6.4.4. Precautions for operation 1) Precautions for operation of engine The following precautions should be observed when starting, operating, or stopping the engine : - 164 - MAINTENANCE OF MAJOR COMPONENTS Operations Precautions Reasons When starting the engine 1) Check oil level 2) Crank the engine with starter to check the increase in oil pres- sure(until the needle of pressure gauge starts to move or pressure indicator lamp is actuated) before starting the engine.
3) When having replaced oil, oil filter element, or lubricating parts, or when having stopped the engine for extended period of time, or in a cold place, loosen the oil pipe con- nections and operate the starter motor until oil is discharged. After completing the operation, be sure to retighten the oil pipe connections portion before starting the engine. 2) Abrupt starting of the engine caus- es the engine to rotate with oil not being distributed not only to each part but also to the turbocharger, resulting in abnormal wear or seizure on the bearing due to insufficient supply of oil.
3) In the case of the engine stopped for extended time or in a cold place, oil fluidity within the pipes can be deteriorated Immediately after starting 1) Run the engine at idle for 5 min- utes after starting off. 2) Check each part for leakage of oil, gas, and air, and take proper mea- sure. 1) Applying load abruptly If load is abruptly applied with the engine and turbocharger rotating unsmoothly, such parts that a suffi- cient amount of oil has not reached can be seized up. 2) Leakage of oil, gas, and air (espe- cially, oil leak) causes drop in oil pressure and loss of oil results in seizure of the bearing. During operation Check the followings: 1) Oil pressure At idle:
0.8 kg/cm2 or more At full load: 3.0 ~ 4.8 kg/cm2 2) If unusual sound or vibration is heard or felt, reduce engine revolu- tions slowly and locate the cause. 1) Excessively low oil pressure caus- es unusual wear or seizure of the bearing. Too high pressure causes oil leakage. 2) The engine is operated continuously with unusual sound or vibration not corrected, it can be damaged beyond repair. When stopping the engine 1) Run the engine at idle for 5 min- utes before stopping. 1) If the engine is put to a stop after being operated at high load, heat from the red-hot turbine blades is transmitted to the bearing portion and burns oil to cause seizure of the bearing metal and rotating shaft.