automotive terms

*Please note this is a simplified glossary for the layperson. Most of the
technical jargon has been omitted.

2wd/ Two wheel drive-Method of moving a vehicle by the engine’s
torque being applied to two wheels. Two front wheels, or two rear
wheels either fwd/front wheel drive, or rwd/ rear wheel drive

4wd/4x4/ Four wheel drive-Method of moving a vehicle by engine
torque being applied to all four wheels. The main advantage of four-
wheel drive is to increase traction while driving through dirt, mud, rain,
or snow.

Abs/Anti lock brakes-Abs systems electronically monitor the speed of
the wheels and regulate hydraulic pressure to each wheel’s brake.
Striving to maximize braking power while preventing the wheels from
locking up and skidding.

Abs light-A light on the dash, or instrument panel that comes on when
the key is turned to the on position, then turns off when the car is
running if the system is working properly.

Accumulator/drier-A canister for receiving liquid refrigerant, vapor
and oil from the evaporator. Its main function is to separate the vapor
from the liquid and oil, then release the vapor to the compressor. The
accumulator also contains a desiccant to absorb the moisture.

A.C./Air conditioning-The system that cools and dehumidifies the air
entering the passenger compartment. The system uses refrigerant to
cool the air and to carry heat away from the passenger compartment.

Air filter-The filter that helps keep dust, dirt, and debris out of the
engine’s air intake.

Airbag light/Srs light-A warning light on the dashboard or instrument
panel that comes on when the key is put in the on position, then goes
out once the car is running, to tell you that the system is working
properly.

Alignment-To check and adjust to factory specs, the vehicle’s caster,
camber, and toe angles of the wheels and suspension.

Alternator-An accessory on the engine that produces the energy that
the car needs to run. The alternator also keeps the battery charged.

Automatic transmission-A type of transmission that shifts without the
use of a clutch, through fluid in the torque converter that connects the
engine’s power to the transmission.

Awd/All wheel drive-A vehicle where all four wheels are driven using
a fluid coupling rather than a transfer case to put the engine’s torque to
all four wheels.

Body magnet-A tool used for checking the thickness of a body filler
material . See Bondo

Bondo/Body filler-When body work is done properly, the car body’s
sheet metal is pounded back into place or replaced. Bondo is a plastic
filler material used to fill in slight imperfections. Some fly by night
backyard body shops will use filler instead of the time consuming work
of pounding and pulling the sheet metal back into place. In this case the
filler is put on very thick, and the body magnet will detect it.

Book time/Flat rate manual- A manual that gives estimates on labor
time and costs for most auto repairs.

Brake caliper-A hydraulically activated device in the disc brake
system. It attaches over the brake rotor and contains piston(s) and
brake pads. Hydraulic pressure on the piston(s) force the pads against
the rotor.

Brake drums-A drum that rotates with the rear wheels . The brake
shoes expand when brake pressure is applied causing friction between
the shoes and the drums. On the rear axle of most cars that do not
have four wheel disc brakes.

Brake master cylinder-The component in the brake system where the
brake fluid is stored

Brake wheel cylinder/wheel cylinder-In the drum brake assembly a
device using internal pistons to push the brake shoes against the
drums. The pistons are operated by hydraulic pressure.

Brake pads-A brake lining material that is used on a disc brake
system, which creates friction against the brake’s rotor.

Brake rotors-The flat discs that provide the friction against which the
brake pads push They must be turned when new pads are applied, as
long as the rotors have enough metal left to be turned.

Brake shoes-On the drum brake assembly it is the brake backing and
lining.

Cabin air filter-A filtering device used to catch dust and dirt before the
air enters the passenger compartment.

Camshaft/cam-A shaft in the engine that contains eccentric shaped
lobes that operate the valves. The camshaft is driven by the crankshaft
via a timing belt or timing chain and gears. It spins at ½ the engine’s
crankshaft speed.

Carburetor-A mechanical device used on older cars to mix the proper
amount of air and fuel for the engine to burn in its combustion
chambers, and powering the engine.

Catalytic converter-An exhaust system device(and emissions control)
that converts harmful byproducts of combustion into CO2 and water
vapor through a chemical reaction

Check engine light/CES light/mil-A warning light that comes on if the
vehicle’s computer system detects an engine performance or emissions
problem.

Clutch-A hydraulically operated device that allows the car to change
gears and synchronizes speeds between the engine and the
transmission.

