A |
back to top |
| Acceleration |
Acceleration
is what occurs when the car moves forward from a stop or from
a slower speed to a higher speed. |
 |
| Accelerator
Pedal |
A
foot operated device which, directly or indirectly, controls
the flow of fuel and/or air to the engine, controlling engine
rpm. Also called the gas pedal. See Throttle. |
|
| Accelerator
pump |
Accelerator
pumps are found in cars equipped with carburetors. When you accelerate,
the accelerator pump delivers extra fuel through the accelerator
pump circuit to allow the engine to deliver more power. |
|
| Accessory |
Refers
to a power-operated feature on a car. For instance, power windows
and power locks would be considered accessories. |
|
| Accumulator |
A
container in the air conditioning system used to remove moisture
or water. This helps to extend a/c compressor and other component
life. |
|
| Actuator |
An
electrical mechanism for moving or controlling something indirectly
instead of by hand, such as a door lock. Output device the PCM
controls such as solenoids, relays, fuel injectors and stepper
motors. |
|
| Air
Conditioning |
An
Original Equipment or Aftermarket accessory system that cools
and dries the incoming passenger compartment air. Aka: a/c |
|
| Air
filter |
This
device filters the air that goes into your engine. Without an
air filter, harmful particles would enter your car's engine and
cause internal wear and damage. |
|
| Air
pump |
Many
emissions systems include an air pump, which pumps fresh air
into a vehicle's exhaust to help complete the combustion process
and reduce emissions. |
|
| Airbag |
A
safety device, consisting of impact sensors, computer, a detonation
device and air bag, that protects the driver (and in some cases,
the passenger) in a crash by inflating a cushion hidden in the
steering wheel and dashboard. |
|
| Alignment |
Alignment
is when all your wheels are pointing in exactly the right direction.
If one wheel is off by even one or two degrees, it is considered
out of alignment. When a vehicle is out of alignment, excessive
tire, steering system and suspension system wear may be the end
result. |
|
| All-wheel
drive (AWD) |
An
all-wheel drive system has differentials which split the engine's
power to the four wheels according to which have the most traction. |
|
| Alternator |
An
alternator is an engine-belt driven device that converts mechanical
energy into electrical energy. The electrical output keeps your
battery charged and operates your vehicle's electrical system. |
|
| Anti-lock
braking system (ABS) |
ABS
uses a series of sensors, a computer and a high-pressure hydraulic
pump to prevent your brakes from locking up during sudden stops
on slippery surfaces. |
|
| Anti-roll
bar |
The
anti-roll bar is a suspension system component that helps a vehicle
to stay flat and not lean excessively when cornering. Also called
a sway bar or stabilizer bar. |
|
| Anti-theft
code (radio) |
Many
modern radios have special anti-theft circuitry that prevents
them from operating after being disconnected from a power source.
For these types of radios, it is necessary to enter a factory-supplied
code to get the radio to work again. |
|
| Antifreeze |
The
fluid mixed with water that is put into your vehicle's radiator.
Antifreeze is traditionally green in color; however, newer long-life
antifreezes may be red or orange. Please refer to your vehicle's
owner's manual for the proper antifreeze for your vehicle. |
|
| Automatic
choke |
Automatic
chokes use either a heat- or computer-controlled element to turn
on and off automatically as needed. |
|
| Automatic
temperature control |
A
computerized system that automatically maintains a selected temperature
for your car's interior. Also called climate control. |
|
| Automatic
transmission |
Automatic
transmissions have hydraulically operated gear sets, which require
no gear shifting or clutching by the driver. |
|
| Axial |
Referring
to a type of air conditioning compressor that compresses the
R-12 refrigerant in a horizontal cylinder and piston compressor.
Compare to Radial. (Remember, Axial is LONG like an axle; Radial
is SHORT like a radial tire.) |
|
| Axle |
The
shaft around which the wheels rotate. |
|
B |
back to top |
| Balance
Tube |
A
tube or pipe connecting the exhaust head pipes in a dual exhaust
system. This balance tube acts like a pressure equalizer enabling
both exhaust pipes to flow at the same pressure. |
|
| Balancing
(tire) |
The
process of making sure a tire will not cause vibration when driving.
By using a computerized machine, a technician can locate a non-balanced
tire and balance it by attaching weights on the wheel rim to
even out the tire's balance. |
|
| Ball
joint |
A
joint between two parts that allows movement in any direction
by the two parts. Ball joints are most often found in a vehicle's
suspension and steering systems. |
|
| Barrel
(carburetor) |
A
barrel is a venturi in a carburetor where air and fuel are mixed,
then taken into the intake manifold and then to a cylinder. Carburetors
usually have from one to four barrels, depending on the engine
application. |
|
| Battery |
An
electrical storage container designed to produce DC voltage by
means of an electrochemical reaction. This reaction occurs in
the container between the lead plates and sulfuric acid. Voltage
is supplied to the starting, ignition and other electrical systems. |
|
| Bearings |
Bearings
are used to prevent wear when two moving parts are placed very
close to each other. |
|
| Bleeding |
Bleeding
removes fluid from a system, such as a brake or clutch system.
When a technician bleeds a brake system, the old fluid is completely
removed and replaced with new fluid. |
|
| Blower
Motor |
An
electric motor with a fan designed to supply a current of air
at a moderate pressure. A blower usually consists of a fan assembly,
a motor, and a suitable case. The blower case is usually designed
as part of the heating/air conditioning system. |
|
| Blueprinting |
The
procedure of dismantling an engine, measuring, machining components,
and reassembling it to the minimum factory tolerances. This procedure
usually will provide more power and efficiency |
|
| Body |
The
assemblage of components, including windows, doors, seats, etc.,
that provide enclosures for passengers and/or cargo in a motor
vehicle. |
|
| Body
Control Module (BCM) |
A
device powered by the main vehicle computer that takes input
from various sensors to control components such as the air bag,
headlight sentinel and door chime. |
|
| Brake |
A
device, such as the disc or drum brake, for retarding motion.
This is usually created by means of friction caused by a clamping
force from a stationary caliper or shoe, against a rotating rotor
or drum. |
|
| Brake
booster |
A
device that uses engine vacuum or hydraulic pressure to multiply
or boost the pedal effort of the driver while braking, thus adding
more hydraulic pressure to the brakes for added stopping power. |
|
| Brake
caliper |
A
c-shaped device used with disc brakes. When a driver presses
on the brake pedal, the caliper piston squeezes the brake pads
against the rotor and causes the car to slow down or stop. |
|
| Brake
drums |
Brake
drums are drum-shaped components which contain internal brake
shoes, which expand and press against the drum, when the driver
presses on the brake pedal, slowing or stopping the car. |
|
| Brake
fluid |
A
special type of hydraulic fluid designed specifically for brakes.
Brake fluid transfers the motion of a driver stepping on a brake
pedal directly to operate a brake caliper or wheel cylinder. |
|
| Brake
lines |
Metal
tubing and rubber hoses which connects each brake caliper or
wheel cylinder to the brake master cylinder. |
|
| Brake
master cylinder |
As
the main component of a braking system, the brake master cylinder
takes the pressure applied to the brake pedal by the driver and
distributes it evenly to all four brakes on a car. |
|
| Brake
pads |
Brake
pads are used specifically with disc brake systems. The pads
fit inside the calipers, and create friction and stopping power
when pressed against the brake rotor. When you have your disc
brakes replaced, it is often just the pads that are being replaced. |
|
| Brake
pedal |
The
pedal to the left of the accelerator pedal that controls a car's
brakes. When you step on the brake pedal, the car slows down
or stops. |
|
| Brake
rotors (discs) |
Brake
rotors, or discs, are fitted to most modern cars. They are flat,
circular plates that rotate with the wheel when you drive. When
you step on the brake, the brake calipers squeeze the brake discs,
slowing or stopping the car. |
|
| Brake
shoes |
Brake
shoes are used specifically with drum brake systems. Brake shoes
fit inside the brake drum, and are pressed against the drum by
a wheel cylinder when the brakes are applied, thus slowing or
stopping the car. |
|
| Braking
system |
The
braking system in a modern car consists of the brake pedal, a
power brake booster, brake master cylinder, brake lines, brake
fluid, brake rotors (including calipers and pads), and, for some
vehicles, brake drums (including wheel cylinders and brake shoes).
In addition, all vehicles have a parking/emergency brake. Taken
together, these components operate in sync to slow or stop your
car. They operate like this: when you press on the brake pedal,
the pressure you apply is multiplied by the brake booster. It
is then distributed by the brake master cylinder and sent via
the brake fluid through the brake lines to each individual wheel.
