30 Basic Parts of The Car Engine with Diagram

Today, we might be moving towards electric vehicles and alternative fuel-powered vehicles but let’s not forget, it was the internal combustion engines where all the magic began.

A car engine is a complex machine that consists of various parts working simultaneously to power your vehicle.

Knowing about the different parts of a car engine and their functions, you can easily identify which part is causing the problem and take appropriate action. Let’s learn how it works!

How Does a Car Engine Work?

Your car’s engine is a complex assembly that uses energy from the combustion of air and fuel to create mechanical motion. When the vehicle is running, the engine pulls in air through the intake system. That air is mixed with fuel supplied by the fuel injectors.

The air-fuel mixture is then compressed and ignited inside of the engine to create a series of small explosions that cause the engine to continually rotate. The rotational force from the engine is then transferred through the drivetrain to the drive wheels to get the vehicle moving.

Four-Stroke Engine Operation

Inside the engine, there is a crankshaft and one or more camshafts. The crankshaft is attached to the connecting rod and piston assemblies, which move up and down inside the engine’s cylinders. At the same time, the intake and exhaust valves are operated by the camshaft(s).

When a piston assembly travels from the top to the bottom of the cylinder or vice versa, that’s referred to as a stroke. Automobile internal combustion engine operation involves a four-stroke cycle of events that repeat in each cylinder.

In a gasoline-powered engine, the four different stroke events take place as follows:

• Intake stroke: During the intake stroke, the camshaft opens the intake valve(s) as the piston moves downward, allowing the air-fuel mixture to be drawn into the cylinder.
• Compression stroke: When the compression stroke begins, the intake and exhaust valves close as the piston moves upward, compressing the air-fuel mixture.
• Power stroke: As the piston reaches the top of its travel, the spark plug ignites the air-fuel mixture, causing an explosion that forces the piston downward. The linear movement of the piston causes the crankshaft to turn, creating the rotational force needed to propel your vehicle down the road.
• Exhaust stroke: During the exhaust stroke, the camshaft opens the exhaust valve(s) as the piston moves upward, allowing spent exhaust gases to be forced from the engine into the vehicle’s exhaust system.

Obviously, the crankshaft and camshaft(s) must be kept in sync (“in time”) so that the pistons are at the correct point of travel when the valves open and close. Depending on the engine design, either a timing belt or timing chain performs this task by connecting the crankshaft to the camshaft(s).

Car Engine Parts Names with Diagram

Let us see a simple car engine parts diagram including all the main parts which are essential to know. Refer to the below car engine parts diagram so that we can understand the exact location of each one and how it looks.

These diagrams typically include the engine block, combustion chamber, cylinder head, pistons, crankshaft, camshaft, timing chain, valves, rocker arms, pushrods/lifters, injectors, spark plugs, oil pan, distributor, connecting rods, piston ring, flywheels.

List Of Car Engine Parts Names

While many of us think of the engine as one major component, it’s made up of several individual components working simultaneously.

The list of Car Engine parts Name:

A typical internal combustion engine has around 200 parts that need to be maintained and possibly replaced if they wear out. An electric vehicle takes that number down to around 20 parts.

But don’t worry, we are only discussing the main parts of a car engine.

Read more: 50 Basic Parts of a Car With Name & Diagram

Parts of A Car Engine

The different parts that make up your car’s engine consist of: the engine block (cylinder block), combustion chamber, cylinder head, pistons, crankshaft, camshaft, timing chain, valve train, valves, rocker’s arms, pushrods/lifters, fuel injectors, and spark plugs.

#1. The Engine Block.

The engine block houses all of the major components that make up the bottom end of a motor. The block, which is also known as the cylinder block, is where the crankshaft spins, and the pistons move up and down in the cylinder bores, fired by the fuel combusting. On some engine designs, it also holds a camshaft.

Usually made from an aluminum alloy on modern cars, on older vehicles and trucks it was commonly cast iron. Its metal construction gives it strength and the ability to transmit heat from the combustion processes to the integral cooling system in an efficient manner.

Aluminum block typically have an iron sleeve pressed into them for the piston bores, or a special hard plating applied to the bores after machining.

The block was originally just a block of metal holding the cylinder bores, the water cooling jacket, oil passages, and the crankcase. This water jacket, as it’s sometimes known, is an empty system of passages, circulating coolant in the engine block. The water jacket surrounds the engine’s cylinders, of which there are usually four, six or eight and which contain the pistons.

