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Title / Remove, disassemble, inspect, reassemble, and refit an engine cylinder head
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: remove a cylinder head from an engine; disassemble, inspect, and reassemble the cylinder head; and refit a cylinder head to an engine.
Classification / Motor Industry > Engines
Available grade / Achieved
Entry information
Recommended skills and knowledge / Unit 24302, Demonstrate knowledge of disassembling, inspecting, and reassembling an engine cylinder head.
Explanatory notes
1Legislation relevant to this unit standard includes but is not limited to – Health and Safety in Employment Act 1992; Resource Management Act 1991, s15 Discharge of contaminants into environment; Land Transport Rule: Vehicle Repair 1998, Rule 34001.
2Land Transport Rules are produced for the Minister of Transport by Land Transport New Zealand. These rules are available online at
3Definitions
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.
Outcomes and evidence requirements
Outcome 1
Remove a cylinder head from an engine.
Evidence requirements
1.1Safe working practices are observed throughout the task in accordance with legislative requirements.
Rangepersonal safety, safety of others, vehicle safety, workshop safety, environmental safety, tools and equipment safety.
1.2Suitable tools and equipment are selected and used to enable a cylinder head to be removed from an engine in accordance with service information.
1.3Procedures to remove the cylinder head are described in accordance with service information.
1.4Coolant is drained from the cooling system in accordance with the Resource Management Act.
1.5The cylinder head is removed from the engine in the manner and sequence prescribed by the manufacturer.
1.6Care is taken during disassembly to note and preserve any evidence that could help in diagnosing the causes of faults, and to tabulate the components for easy identification in accordance with company requirements.
1.7Components are stored in parts trays to prevent loss and damage in accordance with company requirements.
1.8The cylinder block is protected against the disturbance of seals and ingress of foreign matter.
Outcome 2
Disassemble, inspect, and reassemble the cylinder head.
Evidence requirements
2.1Safe working practices are observed throughout the task in accordance with legislative requirements.
Rangepersonal safety, safety of others, vehicle safety, workshop safety, environmental safety, tools and equipment safety.
2.2Suitable tools and equipment are selected and used to enable a cylinder head to be disassembled, inspected, and reassembled in accordance with service information.
2.3Procedures and sequence to disassemble, inspect, and reassemble the cylinder head components are identified in accordance with service information.
2.4Components are stored in parts trays to prevent loss and damage in accordance with company requirements.
2.5Any camshafts (if fitted) are removed and inspected in accordance with service information.
Rangeinspection includes but is not limited to – wear and damage to bearing surfaces, lobes, followers.
2.6Valve gear and valves are removed and inspected in accordance with service information.
Rangeinspection includes but is not limited to wear and damage to – running gear, valves, valve seats, valve springs, seals, valve guides or bores.
2.7The cylinder head mating surfaces are inspected for warpage and damage in accordance with service information.
2.8Cylinder ports are inspected for cleanliness in accordance with service information.
2.9Core plugs, studs, bolts, and threaded holes are inspected for signs of leakage, damage, clogging, and breakage in accordance with service information.
2.10The cylinder head components are reassembled in accordance with service information.
Outcome 3
Refit a cylinder head to an engine.
Evidence requirements
3.1Safe working practices are observed throughout the task in accordance with legislative requirements.
Rangepersonal safety, safety of others, vehicle safety, workshop safety, environmental safety, tools and equipment safety.
3.2Suitable tools and equipment are selected and used to enable a cylinder head to be refitted to an engine in accordance with service information.
3.3The cylinder head and block components are prepared to enable the head to be refitted without damage, and without time delay due to missing and damaged parts, in accordance with service information.
3.4Replacement components are obtained and installed to enable the cylinder head to be refitted to the engine in accordance with service information.
3.5The cylinder head is assembled to the engine in the manner and sequence prescribed by the manufacturer.
3.6Adjustments are carried out in the manner and sequence prescribed by the manufacturer.
Rangetorque settings, clearances.
Replacement information / This unit standard and unit standard 24274 were replaced by unit standard 30888.This unit standard and unit standard 24274 replaced unit standard 923 and unit standard 15440.
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 AssessmentRegistration / 1 / 25 January 2008 / 31 December 2020
Review / 2 / 25 January 2018 / 31 December 2020
Consent and Moderation Requirements (CMR) reference / 0014
This CMR can be accessed at
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 requirements.
MITO New Zealand IncorporatedSSB Code 101542 / New Zealand Qualifications Authority 2018 / / New Zealand Qualifications Aut