When it arrives at a wheel, this pressure causes, for instance,
the caliper (in a vehicle with disc brakes) to close, which then
causes the pads to come in contact with the brake rotor. The
resulting friction causes the car to slow down and eventually
stop. Should this system fail, then the emergency brake may be
used as a backup to stop your vehicle. |
|
| Burning
oil (engine) |
Oil
burning occurs when one or more internal engine components fail,
thus allowing oil into the engine's combustion chamber. There,
the oil is burned along with the air/fuel mixture. |
|
| Bushing |
A
piece of rubber or plastic that fits in between two components.
Bushing protects the two components from excess wear and damage. |
|
| Bypass |
Providing
a secondary path to relieve pressure in the primary passage.
One example would be a water pump or thermostat housing bypass
in the cooling system. |
|
C |
back to top |
| Caliper |
The
housing on disc brakes which holds the disc pads and straddles
the brake rotor. When hydraulically actuated, the pads press
against the rotor, or disc, to stop or slow the vehicleÆs
wheels. |
|
| Camber |
It's
the adjustment of a wheelÆs alignment where the top of
the wheel is moved inward or outward from vertical as viewed
from the front of the vehicle. Incorrect camber reduces tire
life. |
|
| Camshaft |
A
camshaft, with phased cam lobes mounted on it, regulates the
opening and closing of the intake and exhaust valves. Driven
by the crankshaft via a timing chain or timing belt, a camshaft
has a big influence on engine power characteristics. |
|
| Canister |
An
evaporative emission canister contains activated charcoal which
absorbs fuel vapors and holds them until the vapors can be purged
into the engine when it is started. It is a component of the
emissions control system. |
|
| Capacitor |
An
electrical device for accumulating and holding a charge of electricity.
A capacitor is usually found in an electronic ignition system. |
|
| Carb |
See
Carburetor. |
|
| Carbon
Dioxide |
A
heavy, colorless gas that results as a product of complete combustion.
It is considered a greenhouse gas. |
|
| Carbon
Monoxide |
A
colorless, odorless gas that can be found as a product of incomplete
combustion. Breathing high concentrations can be dangerous. |
|
| Carburetor |
A
mechanism which mixes fuel with air in the proper proportions
to provide a desired power output from a spark-ignition internal
combustion engine. On production vehicles, carburetors have been
replaced by electronic fuel injection. |
|
| Carburetor
jet |
A
fitting inside a carburetor that meters fuel into a metering
circuit where it is mixed with air in the venturi. |
|
| Caster |
An
alignment spec where an imaginary line through the ball joints
(steering axis) intersects a vertical line through the front
wheel center. Positive caster delivers directional stability
and improved steering feel. |
|
| Catalyst |
A
substance that can increase or decrease the rate of a chemical
reaction between substances without being physically consumed
in the process. A catalyst, which reduces engine emissions, is
used in a catalytic converter. |
|
| Catalytic
converter |
An
in-line, exhaust system device, containing a catalyst, which
reduces engine exhaust emissions. Converters are located near
the exhaust manifolds or headers for maximum efficiency. |
|
| Charging
system |
The
system which maintains the electrical charge in your vehicle's
battery. The charging system consists of the alternator, voltage
regulator and battery. |
|
| Chassis |
The
suspension, steering, and braking components of a vehicle. Everything
but the body, fenders, etc. |
|
| Choke |
A
device in a carburetor which shuts off airflow so that the engine
runs rich. This is necessary to start a cold engine. |
|
| Circuit |
A
complete electrical path, usually includes the electrical energy
source. May also be used with fluids or air. The headlights and
brake system are examples of an electrical and hydraulic circuit. |
|
| Cleaner
(Air) |
A
housing holding a filter fitted in the intake system of parts
requiring clean air. An engine air cleaner filter removes particulates
before they can enter the intake system and cause damage. |
|
| Clear-coat
finish |
Many
modern cars have a clear-coat finish. This is an extra, clear
layer of paint that goes on top of the last color coat of paint
to protect it from scratches, chips and other environmental damage. |
|
| Climate
Control |
Describes
temperature/ventilation environment in the passenger compartment.
Climate adjustments are made by adjusting the heater/ ventilation
and A/C controls. Aka automatic temperature control. |
|
| Closed
Loop (Engine) |
An
operating mode of the PCM enabling modification of pre-programmed
instructions based on a feedback system. By constant exhaust
sampling, a closed loop system allows pre-programmed engine adjustments
to occur while running in order to minimize exhaust emissions. |
|
| Clutch |
A
mechanical device which uses mechanical, magnetic, or friction
type connections to facilitate engaging or disengaging two rotating
members. Examples: the friction clutch located between the engine
and manual transmission or the a/c clutch. |
|
| Clutch
- cable-operated |
A
cable-operated clutch uses a metal cable between the clutch pedal
and clutch fork to control clutch engagement. |
|
| Clutch
- hydraulic |
A
hydraulic clutch uses a hydraulic circuit between the clutch
pedal and clutch fork to control clutch engagement. |
|
| Clutch
disc |
The
friction material lined plate that delivers power from the engine
to the transmission. |
|
| Clutch
pedal |
The
pedal on manual transmission cars that operates the clutch. |
|
| Clutch
throw-out bearing |
A
bearing that lets the clutch pressure plate and disc smoothly
engage and disengage with minimum wear. |
|
| Clutch-operated
fan |
An
engine cooling fan that uses a heat-activated, viscous-fluid
clutch which turns the fan on and off as needed. |
|
| Code |
A
system of symbols (as letters, numbers, or words) used to represent
the meaning of information. An engine trouble code shows where
a vehicle system or component failure may be occurring. |
|
| Coil
(Ignition) |
A
device consisting of fine wire windings around an iron core,
which is designed to step up battery voltage. The high voltage
created (35,000 volts or more) is delivered to the spark plug
so ignition can occur. |
|
| Coil
Spring |
A
spiral-wound steel wire coil, of various wire diameter thicknesses
and coil stack heights, used to suspend a vehicle. Can be used
in cars and trucks, both front and rear, depending on the application. |
|
| Combustion |
The
process by which the air/fuel mixture burns within an engine
to create power. |
|
| Combustion
chamber |
The
area in the cylinder head where air/fuel is ignited to create
power. |
|
| Comprehensive
insurance coverage |
Comprehensive
coverage includes protection against theft and accident damage,
regardless of fault. |
|
| Compression
gauge |
A
special gauge used by technicians to measure how much pressure
a cylinder can create. |
|
| Compression
test |
A
test to see how much pressure a cylinder can create. |
|
| Computer
(PCM) |
Many
modern cars have a central computer called an engine control
unit (ECU) or powertrain control module (PCM). This controls
the car's fuel and ignition systems by taking information from
various sensors to determine how to run the engine with the most
efficiency and power. |
|
| Constant
Velocity Joint |
A
coupling that allows a shaft to turn continuously at various
angles when coupled with another shaft. Usually associated with
front-wheel or all-wheel drive vehicles. |
|
| Converter
(Torque) |
A
fluid coupling device which multiplies torque between an engine
and automatic transmission/transaxle. When a vehicle is stopped,
a converter allows enough fluid slippage, so the engine can idle
without stalling. |
|
| Coolant |
A
fluid used in the radiator for heat transfer. Mixed with water,
coolants usually contain rust inhibiting additives and provide
antifreeze protection. Some new vehicle coolants are designed
to last 100,000 miles. Please refer to your owner's manual for
the proper antifreeze for your vehicle. |
|
| Coolant
reservoir |
Many
cars have a clear plastic reservoir that allows the owner to
see the level of their vehicle's coolant. Check your owner's
manual to find the coolant reservoir on your vehicle. |
|
| Cooler |
A
heat exchanger that reduces the temperature of the cooling medium.
Two examples would be a engine radiator or oil cooler. |
|
| Cooling
system |
The
system of components that keeps your engine at the correct operating
temperature. The cooling system includes the radiator, radiator
cap, coolant reservoir, cooling fan, water pump, thermostat,
hoses, heater core, heater valve, and antifreeze. |
|
| Core
(Price/Charge) |
A
payment that is credited back to the buyer after they have returned
a rebuildable ôCoreö unit to the retailer. A rebuilt
alternator purchase would have a core charge and would require
returning the old one to receive the credit. |
|
| Cracked
paint |
Cracked
paint occurs when a paint is so damaged, the surface actually
develops cracks. These cracks may spread in a spiderweb fashion
across the surface of the paint. Cracked paint is unrestorable,
and must often be completely removed when a car is repainted. |
|
| Crankshaft |
The
engine component which converts piston reciprocating (up and
down) motion into rotary motion at the flywheel or flexplate.
