Until recently, diesel engines were the preserve of trucks, heavy SUVs and commercial vehicles, but very recently, small turbo engines installed on compact cars began to conquer old Europe cars. This is true; due to the higher efficiency of a diesel engine, you can extract more torque from a smaller volume and still save on fuel and please environmentalists.

Diesel engines are increasingly gaining market share, however, despite all the advantages, consumers treat diesel with great distrust, still preferring proven gasoline engines. Why? Let's find out!

1. The first and most obvious disadvantage of a diesel engine lies not in the engine itself, but in the fuel on which it runs. The whole point is that diesel fuel has a very low freezing threshold, and already at -30C it turns into jelly, and Arctic diesel fuel is not brought to every region. The viscous mass is very difficult for the fuel pump to pump through the system, which makes starting the engine in cold weather very difficult. In addition, the plunger pairs in the injection pump (high pressure fuel pump) are lubricated by fuel, and a decrease in fluidity causes dry friction of the moving pairs. This problem on some SUVs has already been routinely solved by heating the fuel lines and fuel filter.

In addition to this, liquid heaters are installed on diesel cars to prevent cold engine starts, and special devices - separators - are installed to remove water and solid particles from the fuel, since bad diesel fuel can ruin the injection pump and injectors, and replacing or repairing these details can greatly undermine the financial well-being of the owner.

If it is actually quite difficult to kill a gasoline engine with bad fuel, then on a diesel engine one refueling with low-quality fuel will be enough to render the fuel equipment unusable. In addition to bad fuel, it is worth considering that in the Russian Federation, even good diesel fuel at network federal gas stations contains a large amount of sulfur and mechanical impurities, which further reduces the life of the fuel system. In order to exclude possible problems regarding fuel, it is recommended to periodically flush fuel tank.

2. Continuing the topic of operational shortcomings, it is worth mentioning the long warm-up before operating temperature, and as a result, car interiors take a long time to warm up, since cold air enters the heater radiator for a long time. On modern diesel cars, this problem was partially solved by installing additional electric heaters of the “Hairdryer” type, when the air is heated by a powerful electric heater, and the already heated air is carried by a fan through air ducts into the car interior.

Additional heater, which is installed under the panel in the air duct

3. On versions of motors with, you should not forget that it has liquid cooling(oiled) and heated exhaust gases to maximum temperatures, after the engine is turned off, the oil supply stops and the turbine begins to cool without cooling, which is why cracks may appear in its housing. To avoid this, turbo timers are installed on cars. These are devices that, after turning off the engine, do not turn it off for some time until the turbocharger cools down.

4. Diesel engines are very sensitive to oil quality. You should choose not only by viscosity, but also by flash point, and it is better not to invent a bicycle, and pour what the manufacturer recommends.

Since in our country diesel fuel has a high concentration of sulfur, which leads to its faster oxidation, due to which the oil loses its lubricating properties, which can cause scuffing on the cylinder walls and increased wear shaft journals and liners. Overhauling a modern diesel engine is not a cheap procedure; moreover, many of them do not have repair dimensions and you have to resort to Russian ingenuity. Such repairs cannot always return the engine to factory specifications and simply extend its life for some time. To avoid all this, it is recommended, regardless of what the dealer and car manufacturer recommends, to change the engine oil at intervals of every 5-7 thousand kilometers.

Otherwise, the diesel engine is not very different from the gasoline engine. At the time of buying diesel car In an attempt to save money, it should be clearly understood that the cost of maintenance and Supplies higher than for a gasoline engine, and in order for everything to go well with the engine, maintenance should be performed twice as often as with gasoline. And the cost of diesel fuel is now close to AI-95 gasoline, so saving a couple of liters of fuel has two ends and in the end you will have to pay much more for the maintenance of the diesel engine and fuel equipment and in case of repairs you will have to pay an additional tidy sum.

The only thing you can really save on is on transport tax, since having comparable dynamic characteristics gasoline and diesel engines, diesel will have less horsepower and more torque, and as Henry Ford said: “ Horsepower sells a car, but torque wins races.”

A diesel engine has its own number of advantages and disadvantages, and if you take a new car with a diesel engine, and do its maintenance yourself, and do everything that prolongs the life of the engine, then operating such a car will bring only positive emotions.

