There are many parts of a vehicle, and each one plays a vital role in its operation. It’s thanks to the performance of these components that you’re able to get from place to place. While you may understand these parts are important, you might not understand how they operate.

Knowing how things work under the hood can help make you an educated consumer, which can come in handy when your vehicle needs repairs. Being able to have a purposeful conversation with an automotive technician means you’ll know exactly what they’re doing and why.

We’re not saying you must have a master technician’s knowledge! But we are here to help you identify the basic parts of a car and car functions to assist you with troubleshooting problems.

Continue reading to find out more about different car components.

Why Car Part Knowledge is Important for Mechanics

There are many things to cover when it comes to different automotive components and what they do, but starting with the basics is key. Having a foundational knowledge of the major car part names and how they function in your vehicle will serve you well in the long run.

Engine

It makes sense to start with the most important part under the hood of a vehicle, which is the engine. Most modern vehicles are powered by internal combustion engines, which generate energy by igniting a mixture of air and fuel.

There are also electric motors, which store energy in rechargeable batteries. Vehicles with electric engines accelerate faster than those with fuel-powered engines. Whether your car has a traditional or electric engine, it can’t run without it!

Cylinder

The cylinder is the core of an internal combustion engine, where the fuel-air mixture is ignited. The number and arrangement of cylinders affect the engine’s performance and smoothness.

Pistons

Pistons move up and down inside the cylinders. Their motion converts the pressure from combustion into rotational energy that powers the vehicle.

Crankshaft

Connected to the pistons, the crankshaft turns their up-and-down motion into rotational motion, ultimately driving the wheels.

Spark plugs

In a gasoline engine, spark plugs ignite the fuel-air mixture inside the cylinders. This ignition is what drives the pistons.

Camshaft

The camshaft controls the opening and closing of the intake and exhaust valves, ensuring the engine breathes properly at the right time in the combustion cycle.

Battery (electric engines)

In electric vehicles, the battery stores electricity that powers the electric motor. It’s rechargeable and essential to the vehicle’s range and performance.

Electric motor

This component converts electrical energy from the battery into mechanical energy, providing instant torque and smooth acceleration.

Electrical system

Your vehicle’s electrical system powers everything from the ignition and fuel systems to lighting, infotainment and safety features. It includes the battery, alternator and wiring that work together to keep your car running smoothly and safely.

Battery

The battery provides the initial power to start your car when you turn the ignition. It also supplies electricity to components like the lights, radio and dashboard when the engine is off. A weak or dead battery can prevent your vehicle from starting and may cause other electrical issues.

Alternator

The alternator works while the engine is running to power your vehicle’s electrical system and recharge the battery. It keeps systems like the headlights, climate control and power windows functioning while you drive. If the alternator fails, the battery can quickly lose its charge, leading to electrical issues or a stalled engine.

Starter motor

The starter motor is what turns the engine over when you start the car. It draws power from the battery to get the engine running. A faulty starter can cause a clicking noise or complete failure to start.

Fuses and relays

Fuses protect your vehicle’s wiring and electrical components by breaking the circuit if there's an overload. Relays act as switches to control high-current circuits like headlights or the fuel pump using lower-current signals.

Wiring and connectors

The electrical system includes a network of wiring and connectors that carry electricity to various parts of the vehicle. Damaged or corroded wiring can lead to electrical malfunctions or system failures.

Read: What is Battery Terminal Corrosion?

Brakes

The brakes are used to slow down and stop your vehicle, as well as keep it in place when parked. Most cars feature either a disc or drum brake system.

Parts in a disc brake system include calipers, rotors and pads. Drum brake systems are comprised of brake drums and shoes. All these parts have the potential to wear down over time, and any changes to how your brakes sound or feel should prompt you to get them checked.

Brake pads

In a disc brake system, brake pads press against the rotors to create friction and slow the vehicle down. Over time, pads wear down and need to be replaced to maintain effective braking.

Brake rotors (discs)

Rotors are metal discs attached to the wheels. When the brake pads clamp down on the rotors, they create the necessary friction to stop the vehicle. Warped or worn rotors can reduce braking efficiency.

