Deck 32: Intake and Exhaust Systems

Question 1

Intercoolers are radiators for the intake air.

Answer 1

True

Question 2

When intake air is compressed, its temperature decreases significantly.

Answer 2

False

Question 3

Which of the following is NOT a characteristic of a turbocharger?

A) Is used to increase engine power by compressing the air that goes into the combustion chambers
B) Is usually located close to the exhaust manifold
C) Utilizes an exhaust-driven turbine wheel
D) Requires a mechanical connection between the engine and the pressurizing pump to compress the intake air and fuel mixture

Answer 3

D

Question 4

Lack of lubrication and oil lag are major causes of turbocharger failure.

Question 5

Exhaust manifolds for most vehicles are made of cast or nodular iron.

Question 6

Modern intake manifolds for engines with port fuel injection are typically made of die-cast aluminum or plastic.

Question 7

The higher the altitude, the lower the atmospheric pressure.

Question 8

A miniconverter is used _____.

A) on small vehicles where a normal converter will not fit properly
B) on engines that use leaded fuels
C) in conjunction with EGR systems to supply clean exhaust for the cylinders
D) to reduce emissions during engine warmup

Question 9

An engine can be either supercharged or turbocharged, but not both.

Question 10

An engine in good condition will produce a steady, constant vacuum reading above 15 inches at a warm idle.

Question 11

Superchargers are normally lubricated by engine oil through passages in the intake manifold.

Question 12

A pyrometer, an electronic device that measures heat, can be used to check the operation of a catalytic converter.

Question 13

Vacuum refers to any pressure that is higher than the earth's atmospheric pressure at any given altitude.

Question 14

A turbocharged engine is running with 10 psi (69 kPa) of turbo boost. At what pressure is air being fed into the engine when the engine is operating at sea level?

A) 4.7 psi (32 kPa)
B) 10 psi (69 kPa)
C) 14.7 psi (101 kPa)
D) 24.7 psi (170 kPa)

Question 15

Tuned exhaust manifolds are primarily designed to reduce noise.

Question 16

Generally, an engine designed for maximum torque and horsepower at high speeds has longer runners than one that provides high torque at lower speeds.

Question 17

Acoustic supercharging uses the pressure of the air bouncing back and forth between the closed intake valve and incoming air from the plenum to increase the amount of air drawn into the cylinders.

Question 18

Many mufflers are produced with drain holes drilled into them to allow condensation to drip out.

Question 19

A vacuum gauge may be used to check for a restricted exhaust system.

Question 20

A restricted exhaust system can cause ______.

A) stalling
B) loss of power
C) backfiring
D) all answers are correct

Question 21

Which of the following is NOT a metal used for producing exhaust manifolds?

A) cast iron
B) aluminum
C) heavy-gauge sheet metal
D) stainless steel

Question 22

Engine vacuum may be used to operate the ______.

A) power brakes
B) cruise control
C) air-conditioning system
D) all answers are correct

Question 23

What manages turbo output by controlling the amount of exhaust gas entering the turbine housing?

A) waste gate
B) turbine seal assembly
C) hot wheel
D) cold wheel

Question 24

Technician A says an intake manifold that delivers both air and fuel [carburetor or TBI] is designed to cause turbulence so that the air and fuel mix while they are being delivered to the cylinders. Technician B says in an air only type manifold [PFI] the length of the runners is designed to achieve the best performance during a particular range of engine speeds. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 25

Technician A says a vacuum leak will cause an engine to run richer than normal. Technician B says a vacuum leak can cause an engine to detonate. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 26

Variable intake manifolds for engines with port fuel injection are being discussed. Technician A says at low speeds, the air travels through a short or large diameter runner. Technician B says they deliver more power at high speed. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 27

Which of the following statements concerning superchargers is NOT correct?

A) Superchargers must overcome inertia and spin up to speed as the flow of exhaust gas increases
B) Superchargers do not require a waste gate to limit boost
C) A bypass is designed into the system to allow the supercharger to idle along when extra power is not needed
D) Superchargers improve horsepower and torque

Question 28

Technician A says turbocharging uses the heat energy in the engine's exhaust gases to drive a pump that compresses the intake air. Technician B says supercharging relies on the rotation of the engine to compress the air.

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 29

Before replacing an exhaust system component, Technician A soaks all old connections with a penetrating oil. Technician B checks the old system's routing for critical clearance points. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 30

Technician A says the emission vacuum schematic for the vehicle can only be found in the factory service manual. Technician B say an emissions vacuum schematic is given on an under-hood decal. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 31

Technician A says a vacuum leak results in less air entering the engine, which causes a richer air/fuel mixture. Technician B says a vacuum leak in the system can cause the engine to run poorly. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 32

Technician A says the air filter is designed to prevent engine fires in the event of a backfire. Technician B says the air filter assembly is also designed to help reduce the noise caused by the movement of intake air. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 33

Technician A says a catalytic converter may be tested with a pyrometer. Technician B says a converter may tested using an exhaust gas analyzer. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 34

Technician A says engine vacuum is normally measured in inches of mercury (in. Hg). Technician B says a pressure gauge that is labeled psig will read 14.7 psi at sea level. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 35

Variable intake manifolds are being discussed. Technician A says an intake manifold tuning (IMT) system uses a butterfly valve to divide the plenum into two small chambers at low speeds. At high engine speeds, the butterfly valve opens to form one large plenum chamber. Technician B says the intake manifold runner control (IMRC) system changes the path of air between long and short runners or between small-diameter and large-diameter runners according to engine speed. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 36

Technician A says a catalytic converter breaks down HC and CO to relatively harmless by-products. Technician B says OBD-II regulations call for a monitoring system that looks at the effectiveness of the converter. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 37

A catalytic converter is being tested with a pyrometer. The outlet temperature is 100 degrees Fahrenheit higher than the inlet temperature. What is indicated?

