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Writer's pictureThe S in J&S

Mechanic Lingo FAQ

Updated: Jul 31, 2021


We have had many customers ask "what's that?" when explaining what is going on with their vehicle. We get it! Not everyone understands cars and the many components that they have. We have put together a list of FAQ about vehicles to help you better understand what your mechanic is talking about.


A|B|C|D|E|F|G|H|I|J|K|L|M|N|O|P|Q|R|S|T|U|V|W|X|Y|Z


0-9

4WD: 4WD stands for 4-Wheel Drive. 4WD vehicles have a drivetrain that uses 2 differentials and a transfer case to send power to all four wheels.


A

ABS: ABS stands for Antilock Braking System. This prevents the wheels from locking up when you apply the brakes quickly.


Air Filter: A device that filters incoming air fed to the engine. Not to be confused with a Cabin Air Filter.


Alignment: An Alignment refers to the adjustment of a vehicle’s suspension. The suspension are the components that connect a vehicle to its wheels.


Antifreeze: Also known as Coolant. It is a combination of water and ethylene glycol mixed together. This mixture has a higher boiling point and a lower freezing point than water.


AWD: AWD stands for All-Wheel Drive. Similar to 4-Wheel Drive, It sends power to all four wheels. AWD sends torque to all four wheels constantly.


B

Backfire: A mistimed explosion in the engine cylinder or exhaust.


Ball Joint: A flexible joint consisting of a ball in a socket, used primarily in front suspensions because it can accommodate a wide range of angular motion.


Brake Booster: When pressure is applied to power brakes, this device amplifies the pressure.


Brake Caliper: A caliper is part of the disc brake system, the type most cars have in their front brakes. The brake caliper houses your car's brake pads and pistons. Its job is to slow the car's wheels by creating friction with the brake rotors.


Brake Drum: A revolving cylinder on the wheel of a vehicle which the brake shoe or brake band presses against to slow the car's wheels.


Bushing: A simple suspension bearing that accommodates limited rotary motion, typically made of two coaxial steel tubes bonded to a sleeve of rubber between them.


C

Cabin Air Filter: A device that prevents outside allergens and dust from coming through your vehicle’s vents.


Charcoal Canister: Also known as a Vapour Canister or an EVAP Canister. This is used to capture fuel vapors to be recycled back into the engine instead of out the exhaust.


Coil Spring: A bar of resilient metal wound into a spiral that may be compressed or extended without permanent deformation.


Coolant: See Antifreeze.


Coupe: A coupe is a 2 door car with a fixed roof and less than 33 cubic ft of interior volume.


Crossover: A Crossover is an SUV constructed on a car frame.


CVT: A CVT is a Continuously Variable Transmission. It maintains a steady acceleration curve with no pauses for gear changes.


D

Differential: A device to allow a vehicle to turn the outside wheels faster than the inside wheels. It is found in most modern vehicles, especially AWD.


Drivetrain: A drivetrain works in tandem with the transmission. It delivers power from the engine through the transmission to the wheel and axles. It controls the amount of torque your vehicle is getting.


E

EGR Valve: EGR stands for Exhaust Gas Recirculation. This valve recirculates finely metered quantities of exhaust gas to the engine intake system for increased engine efficiency, reduced fuel consumption and lower NOx emissions.


EVAP Canister: See Charcoal Canister.


F

FWD: FWD stands for Front-Wheel Drive. Engine power and torque is channeled to the front wheels only. Rear wheels are just along for the ride.


H

Hatchback: A Hatchback is a car with a rear door that swings upward to access the cargo area. A hatchback has no divider between rear seats and cargo space.


I

Idler Pulley: This pulley tightens the slack on an engine's accessory drive belts, including those for the power steering, water pump, or air conditioning.


L

Lemon: A slang term for a vehicle that has not proven to be a valuable purchase, through the discovery of multiple defects that were not disclosed at the time of buying it.


Lifter: A lifter is a cylindrical component that rides on the Cam Shaft to actuate the Intake and Exhaust Valves. For pushrod engines, the Lifter pushes the pushrod up into the Rocker Arm and opens the valve. For OHC (overhead cam) engines, the lifter pushes directly on the valve tip.


