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
1A – 10IGENERAL ENGINE INFORMATION
DAEWOO V–121 BL4
Valve Mechanism or Valve Train Noises
StepActionValue(s)YesNo
1Is a light tapping sound heard from the engine?–Go to Step 2System OK
2Inspect the valve springs.
Are the springs weak or broken?–Go to Cylinder
Head and
Valve Train
Components
Replacement
ProcedureGo to Step 3
3Inspect the valves.
Are the valves sticking or warped?–Go to Cylinder
Head and
Valve Train
Components
Replacement
ProcedureGo to Step 4
4Inspect the valve lifters.
Are the valve lifters dirty, stuck or worn?–Go to Cylinder
Head and
Valve Train
Components
Replacement
ProcedureGo to Step 5
5Inspect the camshaft lobes.
Are the camshaft lobes damaged or improperly ma-
chined?–Go to Cam-
shaft Replace-
ment Proce-
dureGo to Step 6
6Check the oil supply to the valve train.
Is the oil supply insufficient or poor?–Go to Cylinder
Head and
Valve Train
Components
Replacement
ProcedureGo to Step 7
7Inspect the valve guides.
Are the valve guides worn?–Go to Cylinder
Head and
Valve Train
Components
Replacement
ProcedureGo to Step 8
8Inspect the valve spring seat.
Is the valve spring seat incorrect?–Go to Cylinder
Head and
Valve Train
Components
Replacement
ProcedureSystem OK
SECTION : 1C1
1.4L/1.6L DOHC ENGINE MECHANICAL
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
SPECIFICATIONS1C1–2 . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Specifications 1C1–2. . . . . . . . . . . . . . . . . . . . .
Fastener Tightening Specifcations 1C1–5. . . . . . . . . .
SPECIAL TOOLS1C1–7 . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Tools Table 1C1–7. . . . . . . . . . . . . . . . . . . . . . .
COMPONENT LOCATOR1C1–9 . . . . . . . . . . . . . . . . . . .
Cylinder Head 1C1–9. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder Block 1C1–10. . . . . . . . . . . . . . . . . . . . . . . . . . .
Intake & Exhaust Manifold 1C1–12. . . . . . . . . . . . . . . .
Timing Belt 1C1–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Mounting 1C1–14. . . . . . . . . . . . . . . . . . . . . . . .
MAINTENANCE AND REPAIR1C1–15 . . . . . . . . . . . . .
ON–VEHICLE SERVICE 1C1–15. . . . . . . . . . . . . . . . . . .
Engine Cover 1C1–15. . . . . . . . . . . . . . . . . . . . . . . . . . .
Camshaft Cover 1C1–15. . . . . . . . . . . . . . . . . . . . . . . . .
Intake Manifold 1C1–16. . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust Manifold 1C1–20. . . . . . . . . . . . . . . . . . . . . . . .
Cylinder Head and Gasket 1C1–21. . . . . . . . . . . . . . . .
Camshaft 1C1–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Timing Belt Check and Adjust 1C1–30. . . . . . . . . . . . .
Timing Belt 1C1–34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oil Pan 1C1–38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil Pump 1C1–40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Mount 1C1–43. . . . . . . . . . . . . . . . . . . . . . . . . . .
Camshaft Gears 1C1–45. . . . . . . . . . . . . . . . . . . . . . . . .
Rear Timing Belt Cover 1C1–46. . . . . . . . . . . . . . . . . . .
Engine 1C1–48. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pistons and Rods 1C1–53. . . . . . . . . . . . . . . . . . . . . . . .
UNIT REPAIR 1C1–58. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder Head and Valve Train Components 1C1–58.
Crankshaft 1C1–65. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft Bearing and Connecting Rod
Beadings – Gauging Plastics 1C1–74. . . . . . . . . . . .
GENERAL DESCRIPTION AND SYSTEM
OPERATION1C1–77 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder Head and Gasket 1C1–77. . . . . . . . . . . . . . . .
Crankshaft 1C1–77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Timing Belt 1C1–77. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil Pump 1C1–77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil Pan 1C1–77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust Manifold 1C1–77. . . . . . . . . . . . . . . . . . . . . . . .
