Modern Automotive Technology PowerPoint for by Russell Krick Publisher The Goodheart-Willcox Co., Inc. Tinley Park, Illinois

Chapter 1 The Automobile

Contents Parts, assemblies, and systems Frame, body, and chassis (11 Topics) Parts, assemblies, and systems Frame, body, and chassis Engine Computer system Fuel system Electrical system

Contents Cooling and lubrication systems Exhaust and emission control systems Drive train systems Suspension, steering, and brake systems Accessory and safety systems

Auto mobile Derived from the Greek word autos, which means self. Derived from the French word mobile, which means moving.

Parts, Assemblies, and Systems

Part The smallest removable item on a vehicle Not normally disassembled Electrical or electronic parts are often called components

Assembly Set of fitted parts designed to complete a function the engine is an assembly that converts fuel into usable power to move the vehicle Technicians take assemblies apart and put them back together during maintenance, service, and repair operations

System Group of related parts and assemblies that performs a specific job the steering system is comprised of the steering wheel, gears, swivel joints, and other parts allows the driver to turn the wheels when maneuvering the vehicle

Major Vehicle Systems

Frame, Body, and Chassis

Body Forms the outside of the vehicle Serves as an attractive covering for the chassis Made of steel, aluminum, fiberglass, plastic, or composite materials

Chassis Consists of the vehicle’s frame and everything attached to it except the body Includes the tires, wheels, engine, transmission, drive axle assembly, and frame

Frame Strong metal structure that provides a mounting place for other parts of the vehicle Body-over-frame construction chassis parts and body bolt to the frame Unibody (unitized) construction sheet metal body panels are welded together to form the body and frame

The frame is an integral part of the body Unibody Construction The frame is an integral part of the body

Body-over-Frame Construction The body bolts to a thick steel frame

Body Types Automobiles are available in several body types, including: sedan hardtop convertible hatchback station wagon minivan sport-utility vehicle

Sedan Uses center body pillars, or “B” pillars, between the front and rear doors. A hardtop does not use “B” pillars.

Uses a vinyl or cloth top that can be raised and lowered Convertible Uses a vinyl or cloth top that can be raised and lowered

The large rear door allows easy access when hauling items Hatchback The large rear door allows easy access when hauling items

Provides a large rear interior compartment Station Wagon Provides a large rear interior compartment

Has a higher roofline for more headroom and cargo space Minivan Has a higher roofline for more headroom and cargo space

Sport-Utility Vehicle Provides the comfort of a passenger car, the interior space of a station wagon, and the durability of a truck

Automobile Body Parts

Engine

Engine 1) Provides the energy to propel the vehicle. 2) Operate other systems Most engines burn gasoline or diesel fuel The fuel burns to produce heat, the heat causes gas expansion which creates pressure The pressure moves the internal engine parts to produce power

Automotive Engine

Engine Locations

Engine Placement Transverse (Side to side) Longitudinal (Length of the vehicle) Crankshaft is Perpendicular to the F.E.A.D. belt. Identify by looking for the: F.E.A.D (Front End Accessory Drive) Belt - “V” Belts - Serpentine Belts Worn out by: Glazing, Cracking, or measurement tool. May cause “Squealing” on cold starts or by revving

Crankshaft is “Perpendicular” to the FEAD BELT

Drivetrain Types Front Wheel Drive Rear Wheel Drive All Wheel Drive Four Wheel Drive What do you look for first? The REAR PUMPKIN (Differential)

Rear Differentials

Cylinder Arrangement 3 Main Designs: (Angle of Valve Covers) In-Line V-Block Opposing Cylinder

Number of Cylinders What can we look for to identify how many cylinders it has? - Spark Plugs - Spark Plug wires - Ignition Source (Distributor, Coil Pack, Direct Ignition) - Fuel Injectors - Intake manifold - Exhaust manifold

Vehicle Identification V.I.N. (Vehicle Identification Number) 17 Digit Code Located: - Driver’s side dash – seen through windshield. - Driver’s side door or pillar label.

