Automotive Exam Study Guide

Calculate the airflow for a four-stroke, 4.2L engine running at 2900 rpm at 100% throttle

214.98 ft^3/min

The gear ratio is 1.33. If the driven gear has 32 teeth how many does the driver gear have?

24

A change of 14 degrees C corresponds to what change in degrees F?

25.2

Find the displacement in cubic centimeters of a V6 engine with a bore of 4 inches and a stroke of 3.5 inches.

263.889 cubic inches

The same V6 engine with bore of 4 inches and stroke of 3.5 inches has to be bored out "60 over". Find the total displacement of the engine after the boring has taken place.

271.87 cubic inches

The frequency of the wheel speed sensor output is 333Hz. The car uses P195/65R15 tires while the speed sensor gear has 30 teeth. Calculate the period of the speed sensor.

3 ms

Find the diameter of a tire labeled 245/75R16.

30 inches

Convert 413,920,000 to scientific notation

4.1392 X 10^8

What is the current flow in a series circuit that has a 12V battery and 3 resistors, 2Ω, 4Ω, and 3Ω?

4/3 Amps

The diameter of cylinder 1 is 2 inches while the diameter of cylinder 2 is 4 inches. The force on cylinder 1 is 100 pounds. Find the force for cylinder 2.

400.3 pounds

Convert a 7.5 liter engine to cubic inches?

453 CID

Convert 18 inches to mm.

457.2 mm

You are given a car with a with original tire diameter of 28 in and specs for the original caster angle at 6 ̊. You are going to replace the tires with ones of diameter 30 in. Calculate the new caster angle.

5.6 ̊

The frequency of the wheel speed sensor output is 333Hz. The car uses P195/65R15 tires while the speed sensor gear has 30 teeth. Calculate the speed of the car to the nearest mph.

50 mph

Calculate the adjusted speedometer reading of a vehicle traveling 60 mph with an original tire size of P195/60/R15 with an aftermarket set of tires rated at P215/60/ R15.

57.75mph

Calculate the horse power needed to move 850 pounds 600 feet in 2 minutes.

7.7 HP

Utilizing the below PID data calculate and covert the engine size and speed to grams per second. TPS 10% RPM 600 7.5L

8.9 g/sec

What's another word for a 'driven' rear axle?

A 'live' axle.

A material that allows electrical current to flow easily is called:

A conductor.

The imaginary center line that passes through the steering pivot line is called the steering:

Axis.

Identify a vehicle part that is not sprung weight:

Axle.

A fire involving gasoline is what class of fire?

B class fire.

Technician A says that there are 60 minutes per 1 degree of an angle. Technician B says there are 360 degrees in one rotation. Who is correct?

Both Technician A and B

A basic gasoline throttle-body fuel injection system can be fitted with which

Either one or two fuel injectors.

Wiring diagrams give information about:

Electrical circuits and their components.

The vacuum brake power booster on a gasoline-powered passenger car normally gets assistance from the:

Engine intake manifold

The Lubrication system distributes oil throughout the:

Engine.

What is a known advantage of an electric fuel pump?

Fills the fuel system before cranking of the engine.

The width of a wheel rim is the distance across the rim ________ at the bead seat.

Flanges

Which of the following is a measure of horse power?

Foot pounds per second

If the inertia switch is triggered, it shuts off the power supply to the:

Fuel pump.

Which is the most common oil filtering system employed on automotive vehicles?

Full-flow.

If a master cylinder is applying force to a small and a large cylinder, the force exerted on the smaller cylinder will be _________ than the force applied to the larger cylinder.

Greater.

Combustion of the air-fuel mixture in the cylinders generates:

Heat.

Shock absorbers convert the energy they absorb into what?

Heat.

What is the purpose of a hybrid vehicle?

Hybrid vehicles are designed to drive like conventionally powered vehicles, while producing significantly lower emissions and increased fuel economy.

