Daewoo G424 Gasoline, Service Manual

Page: 114 / 199

G424 Service Manual Cooling System 113
Thermostat
The thermostat is the wax pellet type. A jiggle valve
(which improves air bleeding during water supply) is
provided on the flange part. When the thermostat is
closed, the circulation of coolant is stopped, thereby
making warm-up faster.
Operation
When the temperature of the coolant is low, the valve
is closed by the spring, with the result that the coolant
circulates within the engine, without passing through
the radiator.
When the temperature of the coolant rises and
reaches a certain specified temperature, the valve
opens and the coolant also circulates through the
radiator.
When the temperature increases further and reaches
a certain specified temperature, the valve opens fully,
allowing even more coolant to circulate through the
radiator.
Thus, in this way the degree of valve opening is varied
according to the temperature of the coolant, and the
temperature of the coolant is adjusted by varying the
amount of coolant caused to circulate through the
radiator.
Thermostat Test
To test the thermostat opening temperature, use the
following procedure:
The pan, water and thermostat will be very hot and
can cause burns. Do not touch the pan, water or
thermostat. Handle the components with an
insulated device for protection.
1. Remove the thermostat from the engine.
2. Hang the thermostat in a pan of water. Put a
thermometer in the water. Put the thermostat
completely under water. Do not let the thermostat
make contact with the pan.
3. Put heat to the pan of water. Make the water in the
pan move around. This keeps all of the water at the
same temperature.
4. The thermostat must start to open when the
temperature is 82°C (180°F). The thermostat must
be fully open at 96°C(205°F).
WARNING