2004 DAEWOO LACETTI Automatic

1C2 – 64I1.8L DOHC ENGINE MECHANICAL
DAEWOO V–121 BL4
6. Remove the front timing belt cover bolts.
7. Remove the front timing belt cover.
8. Remove the crankshaft pulley bolts.
9. Remove the crankshaft pulley.
10. Loosen the timing belt automatic tensioner bolt.
11. Rotate the timing belt automatic tensioner hex–key
clockwise to release the tension.
12. Remove the timing belt idler pulley bolt and nut.
13. Remove the timing belt idler pulleys.
14. Remove the timing belt.
15. Remove the engine mount retaining bolts.
16. Remove the engine mount.
17. Disconnect the breather tubes from the camshaft
cover.
18. Remove the spark plug cover bolts.
19. Remove the spark plug cover.
20. Disconnect the ignition wires from the spark plugs.
21. Remove the camshaft cover bolts.
22. Remove the camshaft cover washers.
23. Remove the camshaft cover and the camshaft cov-
er gasket.
Notice : Take extreme care to prevent any scratches,
nicks or damage to the camshafts.
24. While holding the intake camshaft firmly in place,
remove the intake camshaft bolt.
25. Remove the intake camshaft gear.
26. While holding the exhaust camshaft firmly in place,
remove the exhaust camshaft bolt.
27. Remove the exhaust camshaft gear.

1C2 – 70I1.8L DOHC ENGINE MECHANICAL
DAEWOO V–121 BL4
31. Coat the new oil pan gasket with sealant.
32. Install the oil pan gasket to the oil pan.
33. Install the oil pan.
34. Install the oil pan retaining bolts.
Tighten
Tighten the oil pan retaining bolts to 10 NSm (89 lb–in).
35. Rotate the engine on the engine overhaul stand
KM–412.
36. Install the rear timing belt cover.
37. Install the rear timing belt cover bolts.
Tighten
Tighten the rear timing belt cover bolts to 7 NSm (62
lb–in).
38. Install the crankshaft gear and bolt.
Tighten
Tighten the crankshaft gear bolt to 145 NSm (107 lb–
ft) plus 30 degrees plus 15 degrees using the angular
torque gauge KM–470–B.
39. Install the engine mount and retaining bolts.
Tighten
Tighten the engine mount retaining bolts to 45 NSm
(33 lb–ft).
40. Install the timing belt automatic tensioner.
41. Install the timing belt automatic tensioner bolts.
Tighten
Tighten the timing belt automatic tensioner bolts to 25
NSm (18 lb–ft).
42. Install the timing belt idler pulley.
43. Install the timing belt idler pulley bolt and nut.
Tighten
Tighten the timing belt idler pulley nut to 25 NSm (18
lb–ft).

1C2 – 72I1.8L DOHC ENGINE MECHANICAL
DAEWOO V–121 BL4
62. Install a new crankshaft rear oil seal using installer
J–36792 or KM–635.
63. Install the flywheel or flexible plate.
64. Install the flywheel or the flexible plate bolts.
Tighten
Tighten the flywheel bolts to 65 NSm (48 lb–ft). Use
the angular torque gauge KM–470–B to tighten the
flywheel bolts another 30 degrees plus 15 degrees.
For the automatic transmission, tighten the flexible
plate bolts to 45 NSm (33 lb–ft).
65. Install the engine. Refer to ”Engine” in this section.
CRANKSHAFT BEARINGS AND
CONNECTING ROD BEARINGS –
GAUGING PLASTIC
Tools Required
KM–470–B Angular Torque Gauge
Inspection Procedure – Crankshaft
1. Coat the crankshaft bearings with engine oil.
2. Install the upper crankshaft bearings into the engine
block crankshaft journals.
3. Install the lower crankshaft bearings into the crank-
shaft bearing caps.
4. Install the crankshaft.
5. Inspect the crankshaft end play with the crankshaft
bearings installed.
6. Check for permissible crankshaft end play. Refer to
”Engine Specifications” in this section.

