Because combustion takes place in an automobile engine, coolants are needed to avoid overheating. But for the coolants to circulate all around the engine some process are involve so that excess cooling will not occur. An automobile engine needs to be at normal temperature, excess cooling would cause under cooling to the engine. The heat produce during the combustion process could cause serious destruction to the part of the engine, burn excess fuel, drain oil and even breakdowns the engine.
The followings listed below are components of automobile engine that plays important role in the cooling system. They are:

  • Radiator
  • Fan
  • Water Pump
  • Thermostat
  • Coolant Reservoir
  • Heater Core

How automobile cooling system works

When an engine is started, the water pump begins to pump the coolants all around the engine cylinder from the lower radiator tank to the into the coolants passages. The coolants flows from the lower tank to the engine block, then to the cylinder head and finally towards the outlet of the radiator.
The coolants begins to absorb the heat produce during the combustion process and flows towards the radiator inlet.

The thermostat play an important part here. It function is to restrict the coolant to flow towards the radiator until the temperature of the coolant is not raised above the engine operating temperature. At this instant, if the heater inside the cobin is turn on, the coolant is made to flow through the heater core via the bypass holes. The heater core serve as the mini radiator which is use to transfer the heat from the coolant to the air that flows inside the passenger compartment.

The thermostat on the other end, acts as a regulating valve to control the coolant flow into the radiator and maintain the engine temperature within optimum range. The thermostat consist of a chamber filled with wax and rod which is pressed against it. When the coolant pressing through the thermostat is at higher temperature (usually 180f), the wax begins to melt. The melting causes thermal expansion of the wax, which in turn pushes the rod and thereby allowing the coolant to flow outside.

The coolant pass through the thermostat valve and enters into the radiator upper tank through the upper radiator hose. Due to the high temperature of the coolant. There are changes of building up of high that might block the coolant from entering into the upper tank. But to avoid this, the upper tank is provided with a pressure regulating valve, which open when the system increases beyond the recommended valve. This process continues as long as the engine is working