When the cylinder head is in place secured to the top of the engine block, the pistons move up and down within the cylinders and turn the crankshaft, which ultimately drives the wheels. The oil pan sits at the base of the engine block, providing a reservoir of oil for the oil pump to pull from, and supply the oil passages and moving parts.

Common Symptoms of Bad Engine Block:

• Poor engine performance is caused by low engine compression.
• Visible engine smoke.
• Engine overheating is caused by leaking antifreeze.
• Discoloration in a car’s oil or antifreeze.
• Leaking oil or coolant.
• Frozen coolant in the radiator.
• Excessive smoke from the exhaust; and
• Low levels of coolant.

#2. The Piston.

Pistons are part of your car engine. The main function of the piston is to convert the pressure created by the burning air-fuel mixture into a force that acts on the crankshaft.

The shape of the piston mainly depends on the type of internal combustion engine. Gasoline engine pistons tend to be lighter and shorter than diesel engine pistons.

The piston is connected to the crankshaft via a connecting rod, and the piston is attached to the connecting rod by a short hollow tube called a wrist pin, or gudgeon pin.

This piston pin carries the full force of the combustion. These parts together are referred to as the piston assembly.

The narrow gap between the piston and the cylinder wall is bridged by the piston rings, which fit into the piston grooves of the so-called piston band. The spaces between these grooves are called ring lands.

Pistons move up and down within the cylinder twice during each revolution of the crankshaft. Pistons on engines turning at 1300 rpm move up and down 2600 times per minute.

Functions performed by the piston:

• Contributes to the heat dissipation generated during combustion.
• Ensures the sealing of the combustion chamber and prevents gas leakage and oil penetration into the combustion chamber.
• Guides the movement of the connecting rod.
• Ensures continuous gas exchange in the combustion chamber.
• Creates the variable volume in the combustion chamber.

Most Common Symptoms for Bad Piston:

• White or gray exhaust smoke
• Excessive oil consumption
• Low power for acceleration
• Overall loss of power or poor performance

#3. The Crankshaft.

The crankshaft is essentially the backbone of the internal combustion engine. The crankshaft is responsible for the proper operation of the engine and the conversion of linear motion into rotary motion.

It takes the energy of the pistons moving up and down and converts it into rotational energy that moves your car’s wheels. The crankshaft is in the crankcase, which is below the engine block.

Crankshafts are usually made from steel due to the overall strength of the metal.

Crankshafts are often designed in one piece and not in multiple pieces. This is because it allows for heavier stress when driving and limited oscillation space, which is important given how much crankshafts rotate.

The crankshaft is attached to the engine at both ends by large bearings. It connects to the flywheel and thereby to the clutch.

When the clutch is engaged, the rotational energy of the crankshaft is transmitted through the gearbox and further through the differential to the drive shafts attached to the wheels, creating the car’s ability to move.

Symptoms of a Bad or Failing Crankshaft Position Sensor:

• Issues Starting the Vehicle.
• Intermittent Stalling.
• Check Engine Light Comes On.
• Uneven Acceleration.
• Engine Misfires or Vibrates.
• Rough Idle and/or Vibrating Engine.
• Reduced Gas Mileage.

#4. The Camshaft.

A camshaft is a relatively simple component of an engine – a simple piece of rod or shaft along which are positioned shaped cams, these have been known as “cam lobes”.

As the shaft is rotated, the shape of the cam allows a valve to be acted upon to a degree proportional to the strength of its shape – the speed of rotation controls the speed of action.

In a modern internal combustion engine, they are typically, but not necessarily, located directly above the cylinder banks where they act to control the valves.

Their calibration precisely controls the amount of air-fuel mixture entering the chamber and how efficiently the spent exhaust gases from the previous ignition can exit the chamber to make way for the next charge.

Not only does this make them critical to the operation of an engine, but since they open and close the inlet and exhaust valves of the engine at the right time, they also drastically affect performance.

To ensure this timing, the camshafts are connected to the rotation of the crankshaft via a timing belt or chain, which directly moves the pistons in the cylinder. In addition, the shape of the cams themselves is also carefully designed to control the speed at which the valves open and close.

Like all other parts of your car engine, the camshaft is made of strong metal like chilled iron that is stronger than other metals.

Symptoms of a Bad Camshaft:

• Active or flashing check engine light.
• Loss of power.
• Steady popping/backfire in the intake manifold or exhaust (extreme wear).
• Loud ticking or tapping sounds.
• Metal debris in the engine oil.
• Cylinder misfire.
• Increased emissions because of misfiring.
• Visible signs of damage.