Best regards, Andrey Chervyakov.

Malfunctions can occur in any power unit. Especially if we're talking about about a used car. Moreover, along with minor damage, it is possible that serious problems, permanently disabling the machine. Their timely identification can save the car owner from significant financial losses caused by unforeseen major repairs.

This is what diesel diagnostics is intended for, usually performed simultaneously with periodic vehicle maintenance. Timely elimination measures taken minor faults save you from many future troubles.

Self-diagnosis of a diesel engine. Is it possible to do without a car service?

Detecting various engine problems early stages and their timely elimination is the basis proper care behind the car. However, not every owner of a used vehicle is able to pay for diagnostics in a specialized workshop.

In addition, the closest car service center may be located hundreds of kilometers from the garage. Therefore, the question of whether it is possible self-diagnosis diesel engine, and what is required for this. Let's try to figure it out!

The need for diagnostics

The efficiency and efficiency of repairing diesel units is determined by many factors. Correct diagnosis is considered one of the main conditions.

Very high level reliability of functional units and mechanisms equipping diesel products movement is considered their main advantage. Thanks to this quality, most car enthusiasts prefer such cars, abandoning gasoline power units.

Timely replacement of worn-out diesel engine parts minimizes the likelihood of unexpected failure during operation. It has been verified by experts that there are practically no spontaneous breakdowns in a properly functioning unit.

Any malfunction indicates insufficient attention of the owner, who did not notice the defect in time.

Regarding minor details that are not of particular importance to normal use diesel engines, they can suddenly lose their performance. At the same time, the usual ICE functions practically do not change.

In such cases, diagnosis and repair diesel engines can be carried out in hiking conditions. Malfunctions of minor elements power unit are identified and eliminated right on the road, immediately at the moment of their detection.

Experts have identified several obvious reasons indicating problems with diesel components that require the intervention of a mechanic:

1. increased smoke emission accompanying engine operation;
2. difficulties starting the power plant;
3. manifestation of increased noise effects during operation;
4. Not stable work motor, accompanied by a decrease in power.

The detection of the listed symptoms indicates the need for diagnostic measures. They will help you determine the cause of the problems and take measures to eliminate them.

Modern methods of diagnostic examination

Of course, car service workshops have specialized equipment that significantly simplifies efforts to identify faults in power units. Today, there are three ways to diagnose diesel engines:

• specialist performs visual inspection motor, add-on acoustic examination installations;
• deviations are studied existing parameters from optimal values. To do this, they are measured;
• diagnostics on a specialized computer stand.

The purpose of the first method is to identify obvious faults. An experienced mechanic can notice any abnormalities in diesel engines. The condition of engine parts is assessed based on many factors, such as appearance filters or exhaust sound.

The accuracy of the second method is determined by the quality of the measurements. The operation of an internal combustion engine is characterized by certain parameters, deviation from which indicates a malfunction. For example, by measuring compression and the size of leaks in the cylinders, you can detect problems in the engine.

The third method is considered the most accurate. It involves identifying faults in computer system management. Monitoring sensors and other electronic elements allows software establish the cause of the breakdown.

Diesel acoustic inspection

Studying the sounds of a running engine can give an idea of ​​the wear of some components and spare parts. Certain mechanical noises indicate the condition of the power unit. More information about diesel engine malfunctions detected by acoustic diagnostics:

1. When the engine operating at low speeds is loaded, a muffled knock is heard in the piston group. This is the first symptom of piston wear. To eliminate the malfunction, worn out liners are bored out, and pistons that have become unusable are replaced with new parts;
2. exceeding the norm permissible clearances in the valves is manifested by a characteristic clicking knock. Due to the frequency, such a sound cannot be confused with other noise in the power unit. It is heard less often than other knocks. This is explained by the fact that the frequency of rotation camshaft, the cams of which drive the valves at half the crankshaft speed. A separate article is devoted to adjusting valve clearances in power units of passenger cars;
3. if on idle speed engine, press the gas pedal sharply, sometimes you can hear a dull metallic knock. Its frequency is determined by the number of crankshaft revolutions. This phenomenon indicates the need to replace the main bearings. Grinding also helps eliminate faults. crankshaft;
4. worn out ones manifest themselves with a more distinct knocking sound. connecting rod bearings. Definition faulty element performed by turning off the injectors one by one. The breakdown is repaired in a manner similar to the previous one.