Connected to the clutch or torque converter, engine torque is
delivered to the drivetrain to move the vehicle. |
|
| Crazed
paint |
Crazed
paint occurs when paint is so damaged, the surface actually develops
hairline cracks. These cracks may spread in a spiderweb fashion
across the surface of the paint. Crazed paint is unrestorable,
and sometimes has to be completely removed when a car is repainted. |
|
| Cruising |
Cruising
is a driving style whereby the driver maintains a set speed with
very little fluctuation. |
|
| CV
joints |
CV
(constant velocity) joints are part of a car's driveline. They
allow a wheel to rotate freely in any direction while still receiving
power from the axle. |
|
| Cylinder |
Cylinders
are the large round holes in the engine block in which combustion
occurs. This combustion forces the piston down and turns the
crankshaft. |
|
| Cylinder
Head |
A
removable part located on the top of the cylinder block; it usually
contains valvetrain components and combustion chambers. For an
overhead cam engine, it contains the camshafts as well. A head
is an important influence in determining an engineÆs overall
power and efficiency. |
|
D |
back to top |
| Data |
General
term for information, usually represented by numbers, letters
and symbols. A gas gauge is an instrument that provides data
to the driver. |
|
| Defroster |
A
setting of your car's heating controls that lets you easily remove
frost and fog from your vehicle's windows. |
|
| Diagnostics |
The
process of identifying the cause or nature of a condition or
situation. Most cars have computer diagnostic systems that help
the technician to determine corrective repairs. |
|
| Diesel
engine |
A
type of engine that uses heat caused by engine compression rather
than spark plugs to ignite its fuel mixture. Diesels are often
more economical than gasoline engines, however they create extra
noise and vibration. |
|
| Dieseling |
The
continued running of a spark-ignited engine after the ignition
is turned off. There are two basic causes of dieseling: surface
ignition, where combustion chamber surfaces remain hot enough
to ignite fuel after the spark is terminated; compression ignition,
where the conditions of temperature, pressure, fuel composition
and engine idle speed allow ignition to continue. |
|
| Differential |
A
component of the drivetrain with an arrangement of gears designed
to permit the division of power between two shafts. A differential
also lets two wheels on the same axle rotate at different speeds.
With out one, cars wouldn't be able to take sharp turns. Differentials
are located in a drive axle housing. |
|
| Distributor |
Part
of the ignition system, its a mechanical device designed to direct
high voltage electricity from the coil to the spark plugs, via
the spark plug wires. Rotating the distributor permits adjustment
of an engine's initial ignition timing. |
|
| Distributor
cap |
The
distributor cap contains the terminals that the spark plug wires
plug into. When the distributor sends power to a spark plug,
it goes to the cap first and then to the spark plug wire and
to the spark plug. |
|
| Distributor
rotor |
The
rotor spins around inside the distributor. As it turns, it comes
close to the terminals for each spark plug on the distributor
cap. When this happens, it sends current to the spark plug, which
then ignites the air/fuel mixture in the cylinder at exactly
the right time. |
|
| Double
overhead cam (DOHC) |
A
DOHC engine has two camshafts in the cylinder head - one for
the exhaust valves, and one for the intake valves. This allows
greater efficiency and greater power. |
|
| Downshifting |
The
process of going from a higher gear (for instance, fourth gear)
to a lower gear (for instance, second gear) with a manual or
automatic transmission. |
|
| Drive
belt |
Also
called a fan belt or serpentine belt, drive belts are used to
drive the engine's accessories, such as the alternator, power
steering pump, and air conditioning compressor. A serpentine
belt is a wide single drive belt that drives several the engine's
accessories at once. |
|
| Driveline |
The
system of components that connects the transmission to the wheels.
The driveline consists of axles, differentials, constant velocity
(CV) or universal joints, and a driveshaft. |
|
| Driver |
A
switched electronic device housed in a computer that controls
output state. For example, a driver controls how long a fuel
injector remains open. |
|
| Driveshaft |
The
shaft connecting the transmission output shaft to the differential
pinion shaft. It transmits power from the transmission to the
differential. It is found primarily on rear-drive vehicles. There
is usually a universal joint on either end. |
|
E |
back to top |
| Early
Fuel Evaporation |
Used
on carburetor-equipped engines only, a system where heat is used
to help increase early fuel evaporation of the cold-start air/fuel
mixture to achieve more efficient combustion and lower emissions.
GM used an electric grid system. |
|
| Electric
cooling fans |
Electric
cooling fans are part of many cars' cooling systems. They use
a heat activated switch to turn on and off as needed to help
keep your engine cool. |
|
| Electric
motor |
Any
device that converts Electromagnetic force to motion, or vice-versa.
Electric motors are often used in accessories such as power windows
or power seats to provide movement with minimal effort by the
user. |
|
| Emergency
brake |
Also
called the parking brake. A braking system which is independent
of the main hydraulic system. It can be used to slow or stop
the vehicle if the primary brakes fail, or to hold the vehicle
stationary though the brake pedal is not depressed. It usually
consists of a foot pedal or hand lever that actuates either front
or rear brakes mechanically through a series of cables and linkages. |
|
| Emissions |
Emissions
are the byproducts of combustion. After combustion is complete,
water, gases, and carbon are released through the car's exhaust
system as emissions. |
|
| Emissions
equipment |
Emissions
equipment is equipment required by the government to keep a car's
exhaust emissions to a minimum. Emissions equipment includes
catalytic converter, air pump, and oxygen sensor. |
|
| Engine |
A
machine designed to convert thermal energy into mechanical energy
to produce force or motion. Connected to a drivetrain, an engine's
mechanical energy, or torque, moves a vehicle. An engine can
run by using gas, diesel fuel, steam or other fuel sources. |
|
| Engine
accessory |
An
engine accessory is a peripheral piece of equipment that runs
directly off of the engine's power to supply energy or a fluid
to another part of the car. Engine accessories include the alternator,
power steering pump, air pump, air conditioning compressor, as
well as many others. |
|
| Engine
block |
The
engine block is where the cylinders and pistons reside. The block
is the strongest part of the engine and withstands tremendous
pressures while the engine is operating. |
|
| Engine
mounts |
Engine
mounts are often made of metal and rubber. Engine mounts help
support the engine, and also help to prevent engine vibrations
from shaking the entire car. |
|
| Engine
temperature sender |
The
engine temperature switch and sending unit measure the temperature
of the engine's coolant. They send this information to the engine
temperature warning light and engine temperature gauge, respectively.
Compare to coolant temperature sensor (CTS) which transmits the
coolant temperature to the computer, and the radiator fan switch
which engages the radiator's cooling fan. |
|
| Evaporative
Emissions Control |
A
system which filters evaporating fuel fumes from the vehicle's
fuel system and routes them to the engines intake to be burned. |
|
| Exhaust |
Gaseous
by-products of combustion emitted from an engine. Exhaust flows
from the engine, through the muffler and exits from the exhaust
system. |
|
| Exhaust
Gas Recirculation |
An
engine system where a small portion of exhaust gases are recycled
into the combustion chamber. This lowers combustion temperatures
and reduces oxides of nitrogen emissions. The EGR system is important
for a smooth performing engine. |
|
| Exhaust
hanger |
Exhaust
hangers keep the exhaust system in place, while also preventing
excess vibration and noise from reaching the passengers. |
|
| Exhaust
manifold |
The
exhaust manifold carries the exhaust from the cylinder head to
the exhaust system. |
|
| Exhaust
system |
The
exhaust system carries exhaust away from the engine and away
from the car. The exhaust system includes the exhaust manifold,
the catalytic converter, the muffler, and the tailpipe. |
|
F |
back to top |
| Fan |
Designed
to supply air flow as the fan blades rotate, a fan can be driven
by either a motor or belt. |
|
| Fan
belt |
Also
called a drive belt or serpentine belt. Fan belts are used to
drive the engine's accessories, such as the alternator, power
steering pump, or air conditioning compressor. A serpentine belt
is a wide single drive belt that drives multiple engine accessories. |
|
| Fan
clutch |
A
viscous-fluid clutch that controls how fast an engine fan rotates
to help cool an engine. |
|
| Fan
motor |
An
electric motor which drives a fan to direct air, through a radiator
or car's interior, for example. |
|
| Feedback
Carburetor |
A
computer-controlled carburetor that adjusts the air/fuel mixture
according to input from various sensors, via a mixture-control
solenoid. The solenoid's adjustment helps maintain the correct
air/fuel ratio and minimizes exhaust emissions. |
|
| Feeler
Gauge |
An
instrument used to measure the distance between two metal contacts.
A feeler gauge could be use to measure spark plug gap, point
gap or valve clearance. |
|
| Fiberglass
matting and resin |
These
materials are often used to fill in large rust holes where filler
would be unable to work, and where welding in new metal would
be difficult. |
|
| Final
Drive Ratio |
The
ratio between the pinion and ring gear in the drive differential.
