heater DAEWOO MATIZ 2003 Service Repair Manual
[x] Cancel search | Manufacturer: DAEWOO, Model Year: 2003, Model line: MATIZ, Model: DAEWOO MATIZ 2003Pages: 1184, PDF Size: 36 MB
Page 40 of 1184

1D – 2 ENGINE COOLING
DAEWOO M-150 BL2
DESCRIPTION AND OPERATION
GENERAL DESCRIPTION
The cooling system maintains the engine temperature at
an efficient level during all engine operating conditions.
When the engine is cold the cooling system cools the
engine slowly or not at all. This slow cooling of the en-
gine allows the engine to warm up quickly.
The cooling system includes a radiator(a) and cooling
fan(b), a thermostat and housing(c), a coolant pump(d),
a coolant pump drive belt and coolant hose. The timing
belt drives the coolant pump.
All components must function properly in order for the
cooling system to operate. The coolant pump draws the
coolant from the radiator. The coolant then circulates
through water jackets in the engine block and the cylin-
der head, distributor case(e), throttle body(f). When the
coolant reaches the operating temperature of the ther-
mostat, the thermostat opens. The coolant then goes
back to the radiator where it cools.
This system directs some coolant through the hoses to
the heater core(g). This provides for heating and de-
frosting. The surge tank(h) is connected to the radiator
and throttle body to recover the coolant displaced by ex-
pansion from the high temperatures. The surge tank
maintains the correct coolant level.
The cooling system for this vehicle has no radiator cap
and drain cock. The coolant is added to the cooling sys-tem through the surge tank. To drain the cooling system,
disconnect the lower radiator hose and drain the cool-
ant.
RADIATOR
This vehicle has a lightweight tube-and-fin aluminum ra-
diator.
SURGE TANK
The surge tank is a transparent plastic reservoir, similar
to the windshield washer reservoir.
The surge tank is connected to the radiator and throttle
body by a hose. As the vehicle is driven, the engine cool-
ant heats and expands. The portion of the engine cool-
ant displaced by this expansion flows from the radiator
into the surge tank. The air trapped in the radiator is de-
gassed into the surge tank.
When the engine is stops, the engine coolant cools and
contracts. The displaced engine coolant is then drawn
back into the radiator. This keeps the radiator filled with
the coolant to the desired level at all times and increases
the cooling efficiency.
Maintain the coolant level between the MIN and the
MAX marks on the surge tank when the system is cold.
D102D001
Page 41 of 1184

ENGINE COOLING 1D–3
DAEWOO M-150 BL2
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 82C (180F) and is
fully open at 95C (203F). The thermostat closes at
80C (176F).
D102D002
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.
D102D003
Page 43 of 1184

ENGINE COOLING 1D–5
DAEWOO M-150 BL2
COMPONENT LOCATOR
COOLANT HOSE AND COMPONENTS
D12D4011
1 Radiator Coolant Return Hose
2 Upper Radiator Hose
3 Not Used
4 Radiator Assembly
5 Lower Radiator Hose
6 Throttle Body Assembly
7 Surge Tank hose
8 Surge Tank
9 Coolant Temperature Sensor
10 Engine Coolant Temperature Sensor11 Surge Tank Return Hose
12 Water Inlet Cap
13 Heater Outlet Hose
14 Heater Inlet Hose
15 Distributor Case
16 Thermostat
17 Thermostat Housing
18 Throttle Body Inlet Hose
19 Throttle Body Outlet Hose
20 Hose Bracket