What is the fault of the engine emitting black smoke?

Correct. Black smoke from exhaust and high fuel consumption are one of the common faults of EFI engines, and the causes often involve many aspects such as mechanical system, oil supply system, air intake system and electronic control system. Before eliminating this fault, we should first analyze the direct or indirect impact of the above systems on the fault of black smoke and high fuel consumption, and pay attention to the internal relationship between them, so that the fault can be targeted.

The most common cause of this type of failure is the failure of the electronic control system, such as the damage of the air flow meter (pressure sensor), throttle position sensor, oxygen sensor or other important sensors, the signal (voltage or frequency) they transmit to the computer does not truly reflect the air flow, so that the oil supply increases abnormally, resulting in an over-concentrated mixture. Black smoke from exhaust and high fuel consumption are one of the common faults of EFI engines, and the causes often involve many aspects such as mechanical system, oil supply system, air intake system and electronic control system. Before eliminating this fault, we should first analyze the direct or indirect impact of the above systems on the fault of black smoke and high fuel consumption, and pay attention to the internal relationship between them, so that the fault can be targeted.

That depends on what type of engine you have (whether it's petrol or diesel).

If it's a gasoline engine, it means that your fuel mix ratio is too strong!! To put it simply, there is more gasoline and less oxygen! This condition can be caused by a variety of conditions:

Improper adjustment of carburetor-vapor mixing ratio (carburetor car), excessive fuel pump pressure (EFI), mismatch of engine ECU data. And so on and so forth.

If it is a diesel engine, to be honest, most domestic diesel engines will have this phenomenon. The black smoke you see is actually tiny carbon particles produced by diesel fuel when it is not completely combusted!!

If it's your own car, whether it's petrol or diesel, you should go to the service station to have it checked!! You love the car, the car loves you!! Ha ha...

(1) The exhaust back pressure is too high or the exhaust pipe is blocked. This situation will cause insufficient air intake, which will affect the air-fuel mixing ratio, resulting in excessive oil volume. This is the case:

First, there are too many exhaust pipe bends (especially 90° bends), which should be minimized; The second is that the inside of the muffler is blocked by too much soot and should be removed.

2) Insufficient air intake or blocked air intake duct. In order to find out the cause, the following checks should be carried out: first, whether the air filter is blocked; the second is whether the intake pipe is leaking (if this phenomenon occurs, the engine will be accompanied by a harsh whistling sound due to the increase in load); The third is whether the turbocharger is damaged.

The blades of the exhaust gas wheel and booster wheel should be checked for damage and whether the rotation is smooth and flexible; Fourth, whether the intercooler is blocked.

3) Incorrect adjustment of the valve clearance, poor contact of the valve seal line. Valve clearance, valve springs and valve seals should be checked.

4) The oil supply of each cylinder of the high-pressure oil pump is uneven or excessive. The uneven oil supply will produce unstable speed and intermittent black smoke, which should be adjusted to make it balanced or within the specified range.

5) If the injection is too late, the advance angle of the injection should be adjusted.

6) If the injector is working poorly or damaged, it should be removed for cleaning and inspection.

7) Injector model selection is incorrect. Imported high-speed engine has strict requirements for the selected injector (injection hole diameter, number of holes, injection angle), if the choice is not appropriate, it will also cause the engine to emit black smoke, even if the same model of engine, in different use occasions (output power, speed, etc.), the injector model required to be used is not the same. If the incorrect injector is selected, the correct type of injector should be replaced.

8) Diesel is of poor quality or the grade is wrong. The imported high-speed diesel engine equipped with a direct injection combustion chamber with a porous injector has strict requirements for the quality and grade of diesel due to the small aperture and high precision of the injector, otherwise it will also cause the engine to emit black smoke and even make the engine unable to run normally. Therefore, clean and qualified light diesel oil should be selected, and it is recommended to use 0 or +10 in summer, -10 or -20 in winter, and -35 in severe cold areas.

9) The wear of cylinder liner and piston assembly is serious. When this happens, the piston ring seal is not tight, and the air pressure in the cylinder drops seriously, resulting in the diesel fuel can not be fully burned and black smoke is emitted, and the engine power drops sharply. Wear parts should be replaced.

1.The air filter is clogged.

2.The injector is faulty, such as poor atomization, dripping, or excessive injection pressure.

3.The fuel system pressure is too high. If the return pipe is clogged, the oil supply is too large, or the regulator is faulty.