#5. The Connecting Rod.

As the name suggests, a connecting rod is a piece of metal that connects the piston to the crankshaft. They are usually made of either steel or aluminum.

A connecting rod, also called a ‘con rod’, is part of an engine that connects the piston to the crankshaft.

The connecting rod, together with the crank, converts the stroke movement of the piston into the rotation of the crankshaft.

The part of the connecting rod that connects to the piston is called the small end, and the end that attaches around the crankshaft is called the big end. The big end will have bearing inserts that minimize friction and maintain accurate oil clearance with the connecting rod journal on the crankshaft.

The connecting rod is split in two – using a connecting rod cap to clamp the connecting rod bearing and crankshaft.

The connecting rod is needed to transmit compressive and tensile forces from the piston. In its most common form, in an internal combustion engine, it allows pivoting on the piston end and turning on the shaft end.

Many connecting rods have a hole drilled from the big end up through the shaft to an outlet hole somewhere along their length. This passage allows oil to flow up the connecting rod from the big end and spray onto the pressure area of the cylinder wall where friction is greatest.

Symptoms of a Bad Connecting Rod:

• Low Compression
• Engine Knocking Sounds (Rod Knock)
• Low Oil or Oil Pressure
• Visibly Bent or Damaged Rod
• Seized Engine

#6. Timing Belts.

The timing belt is an integral part of your vehicle’s engine and ensures that many of the moving parts work together with precise timing for optimum efficiency and performance.

Your timing belt coordinates the engine’s combustion cycle by connecting the crankshaft and camshaft.

The crankshaft rotates with the movement of the pistons and the camshaft controls the movement of the intake and exhaust valves while ensuring that the pistons do not hit any of the valves.

Modern timing belts are made of rubber, synthetic rubber such as neoprene, polyurethane, or highly saturated nitrile with high-tensile reinforcement cords made of Kevlar, polyester, or fiberglass.

This means they can sometimes wear out as temperature conditions change while driving. It is usually recommended to replace your vehicle’s timing belt every 60,000 to 100,000 miles.

When a timing belt is worn, it can start to slip and severe misfires can occur. Unfortunately, there are no definite signs that the timing belt is going bad. Usually, when timing belts fail, it is not a gradual decline, but a sudden event. As soon as an error occurs, the engine stops immediately or loses significant power.

Symptoms of Bad Timing Belt:

• A ticking noise coming from the engine
• The engine won’t turn over.
• The engine acts up between 2,000 – 4,000 RPM.
• The engine misfires.
• More smoke and fumes than normal
• Oil leaks from the front of the motor

#7. Spark Plugs.

Spark plugs are located above each of the cylinders. As the name suggests, spark plugs are part of your car’s engine that ignites the air and fuel, causing combustion in the engine.

The purpose of a spark plug is to convert high-voltage electricity (produced by an ignition coil in modern engines) into a spark. The spark is created in the combustion chamber and ignites the air-fuel mixture just before the combustion/power stroke.

A spark plug has a threaded metal sleeve electrically insulated from a center electrode by a ceramic insulator. The center electrode, which may contain a resistor, is connected by a heavily insulated wire to the output terminal of an ignition coil or magneto.

The metal housing of the spark plug is screwed into the cylinder head of the engine and is therefore electrically grounded. The center electrode protrudes through the porcelain insulator into the combustion chamber, forming one or more spark gaps between the inner end of the center electrode and commonly one or more projections or structures attached to the inner end of the threaded jacket, called the side earth, or ground electrode.

Spark plugs can become less effective at doing their job due to time, wear, or other problems with the electrical/ignition system. They can become “fouled” over time due to combustion, contamination, or overheating, and lose their ability to ignite the air-fuel mixture and conduct heat away from the combustion chamber.

Symptoms of bad spark plugs can include:

• Reduced gas mileage.
• Lack of acceleration.
• Hard starts.
• Engine misfires.
• Rough idling.

#8. Cylinder Head.

A cylinder head sits on top of the engine block, which covers the cylinder and thus forms the combustion chamber.

Cylinder heads must be robust because they must withstand enormous pressures and very high temperatures while maintaining their shape to seal the cylinder block via the head gasket. They are key to controlling airflow in and out of the cylinders and fuel delivery.

The cylinder head contains many elements including intake and exhaust ports, coolant passages, valves, camshafts, spark plugs, and fuel injectors.

