Every part, explained.
Pick a component to see what it does, how to spot trouble, and roughly what it costs to fix in the UK.
Top 10 Searched
Car Battery
Stores the electricity that starts your car and powers it when off.
Brake Disc
The shiny metal plate your brake pads squeeze to slow you down.
Engine
The heart of the car — where fuel becomes motion.
Clutch
Connects and disconnects the engine from the wheels.
Alternator
The on-board power station that keeps your battery topped up.
Starter Motor
The muscle that turns your engine over when you twist the key.
Oil Filter
Keeps your engine oil clean so internal parts don't wear out.
Suspension Springs
The coiled metal springs that keep your wheels on the road and your ride comfy.
Spark Plugs
Tiny igniters that set fire to the fuel inside your engine.
Ignition Coil
Turns 12 volts into 30,000+ volts to light the spark plug.
Electrical
Alternator
The on-board power station that keeps your battery topped up.
Starter Motor
The muscle that turns your engine over when you twist the key.
Car Battery
Stores the electricity that starts your car and powers it when off.
ECU (Engine Control Unit)
The computer that runs your engine — fuel, ignition, emissions, everything.
Engine
EGR Valve
A small valve that recycles exhaust gas to reduce emissions.
Spark Plugs
Tiny igniters that set fire to the fuel inside your engine.
Turbocharger
Squeezes more air into the engine for extra power.
Oil Filter
Keeps your engine oil clean so internal parts don't wear out.
Timing Belt
The rubber belt that keeps your engine's valves and pistons in perfect time.
Timing Chain
A metal chain (instead of a belt) that times your engine — usually lasts the life of the car.
Serpentine Belt
The long ribbed belt that drives your alternator, power steering and air-con.
Engine
The heart of the car — where fuel becomes motion.
Air Filter
Keeps dirt and grit out of your engine.
Throttle Body
The valve that decides how much air the engine gets.
Mass Air Flow (MAF) Sensor
Measures exactly how much air enters the engine.
Fuel System
Stores, filters and delivers fuel to the engine.
Fuel Pump
Pushes fuel from the tank up to the engine.
Fuel Filter
Keeps rust, water and grit out of your injectors.
Ignition Coil
Turns 12 volts into 30,000+ volts to light the spark plug.
Fuel Injectors
Spray a fine mist of fuel into the engine.
Fuel Tank
Where the fuel lives until the engine needs it.
Ignition System
Creates the spark that fires the engine (petrol only).
Carburettor
The old-school mechanical mixer that fed petrol engines before fuel injection took over.
Exhaust
Catalytic Converter
A clever filter that scrubs harmful gases out of your exhaust.
Diesel Particulate Filter (DPF)
Traps soot from diesel exhaust so it doesn't reach the air.
AdBlue System
The blue fluid modern diesels use to clean up their exhaust.
Exhaust System
Carries waste gases away and quietens the engine.
Oxygen (O2) Sensor
Tells the ECU if the fuel mixture is right.
Braking
Brake Pads
The friction blocks that slow your car when you press the pedal.
Brake Disc
The shiny metal plate your brake pads squeeze to slow you down.
Master Cylinder
The pump behind your brake pedal that turns your foot push into stopping power.
ABS Sensor
The little sensor at each wheel that stops your brakes from locking up.
Brake Calipers
The hydraulic clamp that squeezes the pads onto the disc.
Drivetrain
Clutch
Connects and disconnects the engine from the wheels.
Drive Shaft
The spinning bar that delivers engine power to your wheels.
Wheel Bearing
The greased bearing that lets your wheel spin smoothly for thousands of miles.
Gearbox / Transmission
Lets the engine spin at its happy speed at any road speed.
Differential
Lets your driven wheels turn at different speeds in corners.
Cooling
Suspension
Suspension Springs
The coiled metal springs that keep your wheels on the road and your ride comfy.
Shock Absorbers
The oil-filled tubes that stop your car bouncing after every bump.
Wishbones / Control Arms
The bone-shaped arms that connect the wheel hub to the chassis and control how the wheel moves.
Anti-Roll Bar & Drop Links
The stabiliser bar and its connectors that keep the car flat and stable through corners.
CV Joints
The flexible joints that transfer power from the gearbox to the wheels while the suspension moves up and down.
Car Servicing and Legal
Steering
Power Steering Pump
The pump that makes turning the wheel feel light, even when parking.
Steering Rack
The component that turns your steering wheel into wheel movement.
Track Rod / Tie Rod Ends
The links between the steering rack and the front wheels — a common MOT failure.
Electric Power Steering (EPS) Motor
The electric motor that has replaced the old hydraulic pump on most modern cars.
Comfort
Air Conditioning Compressor
The pump that makes your air conditioning blow cold.
Heated Seats
Electric warming pads built into your seat cushion and backrest.
Heated Steering Wheel
A warming element wrapped around the rim of the wheel.
Climate Control System
The smart brain that keeps the cabin at the temperature you set.
Air Conditioning System
The whole system that cools, dries and freshens the cabin air.
Cabin Air Filter
A pleated paper filter that cleans the air before it reaches the vents.
Visibility and Convenience
Windscreen Wipers
Your first line of defence against rain, snow and road grime
Rain Sensors
How your car knows it is raining before you do
Automatic Headlights
Lights that think for themselves so you never drive in the dark
Auto-Dimming Rear View Mirror
No more dazzling headlights from the car behind
Heated Windscreen
Melts ice and fog away in seconds without a scraper
Rear Window Demister
Clears your back window on frosty mornings in under a minute
Doors and Access
Central Locking
Lock or unlock every door from a single button press
Keyless Entry
Walk up and the car unlocks itself — no key needed
Push Button Start
One press and the engine springs to life
Electric Windows
Effortless glass movement at the touch of a switch
Electric Tailgate
Open or close the boot with a button press or a foot wave
Child Locks
Keep little passengers safely inside
Modern Technology
Infotainment System
The car's entertainment and control hub.
Apple CarPlay
iPhone, simplified, on the car screen.
Android Auto
Your Android phone, projected onto the dashboard.
Bluetooth Connectivity
Pairing your phone wirelessly.
Wireless Charging Pad
Top up your phone without plugging in.
USB Ports
Charging vs data — they're not all the same.
Digital Instrument Cluster
Screens instead of dials.
Heads-Up Display (HUD)
Speed and directions floating on the windscreen.