1.8L DOHC ENGINE MECHANICAL 1C2 – 75
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
CYLINDER HEAD AND GASKET
The cylinder head is made of an aluminum alloy. The cylin-
der head uses cross–flow intake and exhaust ports. A
spark plug is located in the center of each combustion
chamber. The cylinder head houses the dual camshafts.
CRANKSHAFT
The crankshaft has eight integral weights which are cast
with it for balancing. Oil holes run through the center of the
crankshaft to supply oil to the connecting rods, the bear-
ings, the pistons, and the other components. The end
thrust load is taken by the thrust washers installed at the
center journal.
TIMING BELT
The timing belt coordinates the crankshaft and the dual
overhead camshafts and keeps them synchronized. The
timing belt also turns the coolant pump. The timing belt
and the pulleys are toothed so that there is no slippage be-
tween them. There are two idler pulleys. An automatic ten-
sioner pulley maintains the timing belt’s correct tension.
The timing belt is made of a tough reinforced rubber similar
to that used on the serpentine drive belt. The timing belt
requires no lubrication.
OIL PUMP
The oil pump draws engine oil from the oil pan and feeds
it under pressure to the various parts of the engine. An oil
strainer is mounted before the inlet of the oil pump to re-
move impurities which could clog or damage the oil pump
or other engine components. When the crankshaft ro-
tates, the oil pump driven gear rotates. This causes the
space between the gears to constantly open and narrow,
pulling oil in from the oil pan when the space opens and
pumping the oil out to the engine as it narrows.
At high engine speeds, the oil pump supplies a much high-
er amount of oil than required for lubrication of the engine.
The oil pressure regulator prevents too much oil from en-
tering the engine lubrication passages. During normal oil
supply, a coil spring and valve keep the bypass closed, di-
recting all of the oil pumped to the engine. When the
amount of oil being pumped increases, the pressure be-
comes high enough to overcome the force of the spring.This opens the valve of the oil pressure regulator, allowing
the excess oil to flow through the valve and drain back to
the oil pan.
OIL PAN
The engine oil pan is mounted to the bottom of the cylinder
block. The engine oil pan houses the crankcase and is
made of cast aluminum.
Engine oil is pumped from the oil pan by the oil pump. After
it passes through the oil filter, it is fed through two paths
to lubricate the cylinder block and cylinder head. In one
path, the oil is pumped through oil passages in the crank-
shaft to the connecting rods, then to the pistons and cylin-
ders. It then drains back to the oil pan. In the second path,
the oil is pumped through passages to the camshaft. The
oil passes through the internal passageways in the cam-
shafts to lubricate the valve assemblies before draining
back to the oil pan.
EXHAUST MANIFOLD
A single four–port, rear–takedown manifold is used with
this engine. The manifold is designed to direct escaping
exhaust gases out of the combustion chambers with a
minimum of back pressure. The oxygen sensor is
mounted to the exhaust manifold.
INTAKE MANIFOLD
The intake manifold has four independent long ports and
utilizes an inertial supercharging effect to improve engine
torque at low and moderate speeds.
CAMSHAFTS
This engine is a dual overhead camshaft (DOHC) type,
which means there are two camshafts. One camshaft op-
erates the intake valves, and the other camshaft operates
the exhaust valves. The camshafts sit in journals on the
top of the engine (in the cylinder head) and are held in
place by camshaft caps. The camshaft journals of the cyl-
inder head are drilled for oil passages. Engine oil travels
to the camshafts under pressure where it lubricates each
camshaft journal. The oil returns to the oil pan through
drain holes in the cylinder head. The camshaft lobes are
machined into the solid camshaft to precisely open and
close the intake and the exhaust valves the correct
amount at the correct time. The camshaft lobes are oiled
by splash action from pressurized oil escaping from the
camshaft journals.

