Page 1 of 6 Title 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. Classification Motor Industry > Engines Available grade Achieved Explanatory 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/. 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 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.
Page 2 of 6 Outcomes and evidence requirements Outcome 1 Perform a visual inspection of a four stroke petrol engine and secure components. 1.1 Safe working practices are observed throughout the task in accordance with legislative 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 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 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. 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. 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 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. 1.7 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. 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.
Page 3 of 6 1.9 Any signs of oil and coolant entry into the combustion chambers are noted in accordance with company includes but is not limited to at operating temperature, cooling system pressurised, inspection through spark plug holes. 1.10 Spark plugs are refitted to the engine in accordance with service information. 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. Outcome 2 Carry out a compression test on a four stroke petrol engine. 2.1 Safe working practices are observed throughout the task in accordance with legislative 2.2 Suitable tools and equipment are selected and used that enable the engine to be compression tested in accordance with service information. 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. dry test, wet test; cranking speed, cycle.
Page 4 of 6 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 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. 2.11 Spark plugs are refitted to the engine in accordance with service information. includes but is not limited to without damage to components and threads, contact faces clean, tightening torque. Outcome 3 Carry out a cylinder leakage test on a four stroke petrol engine. 3.1 Safe working practices are observed throughout the task in accordance with legislative 3.2 Suitable tools and equipment are selected and used that enable the engine to be tested for cylinder leaks in accordance with service information. 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. piston at top dead centre (TDC), compression stroke, engine locked to prevent crankshaft turning. 3.6 The test equipment is connected and used in accordance with service information. may include but is not limited to air supply, interpreting gauge readings.
Page 5 of 6 3.7 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 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. 3.8 Spark plugs are refitted to the engine in accordance with service information. may include but is not limited to without damage to components and threads, contact faces clean, tightening torque. Outcome 4 Carry out a vacuum test on a four stroke petrol engine. 4.1 Safe working practices are observed throughout the task in accordance with legislative 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 4.5 Vacuum gauge readings are recorded in accordance with company steady hand, fluctuating hand, oscillating, responsive. 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 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.
Page 6 of 6 4.7 The engine vacuum test point is sealed to prevent any vacuum leakage. Replacement information This unit standard and unit standard 24273 were replaced by unit standard 30886. This unit standard is expiring. Assessment against the standard must take place by the last date for assessment set out below. Status information and last date for assessment for superseded versions Process Version Date Last Date for Assessment Registration 1 27 February 1995 31 December 2020 Review 2 21 February 1999 31 December 2020 Review 3 25 January 2008 31 December 2020 Review 4 25 January 2018 31 December 2020 Consent and Moderation Requirements (CMR) reference 0014 This CMR can be accessed at http://www.nzqa.govt.nz/framework/search/index.do. Please note Providers must be granted consent to assess against standards (accredited) by NZQA, before they can report credits from assessment against unit standards or deliver courses of study leading to that assessment. Industry Training Organisations must be granted consent to assess against standards by NZQA before they can register credits from assessment against unit standards. Providers and Industry Training Organisations, which have been granted consent and which are assessing against unit standards must engage with the moderation system that applies to those standards. Requirements for consent to assess and an outline of the moderation system that applies to this standard are outlined in the Consent and Moderation Requirements (CMR). The CMR 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