2004 DAEWOO LACETTI Iat

1.8L DOHC ENGINE MECHANICAL 1C2 – 47
DAEWOO V–121 BL4
19. Disconnect the oxygen (O2) sensor connector, if
equipped.
20. Disconnect the idle air control (IAC) valve connec-
tor.
21. Disconnect the throttle position sensor (TPS) con-
nector.
22. Disconnect the engine coolant temperature sensor
(CTS) connector.
23. Disconnect the CTS connector.
24. Disconnect the generator voltage regulator connec-
tor and power lead.
25. Disconnect all of the necessary vacuum lines, in-
cluding the brake booster vacuum hose.
26. Disconnect the fuel return line at the fuel rail.
27. Disconnect the fuel feed line at the fuel rail.
28. Remove the fuel rail and injector channel cover as
an assembly. Refer to Section 1F, Engine Controls.
29. Disconnect the throttle cable from the throttle body
and the intake manifold bracket.
30. Disconnect the coolant hose at the throttle body.
31. Disconnect the heater outlet hose at the coolant
pipe.
32. Disconnect the coolant bypass hose from the cylin-
der head.
33. Disconnect the surge tank coolant hose from the
coolant pipe.
34. Disconnect the lower radiator hose from the coolant
pipe.
35. Disconnect the starter solenoid ”S” terminal wire
and power lead.
36. Remove the A/C compressor. Refer to Section 7B,
Manual Control Heating, Ventilation, and Air Condi-
tioning Systems.
37. Remove the exhaust flex pipe retaining nuts from
the exhaust manifold studs.
38. Remove the exhaust flex pipe retaining nuts from
the catalytic converter or the connecting pipe.
39. Remove the exhaust flex pipe.

1C2 – 50I1.8L DOHC ENGINE MECHANICAL
DAEWOO V–121 BL4
18. Install the exhaust flex pipe retaining nuts to the
catalytic converter or the connecting pipe.
Tighten
Tighten the exhaust flex pipe–to–catalytic converter
or connecting pipe retaining nuts to 35 NSm (26 lb–ft).
19. Connect the power steering pressure hose.
20. Connect the power steering return hose.
21. Install the A/C compressor, if equipped. Refer to
Section 7B, Manual Control Heating, Ventilation,
and Air Conditioning System.
22. Install the serpentine accessory drive belt. Refer to
Section 6B, Power Steering Pump.
23. Install the right front wheel well splash shield.
24. Install the right front wheel. Refer to Section 2E,
Tires and Wheels.
25. Connect the fuel feed line to the fuel rail.
26. Connect the fuel return line to fuel rail.
27. Install the fuel rail and injector channel cover as an
assembly. Refer to Section 1F, Engine Controls.
28. Connect all of the necessary vacuum lines including
the brake booster vacuum hose.
29. Connect the O2 sensor connector, if equipped.
30. Connect the starter solenoid ”S” terminal wire and
power lead.
31. Connect the generator voltage regulator connector.
32. Connect the CTS connector.
33. Connect the engine CTS connector.
34. Connect the TPS connector.
35. Connect the IAC valve connector.
36. Connect the MAP sensor connector.
37. Connect the knock sensor, if necessary
38. Connect the electrical connector at the DIS ignition
coil and the ECM ground terminal and at the starter
motor.
39. Install the air cleaner outlet hose between the
throttle body and the air cleaner housing.
40. Connect the breather tubes to the camshaft cover.
41. Connect the MAT sensor connector.
42. Install the cooling system radiator and the engine
cooling fans. Refer to Section 1D, Engine Cooling.