4.Air leaks.

5.The vacuum level is reduced.

6.The ignition system energy is too low. For example, the spark plug jumps weakly, which causes carbon deposition and affects the combustion quality.

7.The valve seal is not tight, and there is a leak inside.

8.Improper adjustment of the valve clearance.

9.The gap between the cylinder barrel and the piston is too large.

10.Bad tie wire. For example, the engine hits the wire.

In the case that there are no other abnormalities in the engine, this is a normal phenomenon, the principle is as follows: when the cold car starts, it needs to be thickened to meet the starting performance and stability of the engine, that is, when the cold car starts, the oil supply of the engine will increase, and the speed will be increased for a period of time. Therefore, in a short period of time after the low temperature start, it may lead to the generation of black smoke at the scene, and it will emit at the same time.

If black smoke comes out of the exhaust pipe when the diesel engine is working, it is caused by the injection of diesel fuel that has not been fully combusted. Diesel fuel that is not completely burned decomposes and polymerizes to form soot under the condition of high temperature and lack of oxygen in the combustion chamber, and the soot is not pure carbon, but a polymer with a small diameter. This solid soot reacts much more slowly than gasified fuel, and the black smoke is eliminated before it has time to burn.

Therefore, black smoke when the diesel engine is working is a malfunction. This fuel combustion is incomplete, not only causes the fuel consumption of diesel engine to increase, power decreases, and makes the piston, piston ring valve and combustion chamber form a large amount of carbon deposit, when serious, the piston ring will be stuck, the valve seal is not strict and produces air leakage, and it will also accelerate the wear of parts, thereby reducing the service life of the engine, therefore, the locomotive should be eliminated in time when the fault occurs.

1. The oil supply is too large or the diesel engine is overloaded.

2. The injection advance angle is too large or too small.

3. Poor atomization or oil dripping of the injector.

4. The positioning screw of the plunger sleeve of the oil pump is too long, which blocks the oil return hole on the sleeve, resulting in the oil return hole is not smooth, causing the increase of oil supply, incomplete combustion of diesel fuel, black smoke, and may also cause the diesel engine to fail to turn off.

5. The air filter or intake pipe is blocked, so that the amount of air entering the cylinder is reduced, the diesel combustion is incomplete, and the exhaust emits black smoke. If the injector is normal, the cylinder is compressed well, and the diesel engine emits black smoke at both high and low speeds, at this time, after removing the air filter, the black smoke will disappear immediately, and the air filter needs to be cleaned.

6. The incorrect valve phase, the valve clearance is too large, and the valve cam tip is seriously worn, etc., will reduce the air intake, and the exhaust gas in the cylinder can not be exhausted, resulting in incomplete diesel combustion and black smoke from the exhaust, and the valve mechanism should be checked and adjusted.

7. Poor compression in the cylinder, and the compression resistance is reduced. This could be due to excessive wear of the piston and liner, excessive wear of the piston rings, or the opening in the same direction, causing the cylinder to leak. At the same time, it may also be that the valve seal is not tight, and there is an air leak.

The compression in the cylinder is poor, the temperature at the end of compression is low, and the air leakage reduces the air, and the diesel fuel cannot be completely burned, and black smoke is emitted.

8. The combustion chamber and exhaust pipe have too much carbon deposit, the combustion chamber temperature is too high, the resistance of the intake and exhaust increases, the intake is not sufficient, and the exhaust is not exhausted, resulting in incomplete combustion and black smoke from the exhaust.

9. The diesel brand used is wrong, the viscosity is too large, or the quality of the diesel is too poor, which is not easy to catch fire, so that the exhaust emits black smoke, and the combustion chamber and exhaust pipe are also easy to produce carbon deposits.

10. The diesel engine is poorly lubricated, or the crank connecting rod mechanism is worn too much, and the running resistance increases, which overloads the engine, the diesel combustion is incomplete, and the exhaust emits black smoke.

11. The working temperature of the diesel engine is too high, which reduces the filling density, the air intake in the cylinder is insufficient, the diesel combustion is incomplete, and the exhaust emits black smoke.

12. The plunger parts of the fuel injection pump are seriously worn, which makes the oil supply pressure of the oil pump rise slowly, which affects the normal fuel supply time, prolongs the fuel injection process, and affects the quality of fuel injection atomization, which is a common fault of black smoke from diesel engine exhaust. Therefore, when the oil pump is seriously worn, it should be replaced in time.

