automotive service - grafton school district · automotive service 17. the radiator cap _____ valve...
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Automotive Service Modern Auto Tech Study Guide Chapters 39 & 40 Pages 725 767 Cooling Systems 43 Points
Automotive Service 1. The cooling system must control the ____________ temperature of
the engine for low emissions and maximum efficiency. This will also result in the best fuel economy and performance.
Operating Cooling Heating
Automotive Service 2. The coolant operating temperature is normally between 180º and 210º
degrees Fahrenheit.
Automotive Service 3. Engine coolant is circulated through the _______ to warm the
PASSENGER compartment. Heater Core Skater Core Emitter Core
Automotive Service 4. The _______ ________ is a beltdriven, impeller that circulates coolant
through the water JACKETS.
Automotive Service 5. When the coolant is hot enough to cause the ____________ to open it flows
out of the engine and into the radiator where its heat is transferred to the surrounding (ambient) air.
Thermostat Rheostat Hemostat
Automotive Service 6. Air cooling systems are characterized by cooling ________ on the side of the
cylinders as well as shrouds and duct work to direct air flow from a fan through the fins. Convection carries heat to the ambient air.
Bins Fins Tins
Automotive Service 7. Liquid cooling systems offer more precise ___________ of engine operating
temperature with less variation. This reduces exhaust emissions, increases mpg & performance, and improves heater operation.
Cooling Heating Control
Automotive Service 8. The __________ transfers heat from the coolant to the surrounding outside air.
Heater Core Radiator Condenser
Automotive Service 9. The job of the _____ is to draw air through the radiator, especially when the
car isn’t moving forward.
Fan Shroud Cap
Automotive Service 10. Radiator _______ may be molded or flexible & may have an
internal SPRING to prevent collapsing.
Caps Shrouds Hoses
Automotive Service 11. An automatic TRANSMISSION FLUID cooler is located inside of the
radiator side or bottom tank.
Automotive Service 12. Radiators are either DOWNFLOW (vertical) or CROSSFLOW (horizontal) design.
Automotive Service 13. Radiator tanks are made of either __________ or _____________.
Plastic tanks are used exclusively with aluminum core radiators.
Ceramic or Plastic Metal or Plastic Stone or Plastic
Automotive Service 14. The air conditioning ____________may be mounted along side of or
in front of the radiator.
Accumulator Condenser Evaporator
Automotive Service 15. The radiator _____ seals the filler neck, pressurizes the system to raise the
boiling point, relieves excess pressure to protect against system damage, & allows coolant exchange between the recovery reservoir.
Cap Shroud Fan
Automotive Service 16. For every 1# of pressure that a radiator cap holds on a system,
coolant boil point is raised ___ Fº. (technically 3.25°)
200 F° 50 F° 3 F°
Automotive Service 17. The radiator cap _______ valve allows coolant return to the system when the
engine is cooled off. A malfunctioning vacuum valve would cause radiator hoses and possibly tanks to collapse from vacuum.
Vacuum Pressure Relief
Automotive Service 18. The ___________ cooling system utilizes the cap and recovery reservoir
to maintain proper coolant levels in the engine at all times by burping out hot coolant & later siphoning back in cooled off coolant.
Closed Open Ajar
Automotive Service 19. To conserve horsepower, radiator fans have either thermostatic ___________ or
are ________________ operated. Electric fans have the “ontime” of their motors controlled by sensors, relays, and the PCM.
Clutches or are Electrically Clutches or are Mechanically Clutches or are Hydraulically
Automotive Service 20. The radiator _________ acts like a funnel to direct the air through the
area where the fan is situated.
Cover Shroud Cap
Automotive Service 21.The thermostat works with a springloaded, ______ filled pellet that senses
coolant temperature. Most thermostats are set to open between 180 and 195 Fº. (A thermostat is closed when the engine coolant is cold.)
Wax Mercury Plastic
Automotive Service 22. A thermostat __________ valve is used to maintain circulation of the coolant
through the block, heads, heater core when the engine is not yet warm. (A stuckopen thermostat lowers heater output & overcools the engine)
OverPass ByPass UnderPass
Automotive Service 23. Antifreeze is usually a chemical mixture called ETHYLENE GLYCOL, but
propylene glycol mixtures are now becoming popular because they are less toxic. (Dexcool® is orange in color)
Automotive Service
Automotive Service 24. A 50/50 mixture of antifreeze and water will prevent _____________ to at
least 34 degrees, will prevent rust and corrosion , lubricates the water pump and will cool the engine more effectively than water alone since the boiling point of a 50% mixture is 265 degrees Fahrenheit.
Freezing Pressure Relief
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Automotive Service 25. Engine ___________ heaters are used in extremely cold weather to
warm the coolant, the block, and also the oil so that the engine cranks easier. (crankshaft counterweights move easier through a thinner, warmer oil)
Crock Cloak Block
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26. Coolant leaks can be located by performing a cooling system _____________ test.
Pressure Vacuum Flushing
Automotive Service 27. Suspect an engine that is “consuming coolant” with no external leaks of
having an ______ leak like a cracked block, cracked cylinder head, or a blown head gasket.
Internal Pressure Relief
Automotive Service 28. The presence of exhaust gas (HC & CO) above the coolant level in the
radiator can indicate a blown head gasket, a cracked block, or a cracked cylinder head.
Automotive Service 29. When water, antifreeze, and oil mix, the solution turns MILKY WHITE in color.
Automotive Service 30. Stuck ___________ thermostats, slipping belts, and clogged radiators
can cause overheating.
Automotive Service 31. Stuck _______ thermostats, lockedon fan clutches, or shorted fan switches
can cause overcooling.
Automotive Service 32. Some cooling system have a BLEEDER screw to let trapped air escape
when refilling the system.
Automotive Service 33. Coolant should be FLUSHED at regular intervals. Old antifreeze becomes
ACIDIC and can actually generate a chemical source of voltage in the cooling system. Over .5 volts indicates high acidity.
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Automotive Service 34. A coolant _____________ or special coolant test strips are used to measure
coolant freeze point. A more sophisticated tool known as a refractometer can also be used to determine freeze point.
Tachometer Hydrometer Multimeter
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