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Automotive 101: Basic Car Parts & Their Functions

BY: Larry Witherspoon Jr.
Mechanic checking the brake disk of a car on lift at the workshop

Most people think of a car as a single machine, but a modern vehicle is really a combination of multiple systems. Knowing how each of these key components functions is essential to being a car owner. It’s vital information that can help diagnose a problem, improve communications with a mechanic, and make you better informed about repair decisions.

Let’s explore the major components that make up a modern automobile. We’ll review how these systems work and include the basics of what to look for when there’s an issue.


An internal combustion engine is the heart of the car. Simply put, it’s a container that converts fuel into energy, which powers the vehicle. Fuel is introduced into the combustion chamber and ignited by spark plugs. (Diesel engines don’t use spark plugs.) This results in an explosion that makes the pistons move. The pistons cause the crankshaft to rotate, which powers the wheels via the transmission.

However, the engine is dependent on other components, like the alternator, radiator, and fuel system, for smooth operation. We’ll cover these areas below. Importantly, when a check engine light comes on (a common warning sign), the problem often doesn’t involve the engine itself but one of these supporting systems. Be observant of any unusual sounds or smells coming from the engine compartment as another indicator of trouble.


While most automobiles sold now have an automatic transmission, you’ll still find manual transmissions in sports cars and some economy vehicles. Both of these gearboxes do the same thing, transfer power from the engine to the wheels.

An automatic transmission uses a complex series of gears, bands, and other parts to manage the engine’s power as the vehicle’s speed and torque change. It’s all handled through a driver-selectable gear lever controlled mainly by a computer. On the other hand, a manual transmission relies on a clutch to connect and disconnect the transmission from the engine. The driver uses a lever each time there’s a need for a different speed and torque.

Look for sluggish performance, difficult gear changes, and strange sounds underneath the car as signs of a transmission problem.


A car battery is a rechargeable apparatus that converts stored chemical energy into electric energy. This device provides power to the starter motor and everything else electrical, like the lights and radio. The alternator (see below) charges the battery.

But, no matter how reliable a car is, it will need a new battery at some point. Indicators of a weak battery include a vehicle that’s hard to start (or won’t start at all), a clicking sound when engaging the ignition, and lights that don’t function normally. The typical car battery last three to five years.


In basic terms, the alternator is an electrical generator that converts the engine’s mechanical energy into electrical energy. This power is used for the electric system and to keep the battery charged. In most cars, the alternator is located at the front of the engine and connected to the crankshaft by a belt. A properly operating alternator generates current while the vehicle is idling and in motion.

The signs of a bad battery (a hard-to-start car, dimming lights, and a dead battery) can also indicate a failing alternator. A mechanic can quickly diagnose the source of the problem.


The radiator is a core part of a car’s cooling system and is typically located at the front end, behind the grille. A radiator can be aluminum or plastic and draws excess heat away from the engine through a network of tubes next to the engine block and cylinder heads. Coolant circulates through the system, pulling heat from the powerplant and becoming cool again as it passes through the fins inside the radiator.

Radiator troubles often begin as a coolant leak visible underneath the car. A temperature warning light can also indicate problems with the radiator or cooling system. It’s important to remember that coolant is toxic (so keep children and pets away from leaks), and a radiator should never be opened when hot (pressure can spray scalding coolant).


Brakes are a primary safety system, with discs and drums being the most common types of brakes. Disc brakes use a rotor (a round metal disc) and a caliper, which holds the brake pad. The brake pad’s friction against the rotor restricts the wheel’s rotation and slows the vehicle down during braking. A drum brake relies on a shoe pressed against the inside of the drum for slowing and stopping action.

The other most important parts of the brake system include the master cylinder (which controls system pressure) and the lines that deliver brake fluid to the four wheels. Anti-lock brakes (ABS), which prevent the wheels from locking up during hard braking, are also part of most modern cars. Poor stopping power or a screeching or grinding sound while braking is a sign that the brakes need attention.


Steering is a primary system that allows the driver to control the car’s direction. The steering wheel is connected to the steering column, which is linked to the steering rack or box to direct the movement of the front wheels. The system is supported by either hydraulic or electric power steering to aid the driver in turning the steering wheel.

The most common signs of a steering problem are difficulty turning the wheel, a steering wheel vibration, or a squeal or whine while turning.


A car’s suspension absorbs shocks and vibrations coming from the ground. This combination of shock absorbers, springs, and linkages also helps maximize tire contact with the road for more sure-footed driving.

The springs adjust to soak up a rough road, and the shock absorbers manage the movement of the springs and help with overall vehicle stability. Meanwhile, the suspension linkages connect the wheels and suspension to the car’s frame, allowing vertical wheel movement independently of the frame.

A sudden rough ride is one red flag of a suspension problem. Also, look if the car pulls in one direction or if the body isn’t level.

Exhaust System and Catalytic Converter

Engine exhaust gases travel from the engine manifold through the catalytic converter and muffler and out the tailpipe. These are all the elements of the exhaust system. Specifically, the catalytic converter removes harmful pollutants, and the muffler reduces engine noise.

Corrosion, which causes holes, can happen anywhere along the way. A louder-than-usual exhaust, smoke, smells, sluggish acceleration, and a check engine light are exhaust system warning signs. A failed emissions test also signals a problem with the exhaust system.

Fuel System/Fuel Tank

Several parts comprise the fuel system, including the tank that holds the gas or diesel, the fuel pump that pushes the gas to the engine, and the fuel filter that removes impurities. In addition, fuel injectors or a carburetor feed the fuel into the engine’s combustion chamber.

These components can go bad and show symptoms like sputtering or stalling. Or the vehicle may be reluctant to start or not start at all.

Endurance: The Other Essential Car Part

Knowing how a car works is wise car ownership, but familiarity with automobiles won’t protect you against unexpected breakdowns and surprise repair bills. That’s why Endurance Warranty is the go-to choice for so many.

All Endurance auto protection plans include 24/7 roadside assistance, rental car reimbursement, trip-interruption services, the freedom to choose from any ASE Certified mechanic, a 30-day money-back guarantee, and flexible payment options. Plus, all Endurance customers are eligible for one year of Elite Benefits. A small activation fee opens access to tire services (including replacements), collision repair discounts, key fob replacement, and total loss coverage.

Enjoy the peace of mind that comes with every Endurance vehicle service contract. Request a free quote by calling our customer support team at (800) 253-8203 or shop online today!

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