As you can see, by the sounds of running diesel engines, even an ignorant car enthusiast is able to determine the cause of the unit malfunction, and by eliminating it, the subsequent engine restoration can be performed.

Compression measurement

The second method of diesel diagnostics involves studying deviations in the values ​​of some operational indicators engines using diesel fuel as fuel. To do this, measure required parameters and compare them with the regulatory data set out in the technical documentation.

Unfortunately, the size of this article does not allow detailed description all necessary manipulations required to perform compression measurements. We only note that a special device is used for this. A special tool called a compression meter can provide fairly accurate readings of the desired value.

By comparing them with standard data, you can detect the following malfunctions in the diesel unit:

1. excessive wear of piston group parts, which threatens a major overhaul of the power plant;
2. problems in the valve system are usually solved by adjusting the thermal clearances. If the actions performed did not cause an increase in compression to optimal level, take measures to grind in the valves. Most often, this helps restore normal operation of the system. Otherwise, it is necessary to repair the valve seats.

You can determine which of the listed malfunctions caused the compression level to drop by pouring a small amount of engine oil into each of the cylinders. After this, the measurements are repeated. An increase in indicators indicates a problem in the piston group.

Invariably low level compression is determined by malfunctions of the valve mechanism.

Computer diagnostics

Condition survey electronic systems diesel engine is performed on special equipment. Carrying out such events at home is impossible, since a special computer scanner is required. A fairly complex high-tech device performs multi-stage engine diagnostics, alternately examining the functionality of the fuel and control systems unit.

Such a study consists of several phases, almost equal in importance:

• checking the functionality of the electrical components of the injectors;
• assessment of everyone's testimony temperature sensors, equipping the motor;
• measurement of compression values ​​in the cylinder block;
• establishing indicators of vacuum converters.

The smart scanner combines the received data on detected faults and displays current information on the monitor. A thorough analysis of the causes of detected defects allows the computer to determine optimal ways eliminating them.

Conclusion

From all of the above, we can conclude that every car enthusiast is capable of independently diagnosing a diesel unit. To do this, you just need to thoroughly study performance characteristics his iron horse. Carefully observing the operation of the machine, experienced driver intuitively recognizes the slightest deviations from the norm.

Diesel engines are widely used in engineering machines, trucks and route vehicles. This type of engine is less common in passenger cars, however, due to the general increase in their popularity, diesel engines are increasingly being installed on them.

The design of the combustion chamber of a diesel engine is divided into a separate combustion chamber and a chamber with direct injection. In the first situation, the combustion chamber is connected to the cylinder using a special channel. During compression, the vortex-type air entering the chamber is swirled. This improves the self-ignition that occurs in the main chamber. Such diesel engines are most often found in passenger cars, since their noise level is much lower compared to other engines and the speed range is larger.

In the second case, the combustion chamber is located directly in the piston, and the fuel enters the space above the piston. Low-speed engines with large volumes most often have this design. Such engines initially made a lot of noise and vibration, but consumed a small amount of fuel. Gradually, high-pressure fuel pumps for diesel engines appeared with optimization of the combustion process. Stable engine operation was achieved at a range of up to 4500 rpm. Noise and vibration have also been significantly reduced.

Diesel or gasoline?

Advantages and disadvantages different types engines are often a concern for car owners. Despite the fact that the noise and vibration levels of diesel engines have decreased significantly as a result of their modernization, many car owners are concerned about the question: how to quickly start a diesel engine frosty weather? Indeed, the diesel engine and car interior warm up more slowly due to lower engine operating temperatures. The issue is resolved by installing on motors additional heaters. This option is widely used on modern engines.

It would seem that that’s all, but no. Many motorists buy cars with diesel engines due to the relative cheapness of diesel fuel. Wanting to save on fuel, they do not take into account that diesel engines are much more demanding on fuel quality than gasoline engines. Gasoline engines are more demanding in terms of the required octane number.

Diesel engines are wrongly considered unpretentious, since their demands on the quality of fuel and consumables are quite high. It is no secret that domestic diesel fuel is far behind imported European fuel in quality. Using good old diesel fuel can adversely affect engine performance. However, leading Russian oil companies are trying to solve this problem.

