Glossary of Auto Repair Terms

Below are some key auto repair terms and descriptions that will help you navigate your way through the repair process from beginning to end.

aftermarket auto parts
Auto repair parts that aren’t made by the original manufacturer. Aftermarket parts are made to fit and function the same as original parts, but they’re often less expensive. Some aftermarket auto parts are redesigned to increase performance.
Also known as: aftermarket parts, functionally-equivalent auto parts, off-brand auto parts, off-make auto parts, performance aftermarket parts

all-wheel drive
Four-wheel drive systems increase traction on slippery roads and off-road surfaces. All-wheel drive (AWD) is different from four-wheel drive because drivers can’t disengage AWD systems.
Also known as: AWD

antifreeze
Liquid in the cooling system that dissipates heat. Antifreeze prevents freezing during winter, cools the engine in summer, and protects the cooling system from corrosion and rust.
Also known as: coolant

auto chassis
The undercarriage of a vehicle is known as the chassis. The chassis carries all power train and suspension parts.
Also known as: framework, auto case, auto frame, auto undercarriage

auto electrical repair
Repairs to a vehicle’s electrical system that may include alternator repair, starter repair, ignition repair and electrical wiring repairs or replacement.
Also known as: automobile electrical repair, automotive electrical repair, car electrical repair, auto electrical service

auto repair shop
A business that maintains and repairs the internal working parts of automobiles. Some auto repair shops specialize in specific repairs such as electrical systems, brakes, mufflers and engines, while others offer all types of maintenance and service repairs.
Also known as: car repair shop, auto mechanic shop, car mechanic shop, auto repair shop, auto repair garage

catalytic converter
Isolates exhaust particles and burns them before they leave the tailpipe.
Also known as: catcon, cat

control arms
The moving suspension components mounted between the vehicle frame and the wheels.
Also known as: car wishbone, auto double wishbone, vehicle suspension

crankcase
The largest engine section, the crankcase contains the crankshaft.

crankshaft
The rod that transfers power from the engine to the transmission.
Also known as: crank

differential
A car’s differential is important for turning and cornering. It’s the gear system that allows one wheel to rotate faster than the other.

domestic auto repair shops
Shops that specialize in repairing American vehicles made by manufacturers like General Motors, Ford and Chrysler.

fast idle
When a vehicle’s engine runs fast while it’s stopped and idling.

filter
A paper or synthetic filter that blocks dust, dirt and debris as air enters the engine.
Also known as: auto air filters, car air filter, performance air filter, auto air filter replacements, auto cabin air filter

flooded engine
When too much fuel is in the cylinders and makes starting the vehicle difficult or impossible.
Also known as: engine flooded with gas, car flooded, engine stall, flooded vehicle

foreign auto repair shops
Shops that specialize in repairing foreign vehicles made by manufacturers like BMW, Toyota, Honda and Lexus.

four-wheel drive
A drive system that powers all four wheels and provides better traction during off-road use and poor weather conditions.
Also known as: 4WD, 4×4, four by four, sport utility vehicle

front-wheel drive
A driving system that powers the front wheels of the vehicle. Front-wheel drive systems can be automatic or manual shift.
Also known as: FWD

fuel injection
A fuel delivery system where injectors (also known as nozzles) spray fuel into the cylinders, which provides better fuel control and efficiency.
Also known as: electronic fuel injection (EFI)

hesitation
The momentary loss of power on acceleration that causes a vehicle to hesitate when gaining speed.
Also known as: engine hesitation, engine sputtering, auto stumbling

horsepower
The amount of energy produced by a vehicle’s engine.
Also known as: HP, mechanical horsepower, car horsepower, vehicle horsepower, electrical horsepower

idle
A term used to describe a vehicle that is stationary but running.
Also known as: idling

mechanic
A professional who repairs and maintains vehicles.
Also known as: auto mechanic, automobile mechanic, auto repair technician

mobile auto repair
A mechanic who repairs vehicles onsite. Mobile auto repair shops can often do minor and major repairs and tune-ups.

Original equipment manufacturer (OEM) parts
Auto parts made by the vehicle manufacturer. While they may cost more than aftermarket auto parts, OEM parts usually fit better, last longer and are covered by warranties.
Also known as: Original Equipment Manufacturer parts, stock vehicle parts, stock parts

power loss
When an engine runs at reduced speed or requires more throttle to maintain speed.
Also known as: auto power loss, low power output, automobile hesitating

power train
A term that refers to the transmission and engine (the parts that deliver power to the vehicle).

Revolutions per minute (RPM)
The speed at which the engine crankshaft turns.

rebuilt auto parts
Used auto parts that have been remanufactured, reconditioned and restored.
Also known as: salvage auto parts, salvage car parts, salvaged parts, used auto parts, replacement parts, used car parts, refurbished auto parts, rebuilt auto parts

rough idle
A term that describes when a car’s engine shakes and vibrates while it’s running and stationary.
Also known as: vibrations, auto choking, engine sputtering

salvaged auto parts
Auto parts taken from recycled vehicles. These parts are often cheap, but they usually don’t come with warranties because their reliability can’t be guaranteed. Salvaged auto parts are often a last resort for vehicle owners looking for hard-to-find parts for rare or older vehicles.
Also known as: salvage auto parts, salvage car parts, salvaged parts, used auto parts, replacement parts, used car parts

serpentine belt
A long, continuous belt that runs several automotive engine components, indulging the alternator, power steering pump, air pump and water pump.
Also known as: multi-vee belts, multi-v belts, multi-rib belts

shimmy
The term for a side-to-side motion that causes a vehicle’s tires and steering wheel to shake.
Also known as: car shaking, vehicle vibrations

sluggish performance
When a vehicle doesn’t accelerate smoothly or quickly enough.
Also known as: auto hesitation, vehicle loss of power

suspension system
The shock absorbers and springs that create a smoother ride by dampening the motion of a vehicle as it drives.
Also known as: suspension system

timing belt
A toothed belt that’s operated by the crankshaft and drives the camshaft in a vehicle. Broken timing belts cause valves to remain open and can cause engine damage when the valve is struck and bent by a piston.

undercarriage
The underside of a vehicle that supports and creates the automobile framework.
Also known as: automobile framework, car body, auto frame, vehicle chassis

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