There are many reasons for the failure of marine diesel engines. Caused by improper design structure and material selection, but also caused by poor manufacturing, assembly and debugging quality, but also caused by improper operation and poor maintenance. Here, the main causes of failures in operation, maintenance, and manufacturing are briefly introduced.

1. Operational reasons

Due to the failure of the ship's diesel engine caused by illegal operation, it accounts for a large proportion of the ship's diesel engine failure. There are ideological negligence, technical unfamiliarity, and wrong habits.

Common violations have the following aspects:

(1) The starting time is too long.

(2) The cold start starts quickly and increases the load without passing through the warm car.

(3) If the running-in is insufficient, it will run at high load.

(4) Emergency stop with load.

(5) The oil level is insufficient to drive.

(6) The water surface is not enough to drive.

(7) Overload or overspeed operation.

(8) The water temperature and oil temperature are abnormal and continue to operate.

(9) Emergency stop during high speed and high load operation

2. Maintenance reasons

Failure to perform maintenance as specified may also cause malfunctions. The common causes of failure are as follows:

(1) Adding or replacing new oil is not timely.

(2) The cleaning oil filter is not timely.

(3) Cleaning the diesel filter is not timely.

(4) Cleaning the air filter is not timely.

(5) Check and adjust the valve clearance is not timely.

(6) Check and adjust the fuel supply advance angle is not timely.

(7) Check and adjust the injector not in time.

(8) Checking and replenishing the electrolyte to the battery is not timely.

(9) The water release of the diesel engine in winter is not timely after parking.

3. Reasons for disassembly and assembly during maintenance

Disassembly and assembly errors are also one of the important reasons for the failure of marine diesel engines.

Among them are the following:

(1) The injector gasket is not installed correctly.

(2) The cylinder liner is not installed correctly.

(3) The gear meshing is incorrect.

(4) The nut is not installed correctly.

(5) The value of the matching gap is exceeded.

(6) The piston ring is not installed correctly.

4. Reasons for manufacturing

Most of the reasons for this are material misuse, intrinsic quality problems in the material and neglect of certain parts of the machine, making it unsatisfactory. The defects in this aspect are difficult to find in the assembly and are exposed after a period of use, resulting in damage to the parts. Its main performance is in the following aspects:

(1) The quality does not meet the requirements.

(2) The material does not meet the requirements.

(3) Heat treatment does not meet the requirements.

(4) Machining does not meet the requirements.

(5) The stress relief does not meet the requirements.