check engine DAEWOO NUBIRA 2004 Service Repair Manual
[x] Cancel search | Manufacturer: DAEWOO, Model Year: 2004, Model line: NUBIRA, Model: DAEWOO NUBIRA 2004Pages: 2643, PDF Size: 80.54 MB
Page 16 of 2643

GENERAL INFORMATION 0B – 9
DAEWOO V–121 BL4
MAINTENANCE AND REPAIR
MAINTENANCE AND LUBRICATION
NORMAL VEHICLE USE
The maintenance instructions contained in the mainte-
nance schedule are based on the assumption that the ve-
hicle will be used for the following reasons:
S To carry passengers and cargo within the limitation
indicated on the tire placard located on the edge of
the driver’s door.
S To be driven on reasonable road surfaces and with-
in legal operating limits.
EXPLANATION OF SCHEDULED
MAINTENANCE SERVICES
The services listed in the maintenance schedule are fur-
ther explained below. When the following maintenance
services are performed, make sure all the parts are re-
placed and all the necessary repairs are done before driv-
ing the vehicle. Always use the proper fluid and lubricants.
Drive Belt Inspection
When a separate belt drives the power steering pump, the
air conditioning compressor and the generator, inspect it
for cracks, fraying, wear and proper tension. Adjust or re-
place the belt as needed.
Engine Oil and Oil Filter Change
API Classifications of Engine Oil
The International Lubricant Standardization and Approval
Committee (ILSAC) and American Petroleum Institute
classifies engine oils according to their performance quali-
ty. Always use oil rated API–SL (ILSAC GF–III) or better.
Engine Oil Viscosity
Engine oil viscosity (thickness) has an effect on fuel econ-
omy and cold weather operation. Lower viscosity engine
oils can provide better fuel economy and cold weather per-
formance; however, higher temperature weather condi-
tions require higher viscosity engine oils for satisfactory lu-
brication. Using oils of any viscosity other than those
viscosities recommended could result in engine damage.
Cooling System Service
Drain, flush and refill the system with new coolant. Refer
to ”Recommended Fluids And Lubricants” in this section.
Fuel Micro–Filter Replacement
Replace the engine fuel filter every 45,000 km (27,000
miles).
Air Cleaner Element Replacement
Replace the air cleaner element every 45,000 km (27,000
miles).Replace the air cleaner more often under dusty conditions.
Throttle Body Mounting Bolt Torque
Check the torque of the mounting bolts.
Tighten the throttle body mounting bolts to 15 NSm (11 lb–
ft) if necessary.
Spark Plug Replacement
Replace spark plugs with the same type.
Spark Plug Wire Replacement
Clean wires and inspect them for burns, cracks or other
damage. Check the wire boot fit at the DIS module and at
the spark plugs. Replace the wires as needed.
Brake System Service
Check the disc brake pads and the drum brake linings ev-
ery 15,000 km (9,000 miles) or 12 months. Check the pad
and the lining thickness carefully. If the pads or the linings
are not expected to last to the next scheduledmaintenance
service, replace the pads or the linings. Check the breath-
er hole in the brake fluid reservoir cap to be sure it is free
from dirt and the passage is open.
Transaxle Service
The manual transaxle fluid does not require changing. For
automatic transaxles, refer to ”Scheduled Maintenance
Charts” in this section.
Tire and Wheel Inspection and Rotation
Check the tires for abnormal wear or damage. To equalize
wear and obtain maximum tire life, rotate the tires. If irreg-
ular or premature wear exists, check the wheel alignment
and check for damaged wheels. While the tires and
wheels are removed, inspect the brakes. Refer to ”Each
Time The Oil Is Changed” in this section.
Tire Rotation
Page 17 of 2643

