AUT 101-Chapter 4

18. Which of the following components are used to dampen the upward and downward movement of a vehicle's springs?

Shock absorbers

10. Technician A says that liquid cooling an engine helps to maintain a consistent operating temperature. Technician B says that oil is circulated through the cooling system to remove heat from the engine's parts. Who is correct?

Technician A

13. Technician A says that many vehicles use an AC generator as the charging unit. Technician B says that all vehicles use an alternator as the charging unit. Who is correct?

Technician B

Engine block-

The core of the engine block is the cylinders, capped by the cylinder head

19. True or False? A hybrid electric vehicle uses regenerative braking to recharge the high-voltage battery.

True

Water pump-

a mechanical device that moves fluid or gas by pressure or suction

Positive crankcase ventilation (PCV)-

an automotive-emission control valve that recirculates gases (as from blow-by) through the combustion chambers to permit more complete combustion

Radiator-ir

an engine-cooling device in a motor vehicle or aircraft consisting of a bank of thin tubes in which circulating fluid is cooled by the surrounding a

Transaxle-

an integral driving axle and differential gear in a motor vehicle

Exhaust manifold-

are generally simple cast iron or stainless steel units which collect engine exhaust gas from multiple cylinders and deliver it to the exhaust pipe

Refrigerant-

are usually substances that evaporate quickly. In the process of evaporation they draw heat from surrounding substances

23. While discussing the operation of air-conditioning systems: Technician A says that in order for the refrigerant to release heat, it must be at a low temperature and pressure. Technician B says that in order for the refrigerant to absorb heat, it must be at a high temperature and pressure. Who is correct?

both A and B

Torque converter-

device that transmits or multiplies torque generated by an engine

Master cylinder-

is a control device that converts non-hydraulic pressure (commonly from a driver's foot) into hydraulic pressure

Valve train-

is a device that controls the operation of the valves, in which a sequence of components transmits motion throughout the assembly

Exhaust gas recirculation (EGR)-

is a nitrogen oxide (NOx) emissions reduction technique used in petrol/gasoline and diesel engines

Antilock brake system (ABS)-

is an automobile safety system that allows the wheels on a motor vehicle to maintain tractive contact with the road surface according to driver inputs while braking, preventing the wheels from locking up (ceasing rotation) and avoiding uncontrolled skidding.

Steering gear-

is the device used for controlling the direction of a vehicle

25. Which of the following is not accomplished by the fuel and air system of a gasoline engine?

keeps the fuel and air ratio constant regardless of the conditions under which the engine is operating.

22. The boiling point of the coolant in an engine's cooling system is raised by the

pressure cap

Running gear-

the moving parts of a machine, especially the wheels, steering, and suspension of a vehicle

Port-

the opening in a cylinder head that allows intake air to enter a cylinder or exhaust gas to leave the cylinder

Compressor

- a machine used to supply air or other gas at increased pressure, e.g., to power a gas turbine

Crankshaft

- a shaft driven by a crank

Disc brakes

- a type of vehicle brake employing the friction of pads against a disc that is attached to the wheel

Condenser

- an apparatus or container for condensing vapor

Cylinder Head

- the end cover of a cylinder in an internal combustion engine, against which the piston compresses the cylinder's contents

Constant velocity (CV) joint

-allow a drive shaft to transmit power through a variable angle, at constant rotational speed, without an appreciable increase in friction or play

20. What two major engine components work together to change the reciprocating motion of the pistons into a rotary motion?

Crankshaft and connecting rod

15. Which of the following is not part of the running gear?

Differential

12. Which emission control system introduces exhaust gases into the intake air to reduce the formation of NOx in the combustion chamber?

EGR

4. Which of the following is not a common emission control system?

EVAP

2. Explain the four strokes of the internal combustion engine.

In a four-stroke cylinder engine, the piston moves through four different movements or strokes to complete one cycle. The four strokes are the intake, compression, power and exhaust strokes. On the intake stroke, the piston moves downward, and a charge of air-fuel mixture is introduced into the cylinder. As the piston travels upward, the air-fuel mixture is compressed in preparation for burning. Just before the piston reaches the top of the cylinder, ignition occurs and combustion starts. The pressure of expanding gases forces the piston downward on its power stroke. When it reciprocates, or moves upward again, the piston is on the exhaust stroke. During the exhaust stroke, the piston pushes the burned gases out of the cylinder.

9. What does the valve train do?

It opens and closes the intake and exhaust ports of each cylinder

8. Which is not a common automotive fuel?

Hydrogen

6. Which of the following is not one of the strokes of a four-cycle engine?

Ignition

11. An engine will not start and no spark is found at the spark plugs when the engine is turned over by the starter. Technician A says that the problem is probably the battery. Technician B says that the ignition system is most likely at fault. Who is correct?

Technician B

7. Technician A says that the PCV system is designed to limit CO emissions. Technician B says that catalytic converters reduce HC emissions at the tailpipe. Who is correct?

Technician B

1. Under the CAFÉ standards, for what are vehicles tested?

Under CAFÉ standards, different models from each manufacturer are tested for the number of miles they can be driven on a gallon of gas.