Clutch master cylinder-A reservoir used for holding the clutches
hydraulic fluid

Coil/Ignition coil-A transformer in the vehicle’s ignition system that
bumps up the voltage to the spark plugs.

Compressor-A belt driven air conditioner component that pumps
refrigerant and increases the refrigerant vapor’s pressure and
temperature.

Computer ecm/pcm/brain-The engine’s management system. This
system uses inputs from sensors to control spark timing, air and fuel
mixtures, and other functions including emission control.

Condenser/ air c.c. condenser-A device similar to a radiator. In the
air conditioning system the condenser causes refrigerant gas to turn to
a liquid and gives off heat in the exchange.

Condenser fins-The small fins used for cooling the condenser. If
these fins have debris blocking them, or the fins are bent the system will
not work as it should.

Constant velocity joint/c.v. joint-On drive shafts of front wheel drive
vehicles this joint allows the axle shaft to pivot regardless of the axle’s
angle while it is spinning.

Crankshaft-The internal driving shaft of the engine that converts the
piston’s energy into rotary motion. The crankshaft also moves the valve-
train by use of a belt, chain, or gears.

Dent(s)-A crease or impression left in a cars body after bumping into
something or getting into an accident.

Diagnostics-Using a special computer, or various types of electronic
equipment to check many areas of a car’s performance and emission
systems.

Diesel engine-An engine that runs at a much higher compression than
gasoline engines causing the fuel to burn without the need for spark
plugs. The higher compression makes the diesel engine more efficient
and creates better fuel consumption.

Differential-A gearbox that is designed to allow both drive wheels to
spin at different speeds, when turning, or when each wheel has
different amounts of traction.

Ding(s)-An impression left in a cars body after bumping into something
such as a shopping cart. These are not as pronounced as a dent.

Disc brakes-A hydraulic brake assembly consisting of a brake disc or
rotor, mounted on an axle, and a caliper assembly containing pistons
that push the brake pads against the rotor creating friction that slows
down the vehicle.

Distributor-A mechanical device on an engine that causes the spark
plugs to get fire at the correct time.

Distributor-less ignition/dis-An ignition system that does not use a
distributor to route voltage to the spark plugs. The coil pack(s) run
power directly to the spark plugs.

Documentation fee/doc fee-A fee dealers and used car lots charge
to cover paperwork and accounting costs.

Drive belt-A belt driven by the engine’s crankshaft to turn various
accessories such as the water pump, alternator, power steering pump,
a.c. compressor.

Driveshaft-The shaft that transmits engine torque from the
transmission to the differential, or from the differential to the drive
wheels.

Electronic control module/Ecm- see computer

Electronic Fuel injection/Efi-A type of fuel system that uses
computer controlled fuel injectors to spray the proper amount of fuel
into the engine. Fuel injection being much more precise than
carburetors at delivering the best air fuel mixture to the engine.

Emission tag-The metal tag on the underside of the hood that states
the engine size and all applicable emission components and routings

Engine blown/seized-if an engine runs out of oil or coolant,
lubrication will stop causing the engine to stop turning and lock up.

Engine size-Either written as ci for cubic inches of displacement. Or in
liters with a handwritten small L preceded by the amount of liters .
Examples are 3.0l, 3.8l, 5.4l.Three point o liters, three point eight liters,
and five point four liters respectively.

Exhaust-The system that carries exhaust gases away from the engine,
quiets the engine and helps control pollution.

Exhaust manifold-The passages coming off of the cylinder head
where hot exhaust gases leave the engine heading back to the rear of
the car.

Fan belt-see drive belt

Factory rebate-Money back from the manufacturer to the dealer or to
you. When you buy a specific car. The money can be mailed to you or
be used as part of your down payment.

Factory recall-When a certain production vehicle has safety or
emission related problems, the factory may buy back these vehicles. At
times the dealer who sells these cars will fix the issues and the factory
will pay the dealer to do the repairs at a low cost.

Filler-see body filler or bondo

Flat rate/Flag time-see book time

Flywheel-A disc shaped unit with gear teeth around the outside. The
starter turns the flywheel causing the engine to spin and start. The
flywheel is usually on the rear end of the crankshaft.

Fuel filter-A metal, plastic, or glass cylinder filled with a filter type
media , the gas flows through this filter causing impurities to stop at the
filter rather than reaching the injectors, or carburetor. And potentially
causing premature engine wear.

