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
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–
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–
ENGINE CONTROLS 1F – 629
DAEWOO V–121 BL4
tentially interfere with the operation of the Exhaust Gas
Recirculation (EGR) valve and thereby turn on the MIL.
Small leaks in the exhaust system near the post catalyst
oxygen sensor can also cause the MIL to turn on.
Aftermarket electronics, such as cellular phones, stereos,
and anti–theft devices, may radiate electromagnetic inter-
ference (EMI) into the control system if they are improperly
installed. This may cause a false sensor reading and turn
on the MIL.
Environment
Temporary environmental conditions, such as localized
flooding, will have an effect on the vehicle ignition system.
If the ignition system is rain–soaked, it can temporarily
cause engine misfire and turn on the MIL.
Refueling
A new EOBD diagnostic checks the integrity of the entire
Evaporative (EVAP) Emission system. If the vehicle is re-
started after refueling and the fuel cap is not secured cor-
rectly, the on–board diagnostic system will sense this as
a system fault, turn on the MIL, and set DTC P0440.
Vehicle Marshaling
The transportation of new vehicles from the assembly
plant to the dealership can involve as many as 60 key
cycles within 2 to 3 miles of driving. This type of operation
contributes to the fuel fouling of the spark plugs and will
turn on the MIL with a set DTC P0300.
Poor Vehicle Maintenance
The sensitivity of EOBD diagnostics will cause the MIL to
turn on if the vehicle is not maintained properly. Restricted
air filters, fuel filters, and crankcase deposits due to lack
of oil changes or improper oil viscosity can trigger actual
vehicle faults that were not previously monitored prior to
EOBD. Poor vehicle maintenance can not be classified as
a ”non–vehicle fault,” but with the sensitivity of EOBD
diagnostics, vehicle maintenance schedules must be
more closely followed.
Severe Vibration
The Misfire diagnostic measures small changes in the
rotational speed of the crankshaft. Severe driveline vibra-
tions in the vehicle, such as caused by an excessive
amount of mud on the wheels, can have the same effect
on crankshaft speed as misfire and, therefore, may set
DTC P0300.
Related System Faults
Many of the EOBD system diagnostics will not run if the
engine controlmodule (ECM) detects a fault on a related
system or component. One example would be that if the
ECM detected a Misfire fault, the diagnostics on the cata-
lytic converter would be suspended until the Misfire fault
was repaired. If the Misfire fault is severe enough, the cat-
alytic converter can be damaged due to overheating andwill never set a Catalyst DTC until the Misfire fault is re-
paired and the Catalyst diagnostic is allowed to run to
completion. If this happens, the customer may have to
make two trips to the dealership in order to repair the ve-
hicle.
SERIAL DATA COMMUNICATIONS
Class II Serial Data Communications
Government regulations require that all vehicle manufac-
turers establish a common communication system. This
vehicle utilizes the ”Class II” communication system. Each
bit of information can have one of two lengths: long or
short. This allows vehicle wiring to be reduced by transmit-
ting and receiving multiple signals over a single wire. The
messages carried on Class II data streams are also priori-
tized. If two messages attempt to establish communica-
tions on the data line at the same time, only the message
with higher priority will continue. The device with the lower
priority message must wait. Themost significant result of
this regulation is that it provides scan tool manufacturers
with the capability to access data from any make or model
vehicle that is sold.
The data displayed on the other scan tool will appear the
same, with some exceptions. Some scan tools will only be
able to display certain vehicle parameters as values that
are a coded representation of the true or actual value. On
this vehicle the scan tool displays the actual values for ve-
hicle parameters. It will not be necessary to perform any
conversions from coded values to actual values.
ON–BOARD DIAGNOSTIC (EOBD)
On–Board Diagnostic Tests
A diagnostic test is a series of steps, the result of which is
a pass or fail reported to the diagnostic executive. When
a diagnostic test reports a pass result, the diagnostic
executive records the following data:
S The diagnostic test has been completed since the
last ignition cycle.
S The diagnostic test has passed during the current
ignition cycle.
S The fault identified by the diagnostic test is not cur-
rently active.
When a diagnostic test reports a fail result, the diagnostic
executive records the following data:
S The diagnostic test has been completed since the
last ignition cycle.
S The fault identified by the diagnostic test is current-
ly active.
S The fault has been active during this ignition cycle.
S The operating conditions at the time of the failure.
Remember, a fuel trim Diagnostic Trouble Code (DTC)
may be triggered by a list of vehicle faults. Make use of all
information available (other DTCs stored, rich or lean con-
dition, etc.) when diagnosing a fuel trim fault.