1.8L DOHC ENGINE MECHANICAL 1C2 – 51
DAEWOO V–121 BL4
43. Connect the lower radiator hose to the coolant pipe.
44. Connect the upper radiator hose to the thermostat
housing.
45. Connect the heater inlet hose to the cylinder head.
46. Connect the heater outlet hose to the coolant pipe.
47. Connect the coolant surge tank hose to the coolant
pipe.
48. Connect the coolant hose to the throttle body.
49. Connect the throttle cable to the throttle body and
the intake manifold bracket.
50. Install the fuel pump fuse.
51. Connect the negative battery cable.
52. Refill the engine crankcase with engine oil.
53. Refill the engine coolant system. Refer to Section
1D, Engine Cooling.
54. Bleed the power steering system. Refer to Section
6A, Power Steering.
55. Refill the A/C refrigerant system, if equipped. Refer
to Section 7B, Manual Control Heating, Ventilation,
and Air Conditioning System.
56. Install the hood. Refer to Section 9R, Body Front
End.
PISTONS AND RODS
Tools Required
J–8037 Universal Piston Ring Compressor
J–8087 Cylinder Bore Check Gauge
KM–427 Piston Pin Service Set
KM–470–B Angular Torque Gauge
Removal Procedure
1. Remove the cylinder head with the intake manifold
and exhaust manifold attached. Refer to ”Cylinder
Head and Gasket” in this section.
2. Remove the oil pan. Refer to ”Oil Pan” in this sec-
tion.
3. Remove the oil suction pipe bolts and support
bracket bolts.
4. Remove the oil suction pipe.
5. Remove the crankshaft bearing bridge and the oil
pan scraper bolts.
6. Remove the crankshaft bearing bridge and the oil
pan scraper.

SECTION : 1D
ENGINE COOLING
CAUTION : Disconnect the negative battery cable before removing or installing any electrical unit or when a tool
or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cable will help
prevent personal injury and damage to the vehicle. The ignition must also be in LOCK unless otherwise noted.
TABLE OF CONTENTS
SPECIFICATIONS1D–2 . . . . . . . . . . . . . . . . . . . . . . . . . .
Capacity 1D–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fastener Tightening Specifications 1D–2. . . . . . . . . . .
SPECIAL TOOLS1D–2 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Tools Table 1D–2. . . . . . . . . . . . . . . . . . . . . . . .
DIAGNOSIS1D–3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermostat Test 1D–3. . . . . . . . . . . . . . . . . . . . . . . . . . .
Surge Tank Cap Test 1D–3. . . . . . . . . . . . . . . . . . . . . . .
Cooling System Diagnosis 1D–4. . . . . . . . . . . . . . . . . .
COMPONENT LOCATOR1D–5 . . . . . . . . . . . . . . . . . . . .
Radiator/Fan 1D–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Pump/Thermostat (1.4L/1.6L DOHC) 1D–6. . .
Water Pump/Thermostat (1.8L DOHC) 1D–7. . . . . . .
MAINTENANCE AND REPAIR1D–8 . . . . . . . . . . . . . . .
ON–VEHICLE SERVICE 1D–8. . . . . . . . . . . . . . . . . . . . . Draining and Refilling the Cooling System 1D–8. . . . .
Thermostat (1.4L/1.6L DOHC) 1D–9. . . . . . . . . . . . . . .
Thermostat (1.8L DOHC) 1D–10. . . . . . . . . . . . . . . . . .
Water Pump 1D–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electric Cooling Fan – Main or Auxiliary 1D–13. . . . . .
Surge Tank 1D–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Radiator 1D–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GENERAL DESCRIPTION AND SYSTEM
OPERATION1D–18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Description 1D–18. . . . . . . . . . . . . . . . . . . . . . .
Radiator 1D–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Surge Tank 1D–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Pump 1D–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermostat 1D–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electric Cooling Fan 1D–19. . . . . . . . . . . . . . . . . . . . . . .
Engine Block Heater 1D–19. . . . . . . . . . . . . . . . . . . . . .

1D – 2IENGINE COOLING
DAEWOO V–121 BL4
SPECIFICATIONS
CAPACITY
ApplicationDescription
Coolant in the Cooling System
(1.4L/1.6L DOHC MPFI System)7.0L (1.85 gal) for automatic transaxle
7.0L (1.85 gal) for manual transaxle
Coolant in the Cooling System
(1.8L DOHC MPFI System)7.1L (1.88 gal) for automatic transaxle
7.1L (1.88 gal) for manual transaxle
FASTENER TIGHTENING SPECIFICATIONS
ApplicationNSmLb–FtLb–In
Water Pump Mounting Bolts (1.4L/1.6L DOHC)10–89
Water Pump Mounting Bolts (1.8L DOHC)2518–
Fan Assembly Mounting Bolts4–35
Fan Motor Nut3.2–28
Fan Motor Retaining Screws4–35
Radiator Retaining Bolts, Upper Left and Upper Right8–71
Surge Tank Attaching Bolt5–44
Thermostat Housing Mounting Bolts (1.6L DOHC)2015–
Thermostat Housing Mounting Bolts (1.8L DOHC)1511–
SPECIAL TOOLS
SPECIAL TOOLS TABLE
KM–471
Adapter