Power steering assistance is provided by:

Hydraulic and/or electrical methods.

The piston applies _____________ pressure to the fluid in the cylinder.

Hydraulic.

The potentially explosive gas given off when charging a battery is:

Hydrogen.

Why are fluid specifications important?

Identify proper filling capacities.

The VIN number assists in:

Identifying the make, model and year of vehicle Identifying specific vehicle characteristics Locating specific TSB's/Recalls for that particular vehicle

The steering system center link is supported by which of the following?

Idler arm and Pitman arm.

One reason that disc brake rotors are drilled or slotted is?

Improved cooling.

How are the stop lamps connected in relation to each other?

In parallel.

In a basic gasoline multi-point fuel injection system, the fuel injectors are placed:

In the intake manifold near to the intake ports in the cylinder head.

Since liquid is effectively ____________, pressure applied to a liquid is transmitted without loss throughout the liquid.

Incompressible.

As pressure increases, the boiling point:

Increases

Static electricity can be induced by rubbing 2 ________together:

Insulators.

What are the five key events of an internal combustion engine?

Intake, Compression, Ignition, Power & Exhaust

What are the five key events of an internal combustion engine?

Intake, Compression, Ignition, Power & Exhaust.

In strut suspension, how is the control arm fixed in place?

It is fixed in place with bushes.

What is an auxiliary air valve used for in an EFI system?

It is used as part of a cold starting system.

Why is one end of a chisel softer than the other?

It won't chip when hit with a hammer.

What is a function of the suspension system?

Keep the wheels on the road.

A drum brake creates friction, which creates heat, which transfers __________ ______________, which slows you down.

Kinetic energy

Your workplace would will be a much safer place if you:

Know what to do in an emergency.

In commercial vehicles, metallic bushes are commonly used as shackle bushes for what purpose?

Leaf springs.

A "rack-and-pinion" steering system is used on:

Light passenger vehicle.

An axle that carries vehicle drive power is referred to as:

Live axle.

What term best describes the relationship between temperature and the resistance in the thermistor?

Logarithmic

Conical and barrel shaped springs will allow for which spring ability?

Longer spring travel.

Trailing arms, or control rods, are used to position the axle in which direction?

Longitudinally.

Glass on ice would be expected to have a ___________ coefficient of friction.

Low.

In short/long arm suspension, the lower control arm pivots on bushes that twist on which part?

Lower control arm pin.

Which component operates between the valve and the camshaft in an overhead cam engine?

Rocker arm.

The purpose of the connecting rod is to:

join the reciprocating components to the rotary motion components.

The way parking brakes operate can be described as?

mechanically operated

The trailing arm is attached to the chassis at a rigid cross-member pivot point. This pivot point is fitted with:

Rubber bushes.

When given a table, how can you tell that the relationship is linear?

See if the slope between all pairs of points in the table are the same.

There are three common hybrid systems in automotive use. What are their names?

Series, parallel, and series-parallel.

What forms a multi-leaf spring?

Several single leafs.

Front-engine/front-wheel-drive vehicles normally use a braking system that is:

Split diagonally.

SUV stands for:

Sport utility vehicle.

A dual or divided brake system is safer in the event of a partial failure. This is achieved by a:

Tandem master cylinder.

What tool is used to repair internal threads?

Tap.

Technician A says that a circuit has 3 Ohms of resistance. As the system operates at 12 volts the amperage must be 4 amps. Technician B says that a circuit has 3 Ohms of resistance. As the system operates at 24 volts the amperage must be 12 amps. Who is correct?

Technician A.

Technician A says that tires that have a DOT rating, have been passed a governmental standard of quality. Technician B says that all DOT rated tires will have a speed rating of 118 mph. Who is correct?

Technician A.

The function of a panhard rod is:

To assist in stabilizing the vehicle from lateral movements.

Driving lights should be wired so that they operate when a high beam is operating. Why is this?

