Diesel: black smoke from the exhaust pipe. What is the reason and how to eliminate it?

Diesel engines differ significantly from gasoline engines. But the problems with them are almost the same as with petrol units. Having read motoring forums, you can see a lot of all those topics where one or another of the problems are discussed. But especially often you can see topics where motorists complain about the fact that diesel engines periodically get black smoke from the exhaust. Let's see what the problem is, why this phenomenon occurs. Also we'll see how this problem can be solved.

We put the diagnosis on the colors of the exhaust

Diesel engines, like, however, and gasoline, can have exhausts of different colors. More often it is white, gray, gray and black smoke. Let's start with white. Often white is called the smoke of a bluish hue. This happens when the turbine breaks down, and the lubricant gets straight into the intake path. In such a situation, smoke from the pipe is blown in a blue color. But an inexperienced motorist will completely take him for white smoke. And if he also sniffed, then it is immediately clear and understandable, what is the reason for his appearance.

Many in the kitchen at least once, but burned vegetable or butter in a frying pan. The smell is about the same. Even such a smoke can be confused with the steam, which is more often observed in the winter months from exhaust not only diesel cars. All the fault is the water that appears as a result of combustion.

Later, after warming up the engine, the steam will not be noticeable, although it will not go anywhere. This can be easily verified. You just need to put your palms to the exhaust. The palm will be slightly damp. This steam delivers significant inconvenience when tuning the engine, and especially in winter. For high-quality adjustment you have to warm the unit for a long time. And in a frost, the tuning may not be possible at all.

White smoke is a signal of a serious problem

If the smoke from your diesel is not steam, then it's exactly the coolant that gets into the combustion chambers. Usually the cylinder, which was filled with cooling mixtures, does not have the capacity to work idly. Therefore, the motor can touch.

How does the coolant penetrate into the cylinders?

The coolant gets into the cylinders because of an unsatisfactory condition of the gaskets of the intake manifold. Also, the cause may be a burnt gasket cylinder head, and for diesel engines, this can most often be a cracked block head. In the cracks of the cylinder head, the tank, often full of liquid, also completely leaves the tube.

Repairs

If you find a crack in the cylinder head, then you can only recommend to replace the head. However, prices ... Therefore, many motorists do not disdain contractual details. These are used spare parts from Europe.
Cracked cylinder head can be repaired, but we will not recommend this technology, because during such repairs a hole is drilled that will fall on the crack, and then a copper rod will be pressed into the hole. There will be no gas breakthrough, but one of the cooling valves will be blocked by half. Such a head will have a significantly reduced resource.

Blue Smoke

Those who have smoke from the exhaust pipe, the diesel made me worried at the sight of blue smoke.

Blue, and on some engines it can be a siz, on the working motor is often caused by late injection. About this problem has been said more than once, many motorists managed to discuss this topic along and across.

Experts say that the blue smoke - it's not scary. In most cases, the problem of late injection is associated with the natural process of wear and tear, of course, if the pump was not touched.

Causes of blue smoke

The high-pressure fuel pump under our conditions works as follows. The set of parts in this node constantly rotates, works, rubs. And the lubrication is provided by the pumped diesel. While diesel is moderately greasy, the pump in this mode can work very long. But when the cold comes, diesel fuel tanks are filled with winter diesel fuel. Everything in it is excellent, but there are no lubricating fractions at all. Well, or almost absent. All its fat content, along with various paraffins, was removed at the refinery. So, when winter comes, most of the fuel pump on diesel engines operate without lubrication and are subject to severe wear and tear. Because of this quite natural, but too fast and increased wear, the injection advancement decreases. Diesel fuel stops to heat up, and the cylinder ceases to work in a regular mode. The engine twitches and shakes. Fuel that does not have time to burn, as a result turns into blue smoke. On some engines there is black smoke from the exhaust. If the engine is heated, then it will stop smoking, or at least reduce the amount of exhaust. In this case, the fuel has time to warm up and ignite.

