Engine part descriptions
N - Z
Oil Cooler
The oil cooler is a small radiator-like component that reduces engine oil temperature and recirculates it back to the engine. Signs of failure include engine oil leaks and high oil temperature. When replacing, associated seals should be changed, and accessibility may affect replacement costs.
Oil Drain Plug Gasket
The oil drain plug gasket seals the oil drain plug where it connects to the oil pan. Its primary function is to prevent engine oil leaks. This gasket is typically inspected and replaced during routine oil changes to ensure proper sealing.
Oil Filter
The oil filter removes contaminants from engine oil, preventing damage to engine bearings and other moving parts. It traps particles like metal shavings, dirt, and carbon, ensuring clean oil circulates through the engine to maintain its performance and longevity.
Oil Pan
The oil pan is a reservoir mounted to the bottom of the engine’s crankcase, designed to store and supply engine oil. It holds the oil when the engine is not running and provides a source for the oil pump to distribute lubricant throughout the engine during operation.
Oil Pan Gasket
The oil pan gasket is a seal between the oil pan and the lower part of the engine. It can be made of paper, rubber, or liquid sealant. A failing gasket typically results in engine oil leaks. Proper diagnosis is essential, as leaks from other areas may mimic oil pan issues.
Oil Pressure Sensor
Monitors engine oil pressure, alerting drivers to potentially dangerous low-pressure situations. It operates either as a sender for gauge displays or a switch for warning lights, helping prevent engine damage by signaling when oil pressure drops to unsafe levels.
Oil Pump
The oil pump delivers pressurised oil to keep the engine running smoothly. It maintains proper oil pressure, typically between 10 and 80 PSI, depending on the engine’s design. Failure can lead to low oil pressure, warning lights, engine noise, and potential engine damage.
PCV Filter
A component of the vehicle’s emissions control system that filters oil and fuel vapors from the crankcase before they’re recirculated into the engine. It helps reduce harmful emissions, prevents oil contamination, and maintains engine efficiency by allowing proper crankcase ventilation.
PCV Hose
The PCV (Positive Crankcase Ventilation) hose recirculates crankcase gases back into the engine’s intake system. It helps reduce emissions, prevents oil leaks, and maintains proper engine pressure. Regular inspection and replacement of the PCV hose are essential for optimal engine performance and environmental compliance.
PCV Valve
The PCV (Positive Crankcase Ventilation) valve is an emissions device that prevents pollutants from escaping into the atmosphere. It recirculates combustion gases from the crankcase back into the engine, reducing pressure buildup and keeping engine oil clean. A faulty PCV valve can cause rough idling, oil leaks, sludge buildup, and increased emissions.
Piston
A piston is a cylindrical metal component that moves up and down inside an engine cylinder. It compresses the air-fuel mixture and captures the force from combustion, transferring it to the crankshaft via the connecting rod. Modern pistons are typically made of cast aluminum alloy with spring-loaded rings for optimal sealing.
Piston Pin
The piston pin connects the piston to the connecting rod, allowing the rod to pivot as the piston moves up and down in the cylinder. A failing piston pin often produces a knocking or slapping noise and may require engine replacement.
Piston Rings
Piston rings are located between the piston and cylinder wall. They serve multiple functions, including sealing the combustion chamber, managing oil distribution, transferring heat, and preventing piston-cylinder contact. There are typically three rings per piston: two compression rings and one oil ring.
Platinum/Iridium Spark Plug
Platinum/Iridium Spark Plugs generate the spark to ignite the air/fuel mixture in the combustion chamber. They use harder metals on the electrodes, extending their lifespan to over 100,000 kms in most applications. These plugs can prevent engine misfires and Check Engine Light problems when properly maintained.
Positive Crankcase Ventilation (PCV) System
The Positive Crankcase Ventilation (PCV) System recirculates harmful gases from the engine’s crankcase back into the combustion chambers. This process prevents these gases from escaping into the atmosphere, reducing air pollution and improving engine efficiency.
Radiator
The radiator is responsible for transferring heat from the engine to the outside air. It consists of tubes surrounded by fins, with intake and outlet tanks at each end. The radiator helps prevent engine overheating and maintains optimal operating temperature.
Radiator Cap
The radiator cap maintains proper pressure in the cooling system. It sits atop the radiator, containing a spring-loaded plunger that seals the system. This cap regulates pressure, raises coolant boiling point, and vents excess pressure to the expansion tank.
Radiator Fan
The radiator fan helps remove heat from the engine coolant and air conditioning refrigerant. It can be mechanical or electric, and its primary function is to move air through the radiator and condenser, especially when the vehicle is idling or moving slowly.
Rear Main Seal
The rear main seal, also known as the rear crankshaft, seal seals the rotating crankshaft where it exits the rear of the engine. When failing, it can cause oil leaks between the engine and transmission, potentially leading to clutch issues in manual transmissions.
Spark Plug
Spark plugs provide the hot spark that ignites the air-fuel mixture in engine cylinders. They require regular maintenance and replacement. Signs of faulty spark plugs include engine misfires, rough running, decreased acceleration, poor fuel economy, and difficulty starting.
