© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only 1. Remove Engine Heat  Combustion can reach 4500ºF (2500ºC), hot enough to melt metal parts  Engine heat is used to warm the passenger compartment and defrost windows. 2. Heater Operation

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only 3. Maintain Operating Temperature  180ºF to 210ºF (80ºC to 100ºC)  Ensures correct clearances, proper combustion, minimum emissions and maximum performance 4. Reach Operating Temperature Quickly  This minimizes; poor combustion, part wear, oil contamination, reduced fuel economy, increased emissions

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Air cooling  Liquid cooling

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Air Cooling Systems  Large cylinder cooling fins and outside air remove excess heat

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Liquid Cooling Systems  Circulate coolant through the water jackets  Combustion heat is transferred to the coolant

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  The water pump forces coolant through the engine water jackets

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Conventional Coolant Flow  Hot coolant flows from the cylinder head to the radiator  After being cooled in the radiator, the coolant flows back into the engine block how cooling system works animation

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Components:  water pump  radiator hoses  radiator  fan  thermostat

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Water Pump A ribbed belt powers this pump Crank pulley Water pump pulley Impeller Ribbed belt

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Impeller Pump Coolant is thrown outward by centrifugal force, producing suction in the center of the pump housing

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Hoses  Radiator hoses  carry coolant between the engine water jackets and the radiator  lower hose is exposed to water pump suction, so a spring may be needed to prevent collapse  Heater hoses  carry hot coolant to the heater core  smaller diameter than radiator hoses

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Radiator and Heater Hoses

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Radiator Hoses Two basic types of radiator hoses

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Radiator Transfers coolant heat to the outside air

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Radiator Cap  Seals the radiator  Pressurizes the system  Relieves excess pressure  Allows coolant flow between the radiator and the coolant reservoir

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Radiator Cap  Normally, water boils at 212ºF (100ºC)  Typical pressure: 12–16 psi

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Thermostat  Senses the coolant temperature and controls coolant flow through the radiator  Reduces coolant flow in a cold engine  Increases coolant flow in a hot engine

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Thermostat A temperature-sensitive valve

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Thermostat Operation  Cold engine  wax-filled pellet has contracted  spring holds valve closed  Hot engine  when heated, pellet expands  spring tension is overcome  valve opens

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Cold Engine Operation  The thermostat is closed  The coolant circulates inside the engine  The engine warms quickly

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Hot Engine Operation  At operating temperature, the thermostat opens  Heated coolant then flows through the radiator  Excess heat is transferred from the coolant to the air flowing through the radiator

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Temperature Warning Light  When the coolant becomes too hot, a temperature sending unit (switch) in the block closes, completing a light circuit  Warning light glows

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Composed of ethylene glycol mixed with water  Prevents winter freeze up  Prevents rust and corrosion  Lubricates the water pump  Cools the engine

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Corrosion Protection Protected with antifreeze Water only

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Antifreeze/Water Mixture Lowers the coolant freezing point to about –34 ºF (–37 ºC)

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Aids engine starting in cold weather  120-volt heating element mounted in the block water jacket  Common on diesel engines

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Block Heater Installation

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only The End