fuel SUBARU LEGACY 1999 Service Owner's Manual

TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK
3. Low output, hesitation and
poor accelerationIFuel injection system A
IIntake systemILoosened or cracked intake duct A
ILoosened or cracked PCV hose A
ILoosened or cracked vacuum hose B
IDefective intake manifold gasket B
IDefective throttle body gasket B
IDefective PCV valve B
ILoosened oil filter cap B
IDirty air cleaner element A
IFuel lineIDefective fuel pump and relay B
IClogged fuel line B
ILack of or insufficient fuel C
IBeltIDefective timing B
ICompressionIIncorrect valve clearance B
ILoosened spark plugs or defective gasket B
ILoosened cylinder head bolts or defective gasket B
IImproper valve seating B
IDefective valve stem C
IWorn or broken valve spring B
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing A
IImproper engine oil (low viscosity) B
ILubrication systemIIncorrect oil pressure B
ICooling systemIOverheating C
IOver cooling C
IOthersIMalfunction of evaporative emission control system A
4. SurgingIFuel injection system A
IIntake systemILoosened or cracked intake duct A
ILoosened or cracked PCV hose A
ILoosened or cracked vacuum hose A
IDefective intake manifold gasket B
IDefective throttle body gasket B
IDefective PCV valve B
ILoosened oil filter cap B
IDirty air cleaner element B
IFuel lineIDefective fuel pump and relay B
IClogged fuel line B
ILack of or insufficient fuel C
IBeltIDefective timing B
ICompressionIIncorrect valve clearance B
ILoosened spark plugs or defective gasket C
ILoosened cylinder head bolts or defective gasket C
IImproper valve seating C
IDefective valve stem C
IWorn or broken valve spring C
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing A
IImproper engine oil (low viscosity) B
ICooling systemIOverheating B
IOthersIMalfunction of evaporative emission control system C
75
[K100]2-3aDIAGNOSTICS
1. Engine Trouble in General

TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK
5. Engine does not return to
idle.Fuel injection system A
IIntake systemILoosened or cracked vacuum hose A
IOthersIStuck or damaged throttle valve A
IAccelerator cable out of adjustment B
6. Dieseling (Run-on)IFuel injection system A
ICooling systemIOverheating B
IOthersIMalfunction of evaporative emission control system B
7. After burning in exhaust
systemIFuel injection system A
IIntake systemILoosened or cracked intake duct C
ILoosened or cracked PCV hose C
ILoosened or cracked vacuum hose B
IDefective PCV valve B
ILoosened oil filter cap C
IBeltIDefective timing B
ICompressionIIncorrect valve clearance B
ILoosened spark plugs or defective gasket C
ILoosened cylinder head bolts or defective gasket C
IImproper valve seating B
IDefective valve stem C
IWorn or broken valve spring C
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing A
ILubrication systemIIncorrect oil pressure C
ICooling systemIOver cooling C
IOthersIMalfunction of evaporative emission control system C
8. KnockingIFuel injection system A
IIntake systemILoosened oil filter cap B
IBeltIDefective timing B
ICompressionIIncorrect valve clearance C
IIncorrect valve timing B
ICooling systemIOverheating A
9. Excessive engine oil con-
sumptionIIntake systemILoosened or cracked PCV hose A
IDefective PCV valve B
ILoosened oil filter cap C
ICompressionIDefective valve stem A
IWorn or stuck piston rings, cylinder and piston A
ILubrication systemILoosened oil pump attaching bolts and defective
gasketB
IDefective oil filter seal B
IDefective crankshaft oil seal B
IDefective rocker cover gasket B
ILoosened oil drain plug or defective gasket B
ILoosened oil pan fitting bolts or defective oil pan B
76
2-3a[K100]DIAGNOSTICS
1. Engine Trouble in General

TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK
10. Excessive fuel consump-
tionIFuel injection system A
IIntake systemIDirty air cleaner element A
IBeltIDefective timing B
ICompressionIIncorrect valve clearance B
ILoosened spark plugs or defective gasket C
ILoosened cylinder head bolts or defective gasket C
IImproper valve seating B
IDefective valve stem C
IWorn or broken valve spring C
IWorn or stuck piston rings, cylinder and piston B
IIncorrect valve timing B
ILubrication systemIIncorrect oil pressure C
ICooling systemIOver cooling C
IOthersIAccelerator cable out of adjustment B
77
[K100]2-3aDIAGNOSTICS
1. Engine Trouble in General