To ensure that driving lights turn on when the headlights are dipped from high to low beam.

What is the purpose of the power steering pressure relief valve?

To prevent excessive pressures developing when the steering is on full-lock.

Why is the handle of a box wrench bent'?

To provide full hand grip with work clearance.

For what reason are some cylinder heads made of aluminum alloy?

To save weight.

Bulb filaments are normally made from:

Tungsten.

All passenger vehicles must have at least:

Two independent braking systems.

What is the property of electricity that can be described as "electrical pressure"?

Voltage.

The power consumed by headlight bulbs is normally measured in:

Watts.

When is an engine running lean?

When it has too much O2.

What is the primary characteristic of a negative temperature coefficient thermistor?

When the temperature increases lower resistance values are produced.

Exhaust gases in workshops are a serious health hazard. The best way to get rid of these gases is:

With an exhaust extraction system.

The features of a 'caution' sign are:

Yellow background, black text.

What happens to drum brakes when they get hot?

They lose pressure. Longer stoping distances. Smell

High viscosity liquid is __________ and flows slowly.

Thick.

Fog lights are aimed to strike the road a short distance in front of the vehicle. Why is this?

This reduces the light reflected into the driver's eyes, providing better visibility

How many phases does a typical automotive alternator have?

Three.

What is an overhead camshaft is driven by?

Timing chain or belt.

Convert 800 mV to kV.

0.000800 kV

Utilizing the below specifications calculate and identify the adjusted valve timing. .060 Milled Cam Gear Diameter 150mm

1.1 degrees

You are given a car with a with original tire diameter of 28 in and specs for the original caster angle at 6 ̊. You are going to replace the tires with ones of diameter 30 in. Determine the caster trail.

1.47 in

Given the fact that the driven gear has 20 teeth and the driver gear has 15 teeth, calculate the gear ratio.

1.5

Find I if the voltage is 12 and the resistance is 1.2 ohms.

10 amps

The force on cylinder 1 is 250 pounds and the force on cylinder 2 is 175. If the area for cylinder 2 is 15 square inches, what is the area of cylinder 2?

10.5 sq. inches

What is the total resistance in a parallel circuit with a 12 volt battery and 3 legs each with one resistor? 3Ω, 4Ω, and a 2Ω

12/13 Ohm

Find E when I=15 amps and R=8 ohms.

120 volts

Compute the volume of a cylinder with height of 5 mm and radius of 3 mm.

141.37 cubic mm

Calculate and convert 1/4 of a degree to minutes.

15'

The Becker family has a ford escort and it acquires 14mpg. Mr. Becker drives an average 12,000 miles a year. How much C02 emissions does his car emit in one year?

17,143

The Shorbe family drives a Chevrolet Tahoe and it averages 27.5 mpg however the Shorbe family drives 24,000 miles a year. How much CO2 does the Shorbe family emit yearly?

17,455

On vehicles with four disc brakes, how is the parking brake usually applied?

At the rear caliper and applied by cable.

Tubeless tires have no inner tubes because they have:

A soft-rubber inner-casing liner.

The term alternating current is often shortened to:

AC.

Linings can be riveted, or more often ___________ to the brake shoe?

Adhered.

The inner and outer tie rod ends are connected by the:

Adjusting sleeve.

Why are intake valves usually larger than exhaust valves?

Air-fuel mixture is under lower pressure than exhaust gases.

Most wheels have holes or slots in the wheel flange for what purpose?

Allow air flow to the brakes.

What are the purposes of Antilock Brake Systems?:

Allows driver to maintain steering control Shortens stopping distance

What does the rotating magnet in a very simple alternator induce in the stator windings?

An alternating current flow.

Workplace safety requires:

An awareness of the risks A plan to address the risks An ongoing commitment to safety

As a plunger is pushed in, the air inside a cylinder is forced into a smaller volume. What is the effect on the pressure inside the cylinder?