Euro 4 diesel fuel fully complies with the standards and allows the engine to remain operational for a long time. Some also try to use auto chemicals (anti-gel agents), which can increase the quality of fuel, but it is recommended to use them only if the warranty period has already expired.

Thus, by purchasing cars with diesel engines that are not officially supplied to Russia, you risk quickly rendering the engine, designed for European fuel, unusable.

Maintenance of a diesel engine is almost always more expensive than a gasoline engine. This is explained more high cost spare parts (air, fuel filters, etc.). Oil changes are carried out more often than with its gasoline competitor (on average every 7.5 km).

A good advantage of a diesel engine, relative to a gasoline engine, is more economical consumption fuel at high mileage car. An older gasoline engine does not consume gasoline as economically as a new one. There is practically no such problem in a diesel engine.

Summarizing all of the above, we can conclude that modern diesels Reliability is not inferior to gasoline engines. But purchasing them in order to save money on fuel is justified only if the car is used for a long time.

Principle of operation

Like gasoline engines, diesel engines They are divided into four-stroke and two-stroke depending on the principle of operation. Two-stroke engines quite poorly distributed. Read on to learn more about the operating principle of a four-stroke diesel engine.

The operating cycle of such an engine consists of four strokes:

1. Intake (injection). On this beat crankshaft rotates from 0 to 180 degrees and reaches bottom dead points. Air enters the cylinder through the open intake valve. At the same time Exhaust valve opens only 10-15 degrees, forming an overlap.
2. Compression. The piston, moving upward from 180 to 360 degrees, reaches top dead points. The air is compressed more than 16 times, and the intake valve closes at the beginning of this stroke. The air temperature in the engine can reach from seven hundred to nine hundred degrees Celsius.
3. Working stroke, expansion. The crankshaft rotates from 360 to 540 degrees, again reaching the bottom dead center. As is known from physics, highly compressed air is heated to very high temperatures, due to which the fuel coming from intake valve, self-ignites. At this stage, an important difference between a diesel engine and a gasoline engine appears. Diesel fuel begins to be supplied even before the crankshaft reaches top dead center (ignition timing). Combustion products push the piston down. During the working process in a diesel engine, the gas pressure is constant, and thanks to this they are able to develop greater torque. Proportion air-fuel mixture In a diesel engine it differs from a gasoline engine in the large amount of air.
4. Release. When the crankshaft rotates 720 degrees, the piston pushes the exhaust gases into the open exhaust valve. The gases exit through the exhaust pipe, and the whole cycle repeats.

Power supply system of a diesel internal combustion engine

Purpose

The diesel power system is a whole complex special devices. Its main task is not only to supply fuel to the injection nozzles, but also to ensure high pressure during supply. The power system also performs other important functions:

• dispensing a precisely defined amount of fuel, taking into account the engine load at different modes work;
• ensuring effective fuel injection at a fixed period of time with the required intensity;
• spraying and uniform distribution of fuel throughout the combustion chamber in the cylinders;
• preliminary filtration of diesel fuel before supply to the power system pumps.

The power supply system provides the supply of purified fuel, and the injection pump (high pressure fuel pump) of the diesel engine compresses it to the required pressure. The injectors supply finely atomized diesel fuel into the combustion chamber

As an example, a diagram of the ZMZ-5143.10 diesel engine installed on UAZ vehicles with an electric fuel pump is given.

Main elements of the system

The diesel engine power supply system consists of main and additional elements. The main elements are: fuel tank, coarse filters and fine cleaning diesel fuel, fuel priming pump, injection pump, injection nozzles (through which fuel is injected), pipeline low pressure, high pressure line and air filter.

Additional elements may vary. These include electric pumps, exhaust gases, particulate filters and mufflers. The diesel engine power supply system is divided into two groups depending on the installed fuel equipment: diesel fuel supply equipment and air supply equipment.

In fuel supply equipment, as a rule, injection pumps and injectors are implemented as separate devices. Fuel is supplied to the engine through high and low pressure lines. In the highway high pressure injection pump increases the pressure to supply and inject the required portion of fuel into the working combustion chamber.

In addition to the fuel injection pump, the diesel engine is equipped with a fuel priming pump. It supplies fuel from the fuel tank and passes fuel through fine and rough cleaning. The pressure created by this pump allows fuel to be supplied through a low pressure pipeline to the injection pump.