Basic Engine Parts

Crankshaft Purpose: To convert the up and down motion of the piston into the rotary motion we use at the wheels Stroke: Twice rod journal offset – totaling the distance the piston moves up and down in the cylinder Throw: ½ of Stroke, or rod journal offset

Stroke and Throw

Four-Stroke Cycle Four separate piston strokes are needed to produce one cycle: intake stroke compression stroke power stroke exhaust stroke The piston must slide down, up, down, and up again to complete one cycle Crankshaft turns 2 times per cycle Camshaft turns 1 time per cycle

Draws the air-fuel mixture into the cylinder Intake Stroke Draws the air-fuel mixture into the cylinder

Compresses the air-fuel mixture Compression Stroke Compresses the air-fuel mixture

Produces the energy to operate the engine Power Stroke Produces the energy to operate the engine

Removes the burned gases from the combustion chamber Exhaust Stroke Removes the burned gases from the combustion chamber

Automotive Engines Multi-cylinder engines are used 4,5,6,8, or 10 cylinders may be used Additional cylinders smooth engine operation and increase power output because there is less time between power strokes

Engine Components

Computer System

Computer System Uses electronic and electrical devices to monitor and control various systems The systems controlled include the: fuel system ignition system drive train safety and security systems

3 Main Computer System Components Sensors (Input) input devices that can produce or modify electrical signals with changes in a condition, such as motion, temperature, or pressure Control module computer that uses signals from input devices (sensors) to control various output devices

Computer System Components Actuators (Output) output devices that can move parts when energized by the control module output devices include electric motors and solenoids

Computerized Door Locks The doors are locked as soon as the vehicle starts moving in drive or reverse

Fuel System

Fuel System 2 Purposes for the fuel system: 14.7:1 (Air:Fuel) 1) Provides the correct mixture of air and fuel for efficient combustion 2) Alters the air-fuel ratio with changes in operating conditions such as engine temperature, speed, and load. 14.7:1 (Air:Fuel) Fuel system types: gasoline injection system diesel injection system carburetor system

Maintenance Items -Fuel Filters Most are a maintenance item. - In line or in tank (50,000 miles)

Air Filter All Systems require clean air – usually a maintenance item. Usually square or round. (15-30,000 miles)

Gasoline Injection System Uses a control module, sensors, and electrically operated fuel injectors to meter fuel into the engine An electric fuel pump pressurizes the fuel Uses a Spark Plug to ignite the air/fuel mixture. The control module monitors sensor values and opens the injectors for the correct amount of time to deliver the desired quantity of fuel

Injection System Monitor Air Flow and Mixture (Inputs) Throttle Valve – Controls Air Flow (2 Types): - Manual - Electronic Throttle By Wire Monitor Air Flow and Mixture (Inputs) - Mass Air Flow Sensor - Manifold Absolute Pressure Sensor - Air Temp Sensor - Oxygen Sensor – end of line sensor

Gasoline Injection System

Diesel Injection System Forces fuel directly into the combustion chambers High Pressure Mechanical Fuel pump High pressure produced during compression heats the air enough to ignite the fuel When fuel is injected into the cylinder, the heated air causes the fuel to ignite and burn Compressed Air Ignites the Fuel Mixture – no spark plug! NO THROTTLE VALVE

Diesel Injection System

Carburetor Fuel System Uses vacuum to draw fuel into the engine A mechanical or low pressure electric fuel pump delivers fuel to the carburetor A throttle valve controls airflow and engine power output Spark Plug ignites air fuel mixture

Carburetor Fuel System

Electrical System

Electrical System Consists of several subsystems: ignition system starting system charging system lighting system Each subsystem is designed to perform a specific function

Ignition System Needed on gasoline engines to ignite the air-fuel mixture 2 Things needed to Ignite: Produces an extremely high voltage surge, which operates the spark plugs An electric arc jumps across the tip of each spark plug at the correct time, causing the air-fuel mixture to burn

