Subaru Impreza 2004 User manual

FUJI HEAVY INDUSTRIES LTD. G1870GE3
2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX
ENGINE SECTION 2
This service manual has been prepared
to provide SUBARU service personnel
with the necessary information and data
for the correct maintenance and repair
of SUBARU vehicles.
This manual includes the procedures
for maintenance, disassembling, reas-
sembling, inspection and adjustment of
components and diagnostics for guid-
ance of experienced mechanics.
Please peruse and utilize this manual
fully to ensure complete repair work for
satisfying our customers by keeping
their vehicle in optimum condition.
When replacement of parts during
repair work is needed, be sure to use
SUBARU genuine parts.
All information, illustration and specifi-
cations contained in this manual are
based on the latest product information
available at the time of publication
approval.
FUEL INJECTION (FUEL SYSTEMS) FU(H4DOTC)
EMISSION CONTROL
(AUX. EMISSION CONTROL DEVICES) EC(H4DOTC)
INTAKE (INDUCTION) IN(H4DOTC)
MECHANICAL ME(H4DOTC)
EXHAUST EX(H4DOTC)
COOLING CO(H4DOTC)
LUBRICATION LU(H4DOTC)
SPEED CONTROL SYSTEMS SP(H4DOTC)
IGNITION IG(H4DOTC)
STARTING/CHARGING SYSTEMS SC(H4DOTC)
ENGINE (DIAGNOSTICS) EN(H4DOTC)(diag)

LUBRICATION
LU(H4DOTC)
Page
1. General Description ....................................................................................2
2. Oil Pressure System ...................................................................................6
3. Engine Oil....................................................................................................8
4. Oil Pump ...................................................................................................10
5. Oil Pan and Strainer..................................................................................14
6. Oil Pressure Switch...................................................................................18
7. Engine Oil Cooler ......................................................................................19
8. Engine Oil Filter.........................................................................................20
9. Engine Lubrication System Trouble in General.........................................21

LU(H4DOTC)-2
LUBRICATION
General Description
1. General Description
A: SPECIFICATIONS
Lubrication method Forced lubrication
Oil pump
Pump type Trochoid type
Number of teeth Inner rotor 9
Outer rotor 10
Outer rotor diameter ×thickness 78 ×10 mm (3.07 ×0.39 in)
Tip clearance between inner and outer rotor STANDARD 0.04 —0.14 mm (0.0016 —0.0055 in)
LIMIT 0.18 mm (0.0071 in)
Side clearance between inner rotor and pump
case
STANDARD 0.02 —0.07 mm (0.0008 —0.0028 in)
LIMIT 0.12 mm (0.0047 in)
Case clearance between outer rotor and pump
case
STANDARD 0.10 —0.175 mm (0.0039 —0.0069 in)
LIMIT 0.20 mm (0.0079 in)
Capacity at 80°C (176°F)
600 rpm
Discharge
pressure 98 kPa (1.0 kg/cm2, 14 psi)
Discharge
quantity 4.6 2(4.9 US qt, 4.0 Imp qt)/min.
5,000 rpm
Discharge
pressure 294 kPa (3.0 kg/cm2, 43 psi)
Discharge
quantity 47.0 2(49.7 US qt, 41.4 Imp qt)/min.
Relief valve operation pressure 588 kPa (6.0 kg/cm2, 85 psi)
Oil filter
Type Full-flow filter type
Filtration area 800 cm2(124 sq in)
By-pass valve opening pressure 160 kPa (1.63 kg/cm2, 23.2 psi)
Outer diameter ×width 68 ×65 mm (2.68 ×2.56 in)
Oil filter to engine thread size M 20 ×1.5
Oil pressure
switch
Type Immersed contact point type
Working voltage —wattage 12 V —3.4 W or less
Warning light activation pressure 14.7 kPa (0.15 kg/cm2, 2.1 psi)
Proof pressure More than 981 kPa (10 kg/cm2, 142 psi)
Oil capacity (at replacement) 4.0 2(4.2 US qt, 3.5 Imp qt)