The fuel injection pump of a diesel engine supplies fuel to the injection nozzles under high pressure. The flow depends on the operating order of the diesel engine cylinders.

Diesel injectors are located in the cylinder head. Their main task is precise atomization of fuel in the combustion chamber. There is also a drainage system that removes excess fuel and air through separate pipelines. Nozzles come in open and closed types, but closed type is used more often. The nozzle of such an injector is a hole closed by a shut-off needle. The key element of the nozzle is the atomizer. It receives one or more nozzle holes, which form a torch at the time of fuel injection.

There is also a non-separated type power supply system, in which the injection pump and injection nozzle together they represent a pump-injector device. The service life of such engines is short, and the noise generated often exceeds specified standards.

Features of the turbodiesel power system

The turbocharging system is used in both diesel and gasoline engines. It is designed to increase their power without increasing the volume of the combustion chamber. The fuel supply system in turbocharged diesel engines remains virtually unchanged, while the air supply system undergoes significant changes.

Supercharging occurs using a turbocharger. The turbine consumes the energy released by the exhaust gases (read also,). The air in the turbocharger is compressed, cooled and fed into the combustion chamber of the diesel engine. The value of this pressure classifies compressors according to the degree of boost (low, medium, high).

Diagnostics of the diesel engine power system

Diagnostics of the diesel engine power supply system is carried out in special service centers and is aimed at identifying and eliminating the following faults: wear on the surface of cylinders, gears, sprockets, crankshaft, injection pump, clogging of the radiator, air filter, cooling channels, oil channels, damage to the flywheel, valves, etc.

A variety of malfunctions can occur. Their timely identification will allow the engine to last longer. The main signs by which you can understand that there is a malfunction are the following: the engine does not start, does not develop the declared power, smokes heavily, and knocking noises occur during operation.

Troubleshooting the diesel engine power system

If the engine does not start, the first thing to do is check for fuel. At low temperatures it can thicken, so special heating of diesel fuel will help to start the engine in cold weather. Next reason There may be excess air in the power system. Such situations arise due to leaks in the system. To eliminate excess air, it is necessary to bleed the system and eliminate its leaks.

The lines, tank pickup and fuel filters may be clogged. The water in them may freeze. It is necessary to warm them up, clean them thoroughly with a rag soaked in hot water. If the injection pump does not work, then you must first warm it up warm air or steam, and if this does not help, then the filter elements must be replaced.

If the engine does not develop the declared power and smokes heavily, then it is necessary to check the air filter for clogging, check the content of excess air in fuel system, adjustment of the fuel supply angle, adjustment and clogging of injectors, malfunction of high and low pressure pumps. The malfunction can be eliminated by cleaning the filters, pumping and removing excess air, adjusting the injection advance clutch at the injector, replacing or repairing the high and low pressure pumps if warming up does not help.

Uneven engine operation occurs due to loss of performance of the injectors, malfunction of the injection pump or regulator. Faulty injectors must be replaced immediately, and the pump should be sent for repair.

Knocking in the engine occurs due to too early fuel supply or, conversely, increased supply. This occurs due to the rack lock becoming disengaged. To eliminate it, it is necessary to adjust the angle at which the fuel supply begins or replace the fuel injection pump rack.

Now, in order, about the troubleshooting process. The sediment from the fuel filters is drained provided the engine is warm. Drain plugs are unscrewed and the sediment is drained until clean fuel begins to flow. Then the plugs are tightly wrapped, and the fuel system is pumped with a hand pump. After this, the engine starts. After 3-4 minutes everything air jams will be eliminated. Sludge from fuel tanks is drained using special taps in the same way.

To wash the diesel fuel coarse and fine filter, the fuel is drained, the caps are removed and washed with clean diesel fuel. Then the old filter elements are replaced. After assembly, you must make sure that there is no air leakage when the engine is running. Otherwise, the bolts securing the cups to the housings are tightened manually.

The air filter is removed from the car and the filter element is removed. The body and inertia damper are washed in diesel fuel or hot water, and the parts are blown out compressed air, the air intake mesh is cleaned. Damaged parts are replaced.

Checking for leaks exhaust tract. The filter element is cleaned by blowing with dry compressed air or washing. The filter element must be replaced if it has through-hole damage.

