaust (soot particles, drops, oil films, smell).
Black smoke from the exhaust pipe of a diesel engine is formed during incomplete combustion of fuel, when unburned hydrocarbons are converted to soot. Incomplete combustion means that there is either insufficient oxygen (i.e. air) in the combustion chamber or excess fuel. The obvious cause of a lack of air is a clogged engine filter..
Read about the causes of white and black smoke in.
The reason for the poor filling of the cylinders with air may also be improperly adjusted valve clearances or wear of the camshaft cams. Fuel may not completely burn out if the injection start is incorrectly set (late injection) or if the injector is faulty, which does not provide good fuel atomization.
Causes of soot there may be injector leaks (opening pressure too low), low cetane number of fuel, or excessive ingress of coolant into the combustion chamber.
Video - how to eliminate black smoke
To more accurately determine the cause, check the air intake device or the exhaust system. Also check the boost pressure (on turbocharged diesels), valve adjustment, cylinder compression, condition of the cooling system and oil level, and traces of gas escaping into the crankcase.
Diesel often smokes black smoke as a result of incomplete fuel combustion. The color of the exhaust is caused by hydrocarbons that are not burnt in the cylinder. These elements then turn into soot. The combustion efficiency of the mixture depends on the exact ratio of oxygen to fuel. Lack of oxygen or an excess of diesel fuel equally lead to black diesel exhaust.
The black smoke from a diesel engine is clearly visible during the day, as it contains an abundant amount of soot particles. The smoke is dirty and "heavy". It is the soot that is a direct indication that the diesel fuel in the cylinder does not burn completely. Diesel in this case smokes with thick black smoke, increased consumption of diesel fuel is noted. There are problems with starting the engine "cold",. The operation of the unit is extremely unstable in all modes, the toxicity of exhaust gases increases greatly, power is lost due to large deviations in the composition of the working fuel-air mixture from the optimal parameters.
Read in this article
Diesel exhaust black: the main reasons
One of the most harmless causes of black smoke is the low quality of diesel fuel (cetane number of fuel) c. The color of the exhaust is gradually normalized after an immediate transition to the best diesel fuel.
Diesel on poor fuel usually smokes gray-black exhaust. Also, the reason for the appearance of a small amount of soot in the exhaust is a clogged exhaust system of the engine. In other cases, the presence of black smoke from a diesel exhaust pipe indicates that:
Fuel equipment
Diesel also has black exhaust smoke as a result of fuel injection pump malfunctions, leaking diesel injectors, or too much advance of the injection angle. With a large advance (early fuel supply), strong detonation, increased noise when the engine is operating in different modes may appear. In the list of fuel equipment breakdowns, wear of nozzles and a violation of the shape of the spray pattern, failure of the speed regulator in the high-pressure fuel pump are noted. Prolonged driving on low-quality fuel quickly puts the injection pump out of action, since low-grade diesel fuel does not provide proper lubrication to the pump.
Turbocharger
Diesel black exhaust can also appear as a result of problems with a diesel engine that does not develop the necessary boost for efficient combustion. Lack of tightness in the intake tract often results in black smoke coming from the exhaust pipe of a diesel engine. In this case, such smoke can be seen at the moment of gas re-gas. On a turbodiesel, the fuel supply during re-gasification increases, but the boost pressure occurs with a delay as a result of the inertial rotation of the turbine. For this reason, there is a lack of air in the cylinder for full combustion of the fuel-air mixture, as a result of which the diesel engine emits a lot.
Prolonged driving with an early injection angle or faulty diesel injectors can lead to burnout of the prechambers or destruction of bridges. Burning and destruction of pistons is also likely.
Soot formation and effects
When black smoke from diesel exhaust appears as a result of malfunctions of the high-pressure fuel pump, diesel injectors, as well as in the absence of an optimal injection advance angle, increased soot formation occurs. The diesel particulate filter suffers from its excessive amount. Soot also seeps into the engine oil and quickly contaminates the engine. There is a violation of heat exchange, the piston rings quickly coke, filters are clogged.
Blockage of the oil channels leads to a decrease in pressure in and increased wear of engine parts. A disturbed thermal regime can cause burnout of both pistons (CPG) and valves (). Excess unburned fuel through such burnouts gets into the engine oil. The fuel in the oil immediately reduces its viscosity, the lubricant becomes ineffective, and the antiwear properties of the additives in the engine oil are lost.
The problem is diagnosed by analyzing the condition of the engine oil. It is enough to remove the dipstick and look at its viscosity. If the oil in a diesel engine is very liquid and even in frost drips abundantly from the dipstick, and also has a persistent smell of diesel fuel, then the malfunction must be eliminated immediately. An increase in the oil level also directly indicates that fuel has entered the crankcase.
Parts of the cylinder-piston group get hit. The cylinder walls are the first to suffer, as the diesel oil washes out the oil, as a result of which seizures appear on the cylinder mirror. The wear of the rest of the engine parts is also greatly increased. It is problematic to operate a diesel engine with the indicated malfunction, and further driving will quickly disable the internal combustion engine completely, and overhaul of the diesel engine will be required.
Read also
Self-check of a turbocharger of a diesel engine. Checking the supercharger without removing. The presence of oil in the turbine housing, shaft play, impeller.
