Interactive mechanical encyclopedia
For every component: what it does, how it fails, how to diagnose it and how to maintain it. 73 parts explained, free.
Air intake
3MAF Sensor Cleaning
Cleaning the mass airflow sensor can fix rough idle, poor economy and lean codes without replacing it.
Open →Mass Airflow Sensor
The MAF sensor measures how much air the engine is breathing so the ECU can meter fuel.
Open →Throttle Body
The throttle body controls how much air enters the engine through the accelerator.
Open →Body
1Brakes
9ABS Module & Pump
The ABS module reads wheel speeds and modulates brake pressure to stop wheels from locking.
Open →Brake Booster
The brake booster multiplies your pedal force using engine vacuum, so braking is effortless.
Open →Brake Caliper
The caliper squeezes the pads against the disc using hydraulic pressure.
Open →Brake Disc
The brake disc (rotor) is squeezed by the pads to slow the wheel.
Open →Brake Hoses & Lines
Brake hoses and lines carry hydraulic pressure from the master cylinder to each brake.
Open →Brake Pads
Brake pads press against the disc to convert motion into heat and slow the car.
Open →Brake Pedal Sensor
The brake pedal sensor tells the ECU and brake-by-wire systems when and how hard you press the pedal.
Open →Master Cylinder
The master cylinder converts pedal force into hydraulic pressure for all four brakes.
Open →Wheel Speed Sensor
The wheel speed sensor tells the ABS and stability systems how fast each wheel is turning.
Open →Climate
2AC Compressor
The AC compressor pressurizes the refrigerant so the system can absorb and reject heat.
Open →Cabin Air Filter
The cabin filter cleans the air that reaches the interior through the heating and AC system.
Open →Cooling
5Coolant Temperature Sensor (ECT)
The ECT sensor tells the ECU how hot the engine is so it can manage fuel, fans and gauges.
Open →Cooling Fan
The electric cooling fan draws air through the radiator when the car is slow or stopped.
Open →Radiator
The radiator dissipates engine heat into the air using the cooling fan and airflow.
Open →Thermostat
A small valve that keeps the engine at operating temperature by controlling coolant flow to the radiator.
Open →Water Pump
The water pump circulates coolant through the engine, radiator and heater core.
Open →Electrical
4Alternator
The alternator converts mechanical engine power into electrical power to run the car and recharge the battery.
Open →Battery
The battery stores energy to crank the engine and powers the car when the alternator cannot.
Open →Ignition Switch
The ignition switch controls the start and power circuits from the key or button.
Open →Starter Motor
The starter cranks the engine with a high-torque electric motor and pinion gear.
Open →Emissions
4Catalytic Converter
The catalytic converter turns harmful exhaust gases into less harmful ones.
Open →EGR Cooler
The EGR cooler chills recirculated exhaust gas so it lowers combustion temperature more effectively.
Open →EGR Valve
The EGR valve recycles a little exhaust gas into the intake to lower combustion temperature and NOx.
Open →Oxygen Sensor (O2 / Lambda)
The oxygen sensor measures exhaust oxygen so the ECU can fine-tune the air-fuel mixture.
Open →Engine
17Accessory Belt
The serpentine belt drives the alternator, water pump, power steering and AC compressor.
Open →Air Filter
The air filter cleans the air entering the engine before it is metered by the MAF.
Open →Camshaft
The camshaft controls when the intake and exhaust valves open and close.
Open →Crankshaft
The crankshaft turns the pistons’ up-down motion into rotational power.
Open →Engine Oil Pump
The oil pump pressurizes the oil that protects every bearing in the engine.
Open →Engine Oil System
The oil system lubricates, cleans and cools the engine under pressure.
Open →Harmonic Balancer (Crank Pulley)
The harmonic balancer damps crankshaft vibration and drives the accessory belt.
Open →Intercooler
The intercooler cools the pressurized air from the turbo before it enters the engine.
