2004 DAEWOO LACETTI knock

SECTION : 1A
GENERAL ENGINE INFORMATION
TABLE OF CONTENTS
DIAGNOSIS1A–1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Compression Test 1A–1. . . . . . . . . . . . . . . . . . . . . . . . .
Oil Pressure Test 1A–2. . . . . . . . . . . . . . . . . . . . . . . . . .
Oil Leak Diagnosis 1A–3. . . . . . . . . . . . . . . . . . . . . . . .
Knock Diagnosis 1A–4. . . . . . . . . . . . . . . . . . . . . . . . . . Noise Diagnosis 1A–8. . . . . . . . . . . . . . . . . . . . . . . . . .
GENERAL INFORMATION1A–11 . . . . . . . . . . . . . . . . . .
Cleanliness and Care 1A–11. . . . . . . . . . . . . . . . . . . . .
On–Engine Service 1A–11. . . . . . . . . . . . . . . . . . . . . . .
DIAGNOSIS
COMPRESSION TEST
Important : Disconnect the Crankshaft Position (CKP)
Sensor connector to disable the fuel and the ignition sys-
tems.
Test the compression pressure for each cylinder. Low
compression pressure may be the fault of the valves or the
pistons. The following conditions should be considered
when you check the cylinder compression:
S The engine should be at normal operating tempera-
ture.
S The throttle must be wide open.
S All the spark plugs should be removed.
S The battery must be at or near full charge.
1. Place approximately three squirts of oil from a
plunger– type oiler into each spark plug port.
2. Insert the engine compression gauge into each
spark plug port.
3. Crank test each cylinder with four to five compres-
sion strokes using the starter motor.4. The lowest reading should not be less than 70% of
the highest reading. The compression gauge read-
ing should not be less than 689 kPa (100 psi) for
any of the cylinders.
5. Examine the gauge readings obtained after the four
”puffs” per cylinder are obtained from cranking the
starter motor. The readings are explained in the
following descriptions:
S Normal Condition – Compression builds up quickly
and evenly to the specified compression on each
cylinder.
S Piston Rings Faulty – Compression is low on the
first stroke and tends to build up on following
strokes, but the compression pressure does not
reach normal. The compression pressure improves
considerably with the addition of oil into the cylin-
der.
S Valves Faulty – Low compression pressure on the
first stroke. The compression pressure does not
tend to build up on the following strokes. The com-
pression pressure does not improve much with the
addition of oil into the cylinder.

1A – 4IGENERAL ENGINE INFORMATION
DAEWOO V–121 BL4
Repairing the Leak
Once the origin of the leak has been pinpointed and traced
back to its source, the cause of the leak must be deter-
mined in order for it to be repaired properly. If a gasket is
replaced, but the sealing flange is bent, the new gasket will
not repair the leak. The bent flange must be repaired also.
Before attempting to repair a leak, check for the following
conditions and correct them as they may cause a leak.
Gaskets:
S The fluid level/pressure is too high.
S The crankcase ventilation system is malfunctioning.
S The fasteners are improperly tightened or the
threads are dirty or damaged.
S The flanges or the sealing surface is warped.S There are scratches, burrs or other damage to the
sealing surface.
S The gasket is damaged or worn.
S There is cracking or porosity of the component.
S An improper seal was used, (where applicable).
Seals:
S The fluid level/pressure is too high.
S The crankcase ventilation system is malfunctioning.
S The seal bore is damaged, scratched, burred or
nicked.
S The seal is damaged or worn.
S Improper installation is evident.
S There are cracks in the component.
S The shaft surface is scratched, nicked or damaged.
S A loose or worn bearing is causing excess seal
wear.
KNOCK DIAGNOSIS
Definition for Knock
Engine knock refers to various types of engine noise.
Heavy knock is usually very loud and the result of broken
or excessively worn internal engine components. Lightknock is a noticeable noise, but not as loud. Light knock
can be caused by worn internal engine components.
Loose or broken external engine components can also
cause heavy or light knock.
Engine Knocks Cold and Continues for Two–Three Minutes and/or
Knock Increases with Engine Torque
StepActionValue(s)YesNo
1Does the engine knock when it is cold and continue
for two to three minutes or does the knock increase
with torque?–Go to Step 2System OK
2Inspect the flywheel.
Is the flywheel contacting the splash shield?–Go to Step 3Go to Step 4
3Reposition the splash shield.
Is the repair complete?–Go to Step 1–
4Inspect the balancer and the drive pulleys.
Is either the balancer or the drive pulleys loose or
broken?–Go to Step 5Go to Step 6
5Tighten or replace the balancer or the drive pulleys.
Is the repair complete?–Go to Step 1–
6Inspect the piston–to–bore clearance.
Is the clearance more than the specified value?0.030 mm
(0.001 in.)Go to Step 7Go to Step 8
71. Rebore the cylinder and hone to size.
2. Replace the piston.
Is the repair complete?*–Go to Step 1–
8Inspect the connecting rod.
Is the connecting rod bent?–Go to Step 9System OK
9Replace the connecting rod.
Is the repair complete?–Go to Step 1–
* Cold engine piston knock usually disappears when the cylinder is grounded out. Cold engine piston knock, which disap-
pears in about 1.5 minutes, is considered acceptable.

