ATG 327 - Minor Svc/Repair/GM Engines Credits: 3
Lecture Hours: 2
Lab Hours: 2
Practicum Hours: 0
Work Experience: 0
Course Type: Voc/Tech
Course will provide instruction in the theory and operation of the General Motors four-stroke cycle engines. Emphasis will be placed on both design and proper disassembly/reassembly procedures.
Prerequisite: Admission to Automotive Service Educational Program, AUT 114
- Perform proper shop safety procedures.
- Apply work area safety skills.
- Demonstrate personal safety working habits.
- Practice tool and equipment safety use.
- Follow manufacture’s repair procedures.
- Follow manufacture’s warnings and government regulations.
- Explain the fundamentals of basic engine design and operation.
- Describe basic engine operation.
- Describe the basic laws of physics involved with engine operation.
- Classify engines according to the number of cycles, the number of cylinders, cylinder arrangement, and valve-train type.
- Define the four-stroke cycle theory.
- Describe the different cylinder arrangements and the advantages of each.
- Describe the different valvetrains used in modern engines.
- Define engine measurement terms such as bore and stroke, displacement, compression ratio, engine efficiency, horsepower and torque, horsepower losses, mechanical efficiency, and thermal efficiency.
- Describe the basic operation of alternative engine designs, including diesel, Miller-cycle, and stratified charge.
- Identify engine using vehicle identification number.
- Acquire pertinent service information for specific repair procedures.
- Identify hybrid vehicle internal combustion engine service precautions.
- Diagnose and repair cylinder head and valve train.
- Remove cylinder head; inspect gasket condition; install cylinder head and gasket; tighten according to manufacturer?s specifications and procedures.
- Clean and visually inspect a cylinder head for cracks; check gasket surface areas for warpage and surface finish; check passage condition.
- Inspect valve springs for squareness and free height comparison; determine necessary action.
- Inspect valve guides for wear; check valve stem-to-guide clearance; determine necessary action.
- Inspect valves and valve seats; determine necessary action.
- Check valve fact-to-seat contact and valve seat concentricity (runout); determine necessary action.
- Check valve spring assembled height and valve stem height; determine necessary action.
- Inspect pushrods, rocker arms, rocker arm pivots and shafts for wear, bending, cracks, looseness, and blocked oil passages (orifices); determine necessary action.
- Inspect valve lifters; determine necessary action.
- Adjust valves (mechanical or hydraulic lifters).
- Inspect camshaft drives (including gear wear and backlash, sprocket and chain wear); determine necessary action.
- 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.
- Inspect and/or measure camshaft for runout, journal wear and lobe wear.
- Inspect camshaft bearing surface for wear, damage, out-of-round, and alignment; determine necessary action.
- Establish camshaft(s) timing and cam sensor indexing according to manufacturer’s specifications and procedures.
- Diagnose and repair engine block assembly.
- Disassemble engine block; clean and prepare components for inspection and reassembly.
- Inspect engine block for visible cracks, passage condition, core and gallery plug condition, and surface warpage; determine necessary action.
- Inspect and measure cylinder walls/sleeves for damage, wear and ridges; determine necessary action.
- Deglaze and clean cylinder walls.
- Inspect and measure camshaft bearings for wear, damage, out-of-round, and alignment; determine necessary action.
- Inspect crankshaft for straightness, journal damage, keyway damage, thrust flange and sealing surface condition, and visual surface cracks; check oil passage condition; measure end play and journal wear; check crankshaft position sensor reluctor ring (where applicable); determine necessary action.
- Inspect main and connecting rod bearings for damage and wear; determine necessary action.
- Identify piston and bearing wear patterns that indicate connecting rod alignment and main bearing bore problems; determine necessary action.
- Inspect and measure piston skirts and ring lands; determine necessary action.
- Determine piston-to-bore clearance.
- Remove and replace piston pin.
- Inspect, measure, and install piston rings.
- Inspect auxiliary (balance, intermediate, idler, counterbalance or silencer) shaft(s); inspect shaft(s) and support bearings for damage and wear; determine necessary action; reinstall and time.
- Inspect or replace crankshaft vibration damper (harmonic balancer).
- Assemble engine block assembly.
- Install engine covers using gaskets, seals and sealers as required.
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