1998 OPEL FRONTERA oil

6A–5
ENGINE MECHANICAL
4. Engine Lacks Compression
Condition
Possible causeCorrection
Engine lacks compressionSpark plug loosely fitted or spark
plug gasket defectiveTighten to specified torque or replace
gasket
Valve timing incorrectAdjust
Cylinder head gasket defectiveReplace gasket
Valve incorrectly seatedLap valve
Valve stem seizedReplace valve and valve guide
Valve spring weakened or brokenReplace
Cylinder or piston rings wornOverhaul engine
Piston ring seizedOverhaul engine.
Engine Compression Test Procedure
1. Start and run the engine until the engine reaches
normal operating temperature.
2. Turn the engine off.
3. Remove all the spark plugs.
4. Remove ignition coil fuse (15A) and disable the
ignition system.
5. Remove the fuel pump relay from the relay and fuse
box.
6. Engage the starter and check that the cranking speed
is approximately 300 rpm.7. Install cylinder compression gauge into spark plug
hole.
8. With the throttle valve opened fully, keep the starter
engaged until the compression gage needle reaches
the maximum level. Note the reading.
9. Repeat the test with each cylinder.
If the compression pressure obtained falls below the
limit, engine overhaul is necessary.
Limit; 1000 kPa (145 psi)

6A–7
ENGINE MECHANICAL
Condition CorrectionPossible cause
OthersEngine lacks compressionRefer to “Hard Start”
Valve incorrectly seatedLap valve
Air Cleaner Filter cloggedReplace filter element
Valve timing incorrectReadjust
Idle air control valve brokenReplace
Fast idle solenoid defectiveReplace
Positive Crankcase Ventilation valve
defective or cloggedReplace
Rough Engine Running
ConditionPossible causeCorrection
Engine misfires periodicallyIgnition coil layer shortedReplace
Spark plugs foulingClean or install hotter type plug
Spark plug(s) insulator nose leakingReplace
Fuel injector(s) defectiveReplace
Powertrain control module faultyReplace
Engine knocks periodicallySpark plugs running too hotInstall colder type spark plugs
Powertrain control module faultyReplace
Engine lacks powerSpark plugs fouledClean
Fuel injectors defectiveReplace
Mass Airflow Sensor or Intake
Airflow Sensor circuit defectiveCorrect or replace
Manifold Absolute Pressure (MAP)
Sensor or Manifold Absolute
Pressure Sensor circuit defectiveCorrect or replace
Engine Coolant Temperature Sensor
or Engine Coolant Temperature
Sensor circuit defectiveCorrect or replace
Powertrain Control Module faultyReplace
Intake Air Temperature Sensor or
Intake Air Temperature Sensor
circuit defectiveCorrect or replace
Throttle Position Sensor or Throttle
Position Sensor circuit defectiveCorrect or replace
Knock Sensor or Knock Sensor
circuits defectiveCorrect or replace
Knock Sensor Module or Knock
Sensor Module circuits defectiveCorrect or replace

6A–10
ENGINE MECHANICAL
Engine Lacks Power
ConditionPossible causeCorrection
Trouble in fuel systemFuel Pressure Control Valve not
working normallyReplace
Fuel injector cloggedClean or replace
Fuel pipe cloggedClean
Fuel filter clogged or fouledReplace
Fuel pump drive circuit not working
normallyCorrect or replace
Fuel tank not sufficiently breathing
due to clogged Evaporative
Emission Control System circuitClean or replace
Water in fuel systemClean
Inferior quality fuel in fuel systemUse fuel of specified octane rating
Powertrain Control Module supplied
poor voltageCorrect circuit
Throttle Position Sensor cable
broken or poor connectionsCorrect or replace
Throttle Position Sensor defectiveReplace
Mass Airflow Sensor not working
normallyReplace
Manifold Absolute Pressure Sensor
not working normallyReplace
Intake Air Temperature Sensor not
working normallyReplace
Engine Coolant Temperature Sensor
circuit open or shortedCorrect or replace
Engine Coolant Temperature Sensor
defectiveReplace
Powertrain Control Module defectiveReplace
Trouble in intake or exhaust systemAir Cleaner Filter cloggedReplace filter element
Air duct kinked or flattenedCorrect or replace
Ignition failure————Refer to Hard Start Troubleshooting
Guide
Heat range of spark plug inadequateInstall spark plugs of adequate heat
range
Ignition coil defectiveReplace

