Deck 3: Theory of Engine Operation

Question 1

Energy can be changed into another form but cannot be created or destroyed.

Answer 1

True

Question 2

Approximately how much of a gasoline engine's energy is used to drive the vehicle?

A) 29%
B) 19%
C) 9%
D) 39%

Answer 2

B

Question 3

50 pounds applied to a wrench 24 inches long will produce how much torque:

A) 50 ft lbs
B) 100 ft lbs
C) 150 ft lbs
D) 250 ft lbs

Answer 3

B

Question 4

It takes two complete camshaft revolutions and one revolution of the crankshaft to complete one engine cycle.

Question 5

If the cylinder stroke is larger than the cylinder bore, the engine is said to be oversquare.

Question 6

Which of the following are common cylinder arrangements?

A) V-blocks
B) Opposed
C) Inline
D) All of the above

Question 7

The measurement of the rate at which work is performed is measured in:

A) Horsepower
B) Torque
C) Momentum
D) Energy

Question 8

Glow plugs are used in diesel engines to:

A) Warm the engine oil
B) Ignite the fuel
C) Warm the intake air
D) Warm the combustion chamber

Question 9

The combustion chamber is the space between the top of the piston and the cylinder head.

Question 10

Internal combustion engines convert chemical energy into thermal energy and thermal energy into mechanical energy.

Question 11

Because they both flow, gases and liquids are both classified as fluids.

Question 12

Brake horsepower may be defined as

A) The amount of horsepower required to stop a vehicle
B) The amount of horsepower required to overcome the internal friction of the engine
C) The useable power at the engine's crankshaft
D) The maximum amount of horsepower the engine can produce before it breaks

Question 13

A DOHC V-type engine has two camshafts.

Question 14

The period of time that the exhaust and intake valves are both open is called:

A) valve angle
B) valve clearance
C) valve timing
D) valve overlap

Question 15

Technician A says atmospheric pressure decreases as altitude increases. Technician B says atmospheric pressure increases as altitude increases. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 16

The bore and stroke of a cylinder are measured in inches or millimeters.

Question 17

A vehicle with sequential fuel injection will:

A) Inject fuel only once per engine cycle
B) Inject fuel on every stroke of a four-stroke cycle
C) Have one fuel injector that is used for all of the cylinders in a multi-cylinder engine
D) Inject fuel all the time when an engine is running

Question 18

A low pressure is formed in the engine as the piston moves up during the intake stroke.

Question 19

A typical pressure gauge will read atmospheric pressure as 14.7 psi.

Question 20

Pressure and temperature are inversely proportional to each other.

Question 21

The PCM controls electromagnetic devices or solenoids called ____________________that deliver fuel to the cylinders.

Question 22

GDI systems improve ___________ and reduces fuel ___________ and ___________.

Question 23

The ____________________ connects the piston to the connecting rod.

Question 24

Energy can be stored and changed into other forms, but cannot be ____________________ or ____________________ .

Question 25

All of the following are factors in volumetric efficiency except:

A) Altitude
B) Fuel type
C) Exhaust tuning
D) Piston design

Question 26

How is energy converted by the gasoline engine to propel the vehicle?

Question 27

When an engine is bored oversized during an engine rebuild, what is affected?

A) Piston size
B) Stroke
C) Compression ratio
D) All of the above

Question 28

Diesel engines do not use spark plugs and are referred to as ____________________ engines.

Question 29

The degrees of crankshaft rotation in which both the intake and exhaust valves are open is called ____________________.

Question 30

A ____________________ engine has two rows of cylinders 60 or 90 degrees apart.

Question 31

All of the following can be identified by using the VIN code except:

A) Model year
B) Country of origin
C) Transmission type
D) Engine type

Question 32

____________________ are used to counteract the inherent engine vibrations.

Question 33

Technician A says compression ratio is based only on the distance the piston moves from BDC to TDC. Technician B says increasing the compression ratio of an engine can lead to detonation. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 34

The ____________________ stroke begins when the air/fuel mixture is ignited and the piston is forced downward.

Question 35

If an engine develops 100 indicated HP, the brake HP will be about:

A) 85 HP
B) 90 HP
C) 95 HP
D) 100 HP

Question 36

Which of the following horsepower ratings would best reflect the usable power produced by an engine?

A) Gross HP
B) Brake HP
C) Indicated HP
D) Net HP

Question 37

Technician A says balance shafts are used to reduce the vibrations produced when the pistons are at TDC and BDC. Technician B says balance shafts rotate at crankshaft speed. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 38

____________________ is the unit of measurement of the rate at which an engine produces torque in a given amount of time.

