Deck 21: Cooling System Operation and Diagnosis

Question 1

The upper radiator hose collapses when the engine cools. What is the most likely cause?

A)A defective pressure cap
B)A defective upper radiator hose
C)A defective thermostat
D)The spring is missing from the upper radiator hose which is used to keep it from collapsing

Answer 1

A defective pressure cap

Question 2

What can be done to prevent air from getting trapped in the cooling system when the coolant is replaced?

A)Pour the coolant into the radiator slowly.
B)Use a coolant exchange machine that draws a vacuum on the system.
C)Open the air bleeder valves while adding coolant.
D)Either B or C

Answer 2

Either B or C

Question 3

Heat transfer is improved from the coolant to the air when the ________.

A)Temperature difference is great
B)Temperature difference is small
C)Coolant is 95% antifreeze
D)Both A and C

Answer 3

Temperature difference is great

Question 4

A water pump is a positive displacement-type pump.

Question 5

Water pumps ________.

A)Use engine oil as a lubricant and coolant
B)Are driven by the engine crankshaft or camshaft
C)Disengage during freezing weather to prevent radiator failure
D)Only work at idle and low speeds and are disengaged at higher speeds

Question 6

What diagnostic trouble code (DTC) could be set if the thermostat is defective?

A)P0440
B)P0171
C)P0128
D)P0300

Question 7

Which statement is TRUE about thermostats?

A)Thermostats often cause overheating
B)The temperature marked on the thermostat is the temperature at which the thermostat should be fully open
C)The temperature marked on the thermostat is a temperature at which the thermostat should start to open.
D)Both A and B

Question 8

Technician A says that the radiator should always be inspected for leaks and proper flow before installing a rebuilt engine. Technician B says that overheating during slow city driving can be caused by a defective electric cooling fan. Who is right?

A)Technician A only
B)Technician B only
C)Both technians A and B
D)Neither technician A nor B

Question 9

A customer complains that the heater works sometimes, but sometimes only cold air comes out while Driving. Technician A says that the water pump is defective. Technician B says that the cooling system could be low on coolant. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 10

The normal operating temperature (coolant temperature) of an engine equipped with a 195°F thermostat is ________.

A)195°F to 215°F
B)175°F to 215°F
C)175°F to 195°F
D)185°F to 205°F

Question 11

Technician A says that the purpose and function of the cooling system is to maintain proper engine operating temperature. Technician B says that the water pump controls engine coolant temperature by opening at its rated opening temperature to allow coolant to flow through the radiator. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 12

Technician A says that cooling fans are designed to draw air through the radiator to aid in the heat transfer process. Technician B says that drawing the heat from the coolant transfers this heat to the outside air through the radiator. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 13

Technician A says that the cooling system should be tested for leaks using a pressure-operated pressure pump. Technician B says that the freezing and boiling point of the coolant can be tested using a thermometer. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 14

Technician A says that the automotive water pump is a positive displacement-type pump. Technician B says that the coolant mix should be a 50/50 split between antifreeze and water. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 15

An automotive engine that running at too high of a temperature will have which of these?

A)High oxides of carbon
B)High thermal inefficiency
C)Excessive oil consumption
D)Poor cooling system circulation

Question 16

The water pump uses which of these reactionary forces actions to circulate the coolant?

A)Centrifugal force
B)Centripetal force
C)Magnetic force
D)Gravitational force

Question 17

Pressurizing the automotive cooling system results in ________.

A)Increased coolant warm up rate
B)Reduced engine temperature
C)Reduced coolant boiling point
D)Increased coolant boiling point

Question 18

If a cooling system operates at too cool of a temperature, the engine will ________.

A)Have more efficiency
B)Produce more torque
C)Pre-ignite or detonate
D)Produce higher emissions

Question 19

Electric cooling fans are typically commanded on and off by the ________.

A)Cooling system delta sensor
B)Powertrain control module (PCM)
C)Thermostat
D)Radiator pressure sensor (RPS)

Question 20

Which one of these areas is the water jacker?

A)A
B)B
C)C
D)D

Question 21

In this drawing of a radiator cap, what is occurring within the cooling system?

A)The system is cooling down
B)The system is overheating
C)Coolant is returning to the radiator
D)Both A and C

Question 22

The use of a coolant recovery machine is helpful in preventing ________ from entering the cooling system.

A)Hose residue
B)Oil
C)Excessive vibrations
D)Air

Question 23

A 5 ribbed serpentine belt should be tensioned at about ________.

A)150 lbs.
B)75 to 100 lbs.
C)45 to 60 lbs.
D)None of these

Question 24

For every one PSI increase in cooling system pressure, the coolant's boiling point is raised how many degrees F?

A)One
B)Two
C)Five
D)Three