Lesson 5/Learning Event 1
ENGINE COOLING SYSTEMS
Describe the principles of engine liquid-cooling systems.
Given information about the fundamentals of liquid-cooling system components, and inspecting, testing, and
repairing representative engine liquid-cooling systems.
Solve 70 percent of the multiple-choice test items covering engine liquid-cooling systems.
Learning Event 1:
DESCRIBE THE PRINCIPLES OF OPERATION AND COMPONENTS OF LIQUID-COOLING
All internal combustion engines have some type of cooling system because of the high temperatures created
during their operation. The heat is produced both by friction and burning of fuel, with the largest amount being
caused by the burning of fuel. There is no sure way of telling just exactly how hot it gets inside the
combustion chamber of an engine, but it is thought to be about twice the temperature at which iron melts.
Therefore, if an engine is not cooled, the valves will burn and warp, lubricating oil will break down, pistons and
The engine cooling system is called upon to carry away about one-third of the heat inside the combustion