Ignition Coil

Ohms Law Things to Identify: Ignition Sources: - Ignition Source - Spark Plug Wires - Spark Plugs Ignition Sources: Distributor (Single Coil) Coil Pack Direct Ignition

Ignition System

Starting System An electric starting motor rotates the engine until it “fires” and runs on its own power – TURNS THE CRANKSHAFT AROUND! When the key is turned to the start position, current flows from the battery through the starting system circuit The starting motor turns, and the starting motor pinion gear engages a gear on the flywheel, turning the crankshaft

Starting System 2 major components of the system: Starter Motor Battery

Starting System

Charging System Replaces electrical energy drawn from the battery by forcing electric current back into it (Re-charge the Battery) When the engine is running, the alternator produces electricity to recharge the battery and operate other electrical devices The voltage regulator controls system voltage (13.5-15.5 volts)

Charging System Location: Identify by looking for: Fins (Vents) Fans FEAD Belt (Usually) Identify by looking for: Fins (Vents) Fans

Charging System

Lighting System Consists of the components that operate a vehicle’s interior and exterior lights Components may include: Fuses – (Provides circuit protection) wires switches Relays – (Small amp circuit controls a large amp circuit) control modules

Fuses and Relays Battery Junction Box (late 1990’s and up on most vehicles) Anywhere under the hood on early 1990’s and previous vehicles.

Cooling and Lubrication Systems

Cooling System 1. Maintains a constant engine operating temperature (225-265) 2. Minimizes engine warm-up time Removes excess combustion heat to prevent engine damage Coolant is pumped through the engine, where it absorbs heat Coolant then flows to the radiator, where heat is released to the outside air

Cooling System

Things to identify Radiator – Radiator Cap – Pressure (15-21psi) Usually drops 20-30 degrees – located in front of engine compartment by radiator fan. Do not point through the front of the grill to find. Radiator Cap – Pressure (15-21psi) Upper Radiator Hose – Large Hose Lower Radiator Hose – Large Hose Overflow Bottle – Do not overfill Fan – mechanical or electrical

Things to identify Water Pump – Circulates Coolant Smooth Pulley – usually 4 bolts Follow LOWER radiator hose Thermostat – Controls Flow Follow UPPER radiator hose Antifreeze Mixture = 50/50 water/coolant = -34’F Ethylene Glycol and Propylene Glycol DO NOT MIX COOLANTS Electrolysis in cooling system: Greater than 0.30 volts excessive

Lubrication System Reduces friction and wear between internal engine parts by circulating filtered oil to high-friction points in the engine Helps cool the engine by carrying heat away from internal engine parts

API = American Petroleum Institute Ratings: API = American Petroleum Institute SAE = Society of Automotive Engineers API ratings of oil – can use newer rating in older vehicle but not older ratings in newer vehicle! - API Ratings since before 1930 with oil grade “SA” good until then… - “SN” current since October 2010

Viscosity A quantity expressing the magnitude of internal friction, as measured by the force per unit area resisting a flow in which parallel layers unit distance apart have unit speed relative to one another. The ability of a fluid to flow The weight of the oil (ex: 5W-20)

Lubrication System

Things to Identify Oil Filter – caution: “double gasket” Oil Pan – behind crankshaft pulley Drain Plug – Do not over tighten Oil Fill Spout – in valve cover usually Dipstick – Pull, wipe, recheck

Exhaust and Emission Control Systems

Exhaust System Quiets the noise produced by engine operation Routes engine exhaust gases to the rear of the vehicle body

Things to Identify Exhaust Manifold – Where multiple cylinders converge into a single pipe. Catalytic Converter – may have a single converter or multiple converters Resonance Tube, or chamber Flex Coupler (Chinese finger trap) or Flex Joint (Bolt and Spring) Muffler Tailpipe

Exhaust System

Emission Control Systems 1. remove unburned (CO) and partially burned (HC) fuel from the engine exhaust – Catalytic Converter (Reduce harmful tailpipe emissions) 2. prevent raw fuel vapors from entering the atmosphere – Vapor Storage Canister Nox gasses – contribute to Acid Rain – EGR reduces these.