0B – 10IGENERAL INFORMATION
DAEWOO V–121 BL4
SCHEDULED MAINTENANCE CHARTS
Engine
Maintenance ItemMaintenance Interval
Kilometers or time in months, whichever comes first
x 1,000 km1153045607590105120
x 1,000 miles0.6918273645546372
Months–1224364860728496
Drive belts (Alternator, power steering
and A/C belt)IIII
Engine oil & engine oil filter (1) (3)IRRRRRRRR
Cooling system hose & connectionsIIIIIIII
Engine coolant (3)IIIRIIRII
Fuel filterRR
Fuel line and connectionsIIIIIIII
Air cleaner element (2)IIRIIRII
Spark plugs (1.4D/1.6D)IRIRIRIR
Spark plugs (1.8D)IRIR
Spark plug wiresReplace every 90,000 km(54,000 miles)
EVAP canister, vapor lines & solenoid
valve filterII
PCV systemIIII
Timing beltlRlR
Chart Symbols:
I –Inspect, and if necessary correct, clean, replenish or adjust.
R – Replace or change:
(1) Change the engine oil and oil filter every 7,500 km (4,500 miles) or 6months, whichever comes first, if the vehicle is
operated under any of the following conditions:
S Short distance driving.
S Extensive idling.
S Driving on dusty roads.
(2) Inspect the air cleaner element every 7,500 km (4,500 miles) or 6 months if driving under dusty conditions. If necessary,
correct, clean or replace.
(3) Refer to ”Recommended Fluids And Lubricants”
Note : Check the engine oil and radiator coolant levels every week.
Page 19 of 2643

0B – 12IGENERAL INFORMATION
DAEWOO V–121 BL4
OWNER INSPECTIONS AND SERVICES
WHLE OPERATING THE VEHICLE
Horn Operation
Blow the horn occasionally tomake sure it works. Check
all the button locations.
Brake System Operation
Be alert for abnormal sounds, increased brake pedal trav-
el or repeated pulling to one side when braking. Also, if the
brake warning light goes on, or flashes, something may be
wrong with part of the brake system.
Exhaust System Operation
Be alert to any changes in the sound of the system or the
smell of the fumes. These are signs that the system may
be leaking or overheating. Have the system inspected and
repaired immediately.
Tires,Wheels and Alignment Operation
Be alert to any vibration of the steering wheel or the seats
at normal highway speeds. This may mean a wheel needs
to be balanced. Also, a pull right or left on a straight, level
road may show the need for a tire pressure adjustment or
a wheel alignment.
Steering System Operation
Be alert to changes in the steering action. An inspection
is needed when the steering wheel is hard to turn or has
too much free play, or if unusual sounds are noticed when
turning or parking.
Headlight Aim
Take note of the light pattern occasionally. Adjust the
headlights if the beams seem improperly aimed.
AT EACH FUEL FILL
A fluid loss in any (except windshield washer) system may
indicate a problem. Have the system inspected and re-
paired immediately.
Engine Oil Level
Check the oil level and add oil if necessary. The best time
to check the engine oil level is when the oil is warm.
1. After stopping the engine, wait a few minutes for
the oil to drain back to the oil pan.
2. Pull out the oil level indicator (dip stick).
3. Wipe it clean, and push the oil level indicator back
down all the way.
4. Pull out the oil level indicator and look at the oil lev-
el on it.
5. Add oil, if needed, to keep the oil level above the
MIN line and within the area labeled ”Operating
Range.” Avoid overfilling the engine, since this may
cause engine damage.
6. Push the indicator all the way back down into the
engine after taking the reading.If you check the oil level when the oil is cold, do not run the
engine first. The cold oil will not drain back to the pan fast
enough to give a true oil level reading.
Engine Coolant Level and Condition
Check the coolant level in the coolant reservoir tank and
add coolant if necessary. Inspect the coolant. Replace
dirty or rusty coolant.
Windshield Washer Fluid Level
Check the washer fluid level in the reservoir. Add fluid if
necessary.
AT LEAST MONTHLY
Tire And Wheel Inspection and Pressure
Check
Check the tires for abnormal wear or damage. Also check
for damaged wheels. Check the tire pressure when the
tires are cold (check the spare also, unless it is a stow-
away). Maintain the recommended pressures that are on
the tire placard that is in the glove box.
Light Operation
Check the operation of the license plate light, the head-
lights (including the high beams), the parking lights, the
fog lights, the taillight, the brake lights, the turn signals, the
backup lights and the hazard warning flasher.
Fluid Leak Check
Periodically inspect the surface beneath the vehicle for
water, oil, fuel or other fluids, after the vehicle has been
parked for a while. Water dripping from the air conditioning
system after use is normal. If you notice fuel leaks or
fumes, find the cause and correct it at once.
AT LEAST TWICE A YEAR
Power Steering System Reservoir Level
Check the power steering fluid level. Keep the power
steering fluid at the proper level. Refer to Section 6A, Pow-
er Steering System.
Brake Master Cylinder Reservoir Level
Check the fluid and keep it at the proper level. A low fluid
level can indicate worn disc brake pads which may need
to be serviced. Check the breather hole in the reservoir
cover to be free from dirt and check for an open passage.
Clutch Pedal Free Travel
Check clutch pedal free travel and adjust as necessary.
Measure the distance from the center of the clutch pedal
to the outer edge of the steering wheel with the clutch ped-
al not depressed. Then measure the distance from the
center of the clutch pedal to the outer edge of the steering
wheel with the clutch pedal fully depressed. The difference
between the two values must be greater than 130 mm
(5.19 inches).
Weather–Strip Lubrication
Apply a thin film silicone grease using a clean cloth.
Page 20 of 2643