A numerically high ratio enhances vehicle acceleration and pulling
ability, while a numerically low ratio enhances highway cruising
and fuel economy. |
|
| Flexplate |
Secured
to the end of the crankshaft, it has three functions; the ring
gear for the starter on the outside diameter; helps to balance
out engine vibrations; a connection between the transmission
torque converter and the engine allowing flexing. Compare to
flywheel for manual transmission. |
|
| Flushing |
Flushing
is a means of entirely replacing the fluid in a given system.
For instance, when a technician flushes a cooling system, all
the old coolant is removed and completely replaced with new. |
|
| Flywheel |
Secured
to the end of the crankshaft, it has three functions; the ring
gear for the starter on the outside diameter; helps to balance
out engine vibrations; a connection between the transmission
clutch and the engine. Compare to flexplate for automatic transmission. |
|
| Four-wheel
drive (4WD) |
A
drive system in which both the front and rear wheels are connected
through the driveshaft and axles to the transmission, usually
via a transfer case. A 4WD sytem can be full time or part time.
Sometimes called 4x4 (four by four). |
|
| Front-wheel
drive (FWD) |
A
front-wheel drive vehicle sends its power from the engine to
the front wheels of the car. |
|
| Fuel |
Any
combustible substance burned to provide heat or power. While
gasoline is the most common, other fuels include diesel, ethanol
and natural gas. |
|
| Fuel
filter |
A
car's fuel filter removes debris and contaminants from fuel before
it reaches the carburetor or fuel injection system. |
|
| Fuel
injection |
Fuel
injection is a system by which fuel is directly sprayed into
the intake manifold or intake port at high pressure. Fuel injection
is often controlled by a computer, allowing precise monitoring
of efficiency and performance by the car's computer. |
|
| Fuel
injector |
A
device for delivering metered, pressurized fuel to the intake
system or individual cylinders. An injector sprays fuel, which
helps atomization for a more dense mixture, when combined with
incoming air. |
|
| Fuel
pump |
The
fuel pump moves gas from the gas tank and delivers it to the
fuel injection system or carburetor. |
|
| Fuel
starvation |
Fuel
starvation occurs when fuel, for one reason or another, is prevented
from reaching the carburetor or fuel injectors. |
|
| Fuel
system |
The
fuel system is the system by which fuel is stored and delivered
to each cylinder. The fuel system includes the fuel tank, fuel
tank level sending unit, the fuel pump, the fuel filter, and
fuel lines. For carbureted cars, the fuel system also includes
the carburetor. For fuel injected cars, the fuel system also
includes injectors, fuel pressure regulator and often a main
computer. |
|
| Fuel
tank level sending unit |
This
unit measures the amount of gas in the fuel tank and sends that
information to the vehicle's gas gauge and, if equipped, a low
gas level warning light. |
|
| Fuses |
A
device designed to open and protect equipment or a circuit from
being destroyed when the circuit is subjected to a power overload.
This is a non-reversible action and there are 3 main types of
fuses; glass, ceramic and spade. |
|
G |
back to top |
| G-Force |
Unit
of measurement used to describe ôlateralö acceleration
generated while the vehicle is driven in a steady state turn
on a skid pad circle. An average sedan generates 0.60 G of lateral
acceleration. Measured in "gravities", one G equals
the earth's gravity at sea level. |
|
| Gas
- grade |
This
is a general term that refers to a gasoline's general quality
- for instance, its octane rating and package of additives. The
two common terms for gas grades are "regular" for low-grade
gas, and "premium" for high-grade gas. |
|
| Gasket |
A
material usually made of rubber, cork, metal, paper or a combination
thereof that is placed between two surfaces to ensure proper
sealing against the passage of air, liquid or vapors. Valve cover
gaskets are one example of a popular gasket. |
|
| Gauge |
A
gauge is a type of instrument that measures or displays levels
of a certain system. For instance, the gas gauge in a vehicle
measures the fuel level, while the temperature gauge measures
the engine temperature. |
|
| Gear
selector |
The
gear selector is the lever that lets you select a certain gear
with an automatic transmission. In modern cars, the gear selector
is often connected to the brake pedal, so that you can only shift
into drive or reverse when your foot is on the brake. |
|
| Gear
synchronizers |
Gear
synchronizers allow you to upshift and downshift a manual transmission
without grinding gears. They do this by synchronizing, or matching,
the speed of the engine and the speed of the gear you are selecting.
If your car didn't have gear synchronizers (also known as synchromesh),
you would either have to match the engine speed to the gear speed
(known as double-clutching) or else grind your gears every time
you shifted. See also "synchromesh". |
|
| Gearshift
lever |
The
gearshift lever is the lever that allows you select the different
gears of a transmission. |
|
| Gearshift
linkage |
This
is a series of rods and/or cables that connect the gearshift
lever or gear selector to the transmission. |
|
| Generator |
A
generator is like an alternator in that it generates electrical
current to both keep the battery charged and supply electricity
for a vehicle's electric system. It differs from an alternator
in that a generator generates direct current (DC) where an alternator
generates alternating current (AC). |
|
| Glass
Pack |
A
muffler design that contains fiberglass packing around a perforated
internal pipe (straight through) which slightly deadens exhaust
noise. Usually louder than a conventional replacement muffler. |
|
| Glazing
(belts) |
Glazing
is a shiny coating on the inside surface of a fan, or serpentine
belt. Glazing occurs when the belt slips repeatedly at a high
speed. It is a sign that the belt needs replacement. |
|
| Glow
Plug |
A
combustion chamber heat generating device to aid starting diesel
engines. When the glow plug heats the combustion chamber to the
proper temperature, the ignition key can be turned to engage
the starter. |
|
| Governor |
An
electronic or mechanical device designed to limit engine speed.
Large diesel engines usually are equipped with governors. |
|
| Ground |
An
electrical conductor used as a common return for completing an
electric circuit(s). Car batteries contain a ground terminal,
usually the negative terminal. |
|
H |
back to top |
| Halfshaft |
An
exposed axle driveshaft usually having a CV (constant velocity)
joint on either end, being driven from a differential. Also called
a CV axle. |
|
| Hazard
relay |
The
hazard relay controls the flashing of the hazard warning lights. |
|
| Head
gasket |
The
head gasket seals the cylinder head to the engine block. It is
subject to tremendous pressures, and often fails if and when
an engine overheats. |
|
| Headers |
Constructed
from steel tubing, headers provide a smooth and efficient exhaust
flow path from the exhaust port to the exhaust system. Headers
are frequently used in performance engine applications and are
generally less restrictive than the stock exhaust manifold, resulting
in increased power. |
|
| Heater
core |
The
heater core is a miniature radiator that sits in the dashboard
area. When the heater is turned on, it opens the heater valve
which lets hot coolant into the heater core, which then warms
the air coming into the vehicle's interior. |
|
| Heater
ducts |
The
heater ducts are the passageways through which warmed air enters
the interior of the vehicle. |
|
| Heater
fan |
The
heater fan is the interior fan attached to a blower motor that
controls the speed of air being introduced into the interior. |
|
| Heater
valve |
The
heater valve is controlled by the interior heating controls.
When you turn on your vehicle's heater, the valve opens and allows
hot coolant to enter the heater core, which then warms the air
forced through the heater core by a blower motor, and the warmed
air then enters the vehicle's interior. |
|
| Heater/heating
system |
The
heating system warms the air brought into a vehicle's interior.
The heating system is connected to the cooling system and consists
primarily of the heater core, heater valve, and, if equipped,
a climate-control system. |
|
| Hex
Wrench |
Also
known as an Allen wrench, it is a hexagonal tool that fits and
operates fasteners with hexagonal openings. |
|
| Hoses
(cooling system) |
The
cooling system hoses allow coolant to circulate between the radiator,
engine, and heater. Over time, they deteriorate, and should be
checked annually for condition and possible damage. |
|
| Hub |
Hub
is a generic term for a circular area where a component is mounted.
For instance, there are hubs for every wheel on your car. |
|
| HVAC |
Stands
for Heating, Ventilation, Air Conditioning. These systems are
controlled by the car's climate control panel. |
|
| Hydraulic
circuit |
The
hydraulic circuit is a closed system of tubes and components
that contain hydraulic fluid. When pressure is applied at one
end of the hydraulic circuit, it travels through the tubes to
the other end. |
|
| Hydrocarbon |
An
organic compound containing various carbon and hydrogen molecules
linked together in fuel. Gasoline is a hydrocarbon fuel. If the
fuel is not burned efficiently in the cylinders, hydrocarbon
molecules are released into the atmosphere as pollutants. |
|
I |
back to top |
| Idle |
Running
engine speed with vehicle at rest and accelerator or throttle
pedal not depressed. While waiting at a stop light, the engine
is at idle. |
|
| Idle
circuit |
This
is a special kind of circuit found in a carburetor that only
operates when the engine is at an idle. |
|
| Ignition |
Complete
system used to step up battery voltage to a higher voltage and
deliver it to the spark plug to complete the combustion process.