A cast iron cylinder head is more durable and less expensive. However, cast iron is heavy and offers lower heat dissipation efficiency. For this reason, some manufacturers prefer to use aluminum cylinder heads. These cylinder heads are much lighter than cast iron cylinder heads. High-performance and racing cars commonly have aluminum cylinder heads.

The most common cause of cylinder head failure is overheating, caused by things like coolant loss, head gasket failure, or restricted coolant flow. In extreme cases, a cracked or damaged cylinder head can lead to irreparable damage to the entire engine! You must take care of any issues as soon as possible to try and prevent this from happening.

Symptoms of a Cracked Cylinder Head:

• White Smoke (Steam) From the Exhaust Pipe
• Low Coolant Level
• Engine Overheating
• Rough Running and Misfiring
• Combustion Gases in the Cooling System
• Illuminated Warning Lights
• Coolant-Oil Intermix

#9. The Oil Pan.

With all the metal that makes up the various parts of your car engine, you need oil to lubricate every part to keep it running smoothly.

The oil pan is bolted to the underside of the engine and is the reservoir for oil that is pumped through the engine to lubricate, clean, and cool moving parts.

A pump forces the oil from the pan through a filter to remove dirt and other debris before it circulates through the engine.

After the oil has gone around the engine, it returns to the oil pan and the process begins again. It’s a good idea to check your engine oil regularly as your engine depends on it to run effectively.

The pan is usually made of steel or aluminum and typically holds four to six liters of oil, depending on the engine. The oil dipstick protrudes into the oil pan and measures the oil level in the reservoir. A drain plug on the bottom can be removed to drain oil.

Symptoms of a Bad Oil Pan:

• The low oil warning light comes on.
• You see a puddle of oil under your car.
• Your oil level has dropped unexpectedly.
• Your engine is overheating.
• You notice a burning smell coming from the engine.

#10. Engine Valve.

Engine valves are mechanical components used in internal combustion engines to allow or restrict the flow of fluid or gas to and from the combustion chambers or cylinders during engine operation.

Functionally, they behave similarly to many other types of valves by blocking or redirecting flow, however, they are a purely mechanical device that interfaces with other engine components such as rocker’s arms to open and close in the correct sequence and timing.

Intake valves work to transfer air and fuel levels into the combustion chamber. The exhaust valves work to move the exhaust gas produced during combustion out of the chamber.

The movements of the valves are controlled by pear-shaped lobes, called cams, on a rotating shaft, the camshaft, which is driven by a chain, belt, or set of gears from the crankshaft.

Where the camshaft is mounted in the engine block, small metal cylinder tappets sit in channels above each cam, and a metal pushrod extends from the tappets up into the cylinder head. The top of each pushrod meets a rocker arm that pushes against the stem of a valve, which is held in a raised (closed) position by a strong coil spring, the valve spring.

As the pushrod rises on the cam, it pivots the rocker arm, which pushes the valve down (open) against the pressure of its spring. As the cam continues to rotate, the valve spring acts to close the valve. This is called an overhead valve (OHV) system.

Some engines don’t have pushrods; The valves are actuated more directly by single or dual camshafts in the cylinder head itself, the overhead camshaft system.

The symptoms of bad valves include:

• Cold Engine.
• Off-Throttle Braking.
• Idling.
• Excessive Oil Consumption.
• Excessive Smoke.
• Loss of Engine Power.

#11. Combustion Chamber.

A combustion chamber is an area inside the cylinder where the fuel/air mixture is burned, it’s a closed cylinder.

The main function of the combustion chamber is to burn the air-fuel mixture and produce high-pressure and high-temperature gases.

The piston compresses the fuel/air mixture and touches the spark plug, the mixture is burned and pushed out of the combustion chamber in the form of energy. The energy released during combustion is captured and used to power the engine.

The actual size of the combustion chamber is the volume vacated by the cylinder head when both the intake and exhaust valves are closed, and the piston is at the top of its cycle. A smaller combustion chamber produces a higher compression ratio and therefore produces more power. Higher compression also generated higher temperatures.

The size of the combustion chamber can be changed either by boring the cylinder head or by changing the shape of the piston head.

What happens if oil gets into the combustion chamber? Oil burning in the combustion chamber leads to blue-grey-colored exhaust gases. Oil enters the chamber past the valves and piston rings. Worn valve seals allow oil to seep into the cylinders overnight, resulting in blue-tinted exhaust fumes in the morning.

#12. Intake Manifold.

The intake manifold is part of a car engine that distributes air to the engine’s cylinders. It is also responsible for holding the fuel injectors in many cars.