An increase in pressure.

A material that allows electrical current to flow easily is called:

An insulator.

In the case of a building fire, the procedure will involve leaving the building and:

Assembling at a meeting point.

The main part(s) of a charging system is/are:

Battery Alternator Voltage regulator

When the engine is not running, current to operate electrical circuits is supplied by the?

Battery.

Why are vehicles fitted with lighting systems in parallel to each other?

Because if one system fails the others can still work independently of the failed system.

Why should you disconnect the battery prior to cleaning a vehicle with solvents?

Because some solvents are highly volatile and can explode.

Hydraulic brake fluid containers must not be left open to the atmosphere as the fluid will:

Become contaminated.

Technician A Says that a smaller tire and wheel assembly will speed up the speedometer. Technician B Says a larger tire and wheel assembly will slow down the speedometer. Who is right?

Both A and B

Which of the following moves brake fluid from the brake booster to each of the four brakes?

Brake line.

A _______ _______ is a component of the drum break system that is not associated with the actuator, return spring and brake shoe.

Brake pad.

Which of the following best describes a flat object, typically made ceramic?

Brake pads.

Inner tie rod ends are connected by the:

Center link.

The disc brake hydraulic system creates which kind of force on the brake rotor?

Clamping.

The main function of grooves in the tread is to:

Clear water from the contact patch.

Friction measured in pairs of surfaces is called:

Coefficient.

What is the most common type of pliers?

Combination pliers.

The first part of a DTC code is a letter that identifies the location of the fault. What does the letter U indicate?

Communication system

What links the crankshaft to the piston?

Connecting rod.

When a piston is forced down the cylinder during the power stroke, it applies the force to which part?

Connecting rod.

Identify the force that must be controlled to maintain wheel unit location:

Cornering Force.

Movement of electrons through a conductor is called

Current

Ohms law states:

Current (Amps)=Volts/Resistance(Ohms).

Three components of an engine block are:

Cylinder, Piston and Crankshaft

A soft-faced hammer must be used when?

Damage to the work must be prevented.

The proportioning valve is designed to do what?

Decrease braking at the rear wheels.

Why are different coil springs color coded?

Different load rate.

A _____________ is not part of a 'dead' axle assembly.

Differential.

The electrolyte in an automotive lead acid battery is:

Dilute sulfuric acid.

What is the most widely used hydraulic shock absorber?

Direct-acting telescopic type.

Toe angles ensure that the wheels are in line with the:

Direction of travel.

Rear wheel independent suspension has to allow for which mechanical system?

Drive axles.

A current can be induced by moving a conductor in a fixed __________ field:

Magnetic.

Before you begin a vehicle service, you notice a scratch in the fender paintwork. What should you do about it?

Make a note of the damage on the job sheet, and bring it to the attention of your supervisor or the customer.

The ___________ cylinder provides hydraulic pressure.

Master.

The brake pedal is used to transfer the effort from the driver's foot to the master cylinder. This effort is increased by the use of:

Mechanical advantage.

An alternator converts:

Mechanical energy into electrical energy.

What does the alternator convert?

Mechanical energy to electrical energy.

The starting motor converts electrical energy into:

Mechanical energy.

Injector pulse width determines how much fuel is injected. It is measured in what?

Milliseconds (mS)

You have a 2005 Chevrolet Cobalt. Cobalt is:

Model.

Select the condition that automotive brakes are used for:

Motion.

When using mental math to convert from 0C to 0F, the first step would be to

Multiply the degrees C by 2.

If a standard screwdriver is the correct size it will:

Neatly fit the slot with the blade across the whole width

Technician A says tubeless tires are bonded to the wheel with special glue. Technician B says tubeless tires create a leak proof seal where the tire bead seals against the wheel's flange. Who is correct?

Neither Tech A nor Tech B is correct.

Are fuses rated in ohms or volts?

Neither.

