HOW MANY ENGINES ARE NOT DISMANTLED? IT'S NOT A BIG DEAL DISMANTLED, REINSTALLED, WHEEZING, HEADING TOWARDS SCRAP? GUIDE TO REPAIRING DIESEL ENGINES, SUITABLE FOR BOTH LARGE AND SMALL VEHICLES, PLEASE SPREAD THE MESSAGE A QUALIFIED DIESEL ENGINE REPAIRMAN THESE EIGHT MAJOR LEVELS MUST BE OVERCOME LEVEL 1: "THREE LEAKS" LEVEL TO PREVENT AND SOLVE THE "THREE LEAKS" PROBLEM WHEN REPAIRING DIESEL ENGINES, THE "FIVE CHARACTER" PRINCIPLE CAN BE ADOPTED, WHICH IS STRICT, CLEAN, WIPE, GRIND, AND TIGHTEN. STRICT REQUIREMENTS MUST BE PLACED ON THE DISASSEMBLY AND INSTALLATION OF PARTS, AND OPERATING PROCEDURES MUST BE FOLLOWED. RANDOM TAPPING IS STRICTLY PROHIBITED. WHEN TIGHTENING BOLTS, THEY SHOULD BE TIGHTENED IN SEQUENCE AND SEVERAL TIMES, AND SHOULD NOT BE TWISTED RANDOMLY TO PREVENT PART DEFORMATION. CLEAN: BEFORE ASSEMBLING THE COMPONENTS, THEY MUST BE THOROUGHLY CLEANED TO PREVENT IMPURITIES FROM ENTERING. IF TINY IMPURITIES ARE MIXED IN AT THE CONTACT RING BETWEEN THE OIL OUTLET VALVE AND THE VALVE SEAT, IT WILL NOT ONLY CAUSE OIL LEAKAGE, BUT ALSO DIRECTLY AFFECT THE OPERATION OF THE ENGINE. APPLY SEALANT TO THE OIL LEAKAGE AREAS OF ASBESTOS PADS, PAPER PADS, AND VARIOUS PLUGS. WHEN APPLYING ASBESTOS OIL, IT SHOULD BE THIN AND EVEN, NOT TOO THICK, AND NOT COVER THE ENTIRE SURFACE OF THE PAD. ONLY APPLY THE LEAKED AREA. GRINDING: GRINDING OR MILLING THE JOINT SURFACE OF A COMPONENT, ITS FUNCTION IS TO RESTORE THE SURFACE SMOOTHNESS AND ACCURACY, SO THAT THE OIL PIPE JOINT OR GASKET CAN MAINTAIN SEALING AND PREVENT OIL LEAKAGE AFTER GRINDING. TIGHTNESS: THE TIGHTNESS OF THE SEALING DEVICE SHOULD BE APPROPRIATE AND NOT TOO TIGHT OR TOO LOOSE. FOR EXAMPLE, VARIOUS CONTACT SURFACES AND SEALING NUTS OF DIESEL ENGINES MUST MAINTAIN APPROPRIATE TIGHTNESS. SECOND LEVEL: CYLINDER PRESSURE OFF IN ORDER TO ENSURE SUFFICIENT CYLINDER PRESSURE, THE CLEARANCE BETWEEN THE PISTON AND CYLINDER LINER, THE END AND EDGE CLEARANCE OF THE PISTON RING MUST MEET THE REQUIREMENTS, THE SEALING BETWEEN THE VALVE AND VALVE SEAT, THE SEALING AT THE FRONT END OF THE INJECTOR MUST BE GOOD, THE CYLINDER GASKET MUST BE GOOD, AND THE THICKNESS MUST MEET THE REQUIREMENTS. LEVEL 3: COMBUSTION CHAMBER VOLUME CONTROL AFTER REPAIRING A DIESEL ENGINE, THE COMBUSTION CHAMBER VOLUME OFTEN CHANGES, ALTERING THE ORIGINAL COMPRESSION RATIO AND DIRECTLY AFFECTING THE NORMAL OPERATION OF THE DIESEL ENGINE. FACTORS THAT CAN CAUSE CHANGES IN COMBUSTION CHAMBER VOLUME INCLUDE: REVERSED PISTON POSITION, IMPROPER CYLINDER GASKET THICKNESS, MECHANICAL WEAR OR BENDING OF THE