GENERAL ENGINE INFORMATION 1A – 5
DAEWOO V–121 BL4
Heavy Knock Hot with Torque Applied
StepActionValue(s)YesNo
1Is there a heavy knock when the engine is hot and
torque is applied?–Go to Step 2System OK
2Inspect the balancer and the pulley hub.
Is the balancer or the pulley hub broken?–Go to Step 3Go to Step 4
3Replace the broken balancer or the pulley hub.
Is the repair complete?–Go to Step 1–
4Inspect the torque converter bolts.
Are the bolts tightened to specified value?45 NSm
(33 lb–ft)Go to Step 5Go to Step 6
5Tighten the torque converter bolts.
Is the repair complete?–Go to Step 1–
6Inspect the accessory belts.
Are the belts too tight or nicked?–Go to Step 7Go to Step 8
7Replace and/or tension the belts to specifications,
as necessary.
Is the repair complete?–Go to Step 1–
8Inspect the exhaust system.
Is the system grounded?–Go to Step 9Go to Step 10
9Reposition the system, as necessary.
Is the repair complete?–Go to Step 1–
10Inspect the flywheel.
Is the flywheel cracked?–Go to Step 11Go to Step 12
11Replace the flywheel.
Is the repair complete?–Go to Step 1–
12Inspect the main bearing clearance.
Is the clearance more than the specified value?0.026~0.046
mm (0.0010~
0.0018 in.)Go to Step 13Go to Step 14
13Replace the main bearings, as necessary.
Is the repair complete?–Go to Step 1–
14Inspect the rod bearing clearance.
Is the clearance more than the specified value?0.019 ~
0.070 mm
(0.0007 ~
0.0028 in.)Go to Step 15System OK
15Replace the rod bearings, as necessary.
Is the repair complete?–Go to Step 1–