Brake calipers

Calipers house the brake pads and use hydraulic pressure to press them against the rotors. They’re essential in controlling the braking force applied to the wheels.

Brake shoes

In a drum brake system, brake shoes press outward against the inside of the brake drum to slow the vehicle. Like pads, these wear out over time and need regular inspection.

Brake drums

Brake drums are round components that rotate with the wheel. When the brake shoes press against them, they create the friction needed to slow or stop the car.

Brake lines and fluid

Brake lines carry hydraulic fluid from the master cylinder to the brake components. The fluid transfers the pressure you apply to the pedal into braking force. Low or contaminated fluid can reduce braking power.

Master cylinder

The master cylinder generates hydraulic pressure when you press the brake pedal. It sends this pressure through the brake lines to activate the brakes at each wheel.

Read: What Is Brake Fluid?

Transmission

The transmission, otherwise known as the car’s gearbox, is what takes the engine’s power and transfers it to the wheels through various components. Without it, you would simply go nowhere!

Manual transmissions are controlled by the driver using a gear lever or shifter inside the vehicle, while automatics do not require the driver to change gears. Whether it’s a manual or an automatic, there’s a lot going on inside a transmission!

Changing the transmission fluid at the manufacturer’s recommended intervals will help you maintain this important component and prevent it from wearing out.

Gear sets

Gear sets are responsible for providing different torque and speed ratios to the wheels. They work together to allow the vehicle to accelerate, decelerate and maintain speed efficiently in different driving conditions.

Clutch (manual transmission)

The clutch connects and disconnects the engine from the transmission. When you press the clutch pedal, it temporarily breaks the link so you can change gears smoothly.

Torque converter (automatic transmission)

In place of a clutch, automatic transmissions use a torque converter. It transfers engine power to the transmission while allowing the car to come to a stop without stalling.

Valve body (automatic transmission)

The valve body controls the flow of hydraulic fluid within the transmission, directing it to engage the correct gear based on vehicle speed and throttle input.

Transmission fluid

This special lubricant cools and lubricates the moving parts within the transmission. In automatics, it also plays a role in hydraulic pressure for shifting gears.

Output shaft

The output shaft transfers the power from the transmission to the driveshaft or axle, ultimately turning the wheels.

Synchronizers (manual transmission)

Synchronizers help the gear and shaft spin at the same speed, allowing smooth gear changes without grinding in manual transmissions.

Steering and suspension

The steering and suspension system works to provide control, stability and comfort while driving. While the steering allows you to direct the vehicle, the suspension absorbs shocks from the road and keeps your tires planted for a smoother and safer ride.

Shock absorbers

Shock absorbers are essential to your car’s suspension system. They dampen the impact of road bumps and prevent excessive bouncing by absorbing energy from the wheels. Their main job is to keep your tires in contact with the road, which ensures safe handling and effective braking. Worn shocks can cause vibrations, poor handling and uneven tire wear.

Struts

Struts combine the function of a shock absorber and a structural component in one unit. They support the vehicle’s weight and are often integrated with a coil spring to absorb large shocks. Struts are common in the front suspension of many vehicles.

Coil springs

Coil springs are tightly wound steel coils that compress and expand to absorb the motion of the wheels. They work with shocks and struts to smooth out the ride by cushioning impacts from potholes or uneven roads.

Control arms

Control arms connect the suspension system to the vehicle’s frame and allow the wheels to move up and down while keeping them properly aligned. They are typically fitted with bushings or ball joints to reduce vibration and wear.

Sway bar (stabilizer bar)

The sway bar connects the left and right sides of the suspension to reduce body roll during cornering. It helps keep the vehicle stable and level by distributing weight more evenly during turns.

Steering rack and pinion

This component converts the turning motion of the steering wheel into side-to-side motion that turns the front wheels. Rack-and-pinion systems offer responsive and precise control, especially at higher speeds.

Tie rods

Tie rods connect the steering rack to the wheels via the steering knuckle, helping transmit force that turns the wheels left or right. Worn tie rods can lead to poor alignment, uneven tire wear and unpredictable steering response.

Ball joints

Ball joints serve as pivot points between the suspension and the steering knuckle, allowing smooth movement as the vehicle steers and drives over uneven surfaces. Worn or loose ball joints can affect handling, alignment and tire wear.