If the power unit has low 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, that cylinder, where the compression is smaller, will not work.

Such a picture often happens in parking lots. Cars are trying to start, and the site is filled with blue smoke. But sometimes diesel releases black smoke from the exhaust pipe. After warming up the smoke will disappear. After all, the temperature in the engine increases, and the temperature rise even in worn out cylinders will suffice for ignition.

A case from one's life

Mechanics on this topic tell a story. On the unit, the cylinder head gasket was replaced. After the engine was assembled, they found a strong shaking at idle. After a couple of kilometers, these vibrations ceased, and after a couple of minutes of work again on the single shaking reappeared.

Mechanics analyzed this situation and found out that the new gasket is a little thicker. Until the diesel engine was warmed up to operating temperature, it did not work exactly.
So, the main reason for blue smoke is late fuel injection and low compression characteristics. Many modern engines have a device that performs the injection a little earlier. Machines work harder, but fuel in the cylinders heats up and burns without smoke, that is completely. Next, the unit heats up, the coolant heats the actuators, and they return the injection advancing piston to its rightful place. The motor works softer and more pleasantly.

How to remove blue smoke

If the engine shakes and releases diesel black smoke from the exhaust pipe, well, or blue, then you can safely turn the injection pump. But first you need to see if there is enough fuel. If the pump does not have enough fuel, then the pressure decreases, and this allows the spring to shift the timer to a late injection. This will result in shaking.

Black smoke

Such smoke can be observed if the fuel burns up to the end. It happens, if too much fuel is supplied or an incorrect combustible mixture is supplied. If too little air is supplied to the motor, the effect will be the same as if the fuel was supplied excessively.

Why is black smoke coming from the diesel exhaust pipe?

A larger volume of fuel supply is usually a signal of either improper adjustment of the injection 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. By means of it, the volume of fuel supplied is adjusted. This screw can only roughly adjust the volume. If this screw is screwed, then the volumes increase. And there, where growth of volumes, in the same place and growth of single turns. But the speed can be significantly reduced. Then you can increase the power. But to drive diesel black smoke from the exhaust pipe will continue and further. If the adjusting screw on the injection pump is screwed even more than it should be, the unit will almost cease to reduce the speed.

Depreciation of injectors

Here it can be assumed that the needle of the plunger pair does not fit tightly into its seat. And the level of pressure that this needle should lift is reduced. This leads to the fact that excess fuel enters the combustion chambers. It is superfluous, if only because its delivery is carried out not in a sprayed form, but in droplets. To heat up and ignite, these drops need a lot of time. From here and black smoke from the exhaust pipe, and increased fuel consumption (diesel).

The most sad

One of the most unfortunate breakdowns that awaits the owners of diesel engines is the inevitable wear of the fuel pump. As already mentioned, the inside of the pump is operated without lubrication. If in the summer the diesel is still lubricating something, then in the winter - no. And domestic fuel is generally of poor quality. So the internal parts of the pump wear out.

When the pedal is pressed very sharply, for example, in order to move quickly, the fuel injection pump lever is shifted to increase fuel delivery volumes. This lever will rest on the support. And the position of this very support is already adjusted by the regulator. Therefore, too much to increase the volume will not work. So, by pressing the pedal, the driver only wants to give a larger volume of fuel. And it's not at all a fact that this will lead to an increase in turnover. It depends directly on how much the regulator is worn out. If it is in normal condition, then the car will move with gray smoke. If the wear is large, then the black smoke from the exhaust pipe will spit the black smoke from the big club.

On the 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. Still, there is a decrease in power.

This can lead to a clogged air filter. This is by no means a rare case, and this happens occasionally with everyone. It's not 10 and not 100 times tested on the bitter experience that it will take only 15 minutes in traffic in front of KamAZ, which has black smoke from the exhaust pipe. The diesel burns, and the new filter of the one who stands behind can now be thrown to the dump. But it happens, if the KamAZ has incorrectly adjusted the fuel system, although from whom it is regulated.

