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)

MECHANICAL
ME(H4DOTC)
Page
1. General Description ....................................................................................2
2. Compression .............................................................................................34
3. Idle Speed .................................................................................................35
4. Ignition Timing...........................................................................................36
5. Intake Manifold Vacuum............................................................................37
6. Engine Oil Pressure ..................................................................................38
7. Fuel Pressure............................................................................................39
8. Valve Clearance........................................................................................40
9. Engine Assembly ......................................................................................44
10. Engine Mounting .......................................................................................52
11. Preparation for Overhaul...........................................................................53
12. V-belt.........................................................................................................54
13. Crankshaft Pulley ......................................................................................56
14. Timing Belt Cover......................................................................................57
15. Timing Belt Assembly................................................................................58
16. Camshaft Sprocket....................................................................................66
17. Crankshaft Sprocket..................................................................................68
18. Camshaft...................................................................................................69
19. Cylinder Head Assembly...........................................................................78
20. Cylinder Block ...........................................................................................85
21. Intake and Exhaust Valve .......................................................................105
22. Piston ......................................................................................................106
23. Connecting Rod ......................................................................................107
24. Crankshaft...............................................................................................108
25. Engine Trouble in General ......................................................................109
26. Engine Noise...........................................................................................114

ME(H4DOTC)-2
MECHANICAL
General Description
1. General Description
A: SPECIFICATIONS
1. DOHC TURBO MODEL (EXCEPT FOR STi AND AUSTRALIA MODEL)
NOTE:
STD: Standard I.D.: Inner Diameter O.D.: Outer Diameter OS: Oversize US: Undersize
Engine
Type Horizontally opposed, liquid cooled, 4-cylinder,
4-stroke gasoline engine
Valve arrangement Belt driven, double overhead camshaft, 4-valve/cylinder
Bore ×Stroke mm (in) 92 ×75 (3.62 ×2.95)
Piston displacement cm3(cu in) 1,994 (121.67)
Compression ratio 8.0
Compression pres-
sure (at 200 —300
rpm)
kPa (kgf/cm2, psi) 981 —1,177 (10 —12, 142 —171)
Number of piston rings Pressure ring: 2, Oil ring: 1
Intake valve timing Opening BTDC 10°
Closing ABDC 50°
Exhaust valve timing Opening BBDC 53°
Closing ATDC 7°
Valve clearance Intake mm (in) 0.20±0.02 (0.0079±0.0008)
Exhaust mm (in) 0.35±0.02 (0.0138±0.0008)
Idling speed
[At neutral position on MT or “P”or
“N”range on AT]
rpm 700±100 (No load)
800±150 (A/C switch ON)
Firing order 1 →3 →2 →4
Ignition timing BTDC/rpm 12°±10°/700
Belt
tension
adjuster
Protrusion of adjuster rod 5.2 —6.2 mm (0.205 —0.244 in)
Belt
tensioner
Spacer O.D. 17.955 —17.975 mm (0.7069 —0.7077 in)
Tensioner bush I.D. 18.0 —18.08 mm (0.7087 —0.7118 in)
Clearance between spacer and bush STD 0.025 —0.125 mm (0.0010 —0.0049 in)
Limit 0.175 mm (0.0069 in)
Side clearance of spacer STD 0.2 —0.55 mm (0.0079 —0.0217 in)
Limit 0.81 mm (0.0319 in)
Camshaft
Bend limit 0.020 mm (0.0079 in)
Thrust clearance STD 0.040 —0.080 mm (0.0016 —0.0031 in)
Limit 0.10 mm (0.0039 in)
Cam lobe height
Intake STD 46.25 —46.35 mm (1.821 —1.825 in)
Limit 46.15 mm (1.817 in)
Exhaust STD 46.15 —46.25 mm (1.817 —1.821 in)
Limit 46.05 mm (1.813 in)
Journal O.D. STD
Front 37.946 —37.963 mm (1.4939 —1.4946 in)
Center
rear 29.946 —29.963 mm (1.1790 —1.1796 in)
Oil clearance STD 0.037 —0.072 mm (0.0015 —0.0028 in)
Limit 0.10 mm (0.0039 in)
Cylinder
head
Surface warpage limit 0.05 mm (0.0020 in)
Surface grinding limit 0.3 mm (0.012 in)
Standard height 127.5 mm (5.02 in)

ME(H4DOTC)-3
MECHANICAL
General Description
Valve seat
Refacing angle 90°
Contacting width
Intake STD 1.0 mm (0.039 in)
Limit 1.7 mm (0.067 in)
Exhaust STD 1.5 mm (0.059 in)
Limit 2.2 mm (0.087 in)
Valve guide Inner diameter 6.000 —6.012 mm (0.2362 —0.2367 in)
Protrusion above head 15.8 —16.2 mm (0.622 —0.638 in)
Valve
Head edge thickness
Intake STD 1.2 mm (0.047 in)
Limit 0.8 mm (0.031 in)
Exhaust STD 1.5 mm (0.059 in)
Limit 0.8 mm (0.031 in)
Stem diameter Intake 5.955 —5.970 mm (0.2344 —0.2350 in)
Exhaust 5.945 —5.960 mm (0.2341 —0.2346 in)
Stem oil clearance STD Intake 0.030 —0.057 mm (0.0012 —0.0022 in) Exhaust 0.040 —0.067 mm (0.0016 —0.0026 in)
Limit —0.15 mm (0.0059 in)
Overall length Intake 104.4 mm (4.110 in)
Exhaust 104.7 mm (4.122 in)
Valve
spring
Free length 47.32 mm (1.8630 in)
Squareness 2.5°, 2.1 mm (0.083 in)
Tension/spring height
Set 205 —235 N (20.9 