During the warm-up period, when coolant temperature is
below 160F, the thermostat blocks the flow of coolant to the
With the thermostat closed, the pump circulates the
As the coolant reaches approximately 160F, the thermostat opens and
the coolant then passes through the radiator for cooling.
The crankcase breather
passage make up the
crankcase ventilation system.
There is a
slight pressure in the
engine crankcase caused by the seepage of a
small amount of the air