AUT 236 Mid Term
101. True/False-Heat transfer gets through conduction and convection.
False (also radiation)
45. True/False-The cooling system should never be pressurized beyond the rating on the cap.
True
46. True/False-Heat Transfer. Molecular motion is transmitted to the molecules that have less motion.
True
47. True/False-Heat flow from matter that at a higher temperature to matter a low temperature.
True
48. True/False-Heat never flows from low temperature matter to high temperature matter.
True
50. True/False-Excessive engine heat is a product of combustion.
True
56. True/False-In evaporation, heat is loss.
True
58. A vehicle comes into your shop that has an overheating problem. There are no leaks, either internal or external, the belts are in good condition and the rater has been removed and flow tested. Everything appears to be in good condition. A new thermostat was installed by didn't cure the problem. True or False-The impeller on the water pump could be slipping on the water pump shaft.
True
59. Same scenario as 58. True/False-The impeller blade could be corroded.
True
6. True/False-Air conditioning is the process of controlling the passenger compartment comfort level.
True
64. True/False-Cooling system pressure is regulated by the radiator cap.
True
65. True/False-If a thermostat fails in the open position, it will take long than normal to warmup.
True
66. True/False-If a thermostat fails in the open position, it will have poor heater performance.
True
67. True/False- If a thermostat fails in the open position, it will have erratic computer control.
True
7. True/False-Fluid circulates through the air conditioning system is refer to generically as refrigerant.
True
70. True/False-Sensible heat can be measured.
True
71. True/False-Specific heat is the amount heat to change a substance by 1 degree Fahrenheit.
True
73. A vehicle is in for repair has a burst upper radiator tank. True/False-The thermostat was struck in the open position. Could this be the cause? False. Could a bad radiator cap?
True
75. True/False-If you have no signs of linking, the water pump should be replaced immediately.
True
8. True/False-Heat transfer is accomplished by two pressure and two temperature systems.
True
80. True/False-High thermostat heat ranges are used in modern vehicles to reduce exhaust emissions.
True
32. Can we use the coolant system pressure to check for the operation of the relief valve in the radiator cap?
Yes
88. True/False-Poor passenger heating performance could be thermostat struck in the closed position.
False
27. What is the typical rating of the pressure cap on a vehicle?
15 or 16 pounds
76. When must a thermostat be fully open?
20 degrees after it rating
69. For every pound of pressure you put on a cooling system, you raise the temperature how many degrees?
3 F
115. What the proper mixture of antifreeze and water?
50/50
20. What is the accepted comfort range for the human body?
70 to 80 degree F
93. Heat transferring through convection is moving through what kind of substance?
Air
72. Testing a rated pressure cap. If we put pressure on it, how long should it hold that pressure?
At least one minute
55. The water pump is a unique kind of pump. It moves fluid but it doesn't increase the pressure. What kind of design is that?
Centripetal Force
1. True/False-The compressor is the low side of the system.
False
105. True/False-When the air conditioning is operating, inside the evaporator, we see vapor turn to liquid.
False
111. True/False-Ethylene glycol and water mixture lowers the boiling point of the coolant.
False
114. True/False-Humidity refers to the amount of heat in the air.
False
2. True/False-The engine coolant system is design to remove about 80% of the total engine heat.
False
24. True/False-Cooling system keeps the engine from reaching a operating temperature too quickly.
False
30.True/False-Ozone at ground level protect life from danger alt ultraviolet radiation.
False
39. True/False-A thermostat should be removed from a cooling system only if the engine is overheating.
False
43. True/False-Water pump failure can never be cause by a bend fan blade.
False
49. True/False-Some molecules give up some their energy to other molecules that have more energy.
False
51. True/False-The average automobile engine is only about 15% efficient.
False
57. True/False-The rate of evaporation (how quickly water is loss) is not affected by air movement.
False
63. True/False-Cooling system pressure is regulated by a pressure release valve in the water pump.
False
68. True/False-If a thermostat fails in the open position, it will have a loss of coolant.
False
74. A vehicle come into the shop and has a very noisy water pump but it's not linking fluid. True/False-The owner could continue to drive the vehicle if there is no sign of fluid linking.
False
77. True/False-Overcooling seldom involves problems other than the delivery of slow heat to the passenger compartment.
False
78. True/False-When pressure test a cooling system, a pressure of at least 25 psi should be develop to pinpoint links.
False
79. True/False-Air cooling system circulates fresh air through the internal engine passages to carry away heat.
False
53. A device with two hose connection with cooling fins and plates, what is it?
Heater core
13. Latent heat is known as what type of heat?
Hidden heat
62. Compressor changes low pressure vapor to what state?
High pressure gas (vapor)
60. What tools can be used to test the operation thermostat without removing it from the engine?
IR detector
26. What is the compressor job?
Increase the pressure on the system
123. Refrigerant comes into the compressor in what state?
Low pressure
122. Could the line that feed the coolant be the cause of coolant loss?
No
127. Is the heat sensing switch to control the electric cooling fans located on the heat core?
No
18. True/False-Is it ok to use a lower than standard temperature thermostat in a vehicle?
No
37. Could a defective radiator cap cause overcooling?
No
94. The sun heats the earth by what process?
Radiation
89. A vehicle comes in your shop and the problem is that the engine overheats during long periods of idling but runs normal during highway speeds. The likely problem is what?
