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)

LU(H4DOTC)-10
LUBRICATION
Oil Pump
4. Oil Pump
A: REMOVAL
1) Disconnect the ground cable from battery.
2) Lift-up the vehicle.
3) Remove the under cover.
4) Remove the bolts which install the water pipe of
oil cooler to oil pump.
5) Remove the water pipe and hoses between oil
cooler and water pump.
6) Remove the radiator. <Ref. to CO(H4SO)-19,
REMOVAL, Radiator.>
7) Remove the crankshaft position sensor.
8) Remove the V-belts.
<Ref. to ME(H4DOTC)-54, REMOVAL, V-belt.>
9) Remove the rear side V-belt tensioner.
10) Remove the crankshaft pulley by using ST.
<Ref. to ME(H4DOTC)-56, REMOVAL, Crankshaft
Pulley.>
11) Remove the water pump. <Ref. to CO(H4SO)-
15, REMOVAL, Water Pump.>
12) Remove the timing belt guide. (MT model)
FU-00009
LU-00137
LU-00010
LU-00046
LU-00011
LU-00012
LU-00013

LU(H4DOTC)-11
LUBRICATION
Oil Pump
13) Remove the crankshaft sprocket.
14) Remove the bolts which install the oil pump
onto cylinder block.
15) Remove the oil pump using the flat tip screw-
driver.
CAUTION:
Be careful not to scratch the mating surfaces of
cylinder block and oil pump.
B: INSTALLATION
Install in the reverse order of removal.
Do the following:
1) Apply fluid packing to the matching surfaces of
oil pump.
Fluid packing:
THREE BOND 1215 (Part No. 004403007) or
equivalent
2) Replace the O-ring (A) with a new one.
3) Apply a coat of engine oil to the inside of oil seal.
4) Be careful not to scratch the oil seal when install-
ing the oil pump on cylinder block.
5) Position the oil pump, aligning the notched area
with crankshaft, and push the oil pump straight.
CAUTION:
Make sure the oil seal lip is not folded.
6) Install the oil pump.
Tightening torque:
6.4 N·m (0.65 kgf-m, 4.7 ft-lb)
C: DISASSEMBLY
Remove the screws which secure the oil pump cov-
er and disassemble oil pump. Inscribe alignment
marks on the inner and outer rotors so that they can
be replaced in their original positions during reas-
sembly.
LU-00014
LU-00015
LU-00016
LU-00017
(A)
LU-00018
LU-00019
T
T

LU(H4DOTC)-12
LUBRICATION
Oil Pump
CAUTION:
Before disassembling the oil pump, remove the
relief valve.
D: ASSEMBLY
1) Install the front oil seal by using ST.
ST 499587100 OIL SEAL INSTALLER
NOTE:
Use a new oil seal.
2) Apply a coat of engine oil to the inner and outer
rotors.
3) Install the inner and outer rotors in their original
positions.
4) Install the oil relief valve, relief valve spring and
plug.
NOTE:
Use a new gasket.
5) Install the oil pump cover.
Tightening torque:
T1: 5 N·m (0.5 kgf-m, 3.6 ft-lb)
T2: 44 N·m (4.5 kgf-m, 32.5 ft-lb)
(A) Oil seal
(B) Pump case
(C) Inner rotor
(D) Outer rotor
(E) Pump cover
(F) Relief valve
(G) Relief valve spring
(H) Plug
(I) Gasket
LU-00020
(E)
(D)
(C)
(B)
(A)
(F)
(G)
(I)
(H)
LU-00021
ST
LU-00022
T1
T2

LU(H4DOTC)-13
LUBRICATION
Oil Pump
E: INSPECTION
1. TIP CLEARANCE
Measure the tip clearance of rotors. If clearance ex-
ceeds the limit, replace the rotors as a matched set.
Tip clearance:
Standard
0.04 —0.14 mm (0.0016 —0.0055 in)
Limit
0.18 mm (0.0071 in)
2. CASE CLEARANCE
Measure the clearance between outer rotor and oil
pump rotor housing. If clearance exceeds the limit,
replace the rotor.
Case clearance:
Standard
0.10 —0.175 mm (0.0039 —0.0069 in)
Limit
0.20 mm (0.0079 in)
3. SIDE CLEARANCE
Measure the clearance between the oil pump inner
rotor and pump cover. If clearance exceeds the lim-
it, replace the rotor or pump body.
Side clearance:
Standard
0.02 —0.07 mm (0.0008 —0.0028 in)
Limit
0.12 mm (0.0047 in)
4. OIL RELIEF VALVE
Check the valve for fitting condition and damage,
and the relief valve spring for damage and deterio-
ration. Replace the parts if defective.
Relief valve spring:
Free length
73.7 mm (2.902 in)
Installed length
54.7 mm (2.154 in)
Load when installed
93.1 N (9.49 kgf, 20.88 lb)
5. OIL PUMP CASE
Check the oil pump case for worn shaft hole,
clogged oil passage, worn rotor chamber, cracks,
and other faults.
6. OIL SEAL
Check the oil seal lips for deformation, hardening,
wear, etc. and replace if defective.
LU-00023
LU-00024
LU-00025

