1 The abnormal sound of loader engine "connection with excavator load"
. The abnormal noise appears when a cylinder of the engine is misfired, and will disappear after a while. The reason may be because the engine piston knocks on the cylinder, or because the connecting rod bearing is loose, or the piston ring leaks.
The abnormal noise appears when a cylinder of the engine is misfired, but the abnormal noise is getting louder, it may be because: the copper sleeve of the piston pin is loose, the taper of the piston skirt is too large, the piston pin comes out, and the connecting rod bearing cover The fixing bolts have been loosened or the connecting rod bearing alloy has been melted and removed, etc.
. If there is a misfire between the two adjacent cylinders of the engine, the abnormal sound of the Carter loader engine may appear: the crankshaft bearing is loose.
2 Reasons for abnormal noise of loader engine "Relationship with engine speed"
The abnormal noise of the engine is displayed at idle or low speed. Generally, the reasons for the presentation are: the gap between the piston and the cylinder wall of the Caterpillar loader engine is too large, or the piston pin is installed too tightly, or the Caterpillar loader engine. Clearance between tappet and guide hole
Big wait.
. The abnormal sound of the Carter loader engine appears at a certain speed, which may be due to: the engine crankshaft is broken, the piston pin bush is loose, or the camshaft timing gear of the engine is broken or the fixing nut is loose.
The abnormal noise appears at the time when the Caterpillar loader engine speeds up, which may be due to the following reasons: the connecting rod bearing is loose, the bearing bush is melted or the dimensions are not consistent and rolling, the crankshaft bearing is loose or the bearing bush is burned, the piston pin is broken, the crankshaft is broken and many more.
Fault repair:
3. After disassembly, it was found that the rocker arm of the exhaust valve of the third cylinder was cracked, the upper half of the valve push rod was broken, the valve lock was damaged, and the valve fell into the cylinder. After removing the cylinder head, it was found to fall into the row of the third cylinder The valve rod is stuck on the exhaust valve seat ring, and the valve head in the falling cylinder touches the top of the third cylinder piston
hurt.
4 "The connection with temperature" of the abnormal sound of the loader engine
. Low temperature abnormal noise, the abnormal noise gradually disappears after the temperature rises. The reason for the abnormal noise of the Carter loader engine is: the gap between the piston and the cylinder wall is too large, or the engine oil pressure is low and the lubrication is not good.
High-temperature abnormal noise, the abnormal noise disappears as the temperature decreases. The reason for the abnormal noise of the Carter loader engine is: the piston of the Carter loader engine is deformed, or the gap between the piston rings is too small, and it may be pre-ignition caused by overheating, etc. the reason.
5.Update the third cylinder exhaust valve, exhaust valve seat ring, valve lock plate, valve oil seal, valve spring, valve push rod and rocker arm, etc., and reinvent the third cylinder exhaust valve seat. Repair the damaged part of the piston crown. Then carry out correct installation and commissioning, and prepare to start the test machine
.
6. However, in the process of driving the diesel engine with the starter motor, I still heard the "click, click" knocking sound inside the diesel engine. It was the same after several starts. At the beginning, it was thought that the top of the piston may not be trimmed. Complete, resulting in a recess in the head of the exhaust valve and the top of the piston
The edges collided and the abnormal noise was announced. To this end, the cylinder head was removed, and the top of the third cylinder piston was completely renovated. After reinstalling and trying again, there was still a "click, click" sound inside the diesel engine.
7. When using the starter motor to drive the diesel engine to roll, carefully observe the movement of the valve rocker arm. When it is found that the rocker head of the exhaust cylinder of the third cylinder has just pressed the valve, the "click, click" sound inside the diesel engine will follow. It can be seen that the abnormal sound is not due to the exhaust valve colliding with the piston. This is because,
At this time, the piston is near the bottom dead center. Further judgment, the problem may be between the camshaft and the tappet.
8. Remove the timing gear chamber cover of the diesel engine, remove the oil pan and the intake and exhaust valve tappets of the 4th cylinder, and the intake valve tappets of the 3rd cylinder. Then pull out the camshaft and the 3rd cylinder cracks The bottom of the column falls naturally.
9. Remove the cylinder head, when the third cylinder exhaust valve tappet is taken out upward, the tappet only needs to be cylindrical, and its bottom can not be taken out between the cam and the cylinder block duct. It is clear that the interior of the diesel engine The sound of "tapping" is because the bottom of the tappet after the crack is announced during the movement
Sound of collision.
10.Replace a new valve lifter and adjust the valve clearance to test the machine.The abnormal noise inside the diesel engine is eliminated and everything is normal.
