Coolant Pump; Thermostat; Electric Cooling Fan - Daewoo MATIZ Service Manual

COOLANT PUMP

The belt-driven centrifugal coolant pump consists of an
impeller, a drive shaft, and a belt pulley.
The impeller is supported by a completely sealed bear-
ing.
The coolant pump is serviced as an assembly and,
therefore, cannot be disassembled.

THERMOSTAT

A wax pellet-type thermostat controls the flow of the en-
gine coolant through the engine cooling system. The
thermostat(i) is mounted in the thermostat housing.
The thermostat stops the flow of the engine coolant from
the engine to the radiator in order to provide faster
warm-up, and to regulate the coolant temperature. The
thermostat remains closed while the engine coolant is
cold, preventing circulation of the engine coolant
through the radiator. At this point, the engine coolant is
allowed to circulate only throughout the heater core to
warm it quickly and evenly.
As the engine warms, the thermostat opens. This allows
the engine coolant to flow through the radiator, where
the heat is dissipated through the radiator. This opening
and closing of the thermostat permits enough engine
coolant to enter the radiator to keep the engine within
proper engine temperature operating limits.
The wax pellet in the thermostat is hermetically sealed in
a metal case(j). The wax element of the thermostat ex-
pands when it is heated and contracts when it is cooled.
As the vehicle is driven and the engine warms, the en-
gine coolant temperature increases. When the engine
coolant reaches a specified temperature, the wax pellet
element in the thermostat expands and exerts pressure
against the metal case, forcing the valve open. This al-
lows the engine coolant to flow through the engine cool-
ing system and cool the engine.
As the wax pellet cools, the contraction allows a spring
to close the valve.
The thermostat begins to open at 82_C (180_F) and is
fully open at 95_C (203_F). The thermostat closes at
80_C (176_F).
DAEWOO M-150 BL2
ENGINE COOLING 1D – 3

ELECTRIC COOLING FAN

Caution: Keep hands, tools, and clothing away from
the engine cooling fans to help prevent personal in-
jury. This fan is electric and can turn ON whether or
not the engine is running.
Caution: If a fan blade is bent or damaged in any
way, no attempt should be made to repair or reuse
the damaged part. A bent or damaged fan assembly
should always be replaced with a new one.
The cooling fans are mounted behind the radiator in the
engine compartment. The electric cooling fans increase
the flow of air across the radiator fan and across the
condenser on air conditioner (A/C)-equipped vehicles.
This helps to speed cooling when the vehicle is at idle or
moving at low speeds.
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