Diesel engine

1. What is the reason for the black smoke from the engine? What should be done?

Answer: The main reason is that the fuel is not completely burned. The specific reasons may be that the fuel supply time is too late, and the fuel is too late to burn; the valve clearance is incorrect or the air intake is not smooth (the filter is dirty and blocked), and the air intake is insufficient so that the fuel cannot be completely burned; the piston, piston ring, and cylinder liner are worn out. Seriously wait. The fault location should be identified according to the cause, and the excessively worn parts should be adjusted, repaired or replaced accordingly.

2. What is the reason for the white smoke from the engine? What should be done?

Answer: The main reason is that there is water in the diesel oil used or the engine is loaded without preheating, which makes the fuel combustion incomplete. If there is water in the diesel oil, it may be due to the use of low-quality fuel, or there is water seepage between the cylinder head, cylinder gasket, and cylinder liner. The cause should be found out and eliminated; if the engine is loaded without sufficient preheating, it should be allowed The engine is warmed up enough before putting it into operation; it does not rule out that the fuel injector is not working properly and the fuel supply time is too early, such as the fuel injection pressure is too low or the needle valve is stuck, the faulty part should be found and repaired, such as the fuel supply time If it is too early, the oil supply time should be adjusted correctly.

3. What is the reason for the blue smoke from the engine? What should be done?

Answer: Blue smoke means burning oil. It may be that the oil level of the crankcase is too high, the oil level of the air filter oil pan is too high, the piston ring is stuck due to carbon deposits or excessive wear, and for the engine after overhaul, it may also be due to the cylinder liner and piston ring not running in well. Take corresponding troubleshooting measures for the cause of the fault.

4. What failures will be caused by the deformation of the engine cylinder head?

Answer: It will cause blow-by between two adjacent cylinders, burn the cylinder head gasket, cause cooling water to leak into the cylinder, and make it difficult to start the engine; it will also cause water to flow into the oil pan, diluting the lubricating oil, etc.

5. What is the impact on the oil supply after the wear of the inlet and outlet holes of the plunger coupler?

Answer: The impact on oil supply is as follows: the oil supply time becomes later, and the oil stop is earlier; the oil supply pressure decreases, and the circulating oil supply volume decreases; the unevenness of the oil supply volume and oil supply time between cylinders increases accordingly.

6. What are the hazards of cracks in the cylinder block or cylinder head? What is the main reason?

Answer: It will cause cooling water to escape into the combustion chamber, oil pan, or gas into the cooling system, so that the engine cannot work normally. The main reasons are: (1) Add cold water suddenly when the engine is overheated or overheated; (2) The cooling water freezes and cracks in winter; (3) The water jacket scale is too thick and the heat dissipation is poor; (4) The cylinder head bolts are not tightened according to regulations Sequence and torque are performed.

7. If the cylinder gasket is ablated, what are the signs? What is the main reason?

Answer: It will cause serious air leakage, gas will enter the water jacket or cooling water will enter the combustion chamber, resulting in air bubbles in the water tank, white smoke in the exhaust pipe, and water discharge, seriously preventing the engine from working normally. The main reasons are: (1) The cylinder head bolts are not tightened according to the specified sequence and torque; (2) The joint surface between the cylinder head and the cylinder block is uneven; (3) The cylinder gasket loses its elasticity after being used for a long time; (4) The cylinder liners of each cylinder protrude The height of the plane on the cylinder block is inconsistent.

8. How about cylinder and piston ring wear? What will be the result? What should I do?

Answer: It will cause the cylinder to be not tightly sealed and cause air leakage, which will cause the engine to be difficult to start, the engine will be dull, the power will decrease and the fuel consumption will increase, blue smoke will appear from the exhaust, and engine oil will be burned. If the phenomenon is serious, it means excessive wear, and the piston ring needs to be replaced, and the cylinder liner and piston must be replaced if necessary.

9. What are the main faults in the intake and exhaust pipelines? What will be the consequences? What should I do?

Answer: Mainly there is too much or insufficient oil in the air filter, the filter element is damaged or dirty, and the muffler is blocked. If the air filter has less oil or the filter element is damaged, the filtering effect will be poor and the wear of the cylinder liner, piston and piston ring will be aggravated. On the contrary, too much oil in the filter will cause carbon deposits in the combustion chamber and even speeding up. If the filter or muffler is blocked, the intake air volume will be reduced, the engine power will be significantly reduced, and the fuel consumption will be increased. Therefore, it is necessary to check the oil level of the filter frequently, and keep the oil level in compliance with the regulations. It is also necessary to maintain the filter element frequently to eliminate dirty clogging. If the filter element is damaged, it should be replaced in time.

10. What is the reason for the low oil pressure? What’s the harm? How to rule it out?

Answer: The main reasons are: (1) Lack of oil, blockage of the oil channel or oil filter, and leakage of the oil pipeline; (2) Wrong brand of engine oil, low viscosity, or reduced viscosity due to high oil temperature; (3) The pressure limiting valve and the oil return valve are not tightly closed due to dirt being stuck or worn, and the spring force is weakened or broken; (4) The wear of the main bearing, connecting rod bearing, camshaft bushing, etc. makes the matching clearance too large, causing serious leakage (5) The oil pump is severely worn, the oil pressure is reduced, and even the oil cannot be pumped.

If the oil pressure is too low, the parts will not be lubricated normally, and the wear will be aggravated. In severe cases, the bearings will be burned and the shaft will be locked.

If the engine oil pressure is too low, it should be checked item by item. First check the dirty blockage and engine oil grade, further check the status of each valve, and finally check the wear of bearings and bushings. If these parts are normal, it is caused by the wear of the oil pump itself. According to the cause of the oil pressure drop, it should be eliminated in a targeted manner.

11. What is the main fault of the diesel filter? What harm will it cause? How to solve?

Answer: The main reason is that the filter element is dirty and clogged, which causes the fuel injection pump to lack oil, making the diesel engine weak or even unable to work; there is also a rupture of the filter element, damage to the upper and lower sealing rings and pads, and loss of oil filtering effect. If it is dirty and blocked, it should be cleaned, and if the filter element is damaged, it should be replaced.

Friendly reminder: When an abnormality is found during the use of the diesel engine and you cannot troubleshoot it yourself, it is recommended that professional maintenance personnel carry out the inspection and maintenance, and do a good job of regular maintenance and maintenance of the engine to achieve the purpose of prolonging the service life of the machine and reducing failures.