LU(H4DOTC)-3
LUBRICATION
General Description
B: COMPONENT
(1) Plug (13) Oil cooler (Model with oil cooler) (27) Metal gasket
(2) Gasket (14) O-ring (28) Drain plug
(3) Relief valve spring (15) Oil pump ASSY (29) O-ring
(4) Relief valve (16) Oil pressure switch (30) Oil filler cap
(5) Oil seal (17) Oil filler duct
(6) Oil pump case (18) O-ring Tightening torque: N·m (kgf-m, ft-lb)
(7) Inner rotor (19) Rocker cover T1: 5 (0.5, 3.6)
(8) Outer rotor (20) Baffle plate T2: 6.4 (0.65, 4.7)
(9) Oil pump cover (21) O-ring T3: 10 (1.0, 7.0)
(10) Oil filter (22) Oil strainer T4: 44 (4.5, 32.5)
(11) Oil cooler connector (Model with
oil cooler)
(23) Gasket T5: 69 (7.0, 50.9)
(24) Oil level gauge guide T6: 25 (2.5, 18.1)
(12) Water by-pass pipe (Model with oil
cooler)
(25) Oil pan T7: 54 (5.5, 40)
(26) Oil level gauge
LU-00183
(15)
(14)
T6
T2
T1 T5 T3
T2
T7
T1 T1
T3
T4
T2
T4
T2
(29)
(9)
(8)
(7)
(6)
(13)
(12) (22)
(21)
(23)
(24)
(20)
(19)
(18)
(17)
(16)
(26)
(25)
(11)
(10)
(28) (27)
(5)
(4)
(3)
(2)
(1)
(30)

LU(H4DOTC)-4
LUBRICATION
General Description
C: CAUTION
•Wear working clothing, including a cap, protec-
tive goggles, and protective shoes during opera-
tion.
•Remove contamination including dirt and corro-
sion before removal, installation or disassembly.
•Keep the disassembled parts in order and pro-
tect them from dust or dirt.
•Before removal, installation or disassembly, be
sure to clarify the failure. Avoid unnecessary re-
moval, installation, disassembly, and replacement.
•Be careful not to burn your hands, because each
part in the vehicle is hot after running.
•Be sure to tighten fasteners including bolts and
nuts to the specified torque.
•Place shop jacks or safety stands at the specified
points.
•Before disconnecting electrical connectors of
sensors or units, be sure to disconnect the ground
cable from battery.
D: PREPARATION TOOL
1. SPECIAL TOOLS
ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS
499977400 CRANKSHAFT
PULLEY
WRENCH
Used for stopping rotation of crankshaft pulley
when loosening and tightening crankshaft pulley
bolt.
498547000 OIL FILTER
WRENCH
•Used for removing and installing oil filter.
•For outer diameter 80 mm (3.15 in) filter.
18332AA000 OIL FILTER
WRENCH
•Used for removing and installing oil filter.
•For outer diameter 68 mm (2.68 in) filter.
ST-499977400
ST-498547000
ST18332AA000

LU(H4DOTC)-5
LUBRICATION
General Description
18332AA010 OIL FILTER
WRENCH
•Used for removing and installing oil filter.
•For outer diameter 65 mm (2.56 in) filter.
499587100 OIL SEAL
INSTALLER
Used for installing oil pump oil seal.
ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS
ST18332AA010
ST-499587100

LU(H4DOTC)-6
LUBRICATION
Oil Pressure System
2. Oil Pressure System
A: WIRING DIAGRAM
LU-00207
E
i2
B37
B21
E2
14
E11
i10
1 2 3 4 5 6 7 8 9 10 11 12 13 14
15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 21
9
32
1234 56
10 11 12 13 14 15
7
16
23 30
19 20
22 26 27 28 29
8
17
24 31
18
25
i2
B21
1 2
5 6 7 8
13 14 15 16
9 10 11 12
3 4
17 18 19 20
No.14 SBF-4 SBF-1
B72
14
B72
34
12
C7
B2
i10
i11
B:
C:
14
i11
123456789 10
BATTERY
IGNITION
SWITCH
COMBINATION
METER
OIL PRESSURE WARNING LIGHT
OIL PRESSURE
SWITCH

