1. Air filter factor. The function of an air filter is to remove dust and impurities from the air, sending clean air (or a combustible mixture of air and fuel) into the combustion chamber to reduce wear between the piston and cylinder liner, piston group, and valve group. In addition, it also has the effect of suppressing the intake noise of diesel engines.
If the filter element of the air filter becomes blocked, or if there is an increase in resistance when air passes through due to quality issues, it will result in insufficient intake in the diesel engine. If the amount of air entering the cylinder decreases, it will make the fuel mixture unsuitable (usually too rich), and the direct result is incomplete combustion of the fuel injected into the cylinder. At this point, the diesel engine may experience insufficient power and black exhaust smoke.

2. Intake pipe factor. In the connecting pipeline from the air filter to the intake manifold of the diesel engine (which is the compressor inlet for turbocharged diesel engines), there is usually a rubber hose connection. If the hose is compressed or internally peeled or damaged due to certain reasons, it will affect the air flow rate, and the result is the same as if the air filter is blocked. This will also lead to the phenomenon of insufficient power in diesel engines due to insufficient intake air.

3. If the quality of the air filter is poor or there is damage or air short circuit on the intake pipeline, causing unclean air to enter the cylinder, it will cause serious wear of the diesel engine cylinder liner, piston, and piston ring. And it causes faults such as blue exhaust, black smoke, insufficient power, and oil burning in the diesel engine.

4. The impact of the turbocharging system. The purpose of the exhaust turbocharging system of a diesel engine is to increase the air pressure entering the cylinder, thereby increasing the air density entering the cylinder, and achieving the goal of increasing fuel injection volume and increasing power.
When certain reasons lead to insufficient boost pressure or blockage or leakage of pipelines (such as intercoolers, intake manifold interfaces, etc.) after the turbocharger compressor, diesel engines may also experience faults such as reduced power due to insufficient intake air.
In addition, if the sealing gasket at the intake port on the cylinder head is damaged and leads to poor sealing, it will reduce the boost pressure, which will also lead to insufficient power failure in the diesel engine.

5. When the diesel engine runs normally at idle speed but emits black smoke during load operation, it is highly likely that the air filter is blocked, resulting in insufficient intake. At this point, the air filter can be removed for a short time and the diesel engine can be started to operate under load. If the black smoke disappears, it indicates that the air filter is blocked and needs to be cleaned or replaced.

6. If the diesel engine always experiences abnormal wear of unknown causes such as cylinder pistons, after excluding factors such as accessory quality and oil quality, unclean intake air in the intake system should be the main cause. At this point, the entire intake system from the air filter inlet to the intake manifold inlet on the cylinder head should be carefully checked for damage or air short circuits, especially for any special purpose interfaces on the intake pipe that may cause air short circuits.

7. Under normal circumstances, the air filter should be regularly maintained.