Torsion bar-

a bar forming part of a vehicle suspension, twisting in response to the motion of the wheels and absorbing their vertical movement

Pressure cap-

a cap used to maintain pressure in a radiator

Water jacket-

a casing containing water surrounding and protecting something from extremes of temperature

Hydrocarbons (HC)-

a compound of hydrogen and carbon, such as any of those that are the chief components of petroleum and natural gas

Solenoid-

a cylindrical coil of wire acting as a magnet when carrying electric current

Shock absorber-

a device for absorbing jolts and vibrations, especially on a motor vehicle

Spark plug-

a device for firing the explosive mixture in an internal combustion engine

Thermostat-

a device that automatically regulates temperature or that activates a device when the temperature reaches a certain point

Piston-

a disk or short cylinder fitting closely within a tube in which it moves up and down against a liquid or gas, used in an internal combustion engine to derive motion, or in a pump to impart motion

Differential-

a gear assembly that transmits power for the drive shaft to the wheels and allows two opposite wheels to turn at different speeds for cornering and traction

Regenerative braking-

a method of braking in which energy is extracted from the parts braked, to be stored and reused

Manifold-

a pipe or chamber branching into several openings

Orifice tube-

a precisely sized tube that controls fluid flow

Flange-

a projecting flat rim, collar, or rib on an object, serving to strengthen or attach or (on a wheel) to maintain position on a rail

Spring-

a resilient device, typically a helical metal coil, that can be pressed or pulled but returns to its former shape when released, used chiefly to exert constant tension or absorb movement

Unibody-

a single molded unit forming both the bodywork and chassis of a vehicle

Stud-

a threaded shaft that resembles a bolt without a head

24. While discussing HEV's: Technician A says that in a series hybrid, the engine is only used to power a generator to recharge the batteries. Technician B says that in a parallel hybrid, the engine always supplies some of the power to move the vehicle. Who is correct?

both A and B

Rack and pinion-

denoting a mechanism, as for a car steering system, using a fixed cogged or toothed bar or rail engaging with a smaller cog

Transfer case-

is a part of the drivetrain of four-wheel-drive, all-wheel-drive, and other multiple powered axle vehicles

Thermostatic expansion valve (TEV or TXV)-

is a precision device, which is designed to regulate the rate at which liquid refrigerant flows into the evaporator

Hydroforming-

is a specialized type of die forming that uses a high pressure hydraulic fluid to press room temperature working material into a die

Recirculating ball-

is a steering mechanism commonly found in older automobiles, off-road vehicles, and some trucks

Receiver/dryer-

is a storage tank for the liquid refrigerant from the condenser

Hybrid electric vehicle (HEV)-

is a type of hybrid vehicle and electric vehicle that combines a conventional internal combustion engine (ICE) propulsion system with an electric propulsion system

Ignition coil-

is an induction coil in an automobile's ignition system which transforms the battery's low voltage to the thousands of volts needed to create an electric spark in the spark plugs to ignite the fuel

Gear ratio-

the ratio between the rates at which the last and first gears rotate

5. Automatic transmission use a

torque converter instead of a clutch to transfer power from the flywheel to the transmission's input shaft.

Oxides of nitrogen (NOx)-

various compounds of oxygen and nitrogen that are formed in the cylinders during combustion and are part of the exhaust gas

17. Which type of transmission uses pulleys to change engine speed?

Continuously variable

Distributor

- a device in a gasoline engine for passing electric current to each spark plug in turn

Evaporator

- a device used to turn the liquid form of a chemical into its gaseous form. The liquid is evaporated, or vaporized, into a gas

Clutch

- a mechanism for connecting and disconnecting a vehicle engine from its transmission system

Connecting rod

- a rod connecting two moving parts in a mechanism, especially that between the piston and the crankpin (or equivalent parts) in an engine or pump

Combustion chamber

- an enclosed space in which combustion takes place, especially in an engine or furnace

Corporate Average Fuel Economy (CAFÉ)

- are regulations in the United States, first enacted by the U.S. Congress in 1975, in the wake of the Arab Oil Embargo and were intended to improve the average fuel economy of cars and light trucks (trucks, vans and sport utility vehicles) produced for sale in the United States

Crankshaft position sensor

- is an electronic device used in an internal combustion engine to monitor the position or rotational speed of the crankshaft. This information is used by engine management systems to control ignition system timing and other engine parameters

Combustion

- rapid chemical combination of a substance with oxygen, involving the production of heat and light

Cylinder block

- the main body of an internal combustion engine, containing the pistons

Drivetrain

- the system in a motor vehicle that connects the transmission to the drive axles

Brake Booster

- uses hydraulic pressure generated by the power steering pump rather than engine vacuum to provide the power assistance required

16. Which of the following statements about anybody construction is not true?

All unibodies are constructed from steel.

3. In addition to the battery, what does the charging system include?

AC generator, voltage regulator, indicator light and the necessary wiring.

14. Technician A says that a transaxle delivers torque to the front and the rear drive axles. Technician B says that a transaxle is most commonly found in 4WD pickups and SUVs. Who is correct?

Neither A nor B

21. Technician A says that an air-conditioning system removes heat from inside the engine. Technician B says that the heating system removes heat from the inside of the vehicle. Who is correct?

Neither A or B