LU(H4DOTC)-7
LUBRICATION
Oil Pressure System
B: INSPECTION
Step Check Yes No
1 CHECK COMBINATION METER.
1)Turn the ignition switch to ON. (engine OFF)
2)Check other warning lights.
Does the warning lights go on? Go to step 2. Repair or replace
the combination
meter. <Ref. to
IDI-3, INSPEC-
TION, Combina-
tion Meter
System.>
2 CHECK HARNESS CONNECTOR BETWEEN
COMBINATION METER AND OIL PRES-
SURE SWITCH.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from oil pressure
switch.
3)Turn the ignition switch ON.
4)Measure the voltage of harness between the
combination meter connector and chassis
ground.
Connector & terminal
(E11) No. 1 (+) —Chassis ground (–):
Is the voltage more than 10 V? Replace the oil
pressure switch.
Go to step 3.
3 CHECK COMBINATION METER.
1)Turn the ignition switch to OFF.
2)Remove the combination meter.
3)Measure the resistance of combination
meter.
Terminals
No. C7 —No. B2:
Is the resistance less than 10
Ω?
Replace the har-
ness connector
between combina-
tion meter and oil
pressure switch.
Repair or replace
the combination
meter.

LU(H4DOTC)-8
LUBRICATION
Engine Oil
3. Engine Oil
A: INSPECTION
1) Park the vehicle on a level surface.
2) Remove the oil level gauge and wipe it clean.
3) Reinsert the level gauge all the way. Be sure that
the level gauge is correctly inserted and in proper
orientation.
4) Remove it again and note the reading. If the en-
gine oil level is below the “L”line, add oil to bring
the level up to “F”line.
5) After turning off the engine, wait a few minutes
for oil to drain back into the oil pan before checking
the level.
6) Just after driving or while the engine is warm, en-
gine oil level may show in the range between the
“F”line and notch mark. This is caused by thermal
expansion of engine oil.
NOTE:
To prevent overfilling the engine oil, do not add oil
above “F”line when the engine is cold.
B: REPLACEMENT
1) Open the engine oil filler cap for quick draining of
engine oil.
2) Remove the clips of service hole cover.
3) Drain the engine oil by loosening the engine oil
drain plug.
4) Replace the drain plug gasket.
5) Tighten the engine oil drain plug after draining
engine oil.
Tightening torque:
44 N·m (4.5 kgf-m, 32.5 ft-lb)
6) Install the service hole cover.
7) Fill engine oil through the filler pipe up to upper
level on level gauge. Make sure that the vehicle is
placed level when checking oil level. Use the en-
gine oil of proper quality and viscosity, selected in
accordance with the table in figure.
(A) Oil level gauge
(B) Engine oil filler cap
(C) Upper level
(D) Lower level
(E) Approx. 1.0 2(1.1 US qt, 0.9 Imp qt)
LU-00138
(A) (B)
(C)
(D)
(E)
LU-00185
LU-00186
LU-00186

LU(H4DOTC)-9
LUBRICATION
Engine Oil
Recommended oil
API classification SL, SJ with the “Energy
Conserving”logo is printed, or SH (if you
cannot obtain the oil with SL, SJ or SH
grades, you may use SG grade “ENERGY
CONSERVING”oil.)
ACEA specification, A1, A2 or A3
CCMC specification, G4 or G5
New API certification mark (Star burst mark)
label is on the container.
Engine oil capacity:
Upper level
4.0 2(4.2 US qt, 3.5 Imp qt)
Lower level
3.0 2(3.2 US qt, 2.6 Imp qt)
The proper viscosity helps vehicle get good cold
and hot starting by reducing viscous friction and
thus increasing cranking speed.
CAUTION:
When replenishing oil, it does not matter if the
oil to be added is a different brand from that in
the engine; however, use oil having the API
classification and SAE viscosity No. designat-
ed by SUBARU.
NOTE:
If the vehicle is used in areas with very high temper-
atures or for other heavy duty applications, the fol-
lowing viscosity oils may be used: API
classification: SL or SJ or SH
SAE Viscosity No.: 30, 40, 10W-50, 20W-40, 20W-
50.
8) Close the engine oil filler cap.
9) Start the engine and warm it up for a time.
10) After the engine stops, recheck the oil level. If
necessary, add engine oil up to the upper level on
level gauge.
(1) SAE Viscosity No. and Applicable Temperature
(2) PREFERRED
LU-00076
4030150-15-20-30( C)
104865932
10W-30,10W-40
5-4-22( F)
5W-30 (2)
SAE (1)
(A) Oil level gauge
(B) Engine oil filler cap
(C) Upper level
(D) Lower level
(E) Approx. 1.0 2(1.1 US qt, 0.9 lmp qt)
LU-00138
(A) (B)
(C)
(D)
(E)