The manifold allows air into the combustion chamber on the intake stroke, and this air is then mixed with fuel from the injector, after which the combustion cycle continues.

The air reaches the manifold through the air cleaner assembly, which contains the car’s air filter.

The intake manifold consists of the plenum and the runners. The plenum is the chamber that receives the air from the throttle body while the ducts are the tubes that distribute the air to each cylinder.

Engine performance can be adjusted by varying the size of the intake plenum and the length or opening size of the runners. For this reason, modern cars have a variable intake.

Problems with the intake manifold are relatively rare, but some diesel car models contain so-called swirl flaps, which are placed in front of the intake ports.

They are intended to improve airflow at lower engine speeds, but the flaps can become fouled by the exhaust gas recirculation process and either stick or break off altogether and be sucked into one or more engine cylinders.

The cost of replacing an intake manifold varies depending on the car engine and model, and whether OEM or aftermarket parts are used.

Symptoms Of A Bad Intake Manifold:

• Check Engine Light
• Misfires
• Rough Idle
• Loss in Engine Performance
• External coolant leaks
• Engine Overheating

#13. Exhaust Manifold.

In an engine, an exhaust manifold collects exhaust gases from multiple cylinders into one pipe. It has multiple ports, one for each cylinder, and is attached to the cylinder heads with gaskets.

The exhaust manifold, as the first component of the exhaust system, collects the exhaust gases escaping from the engine cylinders and directs them to the catalytic converter.

In turbocharged engines, the turbocharger is located behind the exhaust manifold. Exhaust manifolds are generally made of tubular steel, stainless steel, or iron.

The exhaust manifold not only takes all the burned engine gases but also completely burns all the unused or incompletely burned gases with its very high temperature. The manifold also houses the oxygen sensor in your exhaust system to check the amount of oxygen entering the system.

The oxygen sensor monitors the amount of oxygen and commands the fuel injection system to increase or decrease the amount of oxygen in the fuel/air mixture used to power the engine.

A leak in the exhaust manifold or its gasket can allow exhaust gases to escape, posing a health hazard to vehicle occupants and can lead to erroneous readings from the oxygen sensor, triggering a check engine light. Larger holes in a manifold will produce loud exhaust noise.

Symptoms of a Cracked or Bad Exhaust Manifold:

• Check Engine Light Will Turn On
• Burning Smells.
• Performance Problems or Sluggish Acceleration.
• Poor Fuel Economy.
• Loud Exhaust Noise
• Visible Damage.

#14. Piston Ring.

A piston ring is a metallic split ring that is attached to the outside diameter of a piston in an internal combustion engine.

Piston rings are usually made of cast iron.

The sliding movement of the piston ring within the cylinder wall causes frictional losses for the engine, which account for approximately 24% of the total mechanical frictional losses for the engine.

Piston rings have four main functions: compression gas sealing, oil control, heat transfer, and wear control.

• The compression gas sealing feature provides an effective gas seal without scuffing with sufficient radial wall pressure/maintain of compression gas between the piston and cylinder wall.
• The oil control function keeps excess oil out of the combustion chamber, keeping oil consumption at an acceptable level and reducing harmful emissions.
• The heat transfer feature transfers heat from the hot piston to the engine’s cooled cylinder block, preventing heat build-up in the piston that could damage the engine.
• The wear control feature helps maintain the piston ring shape and prevent wear.

Car engines typically have three rings per cylinder. The two upper rings, known as compression rings, are primarily used to seal the combustion chamber, while the lower ring, known as the oil scraper ring, is responsible for regulating oil consumption.

Symptoms of Bad Piston Ring:

• Discolored or excessive exhaust.
• Oil leaks or profuse oil consumption.
• Declining engine performance.
• Low acceleration.
• Oil in the intake manifold.

#15. Gudgeon Pin.

A gudgeon pin, also known as a wrist pin in the US, is a component in an internal combustion engine that connects the piston to the connecting rod. It provides a bearing on which the connecting rod can pivot as the piston moves.

The piston pin is typically a forged short hollow rod of high strength and hardness alloy steel, which may be physically separate from both the connecting rod and the piston or crosshead.

The ends of the pin are chamfered, and it is held by a circular saw in the piston surrounded from the center by the small-bore end of the connecting rod.

#16. Cam.

A cam is a rotating or sliding piece in a mechanical linkage, which is used to convert a rotary motion into a linear motion.

