AGM 112W - Engine Service

Credits: 6
Instructional Contact Hours: 8

Introduces the operation, maintenance, and service of GM engines for mechanical performance. Stresses proper repair techniques and diagnosis of engine noises. Credit may be earned in AGM 112 or ACD 112 or SKGM 112 or AGM 141 but not in more than one.

Prerequisite(s): Program Coordinator permission
Corequisite(s): AGM 110, AGM 114, AGM 134
Lecture Hours: 45 Lab Hours: 75
Meets MTA Requirement: None
Pass/NoCredit: No

Outcomes and Objectives 1. Diagnose General Engine; Removal and Reinstallation (R&R). Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3
NATEF tasks as listed below.

A. Locate and interpret vehicle and major component identification numbers (VIN, vehicle certification labels, and calibration decals). P-1

B. Inspect engine assembly for fuel, oil, coolant, and other leaks; determine necessary action.

P-1

C. Diagnose engine noises and vibrations; determine necessary action. P-2

D. Diagnose the cause of excessive oil consumption, unusual engine exhaust color, odor, and

sound; determine necessary action. P-2

E. Perform engine vacuum tests; determine necessary action. P-1

F. Perform cylinder power balance tests; determine necessary action. P-1

G. Perform cylinder compression tests; determine necessary action. P-1

H. Perform cylinder leakage tests; determine necessary action. P-1

I. Remove and reinstall engine in a late model front-wheel drive vehicle (OBDI or newer);

reconnect all attaching components and restore the vehicle to running condition. P-1

2. Diagnose and repair cylinder head and valve train. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

A. Remove cylinder head(s); visually inspect cylinder head(s) for cracks; check gasket surface areas for warpage and leakage; check passage condition. P-2

B. Install cylinder heads and gaskets; tighten according to manufacturer's specifications and procedures. P-1

C. Inspect valve springs for squareness and free height comparison; determine necessary action. P-2

D. Replace valve stem seals on an assembled engine; inspect valve spring retainers, locks, and valve grooves; determine necessary action. P-2

E. Inspect valve guides for wear; check valve stem-to-guide clearance; determine necessary action. P-3

F. Inspect valves and valve seats; determine necessary action. P-3

G. Check valve face-to-seat contact and valve seat concentricity (runout); determine necessary action. P-3

H. Check valve spring assembled height and valve stem height; determine necessary action. P-3

I. Inspect pushrods, rocker arms, rocker arm pivots and shafts for wear, bending, cracks, looseness, and blocked oil passages (orifices); determine necessary action. P-2

J. Inspect hydraulic or mechanical lifters; determine necessary action. P-2

K. Adjust valves (mechanical or hydraulic lifters). P-1

L. Inspect camshaft drives (including gear wear and backlash, sprocket and chain wear); determine necessary action. P-2

M. Inspect and replace timing belts (chains), overhead camdrive sprockets, and tensioners; check belt/chain tension; adjust as necessary. P-1

N. Inspect camshaft for runout, journal wear and lobe wear. P-2

O. Inspect camshaft bearing surface for wear, damage, out-of-round, and alignment; determine necessary action. P-3

P. Establish camshaft(s) timing and cam sensor indexing according to manufacturer’s specifications and procedures. P-1

3. Diagnose and repair engine block assembly. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

A. Disassemble engine block; clean and prepare components for inspection and reassembly. P-2

B. Inspect engine block for visible cracks, passage condition, core and gallery plug condition, and surface warpage; determine necessary action. P-2

C. Inspect internal and external threads; restore as needed (includes installing thread inserts). P-2

D. Inspect and measure cylinder walls for damage, wear, and ridges; determine necessary action. P-2

E. Deglaze and clean cylinder walls. P-2

F. Inspect and measure camshaft bearings for wear, damage, out-of-round, and alignment; determine necessary action. P-3

G. Inspect crankshaft for end play, straightness, journal damage, keyway damage, thrust flange and sealing surface condition, and visual surface cracks; check oil passage
condition; measure journal wear; check crankshaft sensor reluctor ring (where applicable); determine necessary action. P-2

H. Inspect and measure main and connecting rod bearings for damage, clearance, and end play; determine necessary action (includes the proper selection of bearings). P-2

I. Identify piston and bearing wear patterns that indicate connecting rod alignment and main bearing bore problems; inspect rod alignment and bearing bore condition. P-3

J. Inspect and measure pistons; determine necessary action. P-2

K. Remove and replace piston pin. P-3

L. Inspect, measure, and install piston rings. P-1

M. 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. P-2

N. Inspect or replace crankshaft vibration damper (harmonic balancer). P-3

O. Assemble the engine using gaskets, seals, and formed-in-place (tube-applied) sealants, thread sealers, etc. according to manufacturer’s specifications. P-2

4. Diagnose and repair lubrication and cooling systems. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

A. Perform oil pressure tests; determine necessary action. P-1

B. Inspect oil pump gears or rotors, housing, pressure relief devices, and pump drive; perform necessary action. P-2

C. Perform cooling system, cap, and recovery system tests (pressure, combustion leakage, and temperature); determine necessary action. P-1

D. Inspect, test, and replace thermostat and housing. P-2

E. Inspect, test, remove, and replace water pump. P-1

F. Inspect, test, and replace oil temperature and pressure switches and sensors. P-2