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

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 – 18IENGINE COOLING
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM 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 en-
gine slowly or not at all. This slow cooling of the engine al-
lows the engine to warm up quickly.
The cooling system includes a radiator and recovery sub-
system, cooling fans, a thermostat and housing, a coolant
pump, and a coolant pump drive belt. 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, the intake man-
ifold, and the cylinder head. When the coolant reaches the
operating temperature of the thermostat, 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. This provides for heating and defrosting. The
surge tank is connected to the radiator to recover the cool-
ant displaced by expansion from the high temperatures.
The surge tank maintains the correct coolant level.
The cooling system for this vehicle has no radiator cap or
filler neck. The coolant is added to the cooling system
through the surge tank.
RADIATOR
This vehicle has a lightweight tube–and–fin aluminum ra-
diator. Plastic tanks are mounted on the right and the left
sides of the radiator core.
On vehicles equipped with automatic transaxles, the
transaxle fluid cooler lines run through the left radiator
tank. A radiator drain cock is on this radiator.
To drain the cooling system, open the drain cock.
SURGE TANK
The surge tank is a transparent plastic reservoir, similar to
the windshield washer reservoir.
The surge tank is connected to the radiator by a hose and
to the engine cooling system by another hose. As the ve-
hicle is driven, the engine coolant heats and expands. The
portion of the engine coolant displaced by this expansion
flows from the radiator and the engine into the surge tank.
The air trapped in the radiator and the engine is degassed
into the surge tank.When the engine stops, the engine coolant cools and con-
tracts. The displaced engine coolant is then drawn back
into the radiator and the engine. 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.
WATER PUMP
The belt–driven centrifugal water pump consists of an im-
peller, a drive shaft, and a belt pulley. The water pump is
mounted on the front of the transverse–mounted engine,
and is driven by the timing belt.
The impeller is supported by a completely sealed bearing.
The water pump is serviced as an assembly and, there-
fore, cannot be disassembled.
THERMOSTAT
A wax pellet–type thermostat controls the flow of the en-
gine coolant through the engine cooling system. The ther-
mostat is mounted in the thermostat housing to the front
of the cylinder head.
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 thermo-
stat remains closed while the engine coolant is cold, pre-
venting circulation of the engine coolant through the
radiator. At this point, the engine coolant is allowed to cir-
culate 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 en-
gine temperature operating limits.
The wax pellet in the thermostat is hermetically sealed in
a metal case. The wax element of the thermostat expands
when it is heated and contracts when it is cooled.
As the vehicle is driven and the engine warms, the engine
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 allows the engine
coolant to flow through the engine cooling 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 87°C (189°F) and is fully
open at 102°C (216°F). The thermostat closes at 86°C
(187°F).

1E – 6IENGINE ELECTRICAL
DAEWOO V–121 BL4
DIAGNOSIS
NO CRANK
StepActionValue(s)YesNo
11. Turn the headlamps ON.
2. Turn the dome lamps ON.
3. Turn the ignition to START.
Did the lights dim or go out?–Go to Step 2Go to Step 8
2Check the battery state of charge.
Is the green eye showing from the built–in hydrome-
ter?–Go to Step 3Go to
”Charging Pro-
cedure”
31. Connect the voltmeter positive lead to the posi-
tive battery terminal.
2. Connect the voltmeter negative lead to the
negative battery terminal.
3. Turn the ignition to START.
Does the voltmeter indicate the value specified?< 9.6 vGo to
”Charging Pro-
cedure”Go to Step 4
41. Connect the voltmeter negative lead to the
negative battery terminal.
2. Connect the positive voltmeter lead to the en-
gine block.
Does the voltmeter indicate the value specified?> 0.5 vGo to Step 5Go to Step 6
5Clean, tighten, or replace the negative battery cable.
Is the repair complete?–System OK–
61. Connect the voltmeter positive lead to the start-
er ”B+” terminal.
2. Connect the voltmeter negative lead to the
negative battery terminal.
Does the voltmeter indicate the value specified?< 9 vGo to Step 7Go to Step 13
7Clean, tighten, or replace the positive battery cable.
Is the repair complete?–System OK–
8Inspect the engine fuse block fuse Ef5.
Is the fuse OK?–Go to Step 10Go to Step 9
9Inspect the engine fuse block fuse Ef4.
Is the fuse OK?–System OK–
10Check the connection at the starter ”ST” terminal.
Is the connection OK?–Go to Step 12Go to Step 11
11Clean or tighten the connection as needed.
Is the repair complete?–System OK–
121. Connect the voltmeter positive lead to the start-
er ”ST” terminal.
2. Connect the voltmeter negative lead to the
negative battery terminal.
3. Turn the ignition to START.
Does the voltmeter indicate the value specified?< 7 vGo to Step 13Go to Step 14
13Repair or replace the starter as needed.
Is the repair complete?–System OK–
14Determine the type of transaxle on the vehicle.
Is the vehicle equipped with an automatic transaxle?–Go to Step 15Go to Step 32