2. Engine Noise
Type of sound Condition Possible cause
Regular clicking soundSound increases as engine
speed increases.IValve mechanism is defective.
IIncorrect valve clearance
IWorn valve rocker
IWorn camshaft
IBroken valve spring
Heavy and dull clankOil pressure is low.IWorn crankshaft main bearing
IWorn connecting rod bearing (big end)
Oil pressure is normal.ILoose flywheel mounting bolts
IDamaged engine mounting
High-pitched clank
(Spark knock)Sound is noticeable when
accelerating with an overload.IIgnition timing advanced
IAccumulation of carbon inside combustion chamber
IWrong spark plug
IImproper gasoline
Clank when engine speed is
medium (1,000 to 2,000 rpm)Sound is reduced when fuel
injector connector of noisy cyl-
inder is disconnected.
(NOTE*)IWorn crankshaft main bearing
IWorn bearing at crankshaft end of connecting rod
Knocking sound when engine
is operating under idling speed
and engine is warmSound is reduced when fuel
injector connector of noisy cyl-
inder is disconnected.
(NOTE*)IWorn cylinder liner and piston ring
IBroken or stuck piston ring
IWorn piston pin and hole at piston end of connecting rod
Sound is not reduced if each
fuel injector connector is dis-
connected in turn. (NOTE*)IUnusually worn valve lifter
IWorn cam gear
IWorn camshaft journal bore in crankcase
Squeaky sound ÐIInsufficient generator lubrication
Rubbing sound ÐIDefective generator brush and rotor contact
Gear scream when starting
engineÐIDefective ignition starter switch
IWorn gear and starter pinion
Sound like polishing glass with
a dry clothÐILoose drive belt
IDefective engine coolant pump shaft
Hissing sound ÐILoss of compression
IAir leakage in air intake system, hoses, connections or
manifolds
Timing belt noise ÐILoose timing belt
IBelt contacting case/adjacent part
Valve tappet noise ÐIIncorrect valve clearance
NOTE*:
When disconnecting fuel injector connector, Malfunction Indicator Light (CHECK ENGINE light) illuminates and trouble code is
stored in ECM memory.
Therefore, carry out the CLEAR MEMORY MODE and INSPECTION MODE after con-
necting fuel injector connector.
78
2-3a[K200]DIAGNOSTICS
2. Engine Noise

1. Engine Trouble in General
NOTE:
A, B and C shown in the RANK of table refer to the
possibility of reason for the trouble in order (ªVery
oftenº to ªRarelyº).A : Very often
B : Sometimes
C : Rarely
TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK
1. Engine will not start.
1) Starter does not turn.IStarterIDefective battery-to-starter harness B
IDefective starter switch C
IDefective inhibitor switch or neutral switch C
IDefective starter B
IBatteryIPoor terminal connection A
IRun-down battery A
IDefective charging system B
IFrictionISeizure of crankshaft and connecting rod bearing C
ISeized camshaft C
ISeized or stuck piston and cylinder C
2) Initial combustion does
not occur.IStarterIDefective starter C
IFuel injection system A
IFuel lineIDefective fuel pump and relay A
ILack of or insufficient fuel B
IBeltIDefective B
IDefective timing B
ICompressionIIncorrect valve clearance C
ILoosened spark plugs or defective gasket C
ILoosened cylinder head bolts or defective gasket C
IImproper valve seating C
IDefective valve stem C
IWorn or broken valve spring B
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing B
IImproper engine oil (low viscosity) B
3) Initial combustion
occurs.IFuel injection system A
IIntake systemIDefective intake manifold gasket B
IDefective throttle body gasket B
IFuel lineIDefective fuel pump and relay C
IClogged fuel line C
ILack of/or insufficient fuel B
IBeltIDefective B
IDefective timing B
ICompressionIIncorrect valve clearance C
ILoosened spark plugs or defective gasket C
ILoosened cylinder head bolts or defective gasket C
IImproper valve seating C
IDefective valve stem C
IWorn or broken valve spring B
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing B
IImproper engine oil (low viscosity) B
71
[K100]2-3bDIAGNOSTICS
1. Engine Trouble in General

TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK
4) Engine stalls after initial
combustion.IFuel injection system A
IIntake systemILoosened or cracked intake duct B
ILoosened or cracked PCV hose C
ILoosened or cracked vacuum hose C
IDefective intake manifold gasket B
IDefective throttle body gasket B
IDirty air cleaner element C
IFuel lineIClogged fuel line C
ILack of or insufficient fuel B
IBeltIDefective B
IDefective timing B
ICompressionIIncorrect valve clearance C
ILoosened spark plugs or defective gasket C
ILoosened cylinder head bolts or defective gasket C
IImproper valve seating C
IDefective valve stem C
IWorn or broken valve spring B
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing B
IImproper engine oil (low viscosity) B
2. Rough idle and engine
stallIFuel injection system A
IIntake systemILoosened or cracked intake duct A
ILoosened or cracked PCV hose A
ILoosened or cracked vacuum hose A
IDefective intake manifold gasket B
IDefective throttle body gasket B
IDefective PCV valve C
ILoosened oil filler cap B
IDirty air cleaner element C
IFuel lineIDefective fuel pump and relay C
IClogged fuel line C
ILack of/or insufficient fuel B
IBeltIDefective timing C
ICompressionIIncorrect valve clearance B
ILoosened spark plugs or defective gasket B
ILoosened cylinder head bolts or defective gasket B
IImproper valve seating B
IDefective valve stem C
IWorn or broken valve spring B
IWorn or stuck piston rings, cylinder and piston B
IIncorrect valve timing A
IImproper engine oil (low viscosity) B
ILubrication systemIIncorrect oil pressure B
IDefective rocker cover gasket C
ICooling systemIOverheating C
IOthersIMalfunction of evaporative emission control system A
IStuck or damaged throttle valve B
IAccelerator cable out of adjustment C
72
2-3b[K100]DIAGNOSTICS
1. Engine Trouble in General

TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK
3. Low output, hesitation
and poor accelerationIFuel injection system A
IIntake systemILoosened or cracked intake duct A
ILoosened or cracked PCV hose A
ILoosened or cracked vacuum hose B
IDefective intake manifold gasket B
IDefective throttle body gasket B
IDefective PCV valve B
ILoosened oil filler cap B
IDirty air cleaner element A
IFuel lineIDefective fuel pump and relay B
IClogged fuel line B
ILack of/or insufficient fuel C
IBeltIDefective timing B
ICompressionIIncorrect valve clearance B
ILoosened spark plugs or defective gasket B
ILoosened cylinder head bolts or defective gasket B
IImproper valve seating B
IDefective valve stem C
IWorn or broken valve spring B
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing A
IImproper engine oil (low viscosity) B
ILubrication systemIIncorrect oil pressure B
ICooling systemIOverheating C
IOver cooling C
IOthersIMalfunction of evaporative emission control system A
4. SurgingIFuel injection system A
IIntake systemILoosened or cracked intake duct A
ILoosened or cracked PCV hose A
ILoosened or cracked vacuum hose A
IDefective intake manifold gasket B
IDefective throttle body gasket B
IDefective PCV valve B
ILoosened oil filler cap B
IDirty air cleaner element B
IFuel lineIDefective fuel pump and relay B
IClogged fuel line B
ILack of/or insufficient fuel C
IBeltIDefective timing B
ICompressionIIncorrect valve clearance B
ILoosened spark plugs or defective gasket C
ILoosened cylinder head bolts or defective gasket C
IImproper valve seating C
IDefective valve stem C
IWorn or broken valve spring C
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing A
IImproper engine oil (low viscosity) B
ICooling systemIOverheating B
IOthersIMalfunction of evaporative emission control system C
73
[K100]2-3bDIAGNOSTICS
1. Engine Trouble in General

TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK
5. Engine does not return
to idle.IFuel injection system A
IIntake systemILoosened or cracked vacuum hose A
IOthersIStuck or damaged throttle valve A
IAccelerator cable out of adjustment B
6. Dieseling (Run-on)IFuel injection system A
ICooling systemIOverheating B
IOthersIAccelerator cable out of adjustment B
7. After burning in exhaust
systemIFuel injection system A
IIntake systemILoosened or cracked intake duct C
ILoosened or cracked PCV hose C
ILoosened or cracked vacuum hose B
IDefective PCV valve B
ILoosened oil filler cap C
IBeltIDefective timing B
ICompressionIIncorrect valve clearance B
ILoosened spark plugs or defective gasket C
ILoosened cylinder head bolts or defective gasket C
IImproper valve seating B
IDefective valve stem C
IWorn or broken valve spring C
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing A
ILubrication systemIIncorrect oil pressure C
ICooling systemIOver cooling C
IOthersIMalfunction of evaporative emission control system C
8. KnockingIFuel injection system A
IIntake systemILoosened oil filler cap B
IBeltIDefective timing B
ICompressionIIncorrect valve clearance C
IIncorrect valve timing B
ICooling systemIOverheating A
9. Excessive engine oil
consumptionIIntake systemILoosened or cracked PCV hose A
IDefective PCV valve B
ILoosened oil filler cap C
ICompressionIDefective valve stem A
IWorn or stuck piston rings, cylinder and piston A
ILubrication systemILoosened oil pump attaching bolts and defective gasket B
IDefective oil filter seal B
IDefective crankshaft oil seal B
IDefective rocker cover gasket B
ILoosened oil drain plug or defective gasket B
ILoosened oil pan fitting bolts or defective oil pan B
74
2-3b[K100]DIAGNOSTICS
1. Engine Trouble in General

TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK
10. Excessive fuel con-
sumptionIFuel injection system A
IIntake systemIDirty air cleaner element A
IBeltIDefective timing B
ICompressionIIncorrect valve clearance B
ILoosened spark plugs or defective gasket C
ILoosened cylinder head bolts or defective gasket C
IImproper valve seating B
IDefective valve stem C
IWorn or broken spring C
IWorn or stuck piston rings, cylinder and piston B
IIncorrect valve timing B
ILubrication systemIIncorrect oil pressure C
ICooling systemIOver cooling C
IOthersIAccelerator cable out of adjustment B
75
[K100]2-3bDIAGNOSTICS
1. Engine Trouble in General

2. Engine Noise
If noise still exists, conduct diagnostics procedures
in accordance with the following table.CAUTION:
Do not disconnect spark plug cord while
engine is running.
Type of sound Condition Possible cause
Regular clicking soundSound increases as engine
speed increases.Valve mechanism is defective.
IIncorrect valve clearance
IWorn camshaft
IBroken valve spring
Heavy and dull clankOil pressure is low.IWorn crankshaft main bearing
IWorn connecting rod bearing (big end)
Oil pressure is normal.ILoose flywheel mounting bolts
IDamaged engine mounting
High-pitched clank
(Spark knock)Sound is noticeable when
accelerating with an overload.IIgnition timing advanced
IAccumulation of carbon inside combustion chamber
IWrong spark plug
IImproper gasoline
Clank when engine speed is
medium (1,000 to 2,000 rpm).Sound is reduced when fuel
injector connector of noisy cyl-
inder is disconnected.
(NOTE*)IWorn crankshaft main bearing
IWorn bearing at crankshaft end of connecting rod
Knocking sound when engine
is operating under idling speed
and engine is warm.Sound is reduced when fuel
injector connector of noisy cyl-
inder is disconnected.
(NOTE*)IWorn cylinder liner and piston ring
IBroken or stuck piston ring
IWorn piston pin and hole at piston end of connecting rod
Sound is not reduced if each
fuel injector connector is dis-
connected in turn.
(NOTE*)IUnusually worn valve lifter
IWorn camshaft journal bore in crankcase
Squeaky sound ÐIInsufficient generator lubrication
Rubbing sound ÐIDefective generator brush and rotor contact
Gear scream when starting
engineÐIDefective ignition starter switch
IWorn gear and starter pinion
Sound like polishing glass with
a dry clothÐILoose drive belt
IDefective engine coolant pump shaft
Hissing sound ÐILoss of compression
IAir leakage in air intake system, hoses, connections or
manifolds
Timing belt noise ÐILoose timing belt
IBelt contacting case/adjacent part
Valve tappet noise ÐIIncorrect valve clearance
NOTE*:
When disconnecting fuel injector connector, Malfunction Indicator Light (CHECK ENGINE light) illuminates and trouble code is
stored in ECM memory.
Therefore, carry out the CLEAR MEMORY MODE and INSPECTION MODE after connecting fuel injector connector. [T6A0].>
76
2-3b[K200]DIAGNOSTICS
2. Engine Noise