In the engine, the camshaft is a shaft with a number of cams attached, this cam converts the camshaft rotary motion into the valve linear motion. It is also responsible for the opening and closing timing of the valve.

The shape of the cams greatly affects the engine’s characteristics and performance. When the camshaft is rotated, the shape of the cam allows it to act upon a valve or switch to a degree matching the severity of its shape.

If the cam is in bad shape then it affects the timing of the air-fuel mixture in and out of combustion chambers.

#17. Flywheel.

A flywheel is a heavy wheel that is attached to the end of the crankshaft and rotated with it, it is usually made from cast iron and steel.

The main function of the flywheel is to smooth out the pulses of energy provided during the combustion process of the engine, also it gives back momentum for the compression stroke of the pistons.

It also counterbalances the engine and rotates the crankshaft evenly by reducing vibration and noise, which is generated during combustion.

Flywheel also helps the engine to start by providing the initial rotational energy required for the engine to start over. Without a flywheel, most car engines won’t start and run smoothly.

Symptoms of a Bad Flywheel:

• Slipping Gears.
• Cannot Change Gears.
• Burning Odor.
• Vibrations of the Clutch (Clutch Chatter).
• Unable to Start, or Inconsistent Starts.
• Engine Stalling.
• Engine Vibrations with Clutch Engaged.

#18. Head Gasket.

The head gasket is an important part of a car engine, it provides the seal between the engine block and cylinder head(s). A car engine is divided into two main parts, the engine block, which houses the pistons and cylinders, and the cylinder head, which contains parts such as valves, spark plugs, etc.

The main function of the head gasket is to seal the combustion gases within the cylinders and to avoid coolant or engine oil leaking into the cylinders. Leaks in the head gasket can cause poor engine performance.

For this reason, most manufacturers use thin layers of steel when making head gaskets, making them more durable and longer lasting. As an important part of your car frame, it plays the same role as the skeleton of your car body.

As an engine, downsizing is one of the most noticeable trends in modern cars, nowadays head gaskets are also lighter and stiffer.

Signs Your Head Gasket Is Blown:

• Engine Overheating.
• White Smoke from Tailpipe.
• Low Coolant Level.
• Rough Idle/Engine Knock.
• Contaminated Engine Oil.

#19. Cylinder Liner.

A cylinder liner, also known as a cylinder sleeve, is a thin-walled, hard-metal cylinder that is placed in an engine’s cylinder block and in which the piston moves up and down.

The liner becomes an integral part of engine operation and provides the sliding surface for the piston. It is designed to protect the engine from wear, heat, and contamination.

Cylinder liners are usually made of cast iron alloyed with nickel, chromium, molybdenum, vanadium, or other elements.

They are centrifugally cast and must have good wear resistance and the ability to retain oil to lubricate the surface between the walls and the piston rings. The liners are removable and can be replaced when worn or worn out.

There are three basic types of cylinder liners: hot, dry, and wet.

• Hot cylinder liners are used in air-cooled engines and are made of the same dirt-repellent metal as dry liners.
• Dry cylinder liners are used in water-cooled engines and are comparatively thinner than wet ones due to their simpler design.
• Wet cylinder liners interact with the coolant and help disperse heat and contaminants when they are fitted with tiny openings. They have low lubricating oil consumption and excellent heat conduction.

Check the cylinder liner for cracks, fretting or scoring. If cracks, seizures, or scoring are found, the cylinder must be replaced with a new one. If not, continue to look for cavitation erosion on the liner. Erosion results from poor maintenance of the cooling system.

Metal filings, nicks or burrs, and improper fillets can result in a poor liner fit. Dents appear on the cylinder and piston rings due to most liner damage. Low piston ring or compression pressure and rapid piston ring wear are signs of scoring.

#20. Crankcase.

The crankcase is the central component of the engine. It houses the entire crank mechanism including the piston, cylinder, and connecting rod.

Accessories, the gearbox/transmission, and the engine control with cylinder head are attached to the crankcase.

Due to the oil and cooling channels required for cooling and lubrication, the crankcase is the most complex casting of an internal combustion engine.

An open crank engine has no crankcase. This design was used in early engines and continues to be used in some large marine diesel engines.

The crankcase forms the central component of the engine, in which the drive and cooling jacket are housed.

Crankcase pressure can provide information about the factory PCV system and the condition of the engine.

#21. Engine Distributor.

A distributor is an ignition component that, as the name suggests, distributes sparks to each of the engine’s spark plugs.

Voltage is routed from the ignition coil to the distributor cap via a spark plug wire. This voltage then travels from the center terminal of the cap to the rotor inside the distributor.