CRANKSHAFT AND CONNECTING ROD, MISALIGNMENT OF THE SWIRL CHAMBER INSERT, AND EXCESSIVE VALVE DEPRESSION. DURING REPAIR, ATTENTION SHOULD BE PAID TO THESE SITUATIONS. FOURTH LEVEL: TIMING LEVEL TIMING SHUTDOWN INCLUDES FUEL SUPPLY TIMING AND VALVE TIMING. IF THE FUEL SUPPLY TIMING IS NOT CORRECT OR THE VALVE TIMING IS INSUFFICIENT, IT WILL CAUSE THE VEHICLE TO BE DIFFICULT TO START. IF THE VALVE IS NOT TIGHTLY CLOSED OR THE VALVE HEAD HITS THE PISTON, IT WILL BE ACCOMPANIED BY ENGINE SHAKING AND INCORRECT EXHAUST COLOR. LEVEL 5: "THREE FILTERS" LEVEL POOR TECHNICAL CONDITION OF THE AIR FILTER CAN CAUSE DUST TO ENTER THE VALVE. EARLY WEAR OF ACCELERATION PISTON RINGS, CYLINDERS, VALVES, AND VALVE SEATS CAUSES DIFFICULTY IN STARTING AND A DECREASE IN POWER. POOR TECHNICAL CONDITION OF DIESEL AND ENGINE OIL FILTERS CAN ALLOW IMPURITIES TO ENTER BETWEEN RELATED COMPONENTS, CAUSING EARLY WEAR OF THE THREE MAJOR PRECISION COMPONENTS, ACCELERATING CRANKSHAFT AND BEARING WEAR, AND IN SEVERE CASES, LEADING TO EARLY SCRAPPING OF DIESEL ENGINES. LEVEL 6: DIESEL ATOMIZATION POOR TECHNICAL CONDITION OF THE PLUNGER PAIR, OUTLET VALVE PAIR, AND INJECTOR NEEDLE VALVE PAIR CAN ALL CAUSE POOR FUEL ATOMIZATION, MAKING IT DIFFICULT TO START THE DIESEL ENGINE, INCOMPLETE COMBUSTION, INCREASED CARBON DEPOSITS, RESULTING IN DECREASED ENGINE POWER AND INCREASED FUEL CONSUMPTION. THEREFORE, THE FUEL SYSTEM, ESPECIALLY PRECISION COMPONENTS, SHOULD BE CAREFULLY INSPECTED. SEVENTH LEVEL: CLOSING OF THROUGH HOLES AND SMALL HOLES (1) THE 5 THROUGH HOLES OF THE BEARING AND BUSHING SHOULD BE ALIGNED DURING INSTALLATION. A. THE MAIN BEARINGS HAVE OIL HOLES DRILLED ON EACH PAIR OF MAIN BEARING OIL GROOVES, WHICH ARE CONNECTED TO THE OIL ON THE CYLINDER BLOCK AND MAIN SHAFT NECK. DURING INSTALLATION, AS LONG AS THE FLANGE GAP OF THE MAIN BEARING IS ALIGNED WITH THE POSITIONING PIN, IT CAN PREVENT THE MAIN BEARING FROM ROTATING, ENSURE THAT THE OIL HOLES ARE ALIGNED, AND ENSURE THAT THE LUBRICATING OIL CIRCUIT IS UNOBSTRUCTED, AVOIDING BURNING. B. ROCKER ARM BUSHING. WHEN PRESSING THE BUSHING INTO THE ROCKER ARM, IF THE HOLE IS NOT ALIGNED, THE ROCKER ARM SHAFT AND BUSHING WILL BE BURNED DUE TO LACK OF LUBRICATION AND DRY FRICTION, RESULTING IN INCREASED VALVE CLEARANCE AND SEVERE KNOCKING SOUND. C. CONNECTING ROD BUSHING. THE CONNECTING ROD SMALL HEAD IS DRILLED WITH AN OIL COLLECTION HOLE, WHICH IS CONNECTED TO THE OIL HOLE OF THE CONNECTING ROD LINER. WHEN A COPPER SLEEVE IS INSERTED INTO THE CONNECTING ROD SMALL HEAD, IF THE TWO OIL HOLES ARE NOT ALIGNED, THE COPPER