When the key is turned on, the ignition system is energized. |
|
| Ignition
Advance/Retard |
The
advancing or retarding (in crank degrees) of ignition spark relative
to the piston location in the cylinder. Ignition timing should
be set to factory specifications. |
|
| Ignition
condenser |
The
condenser collects and stores excess electrical energy in an
older ignition system that has points. This prevents that extra
energy from jumping across the points when they first open and
close. |
|
| Ignition
module |
Part
of the ignition system which instructs the ignition coil to send
current to the distributor. |
|
| Ignition
points |
Part
of the ignition system which allows the ignition coil to send
current to the distributor in older vehicles. Ignition points
do this by opening and closing, which opens and closes the electric
circuit. Electronic ignition systems have made ignition points
and condensers obsolete. |
|
| Ignition
switch |
This
is the switch where you insert the key that starts the vehicle. |
|
| Ignition
system |
The
ignition system contains the components that supply spark to
the vehicle's spark plugs. These include the battery, the ignition
coil, the distributor (including the cap and rotor), the spark
plug wires, the ignition module, and the spark plugs themselves.
Older cars also have ignition points and an ignition condenser. |
|
| Injector
(fuel) |
A
device for delivering metered, pressurized fuel to the intake
system or individual cylinders. A fuel injector sprays fuel,
which helps atomization for a more dense mixture, when combined
with incoming air. |
|
| Instrument |
An
instrument measures levels of a certain system and provides a
visual key for those levels. For instance, the gas gauge in your
car measures the fuel level, while the temperature gauge indicates
the engine temperature. |
|
| Intake
Air |
Air
used in combustion that flows through an air filter, throttle
valve and is distributed to each cylinder by the intake manifold. |
|
| Intake
manifold |
The
intake manifold is located between the vehicle's fuel system
and the cylinder head(s) to distribute the fuel/air mixture to
individual cylinders. |
|
K |
back to top |
| Knock
(Engine) |
The
sharp, metallic sound produced when two pressure, or flame fronts
collide in the combustion chamber. This could be the result of
incorrect ignition timing or the wrong grade (octane rating)
of gas. Higher octane fuel can eliminate knock due to its increased
resistance to cylinder pressure. |
|
L |
back to top |
| Lathe |
Device
used to machine the outside and/or inside of a metal object as
it rotates. A brake lathe is used to smooth the exterior pad
surface of a brake rotor or the interior of a brake drum. |
|
| Leaf
Spring |
A
thin, long, arched, steel spring that is attached between a vehicleÆs
frame and axle to act as a suspension. More than one spring leaf
are often clamped together to achieve a desired load capacity
or spring rate. |
|
| Leakdown
test |
A
leakdown test is used to find excessive wear in an engine. When
a technician performs a leakdown test on a vehicle, each cylinder
is tested to see how well it holds pressure. If a cylinder is
unable to hold pressure, your technician can pinpoint what component
of the cylinder (piston rings, valves, etc) has the problem that
is causing the pressure loss. |
|
| Liability
insurance |
Liability
insurance is coverage only for damage that you inflict on other
people or their possessions. It does not cover theft or damage
to your vehicle. |
|
| Limited-slip
differential (LSD) |
An
LSD senses the slippage of each wheel and sends and redirects
power to the wheel with the most grip. Many high-performance
vehicles have LSDs. |
|
| Link
(Electrical/Electronic) |
General
term used to indicate a communication connection between two
data points. Mechanics use a link to retrieve trouble codes from
a vehicle's ECU in order facilitate repairs. |
|
| Linkage |
A
series of bars, levers, yokes, rods, or cables used in unison
to transmit motion from one unit to another. Transmission shift
linkage connects the shifter to the transmission and allows gear
selections to be made. |
|
| Loaded
(caliper) |
A
disc brake caliper, which comes complete with all the installation
hardware such as emergency brake lever, spring, bracket and brake
pads. This speeds a caliper installation during replacement. |
|
| Lug
nuts |
Lug
nuts attach a car's wheel to its hub. Also known as wheel nuts. |
|
M |
back to top |
| MacPherson
strut |
A
shock absorbing component in a front suspension system that is
mounted directly above the upper control arm. Many lightweight,
uni-body cars use this uncomplicated type of front suspension. |
|
| Main
Bearings |
Soft
metal alloy inserts, bonded to a steel back, used to allow the
crankshaft to ride on a cushion of oil formed between the crank
journal and bearing surface. Main bearings often last throughout
the life of the engine. |
|
| Manifold |
A
component designed to collect and/or distribute an engine's air
and/or fuel mixture, or exhaust. |
|
| Manual
choke |
A
manual choke system has a cable that lets the driver control
the carburetor's choke operation. Most newer cars with carburetors
have automatic chokes instead of manual chokes. |
|
| Manual
steering |
With
a manual steering system, there is no power assist to the driver. |
|
| Manual
transmission |
A
manual transmission is a transmission with a clutch. In addition,
it is up to the driver to select gears. |
|
| Memory |
A
device in which data can be stored and retrieved when needed;
associated with a vehicle's computer system. |
|
| Mode |
One
of several alternative conditions or methods of operating a system,
device or control module. If a vehicle has a 3-mode electronic
adjusting shock absorber system, the modes (or settings) are
usually soft, medium, or firm. |
|
| Module
(Electrical/Electronic) |
A
self-contained group of electrical/electronic components, which
is designed as a single replaceable unit. An example of a module
is the one that operates the anti-lock braking system. |
|
| Muffler |
The
muffler is a part of the exhaust system designed to reduce the
noise generated by a vehicle. |
|
N |
back to top |
| Neutral
(gear) |
Neutral
is actually not a gear. When your vehicle is in neutral, the
gearbox (transmission) and engine are completely disconnected.
Thus, your car is able to roll freely whether the engine is on
or off. |
|
O |
back to top |
| Octane |
A
fuel octane rating measures a fuel's resistance to knocking or
pinging. The higher the octane rating, the better (and more expensive)
the fuel. |
|
| Odometer |
The
odometer measures how many miles your vehicle has traveled. |
|
| Oil
filter |
The
oil filter removes most particles and contaminates from your
engine's oil to protect your engine's internal moving parts. |
|
| Oil
pan |
The
oil pan is where the oil in your engine is stored. |
|
| Oil
pressure sensor |
The
oil pressure sensor measures the pressure at which your engine's
oil is flowing. If the pressure becomes too high or too low,
the oil pressure sensor sends a signal to the vehicle's oil pressure
warning light located on the dashboard. If you see this light
turn on, pull over as soon as possible and shut off your engine.
Check the oil level of the engine by pulling out the dipstick.
If the engine oil level is low, add oil, restart the vehicle
and see if the oil light goes out. If the oil level is within
parameters, or the oil light remains on, have your car towed
to a service facility to have the problem checked by a technician. |
|
| Oil
pump |
The
oil pump takes oil from the oil pan and pressurizes it, allowing
it to travel throughout the engine and lubricate the engine's
moving parts. |
|
| Open
Loop |
An
operating condition or mode in the vehicle's intake fuel system
controlled by the vehicle's PCM, based on pre-programmed instructions,
usually when an engine is in the cold start-up mode. |
|
| Output
Shaft |
A
shaft that drives the next element in the powertrain, like the
front driveshaft yoke slipping over the output shaft of the transmission,
which drives the wheels. |
|
| Overboost
(turbo) |
Overboost
occurs when a turbo's wastegate does not release excess intake
pressure. This pressure instead enters the engine, causing potentially
significant damage to the engine. |
|
| Overdrive |
Overdrive
is a transmission gear that allows the engine to turn at a reduced
rpm for a given road speed. |
|
| Overhead
cam (OHC) |
An
overhead cam engine has its camshaft in the cylinder head, above
the valves and cylinders. This allows the camshaft to directly
open the valves without using pushrods. |
|
| Overhead
valve (OHV) |
An
overhead valve engine has its camshaft in the engine block. It
uses lifters, pushrods and rocker arms to open and close the
valves in the cylinder head. |
|
| Overheating |
Overheating
occurs when an engine reaches too high of an operating temperature.
