ATG 333 - Major Service Proc/GM Engines

1. Practice safe working habits.
   1. Use proper eye protection.
   2. Select proper tools to work in a safe manner.
   3. Demonstrate a concern for the safety of fellow workers.
2. Evaluate engine performance.
   1. Evaluate engine performance during a road test.
   2. Perform cylinder power balance test; determine necessary action.
   3. Perform engine absolute (vacuum/boost) manifold pressure tests; determine necessary action.
   4. Perform cylinder cracking compression tests; determine necessary action.
   5. Perform cylinder leakage test; determine necessary action.
   6. Perform cylinder running compression test; determine necessary action.
   7. Analyze engine fluid leaks.
   8. Diagnose abnormal engine noises or vibration concerns; determine necessary actions.
   9. Diagnose the cause of excessive oil consumption, coolant consumption, unusual exhaust color, odor, and sound; determine necessary action.
3. Service cooling system.
   1. Discuss types of coolant.
   2. Identify causes of engine overheating.
   3. Inspect, replace, and adjust drive belts, tensioners, and pulleys; check pulley and belt alignment.
   4. Inspect and test coolant; drain and recover coolant; flush and refill cooling system with recommended coolant; bleed as required.
   5. Perform cooling system pressure and dye tests to identify leaks; Inspect and test radiator, pressure cap, coolant recovery tank, heater core and radiator hoses; determine necessary action.
   6. Inspect, remove, and replace water pump.
   7. Remove and replace radiator.
   8. Remove, inspect and replace thermostat and gasket/seal.
   9. Inspect and test cooling fans (electrical and mechanical), fan clutch, and fan shrouds and air dams.
   10. Inspect, test, and replace coolant temperature and pressure switches and sensors.
4. Service engine lubrication system.
   1. Explain engine oil classifications and categories.
   2. Perform engine oil pressure test; determine necessary action.
   3. Inspect, test, and replace oil temperature and pressure switches and sensors.
5. Engine assembly removal and reinstallation.
   1. Inspect engine assembly for fuel, oil, coolant, and other leaks; determine necessary action.
   2. Remove and reinstall engine assembly in and OBD II or newer vehicle; reconnect all attaching components and restore vehicle to running condition.
   3. Perform predetermined operations; clean engine components, inspect components for wear, and perform any necessary measurements; determine any necessary operations to restore engine to manufacturer’s recommendations.
   4. Verify operation of the instrument panel warning indicators.
6. Perform in-vehicle service.
   1. Inspect and replace camshaft and drive belt/chain; includes checking drive gear wear and backlash, end play, sprocket and chain wear, overhead cam drive sprocket(s), drive belt(s), belt tension, tensioners, camshaft reluctor ring/tone-wheel, and valve timing components; verify correct camshaft timing.
   2. Replace valve stem seals on an assembled engine; inspect valve spring retainers, locks/keepers, and valve lock/keeper grooves; determine necessary action.
   3. Adjust valves (mechanical or hydraulic lifters).