Exhaust system

The exhaust system is responsible for directing and treating the gases produced during combustion in your vehicle’s engine. It helps reduce harmful emissions, minimize noise and improve engine performance and fuel efficiency. A well-maintained exhaust system is critical for your car’s environmental impact and overall function.

Exhaust manifold

The exhaust manifold is the first part of the exhaust system. It collects exhaust gases from the engine’s cylinders and funnels them into a single pipe. It's usually made of cast iron or stainless steel and must withstand extreme temperatures.

Oxygen sensors

Oxygen sensors monitor the level of oxygen in the exhaust gases. These readings help the engine control module adjust the air-fuel mixture for better fuel efficiency and lower emissions. Malfunctioning sensors can cause poor performance and result in increased fuel consumption.

Catalytic converter

The catalytic converter reduces harmful emissions by converting toxic gases—like carbon monoxide, hydrocarbons and nitrogen oxides—into less harmful substances such as carbon dioxide, water vapor and nitrogen. It's a critical component for meeting emissions standards.

Resonator

Often located just before the muffler, the resonator helps fine-tune the sound of the exhaust system. It cancels out specific sound frequencies to reduce engine noise and improve sound quality.

Muffler

The muffler is designed to minimize the noise produced by the engine’s exhaust gases. It uses chambers, baffles or perforated tubes to dampen and direct sound waves, making the vehicle quieter.

Exhaust pipes

Exhaust pipes connect all components of the exhaust system and carry gases from the engine to the tailpipe. These pipes must be resistant to heat and corrosion, as they handle hot, high-pressure gases.

Tailpipe

The tailpipe is the final section of the exhaust system, where treated gases exit the vehicle. Though it may seem simple, its placement and size can impact noise levels and overall airflow.

Ignition and fuel systems

The ignition and fuel systems work together to start the engine and keep it running smoothly. The fuel system delivers the right amount of fuel to the engine, while the ignition system ignites that fuel-air mixture to produce power. Proper coordination between these two systems is essential for performance, fuel efficiency and reliability.

Spark plugs

Spark plugs are responsible for igniting the air-fuel mixture inside the engine's cylinders. They create a small electrical spark at just the right moment to start combustion. Worn or fouled spark plugs can cause misfires, rough idling and reduced fuel economy.

Ignition coil

The ignition coil transforms the car battery’s low voltage into the high voltage needed to create a spark in the spark plugs. Some vehicles have one coil per cylinder, while others use a single coil to fire multiple spark plugs.

Distributor (older systems)

In older ignition systems, the distributor routes high voltage from the ignition coil to the correct spark plug at the right time. Modern vehicles often use distributor-less ignition systems (DIS) instead.

Ignition control module

This component controls the timing and duration of the spark. It receives signals from sensors and ensures the spark occurs at the optimal moment for combustion. It works closely with the vehicle’s engine control unit (ECU).

Fuel pump

The fuel pump moves fuel from the gas tank to the engine. In modern vehicles, this is usually an electric pump located inside the fuel tank. A failing fuel pump can result in hard starts, poor acceleration or stalling.

Fuel injectors

Fuel injectors spray a fine mist of fuel into the engine’s intake manifold or directly into the combustion chamber. They are controlled electronically to deliver precise amounts of fuel for efficient combustion.

Fuel filter

The fuel filter removes dirt, rust and other contaminants from the fuel before it reaches the injectors. A clogged fuel filter can reduce engine performance and may even prevent the engine from starting.

Engine control unit (ECU)

The ECU is the brain of the engine and coordinates both the ignition and fuel systems. It uses data from various sensors to adjust ignition timing, fuel delivery and other parameters for optimal performance.

Tires and wheels

Tires and wheels are your vehicle’s direct connection to the road. They impact everything from handling and ride comfort to fuel efficiency and safety. Keeping them in good condition ensures optimal performance and control.

Tires

Tires provide traction, absorb shocks and support the vehicle’s load. They come in various tread patterns and types (all-season, performance, off-road) suited for different driving conditions. Regularly checking tire pressure, alignment and tread depth is essential for safety.