LU(H4DOTC)-14
LUBRICATION
Oil Pan and Strainer
5. Oil Pan and Strainer
A: REMOVAL
1) Set the vehicle on a lift.
2) Remove the front wheels.
3) Disconnect the ground cable from battery.
4) Disconnect the connector from mass air flow
sensor.
5) Remove the air intake boot and air cleaner upper
cover.
6) Remove the intercooler. <Ref. to IN(H4DOTC)-
10, REMOVAL, Intercooler.>
7) Remove the pitching stopper.
8) Remove the radiator upper brackets.
9) Support the engine with a lifting device and wire
ropes.
10) Lift-up the vehicle.
CAUTION:
When lifting up the vehicle, rise up the wire
rope together.
11) Remove the under cover.
12) Drain the engine oil.
FU-00009
LU-00026
LU-00070
ME-00213
LU-00027
LU-00028

LU(H4DOTC)-15
LUBRICATION
Oil Pan and Strainer
13) Remove the nuts which install the front cushion
rubber onto front crossmember.
14) Remove the bolts which install the oil pan on
cylinder block while raising up engine.
15) Insert the oil pan cutter blade between cylinder
block-to-oil pan clearance.
CAUTION:
Do not use a screwdriver or similar tool in place
of oil pan cutter.
16) Remove the oil strainer.
17) Remove the baffle plate.
B: INSTALLATION
CAUTION:
Before installing the oil pan, clean sealant from
oil pan and engine block.
1) Install the baffle plate.
Tightening torque:
6.4 N·m (0.65 kgf-m, 4.7 ft-lb)
2) Install the oil strainer onto baffle plate.
NOTE:
Replace the O-ring with a new one.
Tightening torque:
10 N·m (1.0 kgf-m, 7.2 ft-lb)
3) Apply fluid packing to the mating surfaces, and
then install the oil pan.
Fluid packing:
THREE BOND 1215 (Part No. 004403007) or
equivalent
LU-00030
LU-00031
LU-00032
LU-00033
LU-00033
LU-00032
LU-00034

LU(H4DOTC)-16
LUBRICATION
Oil Pan and Strainer
4) Tighten the bolts which install the oil pan onto
engine block.
Tightening torque:
5 N·m (0.5 kgf-m, 3.6 ft-lb)
5) Lower the engine onto front crossmember.
6) Tighten the nuts which install the front cushion
rubber onto front crossmember.
Tightening torque:
83 N·m (8.5 kgf-m, 61 ft-lb)
7) Install the under cover.
8) Lower the vehicle.
CAUTION:
When lowering the vehicle, lower the lifting de-
vice and wire rope together.
9) Remove the lifting device and steel cables.
10) Install the pitching stopper.
Tightening torque:
T1: 50 N·m (5.1 kgf-m, 36.9 ft-lb)
T2: 58 N·m (5.9 kgf-m, 42.8 ft-lb)
11) Install the radiator upper brackets.
12) Install the intercooler. <Ref. to IN(H4DOTC)-
10, INSTALLATION, Intercooler.>
13) Install the air intake boot and air cleaner upper
cover.
14) Connect the connector to mass air flow sensor.
LU-00031
LU-00030
LU-00028
ME-00218
T2 T1
LU-00027
LU-00070
LU-00026

LU(H4DOTC)-17
LUBRICATION
Oil Pan and Strainer
15) Install the front wheels.
16) Connect the battery ground cable to battery.
17) Fill engine oil. <Ref. to LU(H4DOTC)-8, IN-
SPECTION, Engine Oil.>
C: INSPECTION
By visual check, make sure the oil pan, oil strainer,
oil strainer stay and baffle plate are not damaged.
FU-00009

LU(H4DOTC)-18
LUBRICATION
Oil Pressure Switch
6. Oil Pressure Switch
A: REMOVAL
1) Remove the generator from bracket. <Ref. to
SC(H4SO)-13, REMOVAL, Generator.>
2) Disconnect the terminal from oil pressure switch.
3) Remove the oil pressure switch.
B: INSTALLATION
1) Apply fluid packing to the oil pressure switch
threads.
Fluid packing:
THREE BOND 1324 (Part No. 004403007) or
equivalent
2) Install the oil pressure switch onto engine block.
Tightening torque:
25 N·m (2.5 kgf-m, 18.1 ft-lb)
3) Connect the terminal of oil pressure switch.
4) Install the generator on bracket. <Ref. to
SC(H4SO)-13, INSTALLATION, Generator.>
C: INSPECTION
Make sure oil does not leak or seep from where the
oil pressure switch is installed.
LU-00036
LU-00037
LU-00038
LU-00037
LU-00036

LU(H4DOTC)-19
LUBRICATION
Engine Oil Cooler
7. Engine Oil Cooler
A: REMOVAL
1) Lift-up the vehicle.
2) Remove the under cover.
3) Drain the engine oil.
4) Drain the engine coolant.
5) Remove the water by-pass pipe between oil
cooler and water pump.
6) Remove the engine oil filter. <Ref. to
LU(H4DOTC)-20, REMOVAL, Engine Oil Filter.>
7) Remove the connector, and then remove the oil
cooler.
B: INSTALLATION
1) Install in the reverse order of removal.
Tightening torque:
T1: 54 N·m (5.5 kgf-m, 40 ft-lb)
T2: 69 N·m (7.0 kgf-m, 50.6 ft-lb)
NOTE:
Always use a new O-ring.
C: INSPECTION
1) Check the coolant passages are not clogged us-
ing air blow method.
2) Check the mating surfaces of cylinder block, O-
ring groove and oil filter for damage.
(A) O-ring
(B) Oil cooler
(C) Oil cooler connector
LU-00040
ME-00723
T2
(C)
(B)
(A)
T1
(A) O-ring
(B) Oil cooler
(C) Oil cooler connector
ME-00723
T2
(C)
(B)
(A)
T1