Also, the lack of air can be observed due to incorrect operation of the EGR and throttle, incorrect gaps in the timing valves. Also among the causes may be incorrectly placed gas distribution tags, turbine malfunctions.

When the car is equipped with a turbine, and you observe black smoke from the diesel-turbo exhaust pipe, it is worth checking the boost. Most likely, it is in it. It is also worth looking for cracks in fuel or air system connections.
One of the car owners was pouring fuel into the car. After traveling a little, at a high speed while driving uphill, the car puffed with black smoke. But a little popihtev, the smoke disappeared and since then no longer appeared. At the same time he checked all the above reasons. He believes that the additive helped. The car did not smoke anymore. So, perhaps, the cause of smoke in this case can be simply soot from the fuel system, especially if the diesel is completed with a neutralizer. Sometimes the filter needs to be cleaned from time to time.

Another reason for black smoke from the diesel exhaust pipe

One of the owners of a diesel car suddenly started to smoke the engine. At autopsy nothing intelligible could not be found. But after reading all sorts of forums, communicating with other diesel owners, it turned out that the problem is in the ignition.

After re-opening, an adjustment valve was found on the ignition unit. He was advised to hit the adjusting bolt. After that the car stopped smoking. It turned out that this is a solenoid valve ignition angle.

When the ignition is turned on, the faulty sensor is cracking. What if there was a black smoke from the exhaust pipe (diesel)? At what ignition it would appear, it is necessary to remove the sensor. If the engine stopped smoking, and the machine is working smoothly, then it's time to change this element.

Black smoke and cold start

The study of the forums showed that many complain about the smoke when the diesel engine starts coldly. Some people say that this injection pump, but more experienced car enthusiasts say that this is not so.

It is believed that such a phenomenon is quite normal. Usually it is short-lived. This can be explained by the fact that when the engine is cold, an over-enriched mixture is fed into the cylinders. Hence the black smoke from the exhaust pipe. Diesel "on the cold" often does this. So do not panic about this.

The situation with Kia Sorento

Let us give a concrete example. One of the owners of this car, when pressing the accelerator pedal, is a thick, black smoke. In motion, the machine is very reluctant to gain momentum.

Scanning for possible errors in the electronic system was made, but there are no errors. Analysis of the parameters of the work also did not give the desired result. At first glance, there is simply no defect. The balance of the nozzles is in the normal state, there are no serious deviations, the turbine generates a normal level of pressure, but the black smoke from the exhaust pipe diesel "Kia Sorento" still gave out. When measuring the readings, they thought about the USR. This is a valve that regulates the exhaust gases. After inspecting it, they discovered serious soot deposits behind the throttle. After removal of the branch pipe of exhaust gases, soot and oil in the intake tract were also detected. As a result, everything was removed and cleaned. But with a more detailed inspection of the valve itself, it was found that its seat was damaged. As a result, the valve was replaced.

As a result, there is no smoke, but the car is traveling much better.

Coommon Rail System

Here, too, are problems of the same kind. Many complain about black smoke from the exhaust pipe - the diesel "Komon Rail" with a cold start successfully provides this result. Motorists say that this may be due to poor-quality fuel or with problematic injectors. So, fuel is not sprayed, but poured. Therefore, black soot. And when the engine warms up, the injector pumps the fuel in normal mode.

As a conclusion

We found out the frequent and popular causes of smoke. Also, when running "on a cold" a little black smoke for a diesel engine - this is the norm. Most problems can be easily corrected on their own. However, the problem is that all symptoms are suitable for black smoke, and it is unclear what to treat. Therefore, if you have black smoke from the exhaust pipe, the diesel engine tends and jerks, it is better not to test fate. In this case, you should give the car for diagnosis to experienced specialists.

So, we found out why black smoke from the exhaust pipe is pouring. Diesel - a difficult thing, so these cars need constant care.