6A–11
ENGINE MECHANICAL
Condition CorrectionPossible cause
Engine overheatingLevel of Engine Coolant too lowReplenish
Fan clutch defectiveReplace
Incorrect fan installedReplace
Thermostat defectiveReplace
Engine Coolant pump defectiveCorrect or replace
Radiator cloggedClean or replace
Radiator filler cap defectiveReplace
Level of oil in engine crankcase too
low or wrong engine oilChange or replenish
Resistance in exhaust system
increasedClean exhaust system or replace
defective parts
Throttle Position Sensor adjustment
incorrectReplace with Throttle Valve ASM
Throttle Position Sensor circuit open
or shortedCorrect or replace
Cylinder head gasket damagedReplace
Engine overcoolingThermostat defectiveReplace (Use a thermostat set to
open at 82
C (180F))
Engine lacks compression————Refer to Hard Start
OthersTire inflation pressure abnormalAdjust to recommended pressures
Brake dragAdjust
Clutch slippingAdjust or replace
Level of oil in engine crankcase too
highCorrect level of engine oil
Exhaust Gas Recirculation Valve
defectiveReplace
Engine Noisy
Abnormal engine noise often consists of various noises
originating in rotating parts, sliding parts and othermoving parts of the engine. It is, therefore, advisable to
locate the source of noise systematically.
Condition
Possible causeCorrection
Noise from crank journals or from
crank bearings
(Faulty crank journals and crankOil clearance increased due to worn
crank journals or crank bearingsReplace crank bearings and
crankshaft or regrind crankshaft and
install the undersize bearing
yj
bearings usually make dull noise that
becomes more evident when
accelerating)Crankshaft out of roundReplace crank bearings and
crankshaft or regrind crankshaft and
install the undersize bearing
Crank bearing seizedCrank bearing seized. Replace crank
bearings and crankshaft or regrind
crankshaft and install the undersize
bearing
Troubleshooting Procedure
Short out each spark plug in sequence using insulated
spark plug wire removers. Locate cylinder with defectivebearing by listening for abnormal noise that stops when
spark plug is shorted out.

6A–14
ENGINE MECHANICAL
Condition CorrectionPossible cause
Trouble in emission control systemHeated Oxygen Sensor circuit openCorrect or replace
Heated Oxygen Sensor defectiveReplace
Signal vacuum hose loosely fitted or
defectiveCorrect or replace
EGR Valve circuit open or shortedCorrect or replace
Exhaust Gas Recirculation Valve
defectiveReplace
ECT Sensor circuit open or shortedCorrect or replace
Canister Purge Valve circuit open or
shortedCorrect or replace
Canister Purge Valve defectiveReplace
ECT Sensor defectiveReplace
Positive Crankcase Ventilation
(PCV) valve and hose cloggedCorrect or replace
Evaporator systemRefer to Section 6E
Trouble in ignition system————Refer to “Engine Lacks Power”
Trouble in cylinder head partsCarbon deposits in combustion
chamberRemove carbon
Carbon deposit on valve, valve seat
and valve guideRemove carbon
Engine Oil Consumption Excessive
ConditionPossible causeCorrection
Oil leakingOil pan drain plug looseRetighten or replace gasket
Crankcase fixing bolts loosenedRetighten
Oil pan setting bolts loosenedRetighten
Oil pan gasket brokenReplace gasket
Front cover retaining bolts loose or
gasket brokenRetighten or replace gasket
Head cover fixing bolts loose or
gasket brokenRetighten or replace gasket
Oil cooler adapter crackedReplace
Oil cooler center bolt looseRetighten
Oil cooler O–ring brokenReplace
Oil cooler piping loose or brokenRetighten or replace
Oil filter adapter crackedReplace
Oil filter attaching bolt loose or rubber
gasket brokenRetighten or replace oil filter
Oil cooler brokenReplace
Crankshaft front or rear oil seal
defectiveReplace oil seal
Oil pressure unit loose or brokenRetighten or replace
Blow–by gas hose brokenReplace hose
Positive Crankcase Ventilation Valve
cloggedClean
Engine/Transmission coupling failedReplace oil seal

