The occurrence of abnormal sound fault of Carter excavator engine is often related to the speed of the engine, the load borne by the engine, the temperature of the engine and the working circulating oil pipe of the engine. Therefore, when checking the cause of abnormal sound fault of Carter excavator engine, you can further find out according to the location of abnormal sound
1. Relationship between the cause of abnormal noise of Carter excavator engine and engine speed
Abnormal engine noise occurs when the engine is idling or running at low speed The general causes are: the clearance between the piston and cylinder wall of Carter excavator engine is too large, or the piston pin assembly is too tight, or the clearance between the tappet and guide hole of Carter excavator engine is too large, etc
The sudden occurrence of abnormal noise of Carter excavator engine at a certain speed may be caused by broken engine crankshaft, loose piston pin bushing, or broken camshaft timing gear of the engine or loose fixing nut
The abnormal noise occurs when the engine of Carter excavator accelerates rapidly. The possible reasons are: loose connecting rod bearing, burning of bearing bush or rotation due to inconsistent size, loose crankshaft bearing or burning of bearing bush, broken piston pin, broken crankshaft, etc
2 Relationship between "abnormal noise" of Carter excavator engine and excavator load
The abnormal noise occurs when a cylinder of the engine is off, and it disappears after a while The reason may be that the engine piston knocks, or the connecting rod bearing is loose, or the piston ring leaks
The abnormal noise occurs when a cylinder of the engine is cut off, but the abnormal noise is getting louder and louder, which may be due to: loose copper sleeve of piston pin, excessive taper of piston skirt, channeling of piston pin, loose fixing bolts of connecting rod bearing cap, or even burning and melting of connecting rod bearing bush alloy, etc
If the fire is cut off between two adjacent cylinders of the engine and the engine makes abnormal noise, the reason may be that the crankshaft bearing is loose
3. Relationship between abnormal noise of Carter excavator engine and temperature
Abnormal noise at low temperature. The abnormal noise disappears gradually after the temperature rises The reason for the abnormal noise of Carter excavator engine is that the clearance between piston and cylinder wall is too large, or the engine oil pressure is low and the lubrication is not good
Abnormal noise at high temperature disappears as the temperature decreases The reasons for the abnormal noise of Carter excavator engine are: the piston of Carter excavator engine is deformed, or the clearance of piston ring is too small, and early combustion caused by overheating
Troubleshooting:
1. After disassembly and inspection, it is found that the rocker arm of the exhaust valve of cylinder 3 is broken, the upper half of the valve push rod is broken, the valve key is damaged, and the valve falls into the cylinder After removing the cylinder head, it is found that the exhaust valve rod falling into the third cylinder is stuck on the exhaust valve seat ring, and the valve head falling into the cylinder will bruise the top of the piston of the third cylinder
2. Renew the exhaust valve, exhaust valve seat ring, valve key, valve oil seal, valve spring, valve push rod and rocker arm of cylinder 3, ream the exhaust valve seat of cylinder 3, and repair the damaged part of piston crown Then carry out correct installation and commissioning, and prepare for start-up and commissioning
3. However, when the starting motor is used to drive the diesel engine, the knocking sound of "Da, Da" can still be heard inside the diesel engine This is true after several starts At first, it was thought that the top of the piston was not completely repaired, resulting in the collision between the edge of the exhaust valve head and the edge of the pit on the top of the piston To this end, remove the cylinder head again, completely trim the top of the piston of the third cylinder, reinstall it and try again. There is still a "click, click" sound inside the diesel engine
4. When the starting motor is used to drive the diesel engine to rotate, carefully observe the action of the valve rocker arm It is found that when the rocker arm head of the exhaust valve of cylinder 3 just depresses the valve, the "click, click" sound inside the diesel engine will follow It can be seen that the abnormal noise is not caused by the collision between the exhaust valve and the piston This is because the piston is now near bottom dead center Further judgment, the problem may be between camshaft and tappet
5. Remove the cylinder head. When the exhaust valve tappet of cylinder 3 is taken out upward, the tappet has only a barrel, and its bottom remains between the cam and the cylinder block guide tube Obviously, the "click, click" sound inside the diesel engine is due to the collision sound made by the bottom of the broken tappet during movement
6. Remove the timing gear chamber cover of diesel engine, and remove the oil pan, intake and exhaust valve tappets of cylinder 4 and intake valve tappets of cylinder 3 at the same time Then pull out the camshaft and the bottom of the broken tappet of cylinder 3 will fall naturally
7. Replace a new valve tappet, adjust the valve clearance and try the engine again. The abnormal noise inside the diesel engine is eliminated and everything is normal