The average service life of a filter element is about 30,000 km. It should be washed no more than three times, and purged no more than six times.

The fuel injection advance clutch is lubricated through one of the holes until oil spills from the other hole. It holds 0.3 liters of motor oil.

To check the fuel injection advance angle, you need to turn the crankshaft to a position where the mark on the drive half of the clutch is at the top and the latch fits into the hole on the flywheel. If the marks on the coupling and pump are aligned, then the injection advance angle is correct.

To set the injection advance angle, you need to unscrew the 3 bolts of the driven half-clutch and turn the crankshaft and the advance clutch until the marks align.

Checking the injectors for injection pressure is carried out on a special stand. The value should not deviate from the value of 18+0.5 mPa or 17 mPa for an injector that has worked for a certain period of time. The injector should inject mist-like diesel fuel, and the injected jet should be cone-shaped. If these parameters are not met, then repair is required. diesel injectors. Checking and adjusting the injection pump is also carried out by fuel equipment specialists.

Conclusion

We examined the main components and assemblies of the diesel fuel supply system and its main malfunctions. Timely maintenance will help identify and eliminate these faults and, as a result, increase the service life of your car’s diesel engine. Good luck and easy travels!

(9 ratings, average: 5,00 out of 5)

Today, many motorists have cars that use diesel fuel as fuel. Many owners of such cars will be interested to know about what types of diesel engine malfunctions there are and how to fix them. Especially, it seems to us, this article will be of interest to car owners who, after long-term operation gasoline modifications car, changed to diesel cars. This is due to the large difference in maintenance and operation of such models. To enjoy owning such a car, you need to know as much as possible about it.

Diesel engine malfunctions and their elimination, knowledge of these features, the ability to find and fix problems that arise will be useful for all drivers. Imagine this situation. A trip outside of urban areas in a jeep, and most of these vehicles have diesel power units, was interrupted due to its breakdown. “Civilization” is dozens of kilometers away, there is no one to expect help from, and no one knows what to do. Let's try to tell you in simple words about possible breakdowns such machines.

A little about the features of such cars

The design principle of diesel engines is not very different from gasoline power units. Both designs are characterized by the presence of a cylinder block, pistons, valves and other parts. The only difference is in the reinforcement of the structure of some of them. This must be done because the compression pressure of the combustible mixture of a diesel engine is about 20 units, versus 10-12 for carburetor models.

Diesel engines work a little differently than gasoline units. The combustible mixture is supplied to the compression zone separately. The first air enters the cylinders and its compression begins. At the end of this process, its temperature reaches approximately 700°C, so when diesel fuel is injected under high pressure, it ignites.

At this time, there is a sharp increase in pressure in the ignition zone, which is accompanied by noise and some vibration. Such features of these power units allow the use of inexpensive diesel fuel; operation occurs with a very lean mixture. This predetermines higher efficiency and better “ecology” against gasoline engines. However, there is a caveat here; this is only possible with a fully operational power unit.

About symptoms of malfunction

Breakdowns of any engines, especially diesel engines, most often occur due to wear of parts, violations of maintenance and operating rules, overheating of the power unit, use of poor quality fuel and other problems. However, the most common malfunctions of diesel power units are:

• The diesel engine cannot be started;
• Interruptions during operation and reduction in power;
• High exhaust smoke;
• Sudden stop;
• Knocks during operation;

Now let's talk more specifically about these problems and how to get rid of them.

Why won't the engine start?

This is possible when there is no fuel in the system. The reason for this may be clogged fuel filters coarse and fine purification of diesel fuel. Their clogging can occur due to low-quality fuel or when using summer varieties in the cold season. In this case, washing the filters and replacing them with the appropriate type of diesel fuel helps.

Air getting into the power system will also prevent it from starting. It is necessary to carefully inspect all pipelines for signs and eliminate them. An incorrectly installed injection pump after repair will not allow the engine to start.

Insufficient power and interruptions

This can happen when diesel injector nozzles become coked. It will help to wash the injectors and sprayers in a bath of diesel fuel and clean them with a needle with a diameter of 0.25 mm. Failures can come from the high pressure pump due to a violation of its adjustments. This can also be expected due to jamming of the plunger of this pump. It is best to fix such problems in workshops. It cannot be ruled out that the filters in the power supply system become clogged and air gets in there.

