Basic Knowledge About Engine

1. What are the possible reasons for a significant increase in diesel engine lubricating oil consumption?

Answer: If a significant increase in lubricating oil consumption is observed during the operation and management of a diesel engine compared to normal consumption, the cause should be investigated and eliminated promptly. Possible reasons include:

(1) Rusting and damage at pipe connections or other parts, causing lubricating oil leakage;

(2) Severe internal leakage in the lubricating oil cooler;

(3) Incorrect installation of the oil scraper ring after cylinder overhaul in a cylinder-type engine, or failure of the oil scraper ring after prolonged operation;

(4) Cracks or damage in the oil sump or lubricating oil circulation tank;

(5) Failure of the piston rod packing gland seal, causing lubricating oil to be discharged from the bottom of the cylinder during drainage.

2. How to determine if the filter is in good working condition?

Answer: During diesel engine operation, the filter must maintain good filtration performance. Generally, pressure gauges are installed at both the inlet and outlet of the filter. The working condition of the filter can be determined by the pressure drop across the filter. If the pressure drop significantly exceeds the normal value, it indicates that the filter is clogged with excessive dirt and impurities, and the filter must be cleaned. If there is no pressure drop or the pressure drop is too low, it indicates that the filter screen is damaged or the filter element is improperly installed, and it needs to be disassembled and inspected immediately.

After cleaning the filter, it is essential to fill it with fluid and remove air; otherwise, it will cause interruption of fuel or lubricating oil supply, and even lead to serious accidents such as unexpected shutdowns. Therefore, although the filter is small, it must be carefully managed; otherwise, the consequences of an accident can be very serious.

3. What maintenance and repair work should be done on the diesel engine lubricating oil system?

Answer: In the diesel engine lubricating oil system, the lubricating oil pump is generally very durable as long as no hard foreign objects enter it and it is assembled correctly, because it is adequately lubricated. The coarse and fine filters should be regularly cleaned and inspected. If the coarse filter element is too dirty or damaged, it should be replaced. The filter element must be installed carefully to avoid incorrect installation. The lubricating oil cooler should also be inspected to assess its cooling effect, and cleaned if necessary. In the cooling water system (especially seawater cooling), many debris and impurities can easily clog the waterways. Any scale buildup on the cooling surface should be removed. Pressure relief valves should not be adjusted unless they are confirmed to be malfunctioning. Instruments and alarm devices should be handled with care, protected from impacts and moisture, kept away from high temperatures, and used within their specified operating ranges. When repairing machinery, disassembly and storage of parts should be done carefully. Regular checks should be performed to confirm that the automatic pressure and temperature alarm and control devices are functioning correctly.