GENERAL INFORMATION 0B – 13
DAEWOO V–121 BL4
EACH TIME THE OIL IS CHANGED
Automatic Transaxle Fluid
Refer to fluid level service procedure of Section 5A, ZF
4HP16 Automatic Transaxle.
Manual Transaxle
Check the fluid level and add fluid as required. Refer to
Section 5B, Five–Speed Manual Transaxle.
Brake System Inspection
This inspection should be done when the wheels are re-
moved for rotation. Inspect the lines and the hoses for
proper hookup, binding, leaks, cracks, chafing, etc. In-
spect the disc brake pads for wear. Inspect the rotors for
surface condition. Also inspect the drum brake linings for
wear and cracks. Inspect other brake parts, including the
drums, the wheels cylinders, the parking brake, etc., at the
same time. Check the parking brake adjustment. Inspect
the brakes more often if habit or conditions result in fre-
quent braking.
Steering, Suspension and Front Drive Axle
Boot And Seal Inspection
Inspect the front and rear suspension and the steering
system for damaged, loose or missing parts, signs of wear
or lack of lubrication. Inspect the power steering lines and
the hoses for proper hookup, binding, leaks, cracks, chaf-
ing, etc. Clean and inspect the drive axle boot and seals
for damage, tears or leakage. Replace the seals if neces-
sary.
Exhaust System Inspection
Inspect the complete system (including the catalytic con-
verter if equipped). Inspect the body near the exhaust sys-
tem. Look for broken, damaged, missing, or out–of–posi-
tion parts as well as open seams, holes, loose
connections, or other conditions which could cause heat
buildup in the floor pan or could let exhaust fumes seep
into the trunk or passenger compartment.
Throttle Linkage Inspection
Inspect the throttle linkage for interference or binding,
damaged, or missing parts. Lubricate all linkage joints and
throttle cable joints, the intermediate throttle shaft bearing,
the return spring at throttle valve assembly, and the accel-
erator pedal sliding face with suitable grease. Check the
throttle cable for free movements.
Engine Drive Belts
Inspect all belts for cracks, fraying, wear and proper ten-
sion. Adjust or replace the belts as needed.
Hood Latch Operation
When opening the hood, note the operation of the secon-
dary latch. It should keep the hood from opening all the
way when the primary latch is released. The hood must
close firmly.
AT LEAST ANNUALLY
Lap and Shoulder Belts Condition and
Operation
Inspect the belt system including: the webbing, the
buckles, the latch plates, the retractor, the guide loops and
the anchors.
Movable Head Restraint Operation
On vehicles with movable head restraints, the restraints
must stay in the desired position.
Spare Tire and Jack Storage
Be alert to rattles in the rear of the vehicle. The spare tire,
all the jacking equipment, and the tools must be securely
stowed at all times. Oil the jack ratchet or the screw mech-
anism after each use.
Key Lock Service
Lubricate the key lock cylinder.
Body Lubrication Service
Lubricate all the body door hinges including the hood, the
fuel door, the rear compartment hinges and the latches,
the glove box and the console doors, and any folding seat
hardware.
Transaxle Neutral Switch Operation on
Automatic Transaxle
CAUTION : Take the following precautions because
the vehicle could move without warning and possibly
cause personal injury or property damage:
S Firmly apply the parking brake and the regular
brakes.
S Do not use the accelerator pedal.
S Be ready to promptly turn off the ignition if the ve-
hicle starts.
On automatic transaxle vehicles, try to start the engine in
each gear. The starter should crank only in P (Park) or N
(Neutral).
Parking Brake and Transaxle P (Park)
Mechanism Operation
CAUTION : In order to reduce the risk of personal in-
jury or property damage, be prepared to apply the reg-
ular brakes promptly if the vehicle begins to move.
Park on a fairly steep hill with enough room for movement
in the downhill direction. To check the parking brake, with
the engine running and the transaxle in N (Neutral), slowly
remove foot pressure from the regular brake pedal (until
only the parking brake is holding the vehicle).
To check the automatic transaxle P (Park) mechanism’s
holding ability, release all brakes after shifting the trans-
axle to P (Park).
Underbody Flushing
Flushing the underbody will remove any corrosive materi-
als used for ice and snow removal and dust control. At
least every spring clean the underbody. First, loosen the
sediment packed in closed areas of the vehicle. Then flush
the underbody with plain water.
Page 32 of 2643

