ASVAB - Auto Information

Chassis

Holds all systems and components together

Frame

Supports the vehicle’s body, all mechanical components, and cargo weight

Four-stroke cycle

A piston in the engine must move four times to complete one cycle

Tachometer

Dashboard instrument measuring revolutions per minute

First part of cycle

Piston moves downward in the cylinder, creating a vacuum that draws a mixture of air and fuel into the cylinder from the intake manifold. The intake valve is open, while the exhaust valve is closed (intake stroke)

Second part of cycle

Both the intake and exhaust valves are closed, and the piston moves upward in the cylinder. This movement compresses the air-fuel mixture that was drawn in during the intake stroke (compression stroke)

Third part of cycle

Explosion forces the piston downwards. This downward movement of the piston provides the engine power, turning the crankshaft and propelling the vehicle (combustion stage)

Final stage of cycle

Piston moves upward, forcing the exhaust gases through an open exhaust valve and out of the engine (exhaust stroke)

Piston

Cylindrical object with a solid crown at top. One moves up and down in each cylinder

Piston rings

Seal the piston to the cylinder. Prevent gases from leaking out.

Cylinder

Houses a piston and other components. Where piston and air-fuel mixture work together to transfer energy.

Cylinder head

Part of the cylinder located above the piston. Where you find the combustion chamber as well as the intake and exhaust valves and ports

Combustion chamber

Inside the cylinder head, right above the piston. Air-fuel mixture combusts inside the chamber

Intake valves

Lets air-fuel mix enter the combustion chamber

Exhaust valves

Lets waste gases exit the combustion chamber after combustion

Crankshaft

Turns a piston’s up-and-down motion into a rotary motion

Camshaft

Opens and closes the intake and exhaust valves

Wrist pins

Connects piston to the connecting rod

Connecting rods

Connects each piston and wrist pin assembly to crankshaft

Starter

A motor responsible for rotating the crankshaft in order to start the engine.

Alternator

Sends an electric current back to the battery, keeping it charged, and powers the electronics on your car.

Ignition system

Supplies a high-voltage current to the spark plugs to ignite fuel mixture

Water pump

Pushes liquid coolant through water jackets, which surround parts of the engine that reach the highest temperatures

Radiator

Disperses heat when coolant is exposed to outside air

Coolant (antifreeze)

Raises water’s boiling point and lowers the freezing point

Oil pump

Pushes oil through engine, camshaft control this

Oil galleries

Pathways oil takes through the engine

Oil pan

Reservoir where all the oil pools. It’s at the bottom of the engine.

Pickup tube; Screen

Sends oil into the oil pump; filters out solid materials that clog up system

Oil filter

Cleans out contaminants before the oil gets circulated back through the engine

Exhaust manifold

Connects to the exhaust ports on the cylinder head, where combustion takes place.

Catalytic converter

Contains catalysts transform most toxic compounds into less-harmful compounds

Positive-crankcase ventilation

Forces unspent or partially spent fuel into the cylinder so the fuel can burn

Struts

Support the weight of the vehicle and keep it from collapsing to the ground.

Shock absorbers

Consist of a piston inside a hydraulic fluid-filled, sealed tube. Pushes piston inside of tube instead of jolting the vehicle’s chassis.

Springs

Hold the chassis up and work with the shocks to let the wheels move up and down smoothly

Steering knuckle

Connection point between a tie rod and a wheel. It’s the point that controls where the wheel turns

Control arms

Long, metal pieces connect to steering knuckle and keep it vertical when the wheels move up and down

Tie rods

Transfer force from the steering linkage or steering rack to the steering knuckle, which causes a wheel to turn.