Things to Identify EGR – Exhaust Gas Recirculation Valve Evap Canister – stores raw fuel vapors until the engine can burn them off.

Drive Train Systems

Purpose To transfer the energy produced by the engine to the wheels! Includes everything from behind the engine to the wheels. “Powertrain” includes the engine.

Rear-wheel-drive Front-wheel-drive Drive Train Systems Rear-wheel-drive Front-wheel-drive

Clutch Allows the driver to engage or disengage the engine and manual transmission or transaxle Clutch pedal released clutch locks the flywheel and the transmission together power flows to the transmission Clutch pedal depressed clutch disengages power flow

Transmission Uses various gear combinations (ratios), to multiply engine speed and torque to accommodate driving conditions Low gear ratios allow the vehicle to accelerate quickly High gear ratios permit lower engine speed, providing good fuel economy

Manual Transmission Uses gears and shafts to achieve various gear ratios. Engaged/Disengaged with Clutch

Automatic Transmission Engaged/Disengaged with Torque Converter Does not have to be shifted by the driver Uses an internal hydraulic system and, in most cases, electronic controls to shift gears Internal clutches or bands control gearsets to provide various gear ratios Input shaft is connected to the engine crankshaft through a torque converter

Automatic Transmission - Has a pan – hydraulics need a reservoir - 1 input 1 output – straight line

Drive Shaft Transfers power from the transmission to the rear axle assembly Universal joints allow the rear suspension to move up and down without damaging the drive shaft

Drive Shaft

Rear Axle Assembly Contains a differential and two axles Differential set of gears and shafts that transmits power from the drive shaft to the axles Axles steel shafts that connect the differential and drive wheels

Consists of a transmission and a differential in a single housing Transaxle Consists of a transmission and a differential in a single housing 1 input – 2 outputs

Transaxle Used with front-wheel-drive vehicles Both manual and automatic transaxles are available

Front Drive Axles Connect the transaxle differential to the hubs and wheels of the vehicle Equipped with constant-velocity joints constant-velocity joints allow the front wheels to be turned to the left or right and to move up and down

Suspension, Steering, and Brake Systems

Suspension System Allows the vehicle’s wheels and tires to move up and down with little effect on body movement Prevents excessive body lean when cornering quickly Component that prevent body lean: Sway Bar Various springs, bars, swivel joints, and arms make up the system

Types of Springs A. Coil spring B. Leaf spring C. Air spring D. Torsion bar Springs control Ride Height

Shocks and Struts Shocks control Jounce and Rebound Jounce is the Compression of the shock Rebound is the Extension of the shock Struts - Combine the shock and spring into a single unit. Struts - Provide STRUCTURE in the suspension.

Spring and Shock Short arm long arm suspension

Struts

Suspensions Independent – Little to No direct effect on opposite wheel when hitting bumps. Nonindependent - Direct effect on opposite wheel when hitting bumps.

Steering System Allows the driver to control vehicle direction by turning the wheels right or left Uses a series of gears, swivel joints, and rods Most are Hydraulic System – Check Fluid with engine NOT running

Steering Basic linkage steering Basic rack-and-pinion steering

Suspension and Steering Systems

Brake System The Braking system converts Kinetic energy into Thermal energy through Friction. When the driver presses the brake pedal, fluid (Hydraulic) pressure actuates a brake mechanism at each wheel Master Cylinder – produces Hydraulic pressure used at the brakes Mechanisms force friction material against metal discs or drums to slow wheel rotation

Complete Brake System

Wheel Brake Assembly

Hydraulic Brake Action

Accessory and Safety Systems

Accessory Systems Common accessory systems include: air conditioner sound system power seats power windows rear window defogger

Safety Systems Common safety systems include: seat belts air bags security systems

This vehicle is equipped with front and side-impact air bags Safety Systems This vehicle is equipped with front and side-impact air bags