3400 version 3
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Check a four stroke petrol engine for condition using hand held test
equipment
Level
3
Credits
4
Purpose
This unit standard is for people in the automotive repair industry. People
credited with this unit standard are able to: perform a visual inspection of a
four stroke petrol engine and secure components; carry out a compression
test on a four stroke petrol engine; carry out a cylinder leakage test on a four
stroke petrol engine; and carry out a vacuum test on a four stroke petrol
engine.
Subfield
Motor Industry
Domain
Engines
Status
Registered
Status date
25 January 2008
Date version published
25 January 2008
Planned review date
31 December 2012
Entry information
Open.
Accreditation
Evaluation of documentation and visit by NZQA and
industry.
Standard setting body (SSB)
NZ Motor Industry Training Organisation (Incorporated)
Accreditation and Moderation Action Plan (AMAP) reference
0014
This AMAP can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
Special notes
1
Legislation relevant to this unit standard includes but is not limited to – Health and
Safety in Employment Act 1992; Land Transport Rule: Vehicle Repair 1998, Rule
34001.
2
Land Transport Rules are produced for the Minister of Transport by Land Transport
New Zealand. These rules are available online at
http://www.landtransport.govt.nz/rules/.
 New Zealand Qualifications Authority 2016
3400 version 3
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3
Definitions
Company requirements refer to instructions to staff on policy and procedures which
are documented in memo or manual format and are available in the workplace.
These requirements include but are not limited to – company specifications and
procedures, work instructions, manufacturer specifications, product quality
specifications, and legislative requirements.
Service information may include but is not limited to – technical information of a
vehicle, machine, or product detailing operation; installation and servicing
procedures; manufacturer instructions and specifications; technical terms and
descriptions; and detailed illustrations. This can be accessed in hard copy or
electronic format and is normally sourced from the manufacturer.
Suitable tools and equipment means industry approved tools and equipment that are
recognised within the industry as being the most suited to complete the task in a
professional and competent manner with due regard to safe working practices.
4
For this unit standard, it is essential that the practical assessment evidence is
obtained in the workplace under normal workplace conditions.
Elements and performance criteria
Element 1
Perform a visual inspection of a four stroke petrol engine and secure components.
Performance criteria
1.1
Safe working practices are observed throughout the task in accordance with
legislative requirements.
Range
personal safety, safety of others, vehicle safety, workshop safety,
environmental safety, tools and equipment safety.
1.2
Suitable tools and equipment are selected and used that enable the engine to
be visually inspected and components secured in accordance with service
information.
1.3
Engine oil, coolant, and fuel leaks are reported to the supervisor in accordance
with company requirements.
1.4
The expiry dates of the engine oil, engine oil filter, air filter element, and fuel
filter are determined and reported to the supervisor in accordance with company
requirements.
1.5
Loose engine components are secured and tightened in accordance with
vehicle or engine manufacturer specifications, to enable further engine checks
to be carried out.
Range
may include but is not limited to – drive belts, pulleys, starter unit,
alternator unit, covers and shrouds, fuel components, electrical
connections and components, intake and exhaust components.
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3400 version 3
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1.6
The engine is started and run to operating temperature in accordance with
service information and details concerning its operation are noted and reported
to the supervisor in accordance with company requirements.
Range
1.7
may include but is not limited to – noises, difficulty in starting,
idling and idle speed, misfiring, fuming, emissions,
responsiveness, acceleration, deceleration, flat spots, under load,
overheating, underheating, excessive smoke.
Spark plugs are removed from the engine in cylinder order in accordance with
service information, and an analysis to determine engine condition or tune is
made on their face appearance.
Range
face appearance includes but is not limited to – normal condition,
sooted-carbon fouled, oil fouled, formation of ash, partially melted
electrodes, heavy wear on ground electrode.
1.8
Fuel injectors are disconnected, removed, and replaced in accordance with
service information.
1.9
Any signs of oil and coolant entry into the combustion chambers are noted in
accordance with company requirements.
Range
1.10
includes but is not limited to – at operating temperature, cooling
system pressurised, inspection through spark plug holes.
Spark plugs are refitted to the engine in accordance with service information.
Range
includes but is not limited to – type and heat range, without
damage to components and threads, contact faces clean,
tightening torque.
1.11
Ignition timing is checked to ensure it meets the vehicle or engine manufacturer
specifications.
1.12
Valve clearances are checked to ensure they meet the vehicle or engine
manufacturer specifications.
Element 2
Carry out a compression test on a four stroke petrol engine.
Performance criteria
2.1
Safe working practices are observed throughout the task in accordance with
legislative requirements.
Range
2.2
personal safety, safety of others, vehicle safety, workshop safety,
environmental safety, tools and equipment safety.
Suitable tools and equipment are selected and used that enable the engine to
be compression tested in accordance with service information.