Overheating may lead to potentially significant engine damage. |
|
| Overinflation
(tires) |
Overinflation
occurs when a tire is inflated beyond the pressure recommended
by the manufacturer. Overinflating can lead to increased tire
wear and sudden tire failure. |
|
| Owner's
manual |
The
owner's manual is the booklet supplied with all cars when they
are sold new. It is usually placed in the glovebox. The owner's
manual contains information about the vehicle's equipment and
options, what kinds of fluids and lubricants to use, and how
to maintain your car. If you don't have an owner's manual, one
can be obtained from the vehicle's manufacturer. |
|
| Oxides
of Nitrogen |
Commonly
known as NOX, it is various combinations of one part nitrogen
and one or more parts of oxygen, which is a by-product of combustion
at a very high temperature when using gasoline as a fuel. NOX
is a component of smog. |
|
| Oxygen
sensor |
The
oxygen sensor is part of the exhaust and emission systems and
is usually located in the exhaust manifold. It senses the amount
of oxygen in the exhaust gases and adjusts the fuel system's
operation accordingly to minimize emissions while improving economy
and performance. |
|
P |
back to top |
| Park
(gear) |
This
is a gear found only on automatic transmissions. The park gear
locks a vehicle's transmission in place, preventing the car from
moving. |
|
| Park/neutral
safety switch |
This
is a switch found on many modern automatic transmissions that
prevents a vehicle from starting unless the gear selector is
in park or neutral. |
|
| Parking
brake |
Also
known as the emergency brake. The parking brake is used when
parking on an incline to prevent the car from rolling away. The
parking brake is usually cable operated and can be used as a
backup if the regular hydraulic brake system fails. |
|
| Parking
brake cable |
The
parking brake cable connects the parking brake pedal or handle
to the parking brakes themselves. |
|
| Parking
brake shoes/pads |
The
parking brake shoes/pads are just like normal brake pads or brake
shoes. The only difference is that they work specifically with
the parking brakes, and are independent from the regular brake
system. |
|
| Petcock |
A
small valve used for draining liquids. Petcocks are usually associated
with radiators and are located at the bottom of one of the radiator's
tanks. |
|
| Pinging
(engine) |
A
noise made in the engine caused by a pre-ignition condition.
When your engine knocks or pings, it is a sign that the engine
is firing at the wrong time. This could be because of improper
ignition timing, an incorrect grade of gas, or another ignition
or fuel system fault. |
|
| Piston |
An
aluminum-based cylindrical part located inside an engine's
cylinder (combustion chamber) that moves up and down, transferring
the force of combustion to the connecting rod and then to
the crankshaft, which causes rotation. |
|
| Piston
Ring |
Usually
3-4 rings that fit on the outer diameter of the piston beneath
the piston top which seals the pressure of combustion in the
cylinder (top 2 or 3 rings called the compression rings) and
aids in scraping residual lubricating oil from the cylinderÆs
walls (bottom ring called the oil ring). |
|
| Piston-To-Valve
Clearance |
The
distance or space between the intake and exhaust valves in relation
to the top of the piston when the piston is at the top of its
stroke, known as TDC, or top dead center. |
|
| Pitman
Arm |
Arm
attached to the pitman shaft on a steering box that moves the
relay rod as the steering wheel is turned in a mechanical (not
rack and pinion) steering system.. |
|
| Plastic
polish |
A
special type of polish designed to gently remove scratches and
yellowing from plastic items such as convertible top windows
and plastic lenses. |
|
| Play |
Play
occurs when there is excessive free movement in a vehicle's steering
system. For instance, if you turn your steering wheel either
direction from the center and nothing happens for the first two
inches of travel, your steering system has play in it. |
|
| Porting |
The
enlarging of the exhaust and intake passages to increase flow
through the cylinder head. When done correctly, this process
can add a significant amount of power and increase fuel efficiency. |
|
| Posi |
Also
known as Positraction, which is a limited-slip differential (LSD)
distributing power equally to both drive axles through a series
of plates, clutches and springs. |
|
| Positive
Crankcase Ventilation (PCV) |
This
system relieves pressure and recirculates fumes created by the
motion of the crankshaft, connecting rods and pistons in the
crankcase, by sending them through a one-way valve back into
the engine to be burned in the combustion process. |
|
| Power
Steering |
A
system which provides additional hydraulic force, generated by
a pump, to the steering mechanism, either a steering box or rack,
reducing the driver's turning effort at the steering wheel. |
|
| Power
steering fluid |
A
special type of fluid designed for power steering systems. |
|
| Power
steering pump |
The
power steering pump transfers power steering fluid under pressure
to other power steering system components, allowing the driver
to steer with minimal effort. |
|
| Powertrain |
The
elements of a vehicle by which motive power is generated and
transmitted to the driven axles. Examples of powertrain components
are the engine, transmission and differential. |
|
| Powertrain
Control Module (PCM) |
A
module commonly referred to as the vehicle's "main computer",
it controls how the engine and transmission operate via input
from many sensors. Aka: ECM (Electronic Control Module), EEC
(Electronic Engine Control) and ECU (Electronic Control Unit). |
|
| Prechamber |
A
dual-chamber combustion system for diesel engines with a centrally
located auxiliary combustion chamber for reduced emissions and
less diesel soot. |
|
| Pressure
(Absolute) |
The
pressure referenced to a perfect vacuum, usually found in the
intake manifold. Commonly known as the MAP, or Manifold Absolute
Pressure. |
|
| Pressure
(Atmospheric) |
The
pressure of the air outside of the engine at any given temperature
and altitude. Sometimes called barometric pressure, it is usually
referenced as the "baro" sensor reading in the powertrain
control system. |
|
| Pressure
(Differential) |
The
pressure difference between two areas in the engine, such as
between the pressure in the intake manifold and the atmospheric,
or outside, air pressure. |
|
| Pressure
Plate |
The
part of a manual clutch system with a covered spring and clamping
ring mounted over the friction disk, to the flywheel. When the
pressure plate is engaged, it clamps the friction disk to the
flywheel, which turns the input shaft of the transmission. It
allows the smooth application of power to the transmission. Also
known as a clutch cover. |
|
| Primer |
A
type of paint applied to a vehicle's surface to increase its
compatibility with the topcoat and/or to improve the corrosion
resistance of the base metal. The primer paint is applied first,
then the final topcoat, or color coat of the vehicle is applied
on top of the primer coat. |
|
| Proportioning
Valve |
A
valve in the brake hydraulic system usually located in or near
the brake master cylinder that controls pressure to the rear
wheels to achieve better braking balance front-to-rear. |
|
| Pump |
A
device used to transfer fluids or air by suction, pressure, or
both. An example of this is an oil pump for the vehicle's engine,
or the pump that raises and lowers the air pressure in a vehicle's
air-ride suspension system. |
|
| Pushrod |
Pushrods
are used in engines with overhead valve (OHV) designs. The camshaft
in the engine block pushes up on the lifters and then on the
pushrods, which then push the rocker arms, which then open the
valves. |
|
R |
back to top |
| Radial |
Referring
to a type of air conditioning compressor that compresses its
refrigerant using a radial, or round, piston and cylinder arrangement.
It's a fairly light unit and is associated with 1982 and newer
GM vehicles and used R12 and R-134 refrigerant. Compare to Axial.
(Remember, Axial is LONG like an axle; Radial is SHORT like a
radial tire.) |
|
| Radiator |
A
radiator is a liquid-to-air heat transfer device having a tank(s)
and core(s) specifically designed to reduce the temperature of
the coolant in an liquid-cooled internal combustion engine. Radiators
can be made from aluminum or copper-brass. |
|
| Radiator
cap |
The
radiator cap maintains a specific pressure in the cooling system
so it operates efficiently. |
|
| Rail |
A
manifold for fuel injection which distributes fuel to the fuel
injectors, often called a fuel rail. They are usually made from
an aluminum extrusion or steel pipe. |
|
| Ram
Air |
Type
of induction where fresh air is fed through the hood or underneath
the vehicle and sent to the intake via the air filter. With the
reduced air temperatures associated with fresh, non-underhood,
ram air, more power and efficiency is generated. |
|
| Rear-wheel
drive (RWD) |
Rear
wheel drive cars transmit power to the ground through the rear
wheels. |
|
| Refrigerant |
Commonly
referred to as freon, it is a substance used as a heat transfer
agent in an air conditioning system. There are two types being
used in vehicles today; R134 for newer cars and R12 for older
vehicles. Because R12 refrigerant is harmful to the environment
when it leaks into the atmosphere, it is being phased out in
favor of R134. |
|
| Regulator
(Voltage) |
A
device that automatically controls the output of another device
by adjusting the voltage to meet a specified value. Example:
an alternator can put out over 14 volts, but by sending the voltage
through a regulator, it only allows 12 volts output. |
|
| Relay |
A
electromechanical device in which connections of a higher voltage
circuit are operated by a lower voltage circuit to divert the
current. High-output auxiliary driving lights contain relays
in their circuits so as not to overload and burnout the on-off
switch. |
|
| Remanufactured |
A
component or piece of equipment that has been rebuilt and restored
to its OE (original equipment) specifications to function as
new. Common examples of rebuilt parts include alternators, water
pumps, carburetors and power steering pumps. |
|
| Reservoir |
Reservoir
is a generic term that refers to any container for a fluid. For
instance, most vehicles have a windshield washer fluid reservoir
and a brake fluid reservoir. |
|
| Revving
the engine |
Increasing
the RPM's of an engine without allowing the power to be transferred
to the wheels. When your car is in park or neutral and you press
on the gas without the intention of making the car move, you
are revving the engine. |
|
| Rheostat |
Rheostat
refers to a control which varies the intensity of the lights
and speed of certain accessories that it is connected to. For
instance, an instrument lighting rheostat controls the brightness
of the instrument lighting. |
|
| Riding
the clutch |
When
driving along, if you rest your foot on the clutch pedal, you
are riding the clutch. This practice causes excess wear on the
clutch and the clutch throw-out bearing. |
|
| Rocker
arms |
Rocker
arms are used in overhead valve (OHV) engines. They are operated
by pushrods and open and close the valves. |
|
| Roller
Cam |
A
camshaft which uses lifters, either hydraulic or mechanical,
using rollers at the base of each lifter which contacts the cam.