6A–15
ENGINE MECHANICAL
Condition CorrectionPossible cause
Oil leaking into combustion
chambers due topoor seal in valve
Valve stem oil seal defectiveReplace
chambers due to oor seal in valve
systemValve stem or valve guide wornReplace valve and valve guide
Oil leaking into combustion
chambers due to poor seal in cylinder
t
Cylinders and pistons worn
excessivelyReplace cylinder body assembly and
pistons
partsPiston ring gaps incorrectly
positionedCorrect
Piston rings set with wrong side upCorrect
Piston ring stickingReplace cylinder body assembly and
pistons
Piston ring and ring groove wornReplace pistons and others
Return ports in oil rings cloggedClean piston and replace rings
Positive Crankcase Ventilation
System malfunctioningPositive Crankcase Ventilation Valve
cloggedClean
OthersImproper oil viscosityUse oil of recommended S.A.E.
viscosity
Continuous high speed driving
and/or severe usage such as trailer
towingContinuous high speed operation
and/or severe usage will normally
cause increased oil consumption
Fuel Consumption Excessive
ConditionPossible causeCorrection
Trouble in fuel systemMixture too rich or too lean due to
trouble in fuel injection systemRefer to “Abnormal Combustion”
Fuel cut function does not workRefer to “Abnormal Combustion”
Trouble in ignition systemMisfiring or abnormal combustion
due to trouble in ignition systemRefer to “Hard Start” or “Abnormal
Combustion”
OthersEngine idle speed too highReset Idle Air Control Valve
Returning of accelerator control
sluggishCorrect
Fuel system leakageCorrect or replace
Clutch slippingCorrect
Brake dragCorrect
Selection of transmission gear
incorrectCaution operator of incorrect gear
selection
Excessive Exhaust Gas
Recirculation flow due to trouble in
Exhaust Gas Recirculation systemRefer to “Abnormal Combustion”

6A–16
ENGINE MECHANICAL
Lubrication Problems
ConditionPossible causeCorrection
Oil pressure too lowWrong oil in useReplace with correct engine oil
Relief valve stickingReplace
Oil pump not operating properlyCorrect or replace
Oil pump strainer cloggedClean or replace strainer
Oil pump wornReplace
Oil pressure gauge defectiveCorrect or replace
Crankshaft bearing or connecting
rod bearing wornReplace
Oil contaminationWrong oil in useReplace with correct engine oil
Oil filter cloggedReplace oil filter
Cylinder head gasket damageReplace gasket
Burned gases leakingReplace piston and piston rings or
cylinder body assembly
Oil not reaching valve systemOil passage in cylinder head or
cylinder body cloggedClean or correct
Engine Oil Pressure Check
1. Check for dirt, gasoline or water in the engine oil.
a. Check the viscosity of the oil.
b. Change the oil if the viscosity is outside the
specified standard.
c. Refer to the “Maintenance and Lubrication” section
of this manual.
2. Check the engine oil level.
The level should fall somewhere between the “ADD”
and the “FULL” marks on the oil level dipstick.
If the oil level does not reach the “ADD” mark on the
oil level dipstick, engine oil must be added.3. Remove the oil pressure unit.
4. Install an oil pressure gauge.
5. Start the engine and allow the engine to reach normal
operating temperature (About 80
C).
6. Measure the oil pressure.
Oil pressure should be:
392–550 kPa (56.9–80.4 psi) at 3000 rpm.
7. Stop the engine.
8. Remove the oil pressure gauge.
9. Install the oil pressure unit.
10. Start the engine and check for leaks.

6A–18
ENGINE MECHANICAL
Cylinder Head Cover LH
Removal
1. Disconnect battery ground cable.
2. Drain engine coolant from faucet bottom of radiator.
3. Remove engine cover from the dowels on the
common chamber.
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4. Remove air cleaner duct assembly (3) and air cleaner
element (4).
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Legend
(1) Positive Crankcase Ventilation Hose Connector
(2) Intake Air Temperature Sensor
(3) Air Cleaner Duct Assembly
(4) Air Cleaner Element
(5) Mass Air Flow Sensor
NOTE: Disconnect the mass air flow (MAF) sensor
connector, intake air temperature (IAT) sensor connector,
and positive crankcase ventilation (PCV) hose before
hand the air cleaner duct assembly is removed.5. Disconnect following wiring connectors and bonding
cable:
Manifold Absolute Pressure (MAP) sensor
Vacuum Switching Valve (VSV) for Induction Air
Control Valve (IACV) actuator
Ignition coils for left bank
Fuel injectors for left bank
Idle air control (IAC) valve
Throttle position sensor (TPS)
Bonding cable
Others as necessitated
6. Disconnect following vacuum hoses:
Brake master VAC
Canister
VSV for IACV actuator
Duty solenoid valve
PCV
7. Disconnect radiator upper and lower hoses
8. Remove engine harness from the cylinder head
cover.
9. Remove the upper fan guide.
10. Remove cooling fan and clutch assembly.
11. Remove drive belt by pushing down the auto
tensioner using spanner as illustrated.
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