Intake Manifold 1C1–77. . . . . . . . . . . . . . . . . . . . . . . . . .
Camshaft 1C1–77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1C1 – 40I1.4L/1.6L DOHC ENGINE MECHANICAL
DAEWOO V–121 BL4
OIL PUMP
Tools Required
KM–498–B Pressure Gauge
KM–135 Adapter
Engine Oil Pressure Inspection Procedure
1. Remove the right front wheel, wheel well splash
shield and engine undercover.
2. Disconnect the oil pressure switch connector.
3. Install the adapter KM–135 in place of the oil pres-
sure switch.
4. Connect the pressure gauge KM–498–B to the
adapter.
5. Start the engine and check the oil pressure at idle
speed and engine temperature of 80°C (176°F).
The minimum oil pressure should be 30 kPa (4.35
psi).
6. Stop the engine and remove the pressure gauge
KM–498–B and the adapter KM–135.
7. Install the oil pressure switch.
Tighten
Tighten the oil pressure switch to 40 NSm (30 lb–ft).
8. Connect the oil pressure switch connector.
9. Install the right front wheel well splash shield, en-
gine undercover and wheel.
10. Check the oil level. Pour oil until it reaches the full
mark.
Removal Procedure
1. Disconnect the negative battery cable.
2. Remove the power steering pump, if equipped. Re-
fer to Section 6A, Power Steering System.
3. Remove the timing belt. Refer to”Timing Belt” in this
section.
4. Remove the rear timing belt cover. Refer to ”Rear
Timing Belt Cover” in this section.
5. Disconnect the oil pressure switch connector.
1C1 – 60I1.4L/1.6L DOHC ENGINE MECHANICAL
DAEWOO V–121 BL4
35. Remove the valves. Maintain the original position of
the valves for installation.
36. Remove the valve stem seals.
Cylinder Head Inspection
1. Clean the sealing surfaces.
2. Inspect the cylinder head gasket and mating sur-
faces for leaks, corrosion, and blowby.
3. Inspect the cylinder head for cracks.
4. Inspect the length and the width of the cylinder
head using a feeler gauge and a straight edge.
5. Check the sealing surfaces for deformation and
warpage. The cylinder head sealing surfaces must
be flat within 0.050 mm (0.002 inch) maximum.
6. Measure the height of the cylinder head from seal-
ing surface to sealing surface. The cylinder head
height should be 134.08 to 134.23 mm. If the cylin-
der head height is less than 134.08 mm, replace
the cylinder head.
7. Inspect all threaded holes for damage.
8. Inspect valve seats for excessive wear and burned
spots.
Valve Inspection
1. Inspect the valve stem tip for wear.
2. Inspect the valve key grooves and the oil seal
grooves for chips and wear.
3. Inspect the valves for burns or cracks.
4. Inspect the valve stem for burrs and scratches.
5. Inspect the valve stem. The valve stem must be
straight.
6. Inspect the valve face for grooving. If the groove is
so deep that refacing the valve would result in a
sharp edge, replace the valve.
1.4L/1.6L DOHC ENGINE MECHANICAL 1C1 – 61
DAEWOO V–121 BL4
7. Inspect the valve spring. If the valve spring ends
are not parallel, replace the valve spring.
8. Measure the valve spring height. Refer to ”Engine
Specifications” in this section. If the valve spring
height does not match the specifications, replace
the valve spring.
9. Inspect the valve spring seating surface of the
valve rotators for wear or gouges. Replace as re-
quired.
Cleaning Procedure
1. Clean the cylinder head.
2. Clean the valve guides.
3. Clean all of the threaded holes.
4. Clean the valves of carbon, oil, and varnish.
Cylinder Head Overhaul
Valve Grind–in
1. Lubricate the valve stem using a fine–grained
paste.
2. Lift the valve rhythmically from the seat with a com-
mercially available valve grinding tool in order to
distribute the paste.
3. Check the contact pattern on the valve head and in
the cylinder head.
4. Clean the valves, the valve guides, and the cylinder
head.