Hombre XS Space Cab L4-2.2L CPC (1997)
Thermostat: Description and Operation
DESCRIPTION
A pellet type thermostat, in the coolant outlet passage, controls the flow of the engine coolant, in order to provide fast engine warm-up. The
thermostat also regulates the coolant temperature. A wax pellet element in the thermostat expands when heated. The wax pellet contracts when
cooled. The pellet is connected through a piston to a valve.
OPERATION
When the pellet is heated, pressure exerts against a rubber diaphragm to force the valve open. As the pellet cools, the contraction allows a spring
to close the valve. The valve remains closed while the coolant is cold, preventing circulation of coolant through the radiator. The coolant circulates
throughout the engine with the thermostat closed. The engine warms up quickly and evenly. As the engine warms, the pellet expands and the
thermostat valve begins to open. Coolant now flows through the radiator. The thermostat operation permits enough coolant to enter the radiator in
order to keep the engine within the normal operating temperature limits. The thermostat currently used on these models has a nominal rating of 91°
C (190°F).