If an object is embedded in the eye, you should:

Not attempt to remove it.

Oil is stored in the _________ bolted to the bottom of the engine block

OIl pan sump.

What is the lower piston ring on a 4-stroke engine called?

Oil control ring

Where is the VIN number usually located?

On the left front corner of the windshield.

In one revolution of the crankshaft how many power strokes does the two-stroke engine produce?

One

In one 4-stroke cycle, how many strokes produce energy to turn the crankshaft?

One.

Free electrons are necessary for electric current, but for those electrons to move, they need a complete:

Pathway and circuit.

When two different metals are immersed in an electrolyte, one loses electrons and becomes:

Positive.

In a hydraulic brake booster, what component generates system pressure?

Power steering pump.

One way to prevent coolant boiling is to use a:

Pressure cap

The purpose of an insulator is to:

Prevent current loss.

What method is used to position the idle speed control valve?

Pulse Width Modulation (PWM)

Radiator fans do not:

Push air through the radiator when the temperature reaches a predetermined level.

Over time, engine oil brakes down by _____________ with dissolved atmospheric oxygen.

Reacting.

What are the two main types of steering systems currently used?

Recirculating ball and rack-and-pinion.

What device uses a small amount of current to control a large amount of current?

Relay.

"Work" is the measure of:

Released energy.

Technician A says that milling an OHC engines cylinder head does not affect drivability. Technician B says that excessive milling of an OHC engines cylinder head will affect drivability and emissions. Who is right?

Tech B

Technician A says that the main purpose of OBD computer controls is to improve performance. Technician B says that one purpose of OBD is to control emissions. Who is correct?

Technician B.

What is not a part of the reverse light circuit?

The Ignition switch.

Why must the oxygen sensor be tested when it is hot?

The O2 will pass through the sensor when cold.

At sea level a 16 ounce freon can is punctured venting the gas into the air. When the gas is done venting, why does some freon remain in the can?

The atmospheric pressure keeps some in the can.

Oil Pumps are usually driven by the?

The camshaft or the crankshaft

How will doubling the rpm of the engine affect the graph of the camshaft sensor?

The frequency will double.

The function of the proportioning valve is to distribute the braking effort between:

The front and rear brakes under heavy braking application according to how the load is distributed across the vehicle.

The function of the proportioning valve is to distribute the braking effort between?

The front and rear brakes under heavy braking application according to how the load is distributed across the vehicle.

If the inertia sensor is triggered, it shuts off the power supply to:

The fuel pump

Material Safety Data Sheets provide information about:

The handling, use and storage of chemicals.

What opens and closes the inlet and exhaust ports in a 2-stroke gasoline engine?

The piston

A ratchet handle is not recommended for tightening bolts to a high torque value because?

The ratchet mechanism could be damaged.

The disc brake pad is pressed against which part of the system to create stopping force?

The rotor.

The alternator is not part of:

The starting system.

A socket extension universal joint may be used when?

The turning force must be applied at an angle.

The upper end of the idler arm is bolted to what?

The vehicle frame.

How will the graph of the crankshaft sensor be changed if a tooth breaks off of the gear?

There will be a break in the graph with values at zero for the missing tooth.

Where are inlet and exhaust valves generally located?

cylinder head

In a gasoline/electric hybrid vehicle, what does the inverter do?

drives the vehicle and charges the battery.

What does the internal combustion engine do in a series-parallel hybrid system?

drives the vehicle and charges the battery.

What is the primary reason for fitting a gasket between two surfaces?

form a seal between two mating parts.

The connecting rod joins the piston to the crankshaft by a piston pin or a:

gudgeon(piston, wrist) pin.

What two parts does a head gasket provide a seal between?

the cylinder head and the engine block.

What will occur If an engine is not effectively cooled?

the moving parts will seize up.

A mechanical heat sensitive valve that controls coolant flow is referred to as?

thermostat.