A) The engine is running hot
B) The engine is running too lean
C) Nothing is happening in the converter
D) The converter is operating properly

Question 38

Which of the following is NOT an engine exhaust pollutant that is changed by the catalytic converter?

A) CO
B) HC
C) CO₂
D) NO_X

Question 39

What is the first step in turbocharger inspection?

A) Check the air cleaner for dirty element
B) Open the turbine housing at both ends
C) Start the engine and listen to the system
D) Remove the ducting from the air cleaner to turbo and examine the area

Question 40

Technician A says most turbochargers have their own, self-contained, lubrication system. Technician B says a turbocharger should not be operated at an engine oil pressure lower than 30 psi. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 41

Boost pressure is measured with a pressure gauge ______.

A) at idle
B) in park or neutral at full throttle
C) on a road test at full throttle
D) all answers are correct

Question 42

The function of the catalytic converter on a diesel engine is to eliminate ______.

A) carbon dioxide [CO₂]
B) carbon monoxide [CO]
C) sulphur dioxide [SO₂]
D) particulates [black smoke]

Question 43

The function of the air bypass valve in a modern supercharger is to ______.

A) limit boost to prevent engine damage
B) allow boost pressure to pass through the intercooler
C) reduce air-handling losses [drag] at idle
D) reduce noise at highway cruise speeds

Question 44

All the following statements concerning variable nozzle turbine (VNT) type turbochargers are true EXCEPT:

A) They produce more boost at lower engine speeds
B) They decrease fuel consumption by 20 percent
C) They do not require a wastegate
D) They increase the effects of turbo lag

Question 45

Technician A says the action of the wastegate is controlled directly by manifold pressure. Technician B says the wastegate is controlled by the PCM. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 46

A(n) ____________________ is an electronic device that measures temperature.

Question 47

Atmospheric pressure appears as ____________________ on most pressure gauges.

Question 48

The most popular type of supercharger is the _____ type.

A) scroll
B) roots
C) G-lader
D) centrifugal

Question 49

Technician A says the main advantage of a turbocharger is that it allows for an increase of power without a substantial decrease in fuel economy. Technician B says the use of exhaust gas to drive the turbocharger robs power from the engine when the vehicle is driven at low speeds. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 50

Exhaust manifold gaskets are being discussed. Technician A says many modern vehicles are built without gaskets between the cylinder head and exhaust manifold. Technician B says when performing any service on theses engines that will require removing the manifold from the head, a new gasket should be installed.

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 51

Technician A says the bearings in a turbocharger are cooled by engine oil. Technician B says turbocharger bearings are cooled by engine coolant. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 52

The __________________ is a chart of the vacuum hose routings, vacuum source, and relative component locations for all emissions-related equipment.

Question 53

If a catalytic converter in a late model vehicle is not working properly, the ______________________ will turn on.

Question 54

In a turbocharger, the turbine and compressor wheels rotate at speeds up to ______.

A) 10,000 rpm
B) 50,000 rpm
C) 100,000 rpm
D) 150,000 rpm

Question 55

Technician A tests for a restricted exhaust with an exhaust pressure gauge. Technician B uses a digital infrared pyrometer. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 56

Technician A says proper tuning of the exhaust manifold tubes can create a partial vacuum that helps draw exhaust gases out of the cylinder, improving volumetric efficiency. Technician B says combined headers allow the cylinders next to each other in the firing order to be combined. This increases exhaust efficiency. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 57

The boost pressure of a supercharger is proportional to ______.

A) voltage applied to the boost pressure transducer
B) spring tension on the bypass valve
C) engine speed
D) waste gate position

Question 58

Normal engine vacuum on a normally aspirated engine at idle is between ____________________ in. Hg and ____________________ in. Hg.

Question 59

Technician A says the engine should idle for 20 to 120 seconds after a hard run to allow the turbocharger shaft to cool. Technician B says if the vehicle has not been driven for a few days, start the engine up and run it at 2,000 to 2,500 rpm to flush the old oil out of the turbocharger bearings and oil lines. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 60

The ____________________ cools the turbocharged air before it reaches the combustion chamber.

Question 61

What is the function of the exhaust flex joint?

Question 62

What is turbo lag?

Question 63

What are the three functions of the exhaust system?

Question 64

The butterfly valve in IMRC systems is controlled by an electric motor or __________________ actuator.

Question 65

How is vacuum created inside the engine?

Question 66

An intercooler can reduce the temperature of the inlet air as much as __________________ degrees Fahrenheit.

Question 67

What are the component parts of a turbocharger?

Question 68

Wet intake manifolds have __________________ passages cast directly in them.

Question 69

What is the best way to check whether a catalytic converter is working?

Question 70

What is a vacuum?

Question 71

What are the two ways of artificially increasing the amount of airflow into the engine?

Question 72

The number-one cause of turbocharger failure is __________________.

Question 73

In an intake manifold for a PFI engine, the __________________ serves as a reservoir for the air and is used to distribute the intake charge evenly to the runners and intake ports.

Question 74

Describe the construction of a muffler.

Question 75

Describe the main purpose of a catalytic converter.

Question 76

What materials are exhaust pipes typically made from?