Open →Oil Filter
The oil filter removes particles and sludge from the engine oil.
Open →PCV Valve
The PCV valve vents crankcase gases back into the intake to be burned.
Open →Piston & Rings
Pistons convert combustion pressure into linear motion that the crankshaft turns into rotation.
Open →Timing Belt / Chain
The timing belt or chain keeps the crankshaft and camshaft synchronized for correct valve timing.
Open →Timing Chain System
A timing chain synchronizes the camshafts and crankshaft — it usually lasts the life of the engine.
Open →Turbo Actuator / Boost Control
The turbo actuator adjusts the wastegate or vanes to control how much boost the turbo delivers.
Open →Turbo Wastegate
The wastegate controls turbo boost by diverting exhaust gas away from the turbine.
Open →Turbocharger
A turbocharger uses exhaust gas to force more air into the engine for more power.
Open →Variable Valve Timing (VVT)
VVT advances or retards the camshaft to optimize power, torque and fuel economy across the rev range.
Open →Exhaust
2Diesel Particulate Filter
The DPF traps soot from a diesel engine and burns it off during regeneration.
Open →Exhaust System
The exhaust system carries burnt gases away, reduces noise and cleans emissions.
Open →Fuel
4Fuel Filter
The fuel filter removes dirt and water before fuel reaches the pump or injectors.
Open →Fuel Injector
Fuel injectors spray a fine, precisely metered mist of fuel into the intake or directly into the cylinder.
Open →Fuel Pump
The fuel pump moves fuel from the tank to the engine, often at very high pressure in direct injection.
Open →Fuel Rail
The fuel rail distributes pressurized fuel to all the injectors.
Open →Ignition
3Glow Plug
Glow plugs pre-heat the combustion chamber of a diesel engine for cold starts.
Open →Ignition Coil
The ignition coil transforms battery voltage into the tens of thousands of volts needed for the spark.
Open →Spark Plug
The spark plug ignites the compressed air-fuel mixture at the right moment.
Open →Steering
4Power Steering Fluid
Power steering fluid transmits pressure to assist your steering.
Open →Power Steering Rack
The steering rack converts steering wheel rotation into the left-right movement that turns the wheels.
Open →Steering Column
The steering column carries the wheel to the rack and houses the column lock and controls.
Open →Tie Rod Ends
Tie rod ends link the steering rack to the wheels so your steering input turns the wheels.
Open →Suspension
7Ball Joints
Ball joints connect the control arms to the steering knuckle so the wheel can steer and move.
Open →Coil Springs
Coil springs support the vehicle weight and absorb road shocks.
Open →Control Arms
Control arms locate the wheel and connect it to the chassis through bushes and ball joints.
Open →Shock Absorbers & Struts
Shock absorbers control spring movement so the tires stay in contact with the road.
Open →Stabilizer (Anti-roll) Bar
The anti-roll bar reduces body lean when cornering by connecting the two wheels of an axle.
Open →Wheel Bearing
Wheel bearings let the wheel spin freely on the hub with minimal friction.
Open →Wheel Hub Assembly
The wheel hub carries the bearing and the wheel, and houses the ABS sensor ring.
Open →Tires
1Transmission
7Clutch
The clutch connects and disconnects the engine from the gearbox to change gear and pull away.
Open →Clutch Slave Cylinder
The clutch slave cylinder pushes the release bearing to disengage the clutch hydraulically.
Open →Differential
The differential lets the driven wheels turn at different speeds when cornering.
Open →Driveshaft / CV Joint
Driveshafts carry engine torque to the wheels and allow suspension movement and steering.
Open →Flywheel
The flywheel stores rotational energy to smooth the engine and carries the clutch.
Open →Gearbox (Manual & Automatic)
The gearbox changes the torque-speed ratio between the engine and the wheels.
Open →Transmission Fluid
Transmission fluid lubricates, cools and hydraulically actuates the gearbox.
Open →