1999 SUBARU LEGACY low oil pressure

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

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) Remove left-hand intake camshaft sprocket.
2) Remove left-hand exhaust camshaft sprocket.
3) Remove right-hand intake camshaft sprocket.
4) Remove right-hand exhaust camshaft sprocket.
ST 499207300 CAMSHAFT SPROCKET
WRENCH
S2M0413A
5) Remove crankshaft sprocket.
S2M0414
6) Remove tensioner bracket.
H2M2407
7) Remove left-hand belt cover No. 2.
S2M0415
8) Remove right-hand belt cover No. 2.
B2M0738
B: INSPECTION
1. TIMING BELT
1) Check timing belt teeth for breaks, cracks and
wear. If any fault is found, replace belt.
2) Check the condition of back side of belt; if any
crack is found, replace belt.
CAUTION:
IBe careful not to let oil, grease or coolant
contact the belt. Remove quickly and thor-
oughly if this happens.
IDo not bend the belt sharply.
Bending radius: h
60 mm (2.36 in) or more
G2M0115
2. AUTOMATIC BELT TENSION
ADJUSTER
1) Visually check oil seals for leaks, and rod ends
for abnormal wear or scratches. If necessary,
replace automatic belt tension adjuster assembly.
CAUTION:
Slight traces of oil at rod's oil seal does not
indicate a problem.
2) Check that the adjuster rod does not move
when a pressure of 294 N (30 kg, 66 lb) is applied
to it. This is to check adjuster rod stiffness.
3) If the adjuster rod is not stiff and moves freely
when applying 294 N (30 kg, 66 lb), check it using
the following procedures:
19
[W2B2]2-3bSERVICE PROCEDURE
2. Timing Belt

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

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

1. Specifications
A: 2200 cc MODEL
Lubrication methodForced lubrication
Oil pumpPump type Trochoid type
Number of teethInner rotor 9
Outer rotor 10
Outer rotor diameter´thickness 78´9 mm (3.07´0.35 in)
Tip clearance between inner and outer rotorSTANDARD 0.04 Ð 0.14 mm (0.0016 Ð 0.0055 in)
LIMIT 0.18 mm (0.0071 in)
Side clearance between inner rotor and
pump caseSTANDARD 0.02 Ð 0.07 mm (0.0008 Ð 0.0028 in)
LIMIT 0.15 mm (0.0059 in)
Case clearance between outer rotor and
pump caseSTANDARD 0.10 Ð 0.175 mm (0.0039 Ð 0.0069 in)
LIMIT 0.20 mm (0.0079 in)
Capacity at
80ÉC (176ÉF)700 rpm Discharge- pressure 98 kPa (1.0 kg/cm
2, 14 psi) or more
- quantity 4.2(4.4 US qt, 3.7 Imp qt)/min.
5,000 rpm Discharge- pressure 294 kPa (3.0 kg/cm
2, 43 psi) or more
- quantity 42.0(11.10 US gal, 9.24 Imp gal)/min.
Relief valve operation pressure 490 kPa (5.0 kg/cm
2, 71 psi)
Oil filterTypeFull-flow filter type
Filtration area 1,000 cm
2(155 sq in)
By-pass valve opening pressure 157 kPa (1.6 kg/cm2, 23 psi)
Outer diameter´width 80´70 mm (3.15´2.76 in)
Oil filter to engine thread size M 20´1.5
Relief valve (on rocker shaft) operation pressure 69 kPa (0.7 kg/cm
2, 10 psi)
Oil pressure
switchType Immersed contact point type
Working voltage Ð wattage 12 V Ð 3.4 W or less
Warning light activation pressure 14.7 kPa (0.15 kg/cm
2, 2.1 psi)
Proof pressure More than 981 kPa (10 kg/cm2, 142 psi)
Oil pan capacity4.0(4.2 US qt, 3.5 Imp qt)
2
2-4[S1A0]SPECIFICATIONS AND SERVICE DATA
1. Specifications

B: 2500 cc MODEL
Lubrication methodForced lubrication
Oil pumpPump type Trochoid type
Number of teethInner rotor 9
Outer rotor 10
Outer rotor diameter´thickness 78´10 mm (3.07´0.39 in)
Tip clearance between inner and outer rotorSTANDARD 0.04 Ð 0.14 mm (0.0016 Ð 0.0055 in)
LIMIT 0.18 mm (0.0071 in)
Side clearance between inner rotor and pump
caseSTANDARD 0.02 Ð 0.07 mm (0.0008 Ð 0.0028 in)
LIMIT 0.15 mm (0.0059 in)
Case clearance between outer rotor and
pump caseSTANDARD 0.10 Ð 0.175 mm (0.0039 Ð 0.0069 in)
LIMIT 0.20 mm (0.0079 in)
Capacity at
80ÉC (176ÉF)600 rpm Discharge- pressure 98 kPa (1.0 kg/cm
2, 14 psi) or more
- quantity 4.6(4.9 US qt, 4.0 Imp qt)/min.
5,000 rpm Discharge- pressure 294 kPa (3.0 kg/cm
2, 43 psi) or more
- quantity 47.0(12.4 US gal, 10.3 Imp gal)/min.
Relief valve operation pressure 588 kPa (6.0 kg/cm
2, 85 psi)
Oil filterTypeFull-flow filter type
Filtration area 1,000 cm
2(155 sq in)
By-pass valve opening pressure 157 kPa (1.6 kg/cm2, 23 psi)
Outer diameter´width 80´70 mm (3.15´2.76 in)
Oil filter to engine thread size M 20´1.5
Oil pressure
switchType Immersed contact point type
Working voltage Ð wattage 12 V Ð 3.4 W or less
Warning light activation pressure 14.7 kPa (0.15 kg/cm
2, 2.1 psi)
Proof pressure More than 981 kPa (10 kg/cm2, 142 psi)
Oil pan capacity4.5(4.8 US qt, 4.0 Imp qt)
3
[S1B0]2-4SPECIFICATIONS AND SERVICE DATA
1. Specifications