1A – 6IGENERAL ENGINE INFORMATION
DAEWOO V–121 BL4
Light Knock Hot
StepActionValue(s)YesNo
1Is there a light knock when the engine is hot?–Go to Step 2System OK
2Is detonation or spark knock evident?–Go to Step 3Go to Step 4
3Check the engine timing and the fuel quality.
Was the problem found?–Go to Step 1–
4Inspect the torque converter bolts.
Are the bolts tightened to the specified value?45 NSm
(33 lb–ft)Go to Step 5Go to Step 6
5Tighten the torque converter bolts.
Is the repair complete?–Go to Step 1–
6Inspect the manifold.
Is there an exhaust leak at the manifold?–Go to Step 7Go to Step 8
7Tighten the bolts or replace the gasket.
Is the repair complete?–Go to Step 1–
8Check the rod bearing clearance.
Is the clearance within the specified value?0.019 ~
0.070 mm
(0.0007 ~
0.0028 in.)Go to Step 9System OK
9Replace the rod bearings, as necessary.
Is the repair complete?–Go to Step 1–
Knocks During Initial Start–Up But Last Only a Few Seconds
StepActionValue(s)YesNo
1Does the engine knock during initial start–up but last
only a few seconds?–Go to Step 2System OK
2Check the engine oil.
Is the proper viscosity oil used in the crankcase?–Go to Step 4Go to Step 3
3Install oil of the proper viscosity for the expected
seasonal temperatures.
Is the repair complete?–Go to Step 1–
4Inspect the hydraulic lifters.
Is there evidence of hydraulic lifter bleed–down?–Go to Step 5Go to Step 6
5Clean, test and replace the lifters, as necessary.
Is the repair complete?*–Go to Step 1–
6Inspect the crankshaft end clearance.
Is the clearance more than specified value?0.1 mm
(0.0039 in.)Go to Step 7Go to Step 8
7Replace the crankshaft thrust bearing.
Is the repair complete?–Go to Step 1–
8Inspect the front main bearing clearance.
Is the clearance more than the specified value?0.026~0.046
mm (0.0010~
0.0018 in.)Go to Step 9System OK
9Replace the worn parts of the front main bearing.
Is the repair complete?–Go to Step 1–
* When the engine is stopped, some valves will be open. Spring pressure against the lifters will tend to bleed lifter down.
Attempts to repair this should be made only if the problem is consistent.
An engine that is only operated for short periods between start–ups may have lifter noise that lasts for a few minutes. This
is a normal condition.

GENERAL ENGINE INFORMATION 1A – 7
DAEWOO V–121 BL4
Knocks at Idle Hot
StepActionValue(s)YesNo
1Does the engine knock at idle when hot?–Go to Step 2System OK
2Inspect the drive belts.
Are the belts loose or worn?–Go to Step 3Go to Step 4
3Tension or replace the belts, as necessary.
Is the repair complete?–Go to Step 1–
4Inspect the A/C compressor and the generator.
Is either the compressor or the generator faulty?–Go to Step 5Go to Step 6
5Replace the faulty A/C compressor or the generator.
Is the repair complete?–Go to Step 1–
6Inspect the valve train.
Are valve train components faulty?–Go to Step 7Go to Step 8
7Replace the faulty valve train components.
Is the repair complete?–Go to Step 1–
8Check the engine oil.
Is the proper viscosity oil used in the crankcase?–Go to Step 10Go to Step 9
9Install oil of the proper viscosity for the expected
seasonal temperatures.
Is the repair complete?–Go to Step 1–
10Inspect the piston pin clearance.
Is the clearance more than the specified value?0.020 mm
(0.0008 in.)Go to Step 11Go to Step 12
11Replace the piston and the pin.
Is the repair complete?–Go to Step 1–
12Check the connecting rod alignment.
Is the alignment faulty?–Go to Step 13Go to Step 14
13Check and replace rods, as necessary.
Is the repair complete?–Go to Step 1–
14Inspect the piston–to–bore clearance.
Is the clearance within the specified value?0.030 mm
(0.0012 in.)Go to Step 16Go to Step 15
15Hone the bore and fit a new piston.
Is the repair complete?Go to Step 1–
16Inspect the crankshaft balancer.
Is the balancer loose?–Go to Step 17Go to Step 18
17Torque or replace worn parts.
Is the repair complete?–Go to Step 1–
18Check the piston pin offset.
Is the offset at the specified value?0.5 ± 0.1 mm
(0.020 ~ 0.003
in.)
Toward Thrust
SideGo to Step 19System OK
19Install the correct piston.
Is the repair complete?–Go to Step 1–