HOW TO USE ELECTRICAL WIRING DIAGRAMW1–3
2. CIRCUIT IDENTIFICATION SYMBOL
IDENTIFICATION
SYMBOLMEANING
CConnector
DDiode
EfFuse in engine room fuse box
FFuse in passenger room fuse box
GGround
SSplice pack(Junction connector)
3. FUNCTION OF POWER SUPPLY LINE (NUMBER)
Power supply NoPower supply condition
15Battery Voltage(B+) supply in Ignition Switch ”ON” and ”ST” (IGN 1)
15ABattery Voltage(B+) supply in Ignition Switch ”ON” (IGN 2)
15CBattery Voltage(B+) supply in Ignition Switch ”ON” and ”ACC”
30Battery Voltage(B+) supply directly regardless of Ignition Switch
31Ground connected to battery()
58Battery Voltage(B+) supply in Head Lamp Switch 1st and 2nd step (Illumination circuit)
4. WIRING HARNESS COLOR IDENTIFICATION
AbbreviationColorAbbreviationColor
BrBrownSbSky Blue
GGreenRRed
VVioletLBlue
PPinkYYellow
WWhiteGrGray
OrOrangeBBlack
LgLight Green
5. HOW TO CHECK TERMINAL NUMBER OF CONNECTOR
" Terminal number is given based on Female Terminal Connectorex) Terminal Number 4 of C901 connection
Page 33 of 2643