As the distributor rotates, the rotor also rotates, distributing voltage to each of the outer terminals of the cap in turn.

The voltage then travels from each of the outer terminals of the distributor through individual spark plugs leading to each of the spark plugs. The spark plugs fire and ignites the air/fuel mixture in the engine.

A failed ignition distributor is one that just won’t fire. A failure can occur at any time, resulting in a running engine stalling or a cold engine failing to start at all.

Occasionally the problem will become apparent before a complete failure occurs. For example, if your car shakes at idle or you hear a high-pitched squeak under the hood, the ignition distributor may be the culprit.

Symptoms of a Bad Engine Distributor:

• Your car won’t start.
• Your engine keeps misfiring or backfiring.
• Your car is shaking.
• Your check engine light comes on.
• You hear a high-pitched noise coming from under the hood.
• You failed your last emissions test.

#22. Distributor O ring.

The distributor o-ring is typically a round rubber ring. It may look like an insignificant round piece of rubber, but it plays an important role.

Since the distributor is responsible for “telling” the spark plugs when to fire, the timing must be precise.

If a distributor moves out of alignment it can cause major timing problems and damage the engine.

The distributor O-ring simply seals the distributor housing to the engine and prevents engine misfires, loss of power, and oil leaks. If the O-ring fails, it can cause oil leaks at the base of the manifold, which can lead to other problems.

Over time, the O-ring tends to wear out for a number of reasons, including:

• Contact with the elements inside the engine.
• Excessive heat and electricity
• Accumulation of dirt and debris

If the distributor o-ring begins to leak, oil and dirt will collect on the outside of the inlet and outside of the distributor. One way to prevent this is to have the vehicle serviced and “tuned up” every 30,000 miles. On most professional tunes, the mechanic will examine the distributor housing and determine if the O-ring is leaking or showing signs of premature wear. It will be replaced.

Symptoms of a Bad or Failing Distributor O Ring:

• Oil leaking from the base of the distributor.
• Lack of power.
• The engine running rough.
• Engine misfire.

#23. Cylinder Headcover.

A cylinder head cover serves as a seal of the cylinder head and is usually made from cast iron or aluminum alloy because the aluminum alloy is a lighter and stronger heat dissipation than any other metal.

The cylinder head/cover acts as a cover for the combustion chamber thereby providing an enclosed space where the combustion can take place in the internal combustion engine.

As a result of the operation of the internal combustion engine, blow-by gases from the combustion process and oil droplets from the lubricant system of the engine are present inside the cylinder head.

A cylinder head is usually located on the top of the engine block. It houses many components of the cylinder heads such as the intake and exhaust valves, springs and lifters, and the combustion chamber.

#24. Rubber Grommet.

An automotive grommet is a round rubber item that is inserted through a hole drilled in an engine body or other equipment to protect an electrical wire, tube, or hose from physical abrasion and to prevent water from entering through the hole.  

Grommets are an accessory for wiring devices.

Used for wires going through the center of the hole. The purpose is to protect the wire from being cut by sharp sheet metal. It is also dust and water-repellent.

#25. Oil Filter.

The oil filter helps remove contaminants from your car engine oil that can build up over time as the oil keeps your engine clean.

Clean engine oil is important because if the oil is left unfiltered for a period, it can become saturated with tiny, hard particles that can wear down surfaces in your engine.

The outside of the filter is a metal can with a gasket that allows it to be held snugly against the engine mating surface.

The bottom plate of the can hold the gasket and is perforated with holes around the area just inside the gasket.

A central hole is tapped to mate with the oil filter assembly on the engine block. The can contains filter material, mostly made of synthetic fiber. The engine’s oil pump delivers the oil directly to the filter, where it enters through holes in the perimeter of the base plate.

The dirty oil is channeled through the filter media (pushed under pressure) and back through the central hole where it re-enters the engine.

Many manufacturers recommend replacing the oil filter at every second oil change. So if you are on a 3,000-mile cycle you would change your filter every 6,000; If you are on a 6,000-mile cycle (like most modern vehicles) you would change it every 12,000 miles.

#26. Camshaft Pulley.

A cam pulley is part of the engine’s timing system that is used to control the speed of the camshaft, the timing belt component that controls the poppet valves responsible for exhaust and intake of air into the cylinders.

The cam pulley is pivotally connected to the timing chain to rotate the camshaft synchronously with the crankshaft.

