Inspect the integrity and condition of the exhaust manifold, exhaust pipes, muffler(s), catalytic converter(s), resonator(s), tail pipe(s), hangers, brackets, clamps and heat shield(s); Determine Necessary Action
Lesson Plan for
AUT 156-157 Maintenance and Light Repair Section D
Course HS Title: / Program:KCTCS Courses included in HS Title: (Lesson is prepared for course highlighted.)
KCTCS Course No. / KCTCS Course Title
Introduction/Context / This lesson will instruct students on the proper procedures needed to inspect the integrity of the exhaust manifold, exhaust pipes, muffler(s), catalytic converter(s), resonator(s), tail pipe(s), hangers, brackets, clamps and heat shield(s), and perform necessary action. Knowledge of these techniques and the skills required to correct problems associated with this task are necessary for a student to acquire if they wish to compete for high paying, high skilled jobs in an automotive repair facility. Entry level technicians need to be able to perform this task to 100% accuracy. Incorrectly performing this task can lead to driveability concerns, safety problems, or create customer satisfaction issues.
Prepared By / School / Date:
Grade Level / No. Students / No.IEP's: / Lesson Length:
Tasks
Inspect the integrity of the exhaust manifold, exhaust pipes, muffler(s), catalytic converter(s), resonator(s), tail pipe(s), and heat shield(s); perform necessary action.
Inspect condition of exhaust system hangers, brackets, clamps, and heat shields; repair or replace as needed.
No. / Objective
1 / Given the proper tools and instructions from a vehicle manufacturers shop manual or automotive computer software program, students will be able to inspect the integrity of the exhaust manifold, exhaust pipes, muffler(s), catalytic converter(s), resonator(s), tail pipe(s), hangers, brackets, clamps and heat shield(s), determine necessary action, and pass a written exam on the task with 100% by the end of the course.
Connections
Skills Standards:OH 001
OH 002
OH 003
OD 002
OD 003
OD 005
Common Core Technical Standards:
TD-SYS-2
New Common Core Standards:
RST 11-12 3
RST 11-12 4
INSTRUCTIONAL MATERIALS/TECHNOLOGY
Textbooks and Workbooks
Ken Pickerill / Automotive Engine Performance / Fourth / Thomson Delmar / 201-202
Jack Erjavec / Automotive Technology: A Systems Approach / Fifth / Delmar / 972
Web Addresses
Today's Class / Melior / www.todaysclass.com
Equipment
As Needed / Pressure Gauge / Various
As Needed / Vacuum Gauge / Various
Content/Presentation/Demonstration Outline
Let students know that exhaust system components are subject to rust from inside and outside the components. Explain that since exhaust components are exposed to road splash, they tend to rust on the outside.
Teach students that condensation inside the exhaust system components rusts them on the inside. Explain that a vehicle that is driven short distances and then shut off tends to have more condensation in the exhaust system than a vehicle that is driven continually for longer time periods. If a vehicle is driven for a short distance, the exhaust system heat does not have sufficient time to vaporize the condensation in the system. The rust erodes exhaust system components, causing exhaust leaks and excessive noise.
Exhaust components, particularly mufflers, catalytic converters, and pipes, may become restricted. Mufflers and catalytic converters may become restricted by loose internal components. Pipes may become restricted by physical damage or collapsed inner walls on double-walled pipes. This exhaust restriction causes a loss of engine power and increased fuel consumption. A plugged converter or any exhaust restriction can cause loss of power at high speeds, stalling after starting (if totally blocked), a drop in engine vacuum as engine rpm increases, or sometimes popping or backfiring.
Inform students that exhaust system components can cause a rattling noise if they are touching, or almost touching, chassis components, Let them know that loose internal structure in mufflers and catalytic converters may cause a rattling noise, especially when the engine is accelerated. Explain that a block of wood or a wrench may be used to tap mufflers and catalytic converters to check for loose internal components. If the internal structure is loose, a rattling noise is evident when the component is taped.
SAFETY WARNING: Remind students that during all exhaust inspection and repair work, wear safety glasses or equivalent eye protection.
Instruct students that any inspection of the exhaust system should include listening for hissing or rumbling that would result from a leak in the system. Let students know that an on-lift inspection should pinpoint any damage. All of the exhaust system components should be inspected for physical damage, kinks, dents, holes, rust, loose internal components, loose clamps and hangers, proper clearance, and improperly positioned shields. Explain that physical damage on exhaust system components includes flattened areas; abnormal bends, and scrapes, Remind students that flattened exhaust system components cause restrictions. Components with this type of damage should be replaced.
Inform students to push upward on the muffler and catalytic converter to check for weak, rusted inlet and outlet pipes. Let them know to be sure and check the entire exhaust system for leaks. With the engine running, they can hold a length of hose near their ear and run the other end of the hose around the exhaust system components. Explain that the hose amplifies the sound of an exhaust leak and helps to locate the source of a leak.
Let students know that they should inspect all exhaust system shields for proper position, and check for the correct clearance between the exhaust system components and the shields. Tell students to check the catalytic converter for overheating, which is indicated by bluish or brownish discoloration. Inform students that the system should also be tested for blockage and restrictions using a vacuum and/or pressure gauge and a tachometer.
Inform students that the following are quick references to exhaust problems: If the is rattling, squeaks, or buzzing, tell students to look for loose or damaged heat shield, loose or damaged exhaust isolators or isolator hanger brackets, loose or damaged catalytic converter or muffler, or Exhaust contacting the chassis
If there is droning or clunking, tell students to look for loose or damaged exhaust isolators, or exhaust contacting the chassis. If they hear whistling, humming, or ticking noises that tend to change as the engine warms, tell students to look for broken, loose, or missing exhaust manifold fasteners or gaskets, loose heated oxygen or catalyst monitor sensor, or an exhaust system leak
If students hear a high frequency hissing or rushing noise, tell them to look for an exhaust system leak. If students hear a pinging noise when exhaust is hot and the engine is shut down, explain that cool-down pinging is normal. It is caused by the exhaust system expanding and contracting during heating and cooling. If students feel a vibration at Idle and at low speeds, tell them to look for loose or damaged exhaust isolators or isolator hanger brackets, exhaust damper broken or out of position, or exhaust contacting the chassis.
If the vehicle has low or no Power, tell them to look for an exhaust pipe pinched or crushed, a damaged catalytic converter, a loose obstruction in the exhaust system, or a restricted exhaust (possibly ice in the muffler or tailpipe). If students detect a burning smell, tell them to look for foreign material in the exhaust system or missing heat shields.
If students detect a sulfur or rotten egg smell from exhaust, have them look for rich fuel conditions, misfire conditions, or excessive sulfur content in fuel. If students see visible rust on the surface of the exhaust pipes, let them know that if there are no perforations, the condition is normal.
Applications/Practice
Evaluation and feedback Prior to Testing or Lab Work
STUDENT ASSESSMENT:(Assess student progress with performance criteria.)
IMPACT--Reflection/Analysis of Teaching and Learning: (How did students’ progress in relation to the state objectives? Was the instruction successful? Analyze samples of student work particularly that which is unsatisfactory, for the purpose of planning further instruction.)
REFINEMENT--Lesson Extension and Follow-up: (To be filled in as the lesson is modified during initial planning and/or during the teaching learning process.)