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.
Page 34 of 2643

1A – 2IGENERAL ENGINE INFORMATION
DAEWOO V–121 BL4
OIL PRESSURE TEST
StepActionValue(s)YesNo
1Is the oil pressure warning lamp on?–Go to Step 2System OK
2Check the oil level in the crankcase.
Is the oil level low?–Go to Step 3Go to Step 4
3Add oil so that the oil level is up to the fullmark on the
indicator.
Is the repair complete?–Go to Step 1–
4Check the idle speed.
Is the idle speed below the specified value ?825 rpmGo to Step 5Go to Step 6
5Increase the idle speed.
Is the speed increased?–Go to Step 1–
6Inspect the oil pressure switch.
Is the oil pressure switch incorrect or malfunction-
ing?–Go to Step 7Go to Step 8
7Install a new oil pressure switch.
Is the repair complete?–Go to Step 1–
8Inspect the oil pressure gauge.
Is the oil pressure gauge incorrect or malfunction-
ing?–Go to Step 9Go to Step 10
9Install a new oil pressure gauge.
Is the repair complete?–Go to Step 1–
10Inspect the engine oil.
Is the engine oil in the crankcase diluted or of the im-
proper viscosity?–Go to Step 11Go to Step 12
11Install new engine oil of the proper viscosity for the
expected temperatures.
Is the repair complete?–Go to Step 1–
12Inspect the oil pump.
Is the pump worn or dirty?–Go to Step 13Go to Step 14
13Replace the oil pump.
Is the repair complete?–Go to Step 1–
14Inspect the oil filter.
Is the oil filter plugged?–Go to Step 15Go to Step 16
15Install a new oil filter.
Is the repair complete?–Go to Step 1–
16Inspect the oil pickup screen.
Is the oil pickup screen loose or plugged?–Go to Step 17Go to Step 18
17Tighten or replace the oil pickup screen, as neces-
sary.
Is the repair complete?–Go to Step 1–
18Inspect the oil pickup tube.
Are there any holes in the oil pickup tube?–Go to Step 19Go to Step 20
19Replace the oil pickup tube.
Is the repair complete?–Go to Step 1–
Page 35 of 2643

GENERAL ENGINE INFORMATION 1A – 3
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
20Inspect the bearing clearances.
Are the bearing clearances more than the specified
values?Crankshaft
0.026 ~0.046
mm
(0.0010~0.001
8 in.)
Connecting
Rod 0.019 ~
0.070 mm
(0.0007 ~
0.0027 in.)Go to Step 21Go to Step 22
21Replace the bearing, if necessary.
Is the repair complete?–Go to Step 1–
22Inspect the oil galleries.
Are the oil galleries cracked, porous, or plugged?–Go to Step 23Go to Step 24
23Repair or replace the engine block.
Is the repair complete?–Go to Step 1–
24Inspect the gallery plugs.
Are any of the gallery plugs missing or installed im-
properly?–Go to Step 25Go to Step 26
25Install the plugs or repair, as necessary.
Is the repair complete?–Go to Step 1–
26Inspect the camshaft.
Is the camshaft worn or is there evidence of poor
machining?–Go to Step 27System OK
27Replace the camshaft.
Is the repair complete?–Go to Step 1–
OIL LEAK DIAGNOSIS
Most fluid oil leaks are easily located and repaired by visu-
ally finding the leak and replacing or repairing the neces-
sary parts. On some occasions, a fluid leak may be difficult
to locate or repair. The following procedures may help you
in locating and repairing most leaks.
Finding the Leak:
1. Identify the fluid. Determine whether it is engine oil,
automatic transmission fluid, power steering fluid,
etc.
2. Identify where the fluid is leaking from.
1) After running the vehicle at normal operating
temperature, park the vehicle over a large sheet
of paper.
2) Wait a few minutes.
3) Find the approximate location of the leak by the
drippings on the paper.
3. Visually check around the suspected component.
Check around all the gasket mating surfaces for
leaks. A mirror is useful for finding leaks in areas
that are hard to reach.
4. If the leak still cannot be found, it may be neces-
sary to clean the suspected area with a degreaser,
steam, or spray solvent.
1) Thoroughly clean the area.2) Dry the area.
3) Operate the vehicle for several miles at normal
operating temperature and varying speeds.
4) After operating the vehicle, visually check the
suspected component.
5) If you still cannot locate the leak, try using the
powder or black light and dye method.
Powder Method:
1. Clean the suspected area.
2. Apply an aerosol–type powder, (such as foot pow-
der), to the suspected area.
3. Operate the vehicle under normal operating condi-
tions.
4. Visually inspect the suspected component. Trace
the leak path over the white powder surface to the
source.
Black Light and Dye Method:
A dye and light kit is available for finding leaks. Refer to the
manufacturer ’s directions when using the kit.
1. Pour the specified amount of dye into the engine oil
fill tube.
2. Operate the vehicle under normal operating condi-
tions as directed in the kit.
3. Direct the light toward the suspected area. The
dyed fluid will appear as a yellow path leading to
the source.
Page 36 of 2643

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.
Page 38 of 2643

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.