Diagnosis And Analysis of Lubrication System Faults

a. Excessive oil consumption

Firstly, it is necessary to determine whether the diesel engine has external oil leakage; (Turn on the diesel engine and run it until the outlet water temperature reaches 80 degrees. Check for leaks in the external gaskets, seals, "O" ring seals, plugs, pipe joints, rubber connections, and other parts of the diesel engine.)

Secondly, check if the diesel engine crankcase ventilation system is obstructed;

If the piston ring seal is poor, the engine oil enters the combustion chamber and is burned or leaks too much, and the oil droplets, along with the leaked combustion gas, are blown out of the engine body through the crankcase ventilation mechanism.

b. Internal damage inspection of diesel engine, cutting open the oil filter, and inspecting the following items:

Metal: Possible causes of particle failure

Damaged copper bearing shells or connecting rod small end bushings

Wear of chrome piston rings

Severe wear of lead bearing shell coating material

Wear or damage to aluminum pistons

c. Lubrication system fault diagnosis

To diagnose lubrication system faults, it is necessary to inspect various parts related to the oil, such as the oil pressure gauge, oil fluid, oil contamination, oil viscosity, etc.

d. Oil pressure too high

In cold weather, after the first start of a diesel engine, the oil pressure is usually too high. It is also possible that the oil pressure regulating valve is stuck in the high-pressure position, the oil level is too high, and the oil viscosity is too high.

e. Oil pressure too low

Many lubrication system malfunctions can cause a decrease in oil pressure. When the oil pressure is found to be too low, it is necessary to first determine whether the working conditions of the diesel engine are normal, and then check for faults.

Possible causes: low oil level, clogged oil filter, damaged oil pressure gauge (check for broken wires, failure of pressure sensor components, leaks or breaks in pipelines), excessive wear of oil pump (this fault usually occurs after diesel engines have been running for a long time), thinning of oil (if the oil becomes thin or black, it indicates mixed fuel; if the oil emulsion turns white, it indicates mixed coolant).