heating SUBARU LEGACY 1999 Service Repair Manual

TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK
4) Engine stalls after initial
combustion.Fuel injection system A
IIntake systemILoosened or cracked intake uct 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 stall Fuel 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 filter 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
74
2-3a[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 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
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

1. Engine Cooling System Trouble in General
TroubleCorrective action
Over-heatinga. Insufficient engine coolantReplenish engine coolant, inspect for leakage, and
repair.
b. Loose timing belt Repair or replace timing belt tensioner.
c. Oil on drive belt Replace.
d. Malfunction of thermostat Replace.
e. Malfunction of water pump Replace.
f. Clogged engine coolant passage Clean.
g. Improper ignition timingInspect and repair ignition control system.
On-Board Diagnostics II System
h. Clogged or leaking radiator Clean or repair, or replace.
i. Improper engine oil in engine coolant Replace engine coolant.
j. Air/fuel mixture ratio too leanInspect and repair fuel injection system.
On-Board Diagnostics II System
k. Excessive back pressure in exhaust system Clean or replace.
l. Insufficient clearance between piston and cylinder Adjust or replace.
m. Slipping clutch Repair or replace.
n. Dragging brake Adjust.
o. Improper transmission oil Replace.
p. Defective thermostat Replace.
q. Malfunction of electric fanInspect radiator fan relay, engine coolant temperature
sensor or radiator motor and replace there.
Over-coolinga. Atmospheric temperature extremely low Partly cover radiator front area.
b. Defective thermostat Replace.
Engine coolant
leaks.a. Loosened or damaged connecting units on
hosesRepair or replace.
b. Leakage from water pump Replace.
c. Leakage from water pipe Repair or replace.
d. Leakage around cylinder head gasket Retighten cylinder head bolts or replace gasket.
e. Damaged or cracked cylinder head and crank-
caseRepair or replace.
f. Damaged or cracked thermostat case Repair or replace.
g. Leakage from radiator Repair or replace.
Noisea. Defective drive belt Replace.
b. Defective radiator fan Replace.
c. Defective water pump bearing Replace water pump.
d. Defective water pump mechanical seal Replace water pump.
26
2-5[K100]DIAGNOSTICS
1. Engine Cooling System Trouble in General

1. Specifications
A: HEATER SYSTEM
Item Specifications Condition
Heating capacity 4.652 kW (4,000 kcal/h, 15,872 BTU/h) or more ...
When 300 m
3(10,593 cu ft)/hMode selector switch HEAT
Temp. control lever FULL HOT
Temperature difference
between hot water and
inlet air65ÉC (149ÉF)
Hot water flow rate 360(95.1 US
gal, 79.2 Imp
gal)/h
Air flow rate 300 m
3(10,593 cu ft)/h Heat mode (FRESH), FULL HOT at 12.5
V
Max air flow rate 510 m
3(18,008 cu ft)/h Temperature control
leverFULL COLD
Blower fan speed 4th position
RECIRC switch position RECIRC
Heater core size (height´
length´width´thickness)193.5´152.0´25.0´0.9 mm
(7.62´5.98´0.984´0.035 in)Ð
Blower
motorType Magnet motor 230 W or less at 12 V
Fan type and
size
(diameter´
width)Sirocco fan type
150´75 mm (5.91´2.95 in)
Ð
2
4-6[S1A0]SPECIFICATIONS AND SERVICE DATA
1. Specifications

E: INSPECTION
Check electrodes and inner and outer porcelain of
plugs, noting the type of deposits and the degree
of electrode erosion.
G6M0086
1) Normal
Brown to grayish-tan deposits and slight electrode
wear indicate correct spark plug heat range.
G6M0087
2) Carbon fouled
Dry fluffy carbon deposits on insulator and elec-
trode are mostly caused by slow speed driving in
city, weak ignition, too rich fuel mixture, dirty air
cleaner, etc.
It is advisable to replace with plugs having hotter
heat range.
G6M0088
3) Oil fouled
Wet black deposits show excessive oil entrance
into combustion chamber through worn rings and
pistons or excessive clearance between valve
guides and stems. If same condition remains after
repair, use a hotter plug.
G6M0089
4) Overheating
White or light gray insulator with black or gray
brown spots and bluish burnt electrodes indicate
engine overheating. Moreover, the appearance
results from incorrect ignition timing, loose spark
plugs, wrong selection of fuel, hotter range plug,
etc. It is advisable to replace with plugs having
colder heat range.
G6M0090
33
[W3E0]6-1SERVICE PROCEDURE
3. Spark Plug