The camshaft pulleys are located at the front of the engine at the front of each camshaft. The timing belt runs around these and the crank pulley to properly time the engine. If these are damaged or broken off, they can lead to the failure of the timing belt.

#27. Timing Belt Drive Pulley.

Timing pulleys are used to connect and synchronize rotation between two shaft systems.

For example, in engines, use a timing belt pulley component to connect the camshaft and crankshaft.

The sprocket body of the pulley is lined with teeth that ensure the shafts do not slip.

Timing pulleys have teeth or pockets around the outside diameter of the pulley body. Control teeth engage holes in the metal belt, while control pockets engage drive lugs on the inner circumference of a belt. As the name suggests, these teeth or pockets are used for timing.

Symptoms Of a Bad Timing Belt Pulley:

• Shaky, or otherwise encumbered belt motion.
• Visible wear on your pulleys.
• Belt “squealing” or “whining” noises.
• Knocking or slapping noises.
• Damaged bearings or pulleys.

#28. Water Pump.

A water pump is an important part of your car, truck, or SUV’s cooling system.

Its primary purpose is to continuously circulate coolant from the radiator to the vehicle’s engine block to prevent overheating.

Modern water pumps are much more robust, but there is still a chance that they will fail after many years or kilometers.

It is usually driven by a belt from the crankshaft pulley or sprocket.

A car’s water pump uses impeller blades and centrifugal force to move coolant through the various channels and hoses that make up the cooling system.

Once the coolant has flowed around the engine, it is routed through hoses to the radiator, usually at the front of the car, where the hot coolant is cooled by air movement across the radiator fins. It then exits the radiator and flows back into the water pump, where the process begins again.

Common Causes of Water Pump Failure:

• Contaminated coolant. One of the most common causes of premature water pump failure is excessive levels of contaminants in your coolant supply.
• Mixed coolant types. Many car owners simply assume that all engine coolants have the same basic formula. Each of these coolant types uses a different inhibitor technology designed to protect your engine.
• Cavitation. Cavitation is caused by bubbles – also known as vapor cavities – in the coolant. When such bladders are pressurized within the pump, they often implode. This implosion causes damage to the walls of the pump.

Symptoms of a Failing Water Pump in Your Car:

• Leaking coolant.
• Overheating engine.
• Coolant leaks into the oil.
• Engine noise.

#29. Turbocharger and Supercharger.

“Supercharging” and “turbocharging” are terms you’ve probably heard before. Both devices are used to increase the power output of an engine by compressing the air entering the engine.

The compressed air allows more fuel to be burned, which produces more power. The main difference between the two is how they are powered.

A turbocharger uses the velocity and heat energy of the hot exhaust gases pouring out of an engine’s cylinders to power a turbine, which drives a small compressor or impeller, which in turn crams more air back into the engine. 

A supercharger also pumps additional air into the engine but is instead driven mechanically by the engine via a belt running off the crankshaft, or by an electric motor.

Turbochargers are great for their ability to produce more power from a smaller engine size, and the ceiling for that extra power is pretty high. Not only can you change the size of the turbo for more power, but the turbocharger itself can be switched to produce more or less boost.

Superchargers can deliver their power directly from the engine pulley instead of waiting for the exhaust to build up. As a result, there is no turbo lag. And compared to turbocharged engines (including the associated piping), supercharged engines are relatively simple.

The symptoms of a damaged or failing turbo are:

• Loss of power.
• Slower, louder acceleration.
• Difficulty maintaining high speeds.
• Blue/grey smoke coming from the exhaust.
• The engine dashboard light is showing.

Symptoms of a bad supercharger may include:

• The ticking sound coming from the motor
• Decreased fuel efficiency.
• Immediate loss of power

#30. Oil Pans Drain Bolt.

The oil pan drain bolt is the metal bolt at the bottom of the oil pan. When removed, it allows the engine oil to be drained and is sometimes referred to as the oil pan drain plug. 

Located at the bottom or side of the oil pan, the plug is designed to prevent your engine’s vital blood – its lubricant – from spilling out due to the constant effects of gravity and the pressure generated in the crankcase.

When changing engine oil, the oil pan drain plug is removed to drain the oil from the pan. If you notice an oil leak from the oil pan bolt, this can be easily fixed by replacing the bolt gasket.

Check out some of the most common signs that your oil drain plug is worn out and needs replacing.

• A puddle of engine oil under your car
• Visible damage to the drain plug
• Dropping oil level
• Engine performance problems

Read more: 50 Basic Parts of a Car With Name & Diagram

FAQs.