Heavy exhaust smoke

The appearance of black smoke from exhaust pipe indicates an overload of the power unit. Go to low gear will clean the exhaust. This phenomenon may also be caused by a lack of air due to a dirty air filter. Flushing a car's air cleaner cleans up the exhaust.

Appearance white smoke Possible when the engine is not warmed up or after water gets into the diesel fuel. Blue smoke may serve as a signal to the driver that the oil level in the pan is too high. Bringing it to normal eliminates the appearance of smoke. Signs of piston group wear are also determined by the appearance blue smoke. You should also check the reliability of the connections in the pipelines and do not forget to drain the sediment from the fuel tank.

Unexpected engine stop. The culprit for this problem may be a lack of fuel in the power system. If it is present in the tanks, you should check the cleanliness of the fuel filters. Washing the filters or installing new filter elements will relieve the driver of such a malfunction.

Check the cleanliness of the hole in the gas tank cap; it serves to connect its cavity to the atmosphere. If there is no air in the tank, the fuel pump is unable to supply the engine the right amount fuel.

About possible overheating

First of all, check the coolant level in the radiator and if it is insufficient, add required volume antifreeze. Problems may arise. If it gets stuck in the closed position, the coolant, moving in a small circle, will quickly overheat. In this case, only replacing it will correct the situation. Clogged cooling system, especially the radiator, weak tension fan belt also lead to overheating of the power unit.

Knocking noises during operation. This can happen due to an increased gap in valve mechanism gas distribution, in this case, valve adjustment is necessary. Too much early ignition leads to a knocking sound in the fuel pump. It is necessary to correctly set the timing of the supply of high pressure fuel into the combustion chamber of the cylinder. A faulty injector can also be a source of knocking noise in diesel engines.

A modern diesel engine, even if it is not equipped with electronic control fuel consumption and modification common rail, is more powerful, reliable and economical than gasoline that same volume. The condition of the diesel fuel system directly determines these indicators. If it malfunctions, one or more of these characteristics are significantly reduced. A quick and accurate diagnosis of the cause of a drop in productivity will help reduce the time and money spent on repairs. It is possible to determine which particular component caused the malfunction of the fuel equipment of a diesel engine by analyzing its symptoms.

Common signs of a malfunctioning diesel fuel system

The nature of the operation of a diesel engine immediately before a breakdown occurs indicates how well the flow and combustion of fuel occurred in the cylinders. These readings are used in preliminary diagnosis of the causes of decreased vehicle performance.

Diesel engine is difficult to start

To start the unit, a long rotation of the starter is required; the start does not occur immediately and at first it works intermittently or.

Malfunctions:

• lack of “diesel” at start-up - the regulator or booster pump is faulty;
• lack of fuel in front of the injection pump - air enters the system;
• lack of injection pressure due to wear of fuel injection pump parts;
• advance angle failure;
• poor dispersion of fuel - the injector does not provide a wide enough “torch”.

IN winter period Difficult starting can be caused by: failure of one or more glow plugs; the formation of a “paraffin plug” on the injectors when using the wrong (summer) type of fuel, the formation of “flakes” in the fuel line due to water (condensate) entering the tank.

The diesel engine does not develop the required power

When accelerating, the engine power is limited at a certain moment and the car does not reach maximum speed.

Malfunctions:

• air ingress due to damage to the fuel line;
• line blockage;
• malfunction of injectors, wear of their fastenings;
• fuel injection pump breakdown or incorrect adjustment;
• incorrect setting of the injection advance angle.

The lack of fuel can also be caused by severely clogged air filters and incorrect position of the accelerator pedal due to incorrect adjustment.

The motor is overheating

Temperature readings are constantly above normal, while the vehicle’s cooling system is working properly.

Malfunctions:

• the adjustment of the injection advance angle has gone wrong;
• low dispersion of fuel due to wear of the nozzle;
• detonation due to poor quality fuel.

The phenomenon sometimes occurs when insufficient level oil in the engine crankcase, or loss of properties from prolonged use.

Engine power has noticeably decreased

Traction disappears during sharp acceleration, and the acceleration time of the car increases. The effect is observed regardless of weather conditions and elevation changes.