O

O2 Sensor: Also called an Oxygen Sensor. In a computer-controlled, fuel-injected vehicle, a sensor mounted in the exhaust stream that relays air/fuel ratio information to the fuel control computer that allows the computer to make adjustments.


OE: Many times you will hear your mechanic refer to a part as “OE” or “aftermarket”. “OE” means Original Equipment. These parts are made to the same specifications as the original manufacturer. “OE” parts can sometimes be more expensive when compared to aftermarket parts, but they tend to last longer and fit better. “Aftermarket” parts are cheaper but are designed to fit as many makes/models as possible. This is why some parts may look identical, but the bolts do not line up perfectly every time.


P

Piston Slap: A Piston slap is generally caused when the cold running clearance (piston-to-wall clearance) is large enough that when the piston rocks from side to side in the bore it “slaps” the side of the cylinder and causes noise.


Purge Valve: In an evaporative emissions control system, the valve that allows the venting of fuel vapors from the charcoal canister to a vehicles intake and prevents the canister from becoming saturated and nonfunctional.


Pushrod: Pushrods are long, slender metal rods that are used in overhead valve engines to transfer motion from the camshaft (located in the engine block) to the valves (located in the cylinder head).


R

Rack-and-Pinion: A steering mechanism that consists of a gear in mesh with a toothed bar, called a ""rack."" The ends of the rack are linked to the steered wheels with tie rods. When the gear is rotated by the steering shaft, it moves the rack from side to side: turning the wheels.


Recall: When a vehicle is found to exhibit a defect or safety issue, recall notices are sent to owners of vehicles by the manufacturer. Dealership service departments are responsible for replacing and repairing parts that have been recalled free of charge.


RWD: RWD stands for Rear-Wheel Drive. Engine power is sent to the rear wheels to push the car forward. The front wheels do not receive any power and are free to maneuver the vehicle.


S

Sedan: A sedan is a 4 door car with a separate trunk.


Serpentine Belt: A ribbed drive belt that drives more than one engine accessory.


Steering Gearbox: A mechanism in steering to convert the motion of the steering wheel to the side-to-side motion of the lever that is connected to the linkage.


Steering Knuckle: Where the front wheel hubs are attached, the knuckle provides a pivoting component.


SUV: SUV stands for Sport Utility Vehicle. SUVs are larger than crossovers with taller bodies. SUVs handle off-roading better than cars, as well as keeping performance on pavement.


T

Thermostat: A simple, important part of your cooling system. It regulates the amount of coolant recirculated to the engine and cooled in the radiator prior to recirculation.


Throttle-body: A housing containing a valve to regulate the airflow through the intake manifold. The throttle-body is usually located between the air cleaner and the intake plenum.


Tie Rod Ends: Ball and socket parts of the steering linkage that connect the wheel spindles to the rack and pinion or center link.


Torque: Torque is the twisting/turning force generated by a motor. It’s usually measured by lbs/ft. Torque is how quickly power can be sent to the wheels of a vehicle.


Transmission: A transmission determines the amount of power sent to the wheel at any given speed. Each successive gear sends more power; the higher the speed, the higher the gears. An “Automatic” Transmission switches gears automatically. A “Manual” Transmission allows the driver to determine when to switch gears.


Tread: The pattern of raised lines on a tire that prevents a vehicle from sliding on the road.


U

U-Joint: Universal joints, which are flexible joints used on drive shafts that are composed of two U-shaped yokes that share a common cross-shaped member.


V

Vacuum Leak: A Vacuum leak is when the engine is not getting enough air through a vacuum hose. Primarily caused by a disconnected or damaged vacuum hose. Makes a hissing noise.


Valve Tick: A valve tick or lifter tick is caused when the pushrod or camshaft doesn't make continuous contact with the lifters.


Vapour Canister: See Charcoal Canister.


VIN: VIN stands for Vehicle Identification Number. Each vehicle has a unique number that identifies it. It is usually located on the driver’s side window or door jam.


Have you heard any other "mechanic lingo" that you would like to understand?

Let Us Know!

We will update this list as needed.


 

J&S FixQuik Auto | Mobile Auto Repair | Aurora, IL


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