These high-strength steel cams reduce friction and emissions
and increase power and efficiency with optimized lobe designs. |
|
| Rotary
engine |
A
rotary engine does not have pistons or cylinders; instead, it
has triangular shaped rotors that move in an elliptical path
within chambers to create power. The only companies that have
offered rotary cars for sale are Mazda, NSU, and Citroen. |
|
| Rotor-
Brake |
A
disc made from cast iron or steel, rotating on an integral or
separate hub near the wheel of a vehicle and is stopped by friction
pads located on either side of a hydraulically-operated brake
caliper. |
|
| Rotor-Distributor |
An
electrically conductive component mounted to the rotating distributor
shaft that transfers electrical energy from the centrally located
coil terminal to the individual cylinder terminals within the
distributor cap circumference. Also known as an ignition rotor. |
|
| Rubbing
compound |
A
rubbing compound is a type of paint polish that contains extremely
fine abrasive particles. These particles remove the top layer
of paint, eliminating shallow scratches, and revealing the shiny
paint layer underneath. |
|
| Running
Board |
Usually
a long, flat board that runs along the rocker panel of a truck
or SUV, which is used to help passengers step in and out of the
vehicle. |
|
| Running
rich |
This
is a condition that occurs when too much gas and too little air
is being fed to the engine. A sign of rich running is black,
sooty exhaust. |
|
| Rust-converting
primer |
Rust-converting
primer is a special type of primer paint that stops the progress
of surface rust. |
|
S |
back to top |
| Scan
Tool |
A
device that interfaces with, and communicates vehicle information
to and from a vehicle's powertrain control module or computer,
via an onboard data link. |
|
| Sensor |
The
name for a device that senses the absolute value or a change
in a physical quantity such as temperature, pressure, rotation
or flow rate, and converts that change into an electrical signal,
which is then sent to the vehicle's powertrain control module
(PCM). |
|
| Serpentine
belt |
A
serpentine belt is a wide single drive belt that drives certain
engine accessories (alternator, power steering pump, air conditioning
compressor, etc.). It's a type of fan belt with multiple grooves
that fit into similar grooves on the pulleys. Also know as a
multi-groove belt, micro-groove belt, or multi-v belt. |
|
| Shift
linkage |
This
is a series of rods and/or cables that connect the gearshift
lever or gear selector to the transmission. |
|
| Shift
Solenoid |
A
PCM-controlled electromechanical device which regulates shift
firmness and rpm in an electronically-controlled automatic transmission. |
|
| Shock
Absorber |
A
component using friction to dampen and control a vehicle's suspension
up and down movement. Modern shocks are of the hydraulic type,
using an oil to dissipate the heat of friction to the outside
air. They contribute to your vehicle's ride quality. See also
Strut. |
|
| Short
(circuit) |
A
short circuit occurs when there is a break in an electrical circuit
and the circuit finds a new ground source. |
|
| Shroud |
A
metal or plastic cover used to isolate rotating components or
hot parts of the vehicles' engine or exhaust system. A radiator
shroud surrounds the radiator fan and helps direct incoming air
through the radiator and to the front of the engine as well as
protecting the radiator and fan from foreign objects. |
|
| Single
overhead cam (SOHC) |
A
type of overhead cam engine with a single cam that operates both
the intake and exhaust valves. |
|
| Solenoid |
A
device consisting of an electrical coil, and when energized,
produces a magnetic field in a plunger and is pulled to a central
position. A solenoid may be used as an actuator in a valve or
switch. Power door locks use a solenoid-activated actuator. |
|
| Spark
Plug |
Part
of the ignition system, it's an electrical device with a ground
and center electrode where a spark is created between the two
by a high voltage current from the distributor. The spark ignites
the fuel/air mixture in the combustion chamber at the top of
the compression stroke. |
|
| Spark
plug electrode |
The
electrode is the curved piece(s) of metal (ground electrode)
that reaches over the center electrode. The spark is created
between the electrodes. |
|
| Spark
plug gap |
Gap
is the precise distance between a spark plug's center and ground
electrodes. |
|
| Spark
plug terminal |
The
terminal is the metal part of a spark plug above the ceramic
insulator that the spark plug wire attaches to. |
|
| Spark
plug wires |
Spark
plug wires are the cables that conduct the electric pulses from
the distributor cap to the spark plugs. Also called ignition
wires. |
|
| Speedometer |
An
instrument that indicates a vehicle's speed in miles or kilometers
per hour. |
|
| Sprag |
A
transmission internal component load carrying element, usually
consisting of roller bearings and a cage element. Heavy duty
sprags have more bearings, therefore a greater load capacity. |
|
| Springs
(suspension) |
Springs
absorb road imperfections and vibration, help hold the suspension
up, and help vehicles handle better. Also called coil springs,
or leaf springs. |
|
| Stabilizer
bar |
See
Sway bar. |
|
| Starter
motor (starter) |
This
is the electric motor that turns your engine over when you turn
the key in the ignition switch. |
|
| Starter
solenoid |
This
is a large relay that controls the operation of the starter motor. |
|
| Starting
system |
The
starting system consists of the starter motor, starter solenoid,
battery, ignition switch and ignition key. |
|
| Steering
lock |
The
steering lock is a theft prevention device that locks the steering
wheel in place when the key is removed from the ignition switch. |
|
| Steering
system |
The
steering system allows you to control the direction of your vehicle.
