2003 DAEWOO MATIZ Service Repair Manual

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 82
C (180
F) and is
fully open at 95
C (203
F). The thermostat closes at
80
C (176
F).
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

1D–4 ENGINE COOLING
DAEWOO M-150 BL2
The main fan size is 320 mm (12.6 in.) in diameter with
seven blades(k) to aid the air flow through the radiator
and the condenser. An electric motor(l) attached to the
radiator support drives the fan.
A/C OFF or Non-A/C Model
The cooling fan is actuated by the electronic control
module (ECM) using a low speed cooling fan relay
and a high speed cooling fan relay. On A/C equipped
vehicles, a series/parallel cooling fan relay is also
used.
The ECM will turn the cooling fan on at low speed
when the coolant temperature reaches 93
C (199
F)
and high speed at 100
C (212
F).
The ECM will change the cooling fan from high speed
to low speed at 97
C (207
F) and turn the cooling
fans off at 90
C (194
F).
A/C ON
The ECM will only turn the cooling fan on at high
speed when the A/C system is on regardless of any
condition.
ENGINE COOLANT TEMPERATURE
SENSOR
The engine coolant temperature (ECT) sensor (n) uses
a thermistor to control the signal voltage to the engine
control module (ECM).
D102D004
COOLANT TEMPERATURE SENSOR
The coolant temperature sensor(m) controls the instru-
ment panel temperature indicator. The coolant tempera-
ture sensor is located on the distributor case with the
ECT sensor on an SOHC engine.

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

1D–6 ENGINE COOLING
DAEWOO M-150 BL2
RADIATOR/FAN
D12D4021
1 Radiator Assembly2 Electric Cooling Fan Assembly

ENGINE COOLING 1D–7
DAEWOO M-150 BL2
DIAGNOSTIC INFORMATION AND PROCEDURE
COOLANT LEAKS TEST
1. Remove the surge tank cap after the engine cools.
2. Check the coolant level.
3. Install a suitable cooling system pressure tester(b) to
the surge tank filler neck using the adapter(a) and
pressurize (110–120 kPa (16.0–17.4 psi)).
4. Check the coolant leaks on the hoses and connec-
tions during 2 minutes.
5. If the leak is checked, replace the parts or repair the
connections.
D102D301
SURGE TANK CAP TEST
The surge tank cap(c) is equipped with the pressure
valve(d) and the vacuum valve(e). Therefore, the surge
tank cap maintains proper pressure. And The surge tank
cap protects the system from high-pressure by opening
a pressure valve, and protects the coolant hoses from
collapsing because of a vacuum.
1. Wash any sludge from the surge tank cap and the
valve seat of the vacuum pressure valve for the surge
tank cap.
2. Check for any damage or deformity to the vacuum
pressure valve for the surge tank cap. If any damage
or deformity is found, replace the cap.
3. Install a suitable cooling system pressure tester(b) to
the cap using the Adapter(a).
4. Pull the vacuum pressure valve to the open position.
If the surge tank cap does not seal properly, replace
the surge tank cap.
5. Pressurize the cap to 90 to 120kPa (13 to 17psi).
6. Wait 10 seconds and check the pressure held by the
tank cap tester.
7. If the pressure held by the cooling system pressure
tester falls below 80kPa (11.6psi) replace the surge
tank cap.
D102D302
THERMOSTAT TEST
1. Remove the thermostat(f) from the vehicle. Refer
to“Thermostat” in this section.
2. Make sure the valve spring is tight when the thermo-
stat is fully closed. If the spring is not tight, replace the
thermostat.
3. Suspend the thermostat and a thermometer in a pan
of 50/50mixture of ethylene glycol and water. Do not
let the thermostat or the thermometer rest on the bot-
tom of the pan because the uneven concentration of
heat on the bottom could result in inaccurate temper-
ature measurements.
4. Heat the pan on a burner.
5. Use the thermometer to measure the temperature of
the heated solution.
6. The thermostat should begin to open at 82°C (180°F)
and it should be fully open at 95°C (203.4°F) and it
should be fully close at 80°C (176.4°F). If it does not
open or close at these temperature, replace the ther-
mostat. Also, the thermostat rod’s stroke from the ini-
tially open to the fully open should be 8mm (0.31 in.).
D102D303

