The "National Occupational Standards for Automotive Maintenance Workers" defines job requirements for mid-level auto maintenance workers. Next, Automotive Network School will provide you with a detailed understanding of what professional skills intermediate automotive technicians require in terms of engine maintenance and repair.
1. Engine Maintenance
(1) Definition of engine inspection and additional work before re-maintenance
1. It can determine ignition timing of a gasoline engine. 2. It can detect motor power and speed drop of horizontal bar. 3. It can detect engine cylinder compression pressure, blown crankcase, cylinder leak and intake pipe vacuum. 4. It can detect fuel pressure and fuel advance angle in engine fuel supply system. 5. It can detect engine oil pressure and oil quality. 6. It can detect starting current and starting voltage of motor. 7. It can detect CO, HC emissions and diesel engine smoke under gasoline engine idling conditions. 8. Based on customer feedback, field test results, automotive technical files and other information, comprehensively assess technical condition of engine and determine additional work items. Commonly used engine diagnostic equipment includes: gasoline engine electrical tester, lube oil analyzer, crankcase gas tester, cylinder air leak tester, vacuum gauge, exhaust gas analyzer.
(2) Secondary Engine Additional Maintenance
1. The valve seat can be repaired;2. The valve can be replaced;3. Adjust axial clearance of crankshaft;4. It is possible to replace piston ring;5. You can adjust crankshaft bearing, connecting rod bearing clearance or replace bearing;6. The flywheel ring gear can be replaced;7. The oil advance angle of high pressure fuel pump can be adjusted.
Second, engine repair
(1) Inspection and classification of parts
1. It can disassemble, disassemble and clean engine assembly parts. 2. It can detect major parts such as cylinder head and engine block and identify repair items. 3. The ability to detect engine components, identify usable parts, repairable parts, and defective parts. 4. Ability to analyze causes of abnormal damage to typical parts such as cylinder head, cylinder, crankshaft and camshaft.
(2) Cylinder head and valve train overhaul
1. Knows how to check and remove toothed belt (chain) and gear (chain) of timing drive;2. Able to disassemble, disassemble and clean cylinder head;3. Able to disassemble, disassemble and clean parts Pneumatic mechanism;4. Ability to locate, repair or replace valves, valve springs, valve lifters, valve lifters, valve spring seats, valve rotation mechanisms and other components;5. Ability- grind valves and valves. seats , to detect valve tightness and valve seat;6, with camshaft and valve timing detection;7, with cylinder head detection;8, with cylinder head assembly; 9, ability to assemble and adjust valve mechanism.
(3) Overhaul of cylinder block and crank mechanism
1. It can check crack and corrosion of cylinder block, check passage of oil and water;2. It can determine flatness of each block connecting surface;3. He can measure wear of cylinder and determine repair size, 4. It can measure wear degree, roundness and cylindricity of crankshaft main shaft diameter and connecting rod shaft diameter, as well as bending or twisting deformation of crankshaft. ;5. It can detect bending or twisting deformation of connecting rod and correct connecting rod;6. Be able to detect and select pistons, piston rings, piston pins, piston pin bushings and assemble piston connecting rod groups;7. Be able to inspect and replace crankshaft torsion dampers;8. Be able to inspect and assemble crankshaft and flywheel;9. Be able to assemble and adjust cylinder block and crank mechanism.
(4) Electronic fuel injection system overhaul
1. Able to test, test and replace electric fuel pump and fuel pump relay;2. Able to detect and replace oil pressure regulator;3. Capable of detecting, cleaning and replacing fuel pump. Nozzle; >4. Can detect and clear idle control device;5. Can detect, clean and replace air mass meter;6. Can detect and replace intake air temperature sensor, coolant. temperature sensor and throttle position sensor; 7. Ability to test, clean and replace Exhaust Gas Recirculation (EGR) valves;8. Ability to inspect, clean and replace crankcase ventilation (PCV) valves; 9. Ability to inspect, clean and replace supercharger turbines.
(5) Overhaul of cooling and lubrication system
1. Be able to check working condition of cooling system and determine content of repair;2. Be able to detect thermostat;3. Be able to locate and replace fan temperature control switch. ;4.To be able to overhaul water pump;5.To be able to determine and adjust oil pressure, replace oil pressure control valve;6.To be able to overhaul oil pump.
(6) EFI Ignition Circuit Overhaul
1. It can repair magnetic pulse type crankshaft position sensor;2. It can repair Hall type crankshaft position sensor;3. He can findlive ignition coil;4. It can detect igniter.