Most modern cars have a rack and pinion steering system with
a power assist. Components in your steering system include the
steering rack, tie rods, tie rod ends, ball joints, power steering
pump, power steering hoses, and the pump drive belt. |
|
| Stroke |
The
distance traveled by the piston in its cylinder from top dead
center to bottom dead center. The stroke is determined by the
throw of the crankshaft, and is a determining factor in the displacement
of an engine. |
|
| Struts |
Struts
are part of your vehicle's suspension, and do the same job as
a shock absorber. A vehicle will either have struts or shock
absorbers, or a combination of both (i.e. struts in the front,
and shock absorbers in the rear). They regulate how much your
vehicle can move up and down, and keeps the tires in contact
with the road surface after going over a bump. |
|
| Supercharger |
A
mechanically driven device, usually off the crankshaft, that
pressurizes the intake air, and in turn increases the density
of the air/fuel mixture and subsequently increases the power
output of a given engine displacement. |
|
| Suspension |
The
suspension connects the vehicle body to the frame. A well tuned
suspension helps the vehicle to handle better, while increasing
comfort and isolating passengers from bumps and vibration. |
|
| Sway
bar |
The
sway bar is a suspension system component that helps to minimize
the lean of a vehicle when cornering. Also called a stabilizer
bar. |
|
| Synchromesh |
Synchromesh
is a feature that allows you to upshift and downshift a manual
transmission without grinding gears. It does this by synchronizing,
or evening out, the speed of the engine and the speed of the
gear you are selecting. If the transmission didn't have synchromesh,
you would either have to match the engine speed to the gear speed
(known as double-clutching) or else grind the gears every time
you shift. This term is often shortened to just "synchro". |
|
T |
back to top |
| Tachometer |
An
instrument that indicates engine speed in revolutions-per-minute
(rpm). It measures the speed that the crankshaft is rotating. |
|
| Tailpipe |
The
part of an exhaust system where exhaust gasses exit the car body
from the rear of the vehicle. The tailpipe connects the muffler
to the tailpipe tip (sometimes called a spout). The tailpipe
tip is the part of the exhoust system that you can see sticking
out from under the rear bumper. |
|
| Thermostat |
The
thermostat is a valve located in the cooling system of a vehicle
that automatically regulates the coolant flow through the radiator
and engine based on the coolant temperature. |
|
| Throttle |
A
mechanism for regulating the supply of the fuel/air mixture to
an internal combustion engine, thereby regulating the speed of
the engine. Aka; accelerator pedal |
|
| Tie
rod |
Part
of the steering system, the tie rod connects the spindles/wheels
to the rest of the steering system. |
|
| Timing
(ignition timing) |
Timing
refers to the moment when the spark ignites the air/fuel mixture
in the engine's combustion chamber. Timing needs to be set exactly
right for an engine to run correctly. |
|
| Timing
belt |
Timing
belts are rubber belts that connect an engine's camshaft to its
crankshaft. If a timing belt breaks, these two components will
get out of synch, which can cause potentially significant engine
damage. |
|
| Timing
chain |
Timing
chains are metal chains that connect an engine's camshaft gear
to its crankshaft gear. Timing chains ride on sprockets that
eventually wear out and can cause sloppy timing. When this happens,
it is time to replace the sprockets and chain. If a timing chain
breaks, the camshaft and crankshaft will get out of synch, causing
potentially significant engine damage. |
|
| Timing
gears |
Timing
gears are part of a timing chain system that connects the engine's
camshaft to its crankshaft. On some vehicles, the camshaft gear
meshes directly with the crankshaft gear, eliminating the timing
chain. |
|
| Timing
light |
A
timing light is used to check or set ignition timing. |
|
| Tire
gauge |
Tire
gauges are used to measure the air pressure of a tire. You should
always check tire pressure when your tire is cold (when the vehicle
hasn't been driven for about an hour). |
|
| Tire
valve |
The
fitting in the valve stem of the wheel that allows you to inflate
or deflate the tire. |
|
| Tonneau |
An
accessory cover fitted to protect a vehicle bed or driver's compartment,
most often on pickups and early autos. A tonneau can be constructed
of fabric, metal or fiberglass. In addition to sealing the vehicle
bed or passenger area, it also contributes to vehicle appearance. |
|
| Torque
converter |
A
fluid coupling device which multiplies torque between an engine
and automatic transmission/transaxle. It allows smooth power
transfer from the engine to the transmission. When a vehicle
is stopped, a converter allows enough fluid slippage so that
the engine can idle without stalling. |
|
| Transaxle |
Transaxles
are a combination of components; the transmission and differential.
Most front-wheel drive cars have transaxles. However, some rear
wheel drive cars, such as some Porsches, new Corvettes and Alfa
Romeos, have rear-mounted transaxles. |
|
| Transducer |
A
device that receives an electrical signal from one system and
transfers it, often in a different form, to another system. Example:
the cruise control transducer converts a vehicle speed signal
to a vacuum to control the servo attached to the throttle. |
|
| Transfer
case |
Used
in 4X4 vehicles to transfer power to the front and rear differential
assemblies. There are different selectable ranges to maximize
traction in varying road or trail conditions. |
|
| Transmission |
A
component of the powertrain of a vehicle which selects gear changes
(either manually or automatically), which can increase or decrease
the speed and power between the engine and the drive axles. |
|
| Transmission
fluid |
Transmission
fluid (ATF) is specially developed to allow automatic transmissions
operate smoothly and efficiently. Automatic transmission fluid
needs to be checked and replenished periodically. |
|
| Transmission
interlock |
A
safety device found on many modern automatic transmissions that
prevents the drive or reverse gear from being selected until
the brake pedal is pressed. |
|
| Transmission
linkage |
This
is a series of rods and/or cables that connect the gearshift
lever or gear selector to the transmission, allowing the shifting
of gears. |
|
| Transmission
mounts |
Transmission
mounts are often made of steel and rubber. Transmission mounts
help support the transmission, and also help to prevent transmission
vibrations from being transmitted to the car interior. |
|
| Transmission
oil |
Transmission
oil is specially developed to allow manual transmissions to operate
smoothly and efficiently. Transmission oil rarely needs to be
replenished. |
|
| Travel |
Travel
is a measurement of how much movement, or play, occurs in a given
system. |
|
| Trinary |
Consisting
of three (3) parts, or a progression of a multiple of threes
(3). |
|
| Tune
up |
A
proceedure during which a series of parts that wear out (spark
plugs, ignition rotor, distributor cap, etc.) are replaced to
bring the engine back into proper operating specifications. In
addition, timing is normally checked and reset. A tune up is
usually performed according to a schedule. |
|
| Turbocharger |
A
centrifugal device driven by exhaust gases that pressurizes the
intake air, increasing the density of the air and consequently
increasing the power output from a given engine displacement.
A turbocharger will boost the power of an engine. Aka turbo. |
|
U |
back to top |
| Universal
joint |
Universal
joints are part of a car's driveline. They allow the driveshaft
to continue to rotate at all angles. |
|
V |
back to top |
| Vacuum |
A
condition in which pressure has been reduced below the ambient
atmospheric pressure. Vacuum is created in the intake manifold
and can be used to operate a power brake booster. |
|
| Vacuum
hose |
Vacuum
hoses connect between vacuum-powered accessories and a vacuum
source such as the engine's intake manifold. |
|
| Valve |
A
device by which the flow of a liquid, gas or vacuum may be controlled.
Example: the intake and exhaust valve in the cylinder heads start
and stop the flow of the incoming fuel mixture and outgoing combusted
exhaust gases. |
|
| Valve
cover |
The
valve cover is the metal cover that is attached to the top of
the cylinder head. It allows technicians access to the engine
valves and rocker arms for adjustment and checks. |
|
| Valvetrain |
Components
actuated by the camshaft and can include valve lifters, pushrods,
rocker arms and valve springs. |
|
| Vapor
lock |
Vapor
lock occurs when an engine gets so hot, it boils the fuel traveling
through the fuel lines. This creates vapor, preventing the fuel
from traveling through the lines, causing the engine to stop
running. |
|
| Variable-assist
power steering |
A
power steering system designed to vary the level of power assist
according to vehicle speed or angle of the steering wheel. |
|
| Voltage
regulator |
The
voltage regulator limits the power output of the alternator to
prevent overcharging the battery and electrical system. |
|
W |
back to top |
| Washer
fluid |
This
is special fluid designed to help clean the windshield quickly
and with little residue, used in conjunction with the wiper blades. |
|
| Washer
fluid reservoir |
The
container where washer fluid is kept in a car, usually located
under the hood. |
|
| Washer
nozzles |
These
are the jets on the hood or in the wipers that spray washer fluid
onto the windshield. |
|
| Washer
pump |
An
electric motor that delivers washer fluid to the washer nozzles
for cleaning the windshield with the windshield wipers. |
|
| Wastegate |
A
valve on a turbocharged engine that limits air pressure in the
intake tract by allowing the pressure to bypass to outside air,
after the turbocharger. |
|
| Water
in fuel warning light |
This
is a warning light found only on diesel-engined cars. Because
diesel fuel collects water, a sensor in the fuel tank will indicate
when the ratio of diesel fuel to water reaches a certain level. |
|
| Water
pump |
Part
of the cooling system, the water pump circulates coolant, helping
the engine to stay in the desired temperature range. |
|
| Wax |
Wax
is a product used to protect paint finishes and create extra
shine. |
|
| Weather-stripping |
A
rubber gasket found around vehicle openings to seal out water
and wind. Weather-stripping is located around doors, windows
and trunks. |
|
| Wheel
bearing |
A
bearing or bearing assembly located at each wheel allowing the
wheel to spin around the axle with minimal wear and friction.
Front wheel bearings are contained within the hub, and are sometimes
integral to the hub. A wheel bearing set consists of an inner
and outer bearing. |
|
| Wheel
cylinder (brakes) |
The
wheel cylinder is used with drum-type brakes. When the brake
pedal is pushed, the wheel cylinder pushes the brake shoes against
the drum brake, slowing or stopping the car. |
|
| Wheel
nuts |
Wheel
nuts are used to attach a wheel to a hub. |
|
| Wiper
arms |
The
part of the windshield wipers that are between the wiper pivots
at the base of the windshield and wiper blades. |
|
| Wiper
blades |
The
rubber part and carrier assembly of the windshield wiper that
clears the windshield. |
|
| Wiper
refill |
The
rubber part of the wiper blade that makes contact with the windshield.
A wiper refill will insert into a wiper blade. |
|
| Wire
(electrical) |
An
insulated conductor used in an electrical system to transmit
electricity from one component to another. If a wire breaks,
it creates an open circuit. If a broken wire make contact with
a grounded surface, it creates a short circuit. |
|
