Experience from senior master: What are the reasons for sudden halt of the loader diesel engine, and how to deal with it?
July 07, 2014
When the diesel engine halts suddenly during running, do not restart it immediately; please inspect carefully to find out the solution.
Major reasons for sudden halt of the loader diesel engine:
(I) Fault in the fuel supply system.
The engine may stop suddenly due to ingress of air in the oil-way of the diesel engine or interruption of fuel supply, and before the sudden halt, it always incurs speed fluctuation and runs unsteadily. The interruption of fuel supply may be caused by the followings:
a. Fuel shortage in fuel tank. Add fuel;
b. Poor oil-way tightness. Such fault can be diagnosed through bleeding the fuel system after the halt. If there are many foam-like bubbles discharged from the bleed screw when you pump the fuel with the hand pump, then the halt may be caused by the air invaded in the oil. In this case, check the tightness of the low-pressure oil-way carefully.
c. Breakage or key rolling of the fuel injection pump camshaft, or rupture of the connecting plate. Overhaul the fuel injection pump.
(II) Locking of the crankshaft
Observe whether the water temperature is unusual, and whether there is water in the oil sump (oil emulsified) after the halt. If OK, turn the diesel engine crankshaft. If the crankshaft rotates strenuously or remains still, it can be concluded that bearing bush has burnt out, or even the crankshaft has locked therefrom. If this happens, find out the reason, clean the oil-way, grind the crankshaft, and replace the bearing bush and parts (connecting rod, etc.) prior to assembly and test running.
(III) Cylinder scoring
Major reasons for sudden halt of the loader diesel engine:
(I) Fault in the fuel supply system.
The engine may stop suddenly due to ingress of air in the oil-way of the diesel engine or interruption of fuel supply, and before the sudden halt, it always incurs speed fluctuation and runs unsteadily. The interruption of fuel supply may be caused by the followings:
a. Fuel shortage in fuel tank. Add fuel;
b. Poor oil-way tightness. Such fault can be diagnosed through bleeding the fuel system after the halt. If there are many foam-like bubbles discharged from the bleed screw when you pump the fuel with the hand pump, then the halt may be caused by the air invaded in the oil. In this case, check the tightness of the low-pressure oil-way carefully.
c. Breakage or key rolling of the fuel injection pump camshaft, or rupture of the connecting plate. Overhaul the fuel injection pump.
(II) Locking of the crankshaft
Observe whether the water temperature is unusual, and whether there is water in the oil sump (oil emulsified) after the halt. If OK, turn the diesel engine crankshaft. If the crankshaft rotates strenuously or remains still, it can be concluded that bearing bush has burnt out, or even the crankshaft has locked therefrom. If this happens, find out the reason, clean the oil-way, grind the crankshaft, and replace the bearing bush and parts (connecting rod, etc.) prior to assembly and test running.
(III) Cylinder scoring