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2.3
Engine operating temperature is reached in accordance with service information
before the compression test is carried out.
2.4
Spark plugs are removed from the engine without damage to components and
threads, and without foreign matter entering into the combustion chamber.
2.5
High tension leads are disconnected and the compression test is carried out
without damage to the ignition system.
2.6
Intake and exhaust system in not restricted in any way that will affect
compression readings.
2.7
Compression test is carried out without injecting excess fuel into the cylinders.
2.8
The compression test is carried out in accordance with service information.
Range
dry test, wet test;
cranking speed, cycle.
2.9
Compression readings are recorded and compared with vehicle or engine
manufacturer specifications.
2.10
An analysis of the engine condition based on the compression readings
obtained is undertaken. A recommendation is made to the supervisor in
accordance with company requirements.
Range
2.11
no action required, further investigation recommended;
may include but is not limited to – within manufacturer
specifications, leakage between adjacent cylinders, leakage past
valves, leakage past rings.
Spark plugs are refitted to the engine in accordance with service information.
Range
includes but is not limited to – without damage to components and
threads, contact faces clean, tightening torque.
Element 3
Carry out a cylinder leakage test on a four stroke petrol engine.
Performance criteria
3.1
Safe working practices are observed throughout the task in accordance with
legislative requirements.
Range
3.2
personal safety, safety of others, vehicle safety, workshop safety,
environmental safety, tools and equipment safety.
Suitable tools and equipment are selected and used that enable the engine to
be tested for cylinder leaks in accordance with service information.
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3.3
Engine operating temperature is reached in accordance with service information
before the cylinder leakage test is carried out.
3.4
Spark plugs are removed from the engine without damage to components and
threads, and without foreign matter entering the combustion chamber.
3.5
The cylinder is prepared for testing in accordance with service information.
Range
3.6
The test equipment is connected and used in accordance with service
information.
Range
3.7
may include but is not limited to – air supply, interpreting gauge
readings.
The source of air leakage in each cylinder is located and an analysis of the
engine condition based on the test equipment readings obtained is undertaken.
A recommendation is made to the supervisor in accordance with company
requirements.
Range
3.8
piston at top dead centre (TDC), compression stroke, engine
locked to prevent crankshaft turning.
no action required, further investigation recommended;
may include but is not limited to – past piston, into adjacent
cylinder, past exhaust valve, past inlet valve, into cooling system.
Spark plugs are refitted to the engine in accordance with service information.
Range
may include but is not limited to – without damage to components
and threads, contact faces clean, tightening torque.
Element 4
Carry out a vacuum test on a four stroke petrol engine.
Performance criteria
4.1
Safe working practices are observed throughout the task in accordance with
legislative requirements.
Range
personal safety, safety of others, vehicle safety, workshop safety,
environmental safety, tools and equipment safety.
4.2
Suitable tools and equipment are selected and used that enable the engine to
be vacuum tested in accordance with service information.
4.3
Engine operating temperature is reached in accordance with service information
before the vacuum test is carried out.
4.4
The vacuum gauge is connected to a vacuum source on an engine that gives
true manifold depression in accordance with company requirements.
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4.5
Vacuum gauge readings are recorded in accordance with company
requirements.
Range
4.6
Vacuum gauge readings are interpreted and an analysis of the engine condition
based on the vacuum gauge readings obtained is undertaken. A
recommendation is made to the supervisor in accordance with company
requirements.
Range
4.7
steady hand, fluctuating hand, oscillating, responsive.
no action required, further investigation recommended;
may include but are not limited to – normal reading, late ignition
timing, late valve timing, intake leak, poor rings or bores, sticking
valve, leaky valve, burnt valve, worn valve guides, weak valve
springs, improper idle mixture, small spark gap, head gasket leak,
restricted exhaust system.
The engine vacuum test point is sealed to prevent any vacuum leakage.
Please note
Providers must be accredited by NZQA, or an inter-institutional body with delegated
authority for quality assurance, before they can report credits from assessment against
unit standards or deliver courses of study leading to that assessment.
Industry Training Organisations must be accredited by NZQA before they can register
credits from assessment against unit standards.
Accredited providers and Industry Training Organisations assessing against unit standards
must engage with the moderation system that applies to those standards.
Accreditation requirements and an outline of the moderation system that applies to this
standard are outlined in the Accreditation and Moderation Action Plan (AMAP). The
AMAP also includes useful information about special requirements for organisations
wishing to develop education and training programmes, such as minimum qualifications for
tutors and assessors, and special resource requirements.
Comments on this unit standard
Please contact the NZ Motor Industry Training Organisation (Incorporated)
info@mito.org.nz if you wish to suggest changes to the content of this unit standard.
 New Zealand Qualifications Authority 2016