Malfunctions:

• insufficient fuel volume in the system due to a breakdown of the boost pump;
• “poor” mixture – the fine filter is clogged;
• Significant weakening of injection power - wear of the plunger pair, or incorrect adjustment of the injection pump;
• failure in the settings of the injection control regulator;
• Several injectors or their fastenings are worn out or damaged.

If problems occur in rainy weather or when driving in the mountains, their source is a lack of oxygen or a short circuit.

The engine is rough or noisy

The power unit reacts sharply to the accelerator, there is no smooth acceleration, and when the load increases, a characteristic small knock is heard in the area of ​​the cylinders.

Malfunctions:

• displacement of the injection phase towards early advance;
• discrepancy in the amount of diesel entering the different cylinders due to improper adjustment of the injectors;
• breakage or clogging of one of the nozzles;
• lack of proper sealing in the place where the sprayer is installed (there is no washer, the fastening is too tight or loose);
• air enters the fuel line;

In some cases, the reason is a lack of compression of the CPG.

The engine idles unevenly

It is observed mainly after maintenance (repair), or long-term operation without proper maintenance.

Malfunctions:

• incorrect idle speed adjustment;
• airing in the section between the filter and the high-pressure pump;
• damage to the support plate in the fuel injection pump seal;
• failure of one or more nozzles, or failure of an injector or pump injector.

A separate cause of the problem is limited travel of the accelerator pedal (contamination, broken traction, etc.).

Fuel consumption has increased significantly

Marked regardless of vehicle load.

Malfunctions:

• clogging (loss of tightness) of the return channel of the fuel line (on the way of draining excess into the tank);
• idle speed is too high;
• injection timing adjustment failure;
• airing of the main highway.

Other reasons: the air filter is clogged; low compression in cylinders; Timing belt repair is required.

The computer gives an error

A car equipped with an on-board computer displays a check engine message, or “engine error,” if the pressure in the low pressure line or common rail does not correspond to the operating indicator. Depending on the brand of the car, the error code will be different.

Malfunctions:

• the flow control sensor has failed;
• air entering the fuel line;
• The injection pump valve is not working correctly.

For reliable diagnostics, you will need to connect a car dealer scanner to the on-board computer.

The motor suddenly stops spontaneously.

The car stalls while driving or immediately after starting.

Malfunctions:

• fuel line is damaged (faulty connection);
• the booster pump is broken;
• failure of the drive, separator piston, pistons or rotor of the injection pump due to significant wear;
• the injection timing adjustment is broken.

Other reasons: the air filter is clogged, the seal of the supercharger (turbine) is broken.

Unstable engine operation

The so-called “floating speed” is a spontaneous change by the engine in the crankshaft speed readings.

Malfunctions:

• failure of the speed controller;
• the tightness of the fuel system is broken;
• lack of lubrication, or excess resistance to sliding of parts of the adjustment system.
• significant production of fuel injection pumps or injectors;
• unsatisfactory quality of diesel fuel.

The phenomenon sometimes occurs after a broken ventilation valve crankcase gases(KVKG) and the formation of their excess pressure.

Changing the color of smoke from a car exhaust pipe

from the exhaust pipe indicates overcooling of the engine, severe wear of the CPG, or the timing is set earlier than required. Simultaneously with an increase in the engine oil level, this may be a sign of a cylinder head gasket failure.

Dark (black) smoke is a sign of improper mixture formation (excess fuel and incomplete combustion). Reasons: wear or clogging of injectors, “late” injection advance, wear of the CPG with loss of compression, incorrect valve adjustment.

Associated malfunctions of fuel equipment

They appear either individually or in parallel with the main problems.

• On a car you have to change the glow plug frequently - the corresponding injector is faulty.
• The engine oil level becomes higher - a leak occurs in the fuel injection pump drive seal.
• After a trip, it is impossible to turn off the diesel engine - the shut-off solenoid in the fuel line is faulty.
• The car has ceased to provide sufficient “engine braking” force - the return channel (reset) does not work, or the “idle” speed is set incorrectly.

The consequences of a violation are often general: diesel consumption can increase both from wear of the fuel injection pump and from a lack of air due to a clogged air filter. It is possible to reliably establish that a failure relates specifically to the fuel system only by sequentially troubleshooting the components and assemblies indicated by the problem.