Chapter 11
What mixture concentricity of PROPYLENE glycol to water provides maximum antifreeze protection? A. 100% B. 60% C. 30% D. 20%
100%
What mixture concentricity of ETHYLENE glycol to water provides maximum antifreeze protection? A. 100% B. 60% C. 30% D. 20%
60%
When a diesel engine is operating at maximum efficiency, what percentage of the heat energy of the fuel is discharged as rejected heat? A. 20% B. 40% C. 60% D. 80%
60%
When water freezes, how much does it expand in volume? A. 2% B. 5% C. 9% D. 18%
9%
Which of the following pH readings taken in engine coolant fall in the normal range? A. 3.5 B. 6.0 C. 9.0 D. 13.5
9.0
Which of the following could be handled by data bus communications in a current diesel engine cooling system? A. thermostat opening B. A/C to fan-engage command C. coolant flow through heater core D. shutter cycling
A/C to fan-engage command
Technician A says that downflow radiators use a double pass flow principle. Technician B says that a counterflow radiator uses double pass flow routing. Who is correct?
B only
Technician A says that the first step to take when troubleshooting an engine overheating conditioning is to remove the radiator shroud to permit unimpeded air flow through the engine compartment. Technician B says that an engine overheat condition could be caused by a missing or damaged radiator shroud. Who is correct?
B only
What should always be used to adjust fan belts? A. Torque wrench B. Fish wight scale C. Belt dressing spray D. Belt tension guage
Belt tension guage
What causes wet liner cavitation? A. engine overheating B. Engine lugdown C. Bubble collapse D. air in coolant
Bubble collapse
When rebuilding a diesel engine water pump, which of the following components has to be handled with a great amount of care? A. Steel impellers B. Plastic impellers C. drive pulley D. ceramic seal
Ceramic seal
When the heat of combustion is transmitted through a diesel engine block, the principle is known as: A. conduction B. COnvection C. radiation D. evaporation
Conduction
When heat is transferred by currents in fluids, the principle is known as: A. Conduction B. Convection C. Radiation D. Evaporation
Convection
Which type of radiator uses a double pass principle? A. downflow B. Crossflow C. Counterflow D. Upflow
Counterflow
Which OTF coolants boasts the longest service life? A. Alcohol based coolant B. EG C. ELC D. PG
ELC
What is the pumping member of a diesel engine water pump rotor known as? A. Propeller B. Impeller C. Turbo D. Gearotor
Impeller
What device is used to signal engine coolant temperatures on most current diesel engines? A. PTC thermistor B. NTC thermistor C. Expansion tube D. Bimetal electric sensor
NTC thermistor
Which of the following is NOT true of an extended life coolant (ELC)? A. no inhibitor testing required B. lasts for up to six years C. improves cavitation protection D. never has to be inspected
Never has to be inspected
How does waterless engine coolant (WEC) protect against liner cavitation erosion? A. oxyalate additives B. provides vastly superior ani-boil properties C. boil at lower temperatures than EG D. gels on liner wall
Provides vastly superior anti-boil properties
When truck radiator hoses collapse internally as an engine cools, which of the following components should be checked out first? A. water pump B. Radiator cap D. fanstat
Radiator cap
In an older truck cooling system using radiator shutters, what would happen if the air supply to the shutterstat failed? A. engine overheat B. Shutters remain closed C. Shutters remain open D. Shutters rapidly cycle
Shutters remain open
Which type of thermally managed fan has no external controls? A. thermatic viscous drive B. electrically engagaed C. fanstat controlled D. electric over pneumatic
Thermatic viscous drive
When considering coolant cavitation erosion, what is a vapor bubble composed of? A. Air B. Vaporized coolent C. blow-by gas D. Vaporized engine lube
Vaporized coolant
Which OTF does NOT act as a heat exchanger? A. Radiator B. Oil cooler C. water manifold D. air conditioning
Water Manifold
