1. Focusing only on the quantity of engine oil in the oil pan, neglecting its quality. Some drivers only know to top up the engine oil, ignoring its quality. Unbeknownst to them, long-term use of engine oil contains a large amount of oxides and metal shavings, resulting in reduced lubrication performance and accelerated wear of parts. Therefore, the engine oil should be changed regularly according to the prescribed cycle.
2. Maintaining only the air filter, neglecting the exhaust pipe and muffler. Some drivers never clean carbon deposits from the exhaust pipe and muffler, leading to excessive carbon buildup, reduced exhaust cross-sectional area, incomplete exhaust gas expulsion, insufficient fresh air intake, and poor combustion.
3. Adding coolant without considering its cooling effect. Some drivers never remove scale buildup. Although the coolant level is sufficient, the cooling effect is poor, leading to various malfunctions.
4. Paying attention only to the quality of the plunger assembly and fuel injector needle valve assembly, neglecting the quality of the delivery valve assembly. The functions of the delivery valve are twofold: first, to seal the piston oil chamber from the high-pressure fuel line to prevent backflow; and second, to quickly reduce pressure when fuel supply stops, ensuring a clean fuel cut-off from the injectors. Poor quality or wear of the delivery valve assembly can cause numerous diesel engine malfunctions.
5. Focusing only on the condition of the valves and valve seats, neglecting the quality of the valve springs. When valves leak, people habitually check the valves and valve seats, but overlook the quality of the valve springs. It should be noted that insufficient valve spring force is also one of the causes of valve leakage.