Question 39

A diesel engine generates power by:

A) Compressing the air/fuel mixture until it ignites
B) Igniting the air/fuel mixture with the glow plugs
C) Compressing the air and then injecting the fuel
D) None of the above

Question 40

Pressure lower than atmospheric pressure is called ____________________ .

Question 41

Tailpipe smoke is not a good indicator of internal engine problems.

Question 42

Blue smoke from the exhaust indicates the engine is burning oil.

Question 43

Technician A says communication is important so that the actual customer concern is addressed and fixed. Technician B says poor communication can cause an incorrect diagnosis. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 44

Engine noises can be difficult to communicate between the customer and the technician.

Question 45

A chassis ear is only good for identifying suspension noises.

Question 46

Communicating with the customer in technical terms may be the easiest way to communicate.

Question 47

A repair order is used for which of the following purposes?

A) Tax recording
B) Customer information
C) Concerns and corrections
D) All of the above

Question 48

Test driving with customers is almost always unnecessary.

Question 49

Vehicles with salvage or flood titles often have hidden damage.

Question 50

When test driving with a scan tool attached to the vehicle, equal attention should be paid to the scan tool and to driving.

Question 51

How does atmospheric pressure affect engine operation?

Question 52

Spark ignition occurs just after top dead center during the compression stroke.

Question 53

Improper spark plugs could cause preignition in the combustion chamber.

Question 54

Technician A says the customer complaint should be as detailed as possible on the RO. Technician B says a complaint of "a loud ticking sound" is a good, detailed description of the complaint. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 55

Technicians always have direct contact with the customers when handling engine repair concerns.

Question 56

The customer complaint is sometimes recorded inaccurately on the repair order.

Question 57

A chassis ear may be used to diagnose all of the following concerns except?

A) Faulty wheel bearing
B) Worn suspension bushings
C) Collapsed engine mounts
D) Weak shocks

Question 58

How does an OHV engine's valvetrain differ from that of an OHC engine?

Question 59

Customers may understand terms like "piston" but not know what one looks like.

Question 60

Describe a situation where incorrectly identifying the 8th digit of the VIN may cause problems.

Question 61

A ____________________ uses several microphones connected to a set of headphones to isolate noises.

Question 62

Which of the following may be necessary during a test drive to confirm a complaint?

A) Using a scan tool
B) Riding with the customer
C) Installing a chassis ear
D) All of the above

Question 63

The technician diagnosis and completes the ____________________ section of the repair order.

Question 64

Technician A says previous invoices from other shops and repairs may provide clues about a customer's complaint. Technician B says the technician should have prior permission to go through papers and the glovebox in a customer's car to look for previous service information. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 65

Technician A says if a car appears normal inside the passenger compartment and the exterior looks good, it is probably in good mechanical condition. Technician B says a car can appear fine but have hidden damage. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 66

Which of the following are also names for a repair order?

A) Service order
B) Repair order
C) Service record
D) All of the above

Question 67

Which of the following are not generally found on the RO?

A) Car color
B) VIN
C) The "3 C's"
D) Vehicle mileage

Question 68

Technician A says all vehicles with possible engine-related problems should be test-driven. Technician B says to obtain the best possible diagnosis, the vehicle may have to be driven with the customer along. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 69

When communicating with a customer, avoid technical terms and try to use ____________________.

Question 70

The 3 C's stand for ____________________, ____________________, and ____________________.

Question 71

Technician A says the RO is a legal document between the shop and the customer. Technician B says the RO should be well written, clean, and legible. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 72

A ____________________ is a legal document that describes the customer's complaint, cause, and correction.

Question 73

A ____________________ with flight recorder functions may be useful during a test drive.

Question 74

Clear communication is the responsibility of:

A) The technician
B) The service writer
C) The customer
D) All of the above

Question 75

____________________ smoke may provide clues about engine condition.

Question 76

A vehicle with a ____________________ or ____________________ title may have preexisting damage.

Question 77

Blue exhaust smoke is noted from a vehicle when the engine is running. Technician A says this could indicate a serious engine problem. Technician B says a small amount of blue smoke when the engine starts is normal. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 78

The technician, ____________________ , and the ____________________ , may need to work together to solve a problem.

Question 79

Who is responsible for completing the "cause" and "correction" sections of the RO?

A) The service writer
B) The customer
C) The technician
D) None of the above

Question 80

The first step in diagnosing a problem is to _____________.