1D – 4IENGINE COOLING
DAEWOO V–121 BL4
COOLING SYSTEM DIAGNOSIS
Engine Overheats
ChecksAction
Check for a loss of the coolant.Add the coolant.
Check for a weak coolant solution.Confirm that the coolant solution is a 50/50 mixture of eth-
ylene glycol and water.
Check the front of the radiator for any dirt, any leaves, or
any insects.Clean the front of the radiator.
Check for leakage from the hoses, the coolant pump, the
heater, the thermostat housing, the radiator, the core
plugs, or the head gasket.Replace any damaged components.
Check for a faulty thermostat.Replace a damaged thermostat.
Check for retarded ignition timing.Perform an ECM code diagnosis. Confirm the integrity of
the timing belt.
Check for an improperly operating electric cooling fan.Replace the electric cooling fan.
Check for radiator hoses that are plugged or rotted.Replace any damaged radiator hoses.
Check for a faulty water pump.Replace a faulty water pump.
Check for a faulty surge tank cap.Replace a faulty surge tank cap.
Check for a cylinder head or an engine block that is
cracked or plugged.Repair the damaged cylinder head or the damaged engine
block.
Loss of Coolant
ChecksAction
Check for a leak in the radiator.Replace a damaged radiator.
Check for a leak in the following locations:
S Surge tank.
S Hose.Replace the following parts, as needed:
S Surge tank.
S Hose.
Check for loose or damaged radiator hoses, heater hoses,
and connections.Reseat the hoses.
Replace the hoses or the clamps.
Check for leaks in the coolant pump seal.Replace the coolant pump seal.
Check for leaks in the coolant pump gasket.Replace the coolant pump gasket.
Check for an improper cylinder head torque.Tighten the cylinder head bolts to specifications.
Replace the cylinder head gasket, if needed.
Check for leaks in the following locations:
S Intake manifold.
S Cylinder head gasket.
S Cylinder block plug.
S Heater core.
S Radiator drain plug.Repair or replace any components, as needed, to correct
the leak.
Engine Fails to Reach Normal Operating Temperature or Cool Air
from the Heater
ChecksAction
Check to determine if the thermostat is stuck open or is the
wrong type of thermostat.Install a new thermostat of the correct type and heat range.
Check the coolant level to determine if it is 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 – 5
DAEWOO V–121 BL4
COMPONENT LOCATOR
RADIATOR/FAN
1. Holder Transmission Fluid Pipe (Automatic Trans-
mission Only)
2. Upper Radiator Bumper
3. Front Upper Center Panel
4. Radiator
5. Lower Radiator Bumper6. Spring Clamp
7. Upper Radiator Hose
8. Main Cooling Fan
9. Auxiliary Cooling Fan
10. Drain Cock

1D – 8IENGINE COOLING
DAEWOO V–121 BL4
MAINTENANCE AND REPAIR
ON–VEHICLE SERVICE
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. Remove the surge tank cap.
3. Unplug the drain cock.
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 system or the
ground water can contaminate the local environment.
4. Catch the escaping fluid in a drain pan.
5. Remove all sludge and dirt from inside the surge
tank. Refer to ”Surge Tank” in this section.
6. Plug the drain cock.
7. Add the clean water to the surge tank.
8. Fill the tank slowly so that the upper reservoir hose
remains above the water line. This allows the air
inside the cooling system to escape.
9. Start the engine.
10. Run the engine until the thermostat opens. You can
tell the thermostat is open when both radiator
hoses are hot to the touch.
11. Stop the engine.
12. Repeat Steps 1 through 9 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 concentration.
13. 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.
14. Fill the surge tank to the specified MAX fill mark on
the outside of the tank.