Fuel pump-A mechanical or electrical device used to pump fuel from
the gas tank to the engine.

Front wheel drive-A vehicle that has the two front wheels delivering
the vehicles torque to the ground. A front wheel drive vehicle will have
the engine turned sideways in the engine bay to allow the trans-axle to
power the two front axles.

Fuse-A protective device that contains a small strip of wire to protect
the circuit from overloads.

Gasket-A way to seal to surfaces together to keep oil, fuel, or coolant
in the places where they belong.

Glow plugs-A device used on a diesel engine similar to a spark plug to
create the initial heat to start a diesel engine firing. Once the engine is
running the glow plug is not used because of the high compression that
the engine creates will cause the fuel mixture to ignite on its own.

Headers-An exhaust manifold designed with near optimal specifications
can increase performance.

Hood-The metal cover that goes over the engine bay.

Hood latch-A safety mechanism used to keep the hood from opening .

Hood struts-Thin hydraulic tubes used on large hoods to keep the
hood from falling down when it is opened. A hood prop is a thin metal
bar that pivots up, when opening the hood you move this bar into a slot
in the hood which will keep the hood from falling down.

Hydraulic fluid-Fluid cannot be compressed, this type of oil is put into
a hose or a cylinder when pressure is exerted on one end, the fluid is
forced out the other end which can move a piston such as in your brake
system.

Ignition cylinder lock-The tumbler that the ignition key goes into to
start up the car.

Ignition module/icm-An electronic control device used on some cars.
It’s purpose is to receive a signal from a magnetic pickup or hall effect
switch and then use that signal to open and close the ground circuit to
the coil causing the coil to fire the spark plugs.

Ignition switch-This is the electric part of the ignition. When the
ignition key is turned the electrical part being connected to it also turns,
completing the ignitions circuit.

Instrument panel-The part of the dash that contains your gauges,
speedometer, odometer, and other lights such as the check engine
soon (mil) light.

Jack-A hydraulic or screw type device used for lifting a vehicle.

Jack stands-A safety device that ratchets into position. It is used to
hold a side or corner of a vehicle off the ground. When getting under a
vehicle. It is usually put under a shock mount, the chassis, or other solid
part of the vehicle.

Lemon- A car that has many problems.

Lowball-Giving someone an unrealistically low price over the phone to
get them to bring in their car. Also can be used as a price that you offer
the seller, a lowball price. The seller responds with I can’t go that low
then precedes to give you the lowest price that he will go.

Lug nuts-Nuts used to hold the wheels on the car.

Lug wrench-A tool used to loosen the wheels bolts or lug nuts.

Manual transmission-A transmission that uses a clutch to link the
engine to the transmission. This type of transmission is shifted by use
of a shift knob each time the gears need to be changed.

Mass airflow sensor/Maf-One of a series of sensors that sends
signal to the car’s computer. It measures the amount of air entering the
engine to allow the computer to adjust for the best air/fuel mixture.

Master cylinder-see brake master cylinder

Muffler-A device used in the exhaust system to quiet the engine’s
exhaust noise.

Multimeter-An electric or electronic tool made for testing many items.
They can test voltage, ohms, current drain, and have many uses.

Oil-A petroleum based fluid that lubricates and cools an engine’s
moving parts.

Oil dipstick-A long thin metal strip that comes out of the oil-pan , and
comes up to the top of the engine. It is used for checking the oil’s level.

Oil filler tube-The area on a valve cover where you remove a cap and
pour in the engine’s oil.

Oil filter-A filter used to strain oil as it moves through the engine.

Oil pan-A removable pan that is attached to the bottom of the
crankcase. This pan houses the oil like a reservoir and has a drain plug
on its lowest point.

Oil pressure sending unit-A sensing device that is usually on the
back of the engine’s block. It sends a signal to the oil gauge to tell you if
pressure gets too low or to high.

Oil pump-A mechanical pump that distributes oil throughout the engine.

Pcv valve/Positive crankcase ventilation-This valve is an
emissions control device that routes unburned crankcase gases back
into the manifold where they can be reburned.

Piston rings-These are rings that fit in a groove on the outside of the
piston. Their main purpose is to help form a seal between the piston
and the cylinder wall. They help give the engine compression and keep
the cylinder walls lubricated.

Power steering-Hydraulically assisted steering. Helps to steer while at
slow speeds or stopped.

Power steering pump-The pump that circulates the power steering
fluid assisting the driver to turn the steering with less effort.