Something wrong with the fan
19. What is the layer of the ozone layer that is 7-30 miles above the earth's surface?
Stratosphere
14. What kind of heat do we add to a vapor to cause that vapor to become warmer?
Superheat
54. A hose that is an inch and a half in diameter. What is it measured from?
The inside of the hose
52. The petcock valve is located where?
The lowest point in the radiator
12. Which one of the hose on the automotive cooling system is usually subjected to the roughest service life?
The upper radiator hose
5. Vehicle is driven for about 10 to 15 miles and the heater continues to blow cold air. What is the most likely the problem? What is the next likely problem?
Thermostat. Heater core
35. What device controls an electric coolant fan?
Thermostatic switch
95. What is the most common cause of freeze plug failure that cause the coolant to leak into the belt.
They corrode (rust)
25. When the thermostat is closed, the engine is warming up. Where does the coolant go?
Through the bypass passage
10. True/False-Pressure/Temperature change can cause a change in state.
True
100. True/False-Must of the heat generated by the engine leave through the engine exhaust system.
True
102. True/False-When the two systems operate all the following will happen inside the evaporator: the refrigerant will remove all of the heat from the outside air.
True
103. True/False-Heat entering the refrigerant will cause a change in its state.
True
104. True/False-The refrigerant absorbs heat.
True
106. True/False-Ethylene glycol and water mixture lowers the freezing point of the coolant.
True
107. True/False-Ethylene glycol and water mixture lowers the boiling point of the coolant.
True
108. True/False-Ethylene glycol and water mixture can provide lubricant to the water pump.
True
109. True/False-Ethylene glycol and water mixture can inhibit rust and corrosion.
True
11. True/False-Convention is the process of heat moving to cold.
True
110. True/False-Ethylene glycol and water mixture can lower the freezing point of the temperature.
True
113. True/False-The heat required to change water into steam is called latent heat.
True
117. True/False-The thermostat is usually located at the engine coolant outlet.
True
15. True/False-Electric cooling fans may turn on even while the engine is not running?
True
16. True/False-Can the extended life coolant be rated to last an excess of 100,000 miles?
True
17. True/False-Extended life coolant and standard life coolant are ethylene glycol based?
True
21. True/False-Cooling systems provide a means of warming the passenger compartment.
True
22. True/False-Cooling systems work to remove engine heat.
True
23. True/False-Cooling systems maintain a proper engine operating temperature.
True
28. True/False-Serpentine belts made of EPDN rubber resist cracking and instead exhibit wear to the belt ridge similar to tire wear and which a depth gauge should be used to assess the wear of the belt.
True
29. True/False-Neoprene serpentine belt ages and wears and cracks will formed in the belt ribs and if there are more than three cracks in a 3 inches span the belt should be replaced.
True
3. True/False-Thermostats open and closed gradually as the temperature of the coolant increases or decrease.
True
31. True/False-Coolant system pressure testers are used to test for leaks in the radiator, hoses, water pump, thermostat and engine assembly.
True
33. True/False-A defective radiation cap vacuum valve made cause hoses to collapse.
True
34. True/False-A defective pressure valve made cause coolant to boil over and end up with coolant loss.
True
36. True/False-We should always follow original equipment specifications for rating pressure cap ratings.
True
38. True/False-Primary purpose of a thermostat is to cause the engine to warm up as soon as possible.
True
4. True/False-The most common cooling system problems is the result of leaks.
True
40. True/False-The water pump on many late model vehicles or driven by the engine's timing belt or timing chain.
True
41. True/False-Coolant to pump water pump leaks are often caused by worn bearings.
True
42. True/False-If the cooling fan can be moved up or down, the water pump will likely need replacement.
True
44. True/False-Cooling system must be full for a pressure test or be effective.
True
81. During a routine fluid inspection, the radiator is found to be low on coolant but the recovery tank was at the proper level. True/False-A faulty radiator cap could be the cause?
True
82. Same scenario of 81. True/False-A cracked radiator tank could also be the cause?
True
83. A vehicle has an engine that is overcooling. True/False-Missing thermostat could be the cause of this problem.
True
84. True/False-A thermostat struck open could be the cause of overcooling problem?
True
85. True/False-Poor passenger heating performance could be caused by an air pocket in the heater core.
True
86. True/False-Poor passenger heating performance could be heater control valve could be struck in the open position.
True
87. True/False-Poor passenger heating performance could be a restriction in the heater core.
True
9. True/False-Whenever there is a pressure change, then is a temperature change.
True
90. True/False-The evaporator is a heat exchanger.
True
91. True/False-The condenser is a heat exchanger.
True
92. True/False-Sensible heat can be measured with a thermometer.
True
96. True/False-The air conditioning system is designed to remove heat from the passenger compartment.
True
97. True/False-The air conditioning system is designed to transfer heat to the outside air
True
98. True/False-Engine heat is transferred to the coolant.
True
99. True/False-Coolant heat is transferred to the ambient air.
True
116. True/False-The radiator outlet is connected to the water pump inlet by a rubber hose.
True (the lower hose)
61. True/False-The following items can cause symptoms of overcooling even though the engine temperature is normal: defective thermostat (True), a missing thermostat (True), defective temperature sending unit (False)
True, True & False
118. True/False-There are dividing lines between the high and low side pressure in the air conditioning system. Two components divide the high and low. What are those two?
True; Orifice Tube and the compressor
112. Can we lose heat by the process of evaporator in the human body?
Yes
119. Could a linking head gasket be the cause of coolant loss?
Yes
120. Could a faulty pressure cap be the cause of coolant loss?
Yes
121. Could a transmission cooler be the cause of coolant loss?
Yes
124. Is the heat sensing switch to control the electric cooling fans located on the radiator?
Yes
125. Is the heat sensing switch to control the electric cooling fans located on the engine block?
Yes
126. Is the heat sensing switch to control the electric cooling fans located on the thermostat housing?
Yes