1D–8 ENGINE COOLING
DAEWOO M-150 BL2
COOLING SYSTEM DIAGNOSIS
Condition Probable Cause Correction
Engine OverheatsA loss of the coolant.Add the coolant.
A weak coolant solution.Confirm that the coolant solution is a
50/50 mixture of ethylene glycol and
water.
Any dirt, any leaves, or any insects
on the front of the radiator.Clean the front of the radiator.
The leakage from the hoses, the
coolant pump, the heater, the
thermostat housing, the radiator, the
heater core, or the head gasket.Replace any damaged components.
A faulty thermostat.Replace a damaged thermostat.
Retarded ignition timing.Perform an ECM code diagnosis.
Confirm the integrity of the timing
belt.
An improperly operating electric
cooling fan.Replace the electric cooling fan.
Plugged or rotted radiator hoses.Replace any damaged radiator
hoses.
A faulty water pump.Replace a faulty water pump.
A faulty surge tank cap.Replace a faulty surge tank cap.
A cracked or plugged cylinder head
or engine block.Repair the damaged cylinder head or
the damaged engine block.
A faulty radiator.Replace a faulty radiator.
Loss of CoolantA leak in the radiator.Replace a damaged radiator.
A leak in the surge tank or the hose.Replace the surge tank or the hose.
Looseness or damage of radiator
hoses, heater hoses, or connections.Reseat the hoses.
Replace the hoses or the clamps.
Leaks in the coolant pump seal.Replace the coolant pump seal.
Leaks in the coolant pump gasket.Replace the coolant pump gasket.
An improper cylinder head torque.Tighten the cylinder head bolts to
specifications.
Replace the cylinder head gasket, if
needed.
Leaks in the intake manifold, cylinder
head gasket, heater core.Repair or replace any components,
as needed to correct the leak.
Engine Fails to Reach
Normal OperatingThermostat to be stuck open or to be
wrong type.Install a new thermostat of the
correct type and heat range.
Temperature or Cool Air
from the HeaterThe coolant level below the MIN
mark on the surge tank.Add sufficient coolant to raise the
fluid to the specified mark on the
surge tank.

ENGINE COOLING 1D–9
DAEWOO M-150 BL2
REPAIR INSTRUCTIONS
ON–VEHICLE SERVICE
D12D5011
DRAINING AND REFILLING THE
COOLING SYSTEM
Caution: Do not remove the surge tank cap while
the engine and the radiator are hot. Scalding fluid
and steam may be blown out under pressure.
1. Place a pan below the vehicle to catch the draining
coolant.
2. Drain the coolant.
Remove the surge tank cap (1).
Disconnect the lower radiator hose (2).
Caution: Dispose of the used coolant to a used
coolant holding tank to be picked up with the used
oil for disposal. Never pour the used coolant down
the drain. Ethylene glycol antifreeze is an extremely
toxic chemical. Disposing of it into the sewer sys-
tem or the ground water can contaminate the local
environment.
D102D502
3. Connect the lower radiator hose.
4. Clean the cooling system.
Remove all sludge and dirt from inside the surge
tank. And install the surge tank. Refer to “Surge
Tank” in this section (1).

1D–10 ENGINE COOLING
DAEWOO M-150 BL2
D102D503
Add the clean water to the surge tank (2).
5. Run the engine until the thermostat opens. You can
tell the thermostat is open when both radiator hoses
are hot to the touch.
6. Stop the engine and disconnect the lower radiator
hose to drain the coolant.
7. Repeat steps 3 through 6 until the drained water is
clear and free of coolant and rust.
Notice: Never use an antifreeze mixture more concen-
trated than 60 percent antifreeze to 40 percent water.
The solution freezing point increases above this con-
centration.
8. Fill the cooling system through the surge tank with a
mixture of ethylene glycol antifreeze and water. The
mixture must be at least 50 percent antifreeze, but
not more than 60 percent antifreeze for cold weather
operation.
9. Fill the surge tank to the specified MAX fill mark on
the outside of the tank.
10. Install the surge tank cap.
D102D504
SURGE TANK
Removal Procedure
Caution: To prevent personal injury, do not remove
the surge tank cap while the engine and the radiator
are hot, because the heat causes the system to re-
main under pressure scalding fluid and steam may
be blown out under pressure.
1. Drain the engine coolant to below the level of the
surge tank.
2. Remove the surge tank.
Loosen the overflow hose clamps and disconnect
the overflow hoses from the surge tank (1).
Remove the surge tank (2).
3. Clean the inside and the outside of the surge tank and
the surge tank cap with soap and water.
4. Rinse the surge tank and the cap thoroughly.
5. Check the surge tank and the cap for crack or other
damage.