Production date-The date that the car was produced. Stamped on the
plate on the driver’s door jamb

Quarter panel-The sheet metal around the car’s wheel wells.

Rack and pinion-A lightweight steering gear assembly that uses a
beveled gear to drive a horizontal bar.

Relay-a switch that opens or closes a circuit.

Reserve price-The price that is the minimum that the seller will take in
an auction.

Rims-see wheels

Rotor-see brake rotor

Seals-A plug like device used for the purpose of keeping fluid in the
area where it is intended to stay in.

Serpentine belt-A flat rubber drive belt that turns multiple accessories
on the front of an engine. A spring loaded tensioner keeps the belt tight.

Shocks/shock absorber-An air or fluid filled device that dampens
suspension movement.

Smog certificate-A printout given by a state licensed center that
states that the car has passed minimum emission requirements.

Sniffer-An electronic device used for detecting leaks in an air
conditioning system.

Spark plugs-A device that is screwed into the combustion chamber.
Electrical current passes through it and ignites the air/fuel mixture in the
combustion chamber.

Springs-A suspension component that supports the weight of the
vehicle.

Starter-The electrical device that spins a gear when the car is cranked,
causing the flywheel to turn fast and start the engine.

Struts-Similar to a shock but used on unibody cars where there is
inadequate room to fit or mount shocks.

Tail pipe-The back end of the exhaust system where the exhaust is
exiting the car.

Tensioner-A spring loaded device that is used for keeping tension on
a serpentine belt, or a timing belt.

Thermostat-A device used to allow coolant to flow through the engine
when normal operating temperature is reached.

Timing belt-A belt used to connect the gear on the crankshaft to the
gear(s) on the camshaft.
Timing chain-A metal chain that connects the crankshaft to the
camshaft.

Tire iron-A bent metal bar used for changing tires. One end will be a
lug nut wrench the other end will usually be like a wedge shaped
screwdriver for popping off the hub-caps.

Title fee-A state charge imposed when you title a vehicle.

Toe in/toe out-The difference between front and rear edges of tires as
far as distance between them is concerned. Toe in means the front
edges of the tires are closer together and the tires point inward. Toe
out means just the opposite.

Torque converter-On an automatic transmission the turbine like
device that is full of hydraulic fluid. This device couples the engine to
the transmission.

Tps/Throttle position sensor-This sensor is located on the throttle
body of most fuel-injected cars. It tells the computer how far the throttle
is open allowing the computer to adjust the air/fuel mixture.

Transmission-A gearbox that changes engine torque by gear
reduction on a manual transmission, Or uses a torque converter on an
automatic transmission. The transmission couples the engine’s power to
the drive axle.

Transmission cooler-A device similar to a mini radiator for the
purpose of helping cool the transmission fluid on heavy vehicles, or
vehicles that are towing a load.

Transportation cost-The cost accrued to get a vehicle from one place
to another.

Trim package-A manufacturer will make two or more versions of a
specific vehicle. One may be the base unit, Where the other unit may
be a lx version(luxury). The luxury version may have a sunroof, leather,
power windows and door locks and maybe a larger engine.

Trunk struts-see hood struts

V belt-A rubber drive belt with a v shaped cross-section. Used to run
one or two engine accessories per belt. Most new cars have a
serpentine belt that runs all engine accessories.

Valve covers-A cover that keeps the valve-train clean, and keeps the
oil inside to lubricate the valve components. There will normally be a
cap that is removed to add engine oil.

Valve cover gasket-The rubber or cork gasket that keeps the oil of
the valve assembly from leaking out.

Valves-Intake and exhaust valves are metal components of the valve-
train that control pressure and the direction of flow of intake gases and
exhaust gases.

Vin/Vehicle identification number-A 17 digit code unique to each
car that tells the car’s engine size, year, model, fuel injection type and
engine type. The last few digits are usually the vehicles unique serial
number.

Water pump-A mechanical or electrically operated pump that circulates
coolant throughout the engine and radiator.

Wheel bearings-Bearings are usually on the axle that carry the vehicle’
s weight. A bad wheel bearing will make a grinding or wining noise. You
may feel the looseness if the bearing is going out on the vehicle by
trying to move the wheel back and forth, if it is loose the bearing is
going out..

Wheel well-The wheel well is located under the fender and surrounds
the tires.

Wheels-The metal cylinder shaped piece that the tire is mounted on.