Rims (wheels)

Rims support the tire and connect it to the hub of the vehicle. They come in a range of materials and sizes that influence ride quality and performance. Alloy wheels are popular for being lightweight and stylish, while steel wheels are more durable and cost-effective.

Valve stem

The valve stem allows air to be added or released from the tire and houses the valve core that maintains air pressure. Damaged valve stems can lead to slow leaks.

Wheel bearings

Wheel bearings help the wheel rotate smoothly with minimal friction. They are sealed components but can wear out over time, often causing grinding noises or wobbling when driving.

Lug nuts

Lug nuts fasten the wheel to the hub. Proper torque is essential to ensure the wheels stay secure without damaging the studs.

TPMS (Tire Pressure Monitoring System)

TPMS sensors monitor air pressure in real time and alert the driver if any tire is under-inflated. Maintaining proper tire pressure improves safety and fuel efficiency.

Cooling systems

The cooling system regulates the engine's temperature, preventing it from overheating and ensuring it operates efficiently. It circulates coolant through the engine and radiator to absorb and dissipate heat.

Radiator

The radiator is the main component that cools the engine coolant by allowing it to release heat to the outside air. It’s usually located at the front of the vehicle for maximum airflow.

Water pump

The water pump circulates coolant through the engine and to the radiator. It’s typically driven by a belt and is essential for maintaining consistent engine temperature.

Thermostat

The thermostat regulates the flow of coolant based on engine temperature. It remains closed during warm-up, then opens once the engine reaches operating temperature to allow coolant to circulate.

Radiator fan

The radiator fan pulls air through the radiator when the vehicle isn’t moving fast enough for natural airflow. It helps maintain proper coolant temperature, especially in stop-and-go traffic.

Coolant (antifreeze)

Coolant is a specially formulated fluid that absorbs engine heat and resists freezing and boiling. It also contains additives that protect against corrosion inside the cooling system.

Coolant reservoir

The coolant reservoir holds excess coolant that expands as it heats up. It allows the system to maintain the correct fluid level and pressure as temperatures fluctuate.

Hoses and clamps

Rubber hoses carry coolant between the radiator, engine and other components. Clamps secure the hoses and prevent leaks. Over time, hoses can become brittle and may need replacing.

Components of a Car & Their Functions FAQs

How are car parts labeled or identified?

Parts of a car are identified or labeled by a variety of methods to ensure easy identification, cataloging and replacement. Each car part typically has a unique part number assigned by the manufacturer, along with OEM (original equipment manufacturer) or aftermarket labels. Barcodes or QR codes have also been popular additions to newer car parts.

How many parts are in a car?

Typical cars consist of thousands of parts, though the exact number can vary widely depending on the make, model and complexity of the vehicle. Estimates generally range from 30,000 to 40,000 individual components.

What are considered critical auto parts?

Critical auto parts are those essential to the safe and functional operation of your vehicle. These include the engine, transmission, brakes, steering components, suspension system and tires. Safety-related parts such as airbags, seat belts and lighting systems are also considered critical. If any of these fail, they can directly affect drivability or increase the risk of accidents.

How do mechanics evaluate car part quality during repairs?

Mechanics evaluate part quality using a combination of visual inspections, performance tests and diagnostic tools. They look for signs of wear, damage or corrosion, check for abnormal sounds or movement, and use manufacturer specifications to assess tolerances. For replacement parts, they consider brand reputation, OEM standards, warranty coverage and material durability before installation.

Learn Even More About Parts of a Car at UTI

Now that you know about some of the basic car parts, are you itching to learn more? This could mean you’re suited for a job as an automotive technician, where you’ll get to work hands-on and up close on projects featuring these car components!

At Universal Technical Institute (UTI), our Automotive Technology program can equip you with the knowledge you need to maintain and repair import and domestic vehicles. Also, we provide specialized automotive training programs for top brands in the industry. From working on engine systems to performing emissions tuning, the courses can help you gain valuable hands-on training and knowledge that you can lead you toward the workforce.^1,18

The best part is that you can graduate from the program in less than a year.⁷ You’ll gain an education that will help you prepare for a career you’re excited about—and help you out when you need to make repairs on your own ride!

Interested in finding out more? Request information here from an Admissions Representative or call 1-800-834-7308.