Troubleshooting of the failure to start the hottes

Troubleshooting of the failure of 320b excavator to start

(20:06:04) a Carter 320b10 sample can only succeed in about 1.5 type excavator. During long-distance transportation, it accidentally overturned beside the road. After lifting the controller 86 times higher than ABS plastic with a crane, it was found that the protective shell on only one side of the engine of the excavator was damaged, while the rest was intact. The driver checked and found that the oil, diesel and cooling water were all lost to varying degrees. When starting the engine after adding oil, diesel and water respectively, he only heard a strong impact sound between the starter and the engine flywheel. At the same time, he observed that the engine fan blade only turned slightly, and the fault remained when starting again

to find out "why the starter can't drive the engine", first, check whether the electrical part or the motor part is faulty. When the wrench is used to pull the bolt back and forth on the crankshaft pulley, it feels very laborious, and the pulley can only rotate back and forth at a small angle, which indicates that the starter can not drive the engine to rotate is caused by excessive engine resistance, not electrical failure. The analysis shows that before the excavator is placed on the trailer for long-distance transportation, the technical state of the engine is normal, so it is impossible for the timing system, connecting rod valve train to be stuck and the crankshaft to be locked; The failure of the starter to drive the engine to rotate occurs after the excavator rolls over. When the excavator rolls over, the I cylinder of the engine is higher than the VI cylinder, and the oil pan is higher than the cylinder head. When the engine is in this state, the oil in the oil pan will slowly flow into the combustion chamber from the cylinder wall gap; Since the position of cylinder VI is the lowest and that of cylinder I is the highest, cylinder VI is the most likely to flow oil into the fuel chamber, followed by cylinder V, cylinder IV, and cylinder I is the least likely. So remove the valve covers of cylinders IV, V and VI, and insert a slotted screwdriver into the gap between the intake and exhaust valves of cylinder VI, in order to keep the intake and exhaust valves of cylinder VI open all the time. At this time, pull the crankshaft pulley back and forth with a wrench, and feel that the crankshaft rotation angle is slightly larger than before, and then calibrate the sensor again to work normally. In the same way, make the intake and exhaust valves of cylinder v open. When rotating the crankshaft pulley, feel that the crankshaft can rotate at a larger angle; Make the intake and exhaust valves of cylinder IV open, and when the crankshaft pulley is turned, the crankshaft can rotate 360 °. This proves that it is the oil in the engine oil pan that flows into the combustion chamber through the cylinder wall gap. Because a large amount of oil flows into the combustion chamber, when the starter (or wrench the crankshaft pulley) makes the crankshaft rotate, the compression ratio is too high during the upward process of the piston (all gaps are completely sealed). The crankshaft rotation resistance is too large, so it shows that the starter cannot drive the engine to rotate. After finding out the cause of the fault, it was decided to use a 1mm feeler gauge to insert into the gap between the inlet and exhaust valves of cylinders IV, V and VI to replace the slotted screwdriver (because the slotted screwdriver is too thick) to prevent the valve from being pressed down too much and damaging the piston, but the starter also failed to start during the test run, so the thickness of the feeler gauge was increased from 1mm to 1.5mm, and the engine could start smoothly when it was started again, and a large amount of oil was discharged from the exhaust pipe. At this time, a two cylinder feeler gauge slipped out of the valve clearance to learn the operating instructions of the experimental machine, and the engine was immediately suppressed and stalled; Insert the feeler gauge again, start the engine smoothly again, and idle for about 1min, but after the feeler gauge of cylinder IV is pulled out, the engine is smothered again, indicating that there is still a lot of oil in the combustion chamber, so insert the feeler gauge again, start the engine again, and idle for 5min. After it is estimated that the oil in the combustion chamber has been drained, extract the feeler gauges of cylinder IV and cylinder V successively, and the engine can operate normally. Finally, extract the feeler gauge of cylinder IV, The engine also operates normally. It indicates that the fault has been completely eliminated

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