Spark Plug Wires
High-voltage cables that deliver electricity from the distributor or ignition coils to spark plugs, igniting the air-fuel mixture in engine cylinders. Failing wires can cause poor engine performance, increased emissions, and reduced fuel economy. They typically last 60,000-100,000 kms but may require earlier replacement if damaged.
Supercharger
A supercharger is a mechanically driven air compressor that forces air into the engine’s induction system, providing more oxygen to the cylinders for increased power. Symptoms of a failing supercharger include check engine light illumination, lack of power, and abnormal noise.
Thermostat
The thermostat is a valve that regulates coolant flow between the engine and radiator, maintaining optimal engine temperature. It can malfunction by getting stuck open or closed, leading to various issues such as engine overheating, poor fuel economy, or inefficient heating. Replacement is typically a simple and inexpensive fix.
Thermostat Gasket
The thermostat gasket forms a seal between the thermostat housing and the engine. It prevents coolant leakage and helps maintain proper engine temperature. A failing gasket may cause coolant leaks and engine overheating. Replacement is recommended during major cooling system repairs.
Throttle Body
The throttle body controls airflow into the engine, regulating power output. It contains a throttle plate that opens as you press the gas pedal. Modern vehicles use electronic throttle control systems. Signs of a faulty throttle body include check engine light, poor performance, rough idle, and reduced power.
Timing Belt
An engine component made of rubber or synthetic material that synchronizes the rotation of the camshaft and crankshaft. It ensures proper valve timing and piston movement. Typically requiring replacement every 100,000 to 130,000 km, a failing timing belt can cause poor engine performance, ticking noises, and potential catastrophic engine failure.
Timing Belt Idler
A timing belt idler is a small pulley that guides and stabilises the timing belt in its correct position. Engines may have one or more idler pulleys depending on their size and belt length. Signs of failure include grinding noises, belt skipping, trouble codes, and slapping sounds.
Timing Belt Tensioner
The timing belt tensioner maintains proper tension in the timing belt using spring tension or hydraulic pressure. It’s crucial for engine synchronization and performance. Signs of failure include grinding noises, belt skipping, check engine light, and slapping sounds. Replacement is often recommended when changing the timing belt.
Timing Chain
The timing chain connects the camshaft and crankshaft, ensuring they rotate in sync for proper valve and piston timing. It’s more durable than a timing belt but can stretch or break over time, potentially causing engine performance issues or severe damage if left unaddressed.
Timing Chain Tensioner
The timing chain tensioner maintains proper tension in the timing chain using spring tension or hydraulic pressure. It’s crucial for smooth engine operation. Symptoms of failure include engine stalling, rough running, front engine noise, and illuminated Check Engine Light. When replacing, it’s recommended to replace the entire timing chain set.
Timing Cover
The timing cover is a metal or plastic enclosure that protects the engine’s timing components from dirt, dust, and debris. It covers the timing chain or belt, which synchronizes the crankshaft and camshaft. A failing timing cover can cause oil leaks, low oil levels, engine misfires, and potentially serious engine damage.
Timing Cover Gasket
The timing cover gasket is a seal between the timing cover and engine block. It prevents oil or coolant leaks. Made from standard gasket material, O-ring style seal, or silicone-type sealant, it’s essential for proper engine function. When replaced, timing components should be inspected.
Turbo Hose
Turbo hoses connect the turbocharger to other engine parts, carrying pressurized air and oil. They must withstand high temperatures and pressures. If a turbo hose fails, it can lead to reduced engine performance, oil leaks, and potential engine damage.
Turbocharger
A turbocharger is a device that increases engine power by forcing extra air into the combustion chamber. It uses exhaust gases to spin a turbine, which drives a compressor, boosting air intake and allowing more fuel to be burned, resulting in increased horsepower.
Upper Radiator Hose
The upper radiator hose is a component of a vehicle’s cooling system, carrying hot coolant from the engine to the radiator for cooling. It’s prone to wear and can cause coolant leaks, high temperature readings, and engine overheating when failing. Regular inspection is recommended.
Vacuum Pump
A vacuum pump generates supplemental vacuum for essential functions like brake assistance, climate control, and emissions systems. It’s either mechanically engine-driven or electrically powered and is particularly necessary for diesel engines, turbocharged vehicles, and those with direct injection or variable valve timing.
Valve Cover
A valve cover is located at the top of the engine above the cylinders. It seals the valve train, retaining oil and keeping out debris. Made of metal or plastic, valve covers are secured with gaskets and can be single or paired depending on engine configuration.
Valve Cover Gasket Set
The valve cover gasket set is a complete set of gaskets that create a seal between the valve cover(s) and cylinder head(s). It prevents oil leaks, which can cause engine misfires and burning smells. Replacing worn gaskets is crucial to prevent damage to other engine components.
Water Pump
The water pump is responsible for circulating coolant through the engine, hoses, and radiator to maintain optimal operating temperature. It uses centrifugal force to move coolant and is typically mounted on the front of the engine, driven by the serpentine or timing belt.
Water Pump Gasket
A mechanical seal between the engine block and water pump, preventing coolant leaks. Signs of failure include coolant leaks, sweet smell, low coolant warning, and engine overheating. Replacement is complex, often requiring extensive disassembly. It’s advisable to replace related components during repair due to labor costs.