SLEEVE AND PISTON PIN WILL MAKE A "CLANGING" SOUND, AND EVEN BITE TO DEATH. D. WHEN INSTALLING THE STARTER SHAFT BUSHING, THE OIL HOLES OF THE TWO BUSHINGS SHOULD BE CONNECTED TO THE CORRESPONDING OIL COLLECTION GROOVES ON THE ENGINE BODY AND GEAR COVER. OTHERWISE, THE WEAR OF THE STARTER SHAFT AND BUSHING WILL ACCELERATE, CAUSING CHANGES IN THE FUEL SUPPLY ANGLE AND VALVE TIMING, RESULTING IN A DECREASE IN DIESEL ENGINE POWER. (2) THERE ARE MAINLY FOUR SMALL HOLES IN XIAOKOUGUAN A. FUEL TANK CAP VENT HOLE. AFTER THE HOLE IS BLOCKED, THE FUEL TANK IS NO LONGER CONNECTED TO THE ATMOSPHERE, AND NEGATIVE PRESSURE WILL OCCUR IN THE UPPER PART OF THE TANK DUE TO THE DECREASE IN OIL LEVEL, CAUSING FUEL SUPPLY INTERRUPTION; AFTER THE FUEL IS HEATED AND EVAPORATES, THE PRESSURE INSIDE THE FUEL TANK INCREASES, WHICH CAN CAUSE OIL LEAKAGE AT THE FUEL TANK SWITCH. THEREFORE, THIS HOLE CANNOT BE BLOCKED. B. WHEN THE CRANKCASE AIR CHANGE HOLE IS BLOCKED, THE EXHAUST GAS INSIDE THE CRANKCASE ACCUMULATES MORE AND MORE, AND THE AIR PRESSURE INSIDE THE CRANKCASE INCREASES, WHICH WILL CAUSE OIL LEAKAGE. HIGH HUMIDITY EXHAUST GAS WILL MIX INTO THE OIL, ACCELERATE OIL DETERIORATION, AND ACCELERATE MECHANICAL WEAR. THEREFORE, IT IS NECESSARY TO CLEAR THIS HOLE DURING MAINTENANCE. C. OIL PUMP DRAIN HOLE. THE BLOCKAGE OF THE OIL DRAIN HOLE ON THE FUEL PUMP CAN CAUSE A SMALL AMOUNT OF DIESEL TO LEAK INTO THE FUEL INJECTION PUMP BETWEEN THE PUSH ROD AND THE CONDUIT, DILUTING THE LUBRICATING OIL IN THE HOUSING AND ACCELERATING THE WEAR OF THE PARTS. THEREFORE, THIS HOLE CANNOT BE BLOCKED. D. IF THE WATER PUMP DRAIN HOLE IS BLOCKED, THE LEAKED WATER CANNOT BE DISCHARGED FROM THE PUMP BODY AND ENTER THE BEARING SEAT, WHICH WILL ACCELERATE THE DAMAGE OF THE BEARING. THEREFORE, IT IS NECESSARY TO CLEAR THIS HOLE DURING MAINTENANCE. EIGHTH LEVEL: BREAK IN LEVEL (1) COLD BREAK IN. REMOVE THE FUEL INJECTOR AND USE EXTERNAL FORCE TO DRIVE THE DIESEL ENGINE. AT THE SAME TIME, CHECK THE OIL PRESSURE AND TEMPERATURE OF EACH PART, AND PAY ATTENTION TO THE SOUND OF EACH COMPONENT. AFTER COLD RUNNING IN, WHEN THE TEMPERATURE IS HIGH, RELEASE THE OIL AND CLEAN THE OIL FILTER AND OIL PASSAGE. (2) HOT BREAK IN. NO LOAD HOT RUNNING IN, PAY ATTENTION TO THE WORKING CONDITION OF THE DIESEL ENGINE AND THE SOUND OF VARIOUS PARTS; ACCORDING TO THE PRESCRIBED LOAD AND TIME FOR HOT RUNNING IN, PAY ATTENTION TO THE SOUND OF VARIOUS PARTS AND THE AIR LEAKAGE, SMOKE EXHAUST, AND FUEL INJECTOR RETURN OF THE OIL PORT. IF ANY PROBLEMS ARE FOUND, THEY SHOULD BE PROMPTLY ELIMINATED.