Black smoke from the car is a relatively common symptom, indicating that the engine mixture is too thick and causes insufficient combustion, which is a manifestation of engine failure, when the air filter is too dirty, the spark plug is damaged, the ignition coil is faulty, etc., all of which will cause black smoke from the engine exhaust.

Black smoke from a car is a relatively common symptom, indicating that the engine mixture is too thick and causes insufficient combustion, which is a sign of engine failure. However, there are relatively many reasons for it, when the air filter is too dirty, the spark plug is poor, the ignition coil is faulty, etc., it will cause black smoke from the engine exhaust, if your vehicle has this problem, then it is recommended to go to the repair shop for maintenance.

There are three common reasons for black smoke in automobile engines: 1. The reason for the quality of the fuel used, when you use inferior gasoline, it is easy to have a similar situation.

2. The air filter is blocked, resulting in excessive concentration of mixed gas, which causes insufficient oxygen supply to the engine and produces insufficient combustion.

3. When the ignition system of the car fails, it will also make the car emit black smoke, which is likely to be caused by spark plug leakage, too weak high voltage, weak flashover, etc.

Photo by Q&A) Xpeng P7 Model Y Aion V Ideal One NIO EC6 Model X @2019

The reasons for the black smoke of the engine caused by the incomplete combustion of the mixture: 1. The air filter is too dirty, which causes the intake air to be blocked, resulting in the mixture being too thick.

It is manifested as weak stepping on the accelerator, and even the phenomenon of fire failure, excessive intake noise, muffled engine sound, etc.

Workaround: Replace the air filter.

2. The air flowmeter is too dirty, and the oil distribution amount is inaccurate due to poor contact and damage, resulting in excessive concentration of mixed gas.

Fuel consumption suddenly increases in a short period of time, acceleration is strong or weak, and the fault light lights are on or off after being lit up, and the above performance is performed throughout the vehicle.

Solution: Look at the air flow meter or inlet pressure sensor fittings and clean or replace them.

3. A large amount of carbon deposits remain on the intake valve, and the fuel cannot enter the combustion chamber normally, and the intake valve is stuck.

The performance is mostly in the morning when the cold start, the car is slow and repetitive. There is a noticeable "click" sound of the valve. After the car, there is a shaking phenomenon at idle, the engine is weak, the power is significantly reduced compared with before, and there is an irregular "snort" air leakage sound.

The solution: Routine cleaning of the air intake system, especially the intake valve assembly.

4. The fuel injector is stuck and in a long open state, resulting in excessive concentration of mixed gas.

Manifested as an engine with irregular shaking. Fuel consumption increases, acceleration is slow, and exhaust emissions smell of gasoline.

Solution: Clean or replace the fuel injector.

5. There is air leakage in the intake pipeline, resulting in insufficient air intake, deviation of the starting opening of the throttle, and inaccurate oil distribution.

It is manifested as the sound of "snort" air leakage can be heard at the engine, the idle speed remains high, the descent is slow, the regular shaking, the phenomenon or signs of stalling when accelerating, the acceleration is slow, and the fuel consumption increases.

Solution: Overhaul the air leakage on the engine intake duct, and regularly clean and maintain the throttle.

6. The ignition energy of the spark plug is missing, and the cylinder is broken from time to time.

It is manifested as the sound of firing guns at the same time as the engine shakes, the rhythmic shaking phenomenon of the engine at high, medium and low speeds, the irregular discharge of black smoke, the weak acceleration, and the rapid decline of power.

Solution: Check the spark plug ignition coil and replace it as appropriate.

7. Exhaust back pressure, exhaust system blockage, resulting in insufficient air intake, insufficient combustion, and excessive concentration of mixture.

It is manifested as heavy throttle, accompanied by strong exhaust noise, and even stalling when accelerating sharply, the exhaust is stuffy, and the engine speed rises slowly.

Solution: Overhaul the exhaust system, clean the three-way catalytic, and consider replacing the three-way catalysis as appropriate.

8. The oil pump or oil pressure regulating valve is damaged, the pressure increases, and the oil supply increases, resulting in the mixture being too concentrated.

It is manifested as a slow cold start, difficult to start, without excessive loss of power, and increased fuel consumption.

Solution: Replace the gasoline filter and overhaul the gasoline pump.

Black smoke from cars is a comprehensive problem that needs to be eliminated by professionals one by one. These are just to provide you with a solution idea, non-professionals, hope to consult the car service agency to solve the problem!