1A – 8IGENERAL ENGINE INFORMATION
DAEWOO V–121 BL4
NOISE DIAGNOSIS
Main Bearing Noise
StepActionValue(s)YesNo
1Are dull thuds or knocks heard with every engine
revolution?–Go to Step 2System OK
2Check the oil pump pressure.
Is the oil pump pressure low?–Go to Oil Pres-
sure TestGo to Step 3
3Inspect the crankshaft end play.
Does the crankshaft end play exceed the specified
value?0.1 mm
(0.0039 in.)Go to Crank-
shaft Replace-
ment Proce-
dureGo to Step 4
4Inspect the crankshaft journals.
Are the crankshaft journals out–of–round?0.004 mm
(0.0002 in.)
max.Go to Crank-
shaft Replace-
ment Proce-
dureGo to Step 5
5Inspect the belt tension.
Does the belt tension exceed the specified value?–Go to Timing
Belt Replace-
ment Proce-
dureGo to Step 6
6Inspect the crankshaft pulley.
Is the crankshaft pulley loose?–Go to Crank-
shaft Replace-
ment Proce-
dureSystem OK
Connecting Rod Bearing Noise Symptom
StepActionValue(s)YesNo
1Is a knock noise heard under all engine speeds?–Go to Step 2System OK
2Inspect the crankshaft connecting rod journal.
Is the crankshaft connecting rod journal worn?–Go to Crank-
shaft Replace-
ment Proce-
dureGo to Step 3
3Check the oil pump pressure.
Is the oil pump pressure low?–Go to Oil Pres-
sure TestGo to Step 4
4Inspect the crankshaft connecting rod journals.
Are the journals out–of–round?–Go to Crank-
shaft Replace-
ment Proce-
dureGo to Step 5
5Inspect the connecting rods.
Is there a misaligned connecting rod?–Go to Pistons
and Rods Re-
placement Pro-
cedureGo to Step 6
6Inspect the connecting rod bolts.
Are the connecting rod bolts torqued properly?–System OKGo to Pistons
and Rods Re-
placement Pro-
cedure

GENERAL ENGINE INFORMATION 1A – 9
DAEWOO V–121 BL4
Piston Noises
StepActionValue(s)YesNo
1Are any of the following noises heard: a sharp double
knock when the engine is idling, a light ticking with
no load on the engine, or a ”slapping” noise when the
engine is cold?–Go to Step 2System OK
2Inspect the piston pin and the bushing.
Is the piston pin or the bushing worn or loose?–Go to Pistons
and Rods Re-
placement Pro-
cedureGo to Step 3
3Inspect the piston.
Is the piston broken or cracked?–Go to Pistons
and Rods Re-
placement Pro-
cedureGo to Step 4
4Inspect the connecting rods.
Is there a misaligned connecting rod?–Go to Pistons
and Rods Re-
placement Pro-
cedureGo to Step 5
5Inspect the piston position.
Is the piston 180° out of position?–Go to Pistons
and Rods Re-
placement Pro-
cedureSystem OK

1.4L/1.6L DOHC ENGINE MECHANICAL 1C1 – 11
DAEWOO V–121 BL4
1. Piston Ring Set
2. Piston
3. Piston Pin
4. Connecting Rod
5. Connecting Rod Bearing Set
6. Oil Level Gauge Stick
7. Gauge Stic Tube
8. Sleeve
9. Clutch Housing Sleeve
10. Cylinder Block
11. Plug
12. Gap
13. Bypass Valve
14. Connecting Piece
15. Oil Filter
16. Oil Pump Body Gasket
17. Water Inlet Neck
18. Knock Sensor
19. Fly Wheel (M/T)
20. Flexible Plate (A/T)
21. Shaft Seal Ring
22. Crank Shaft Upper Bearing Set
23. Crank Shaft24. Crank Shaft Lower Bearing Set
25. Transmitter Disc
26. Crankshaft Bearing Cap
27. Oil Pan
28. Threaded Ring
29. Washer
30. Oil Pan Drain Plug
31. Oil Pump
32. Oil Pump Cover
33. Oil Pump Inner Rotor
34. Oil Pump Outer Rotor
35. Oil Pump Plug
36. Shaft Sealing
37. Pressure Relief Valve Plunger
38. Relief Valve Spring
39. Sealing
40. Relief Valve
41. Oil Pressure Switch
42. Sleeve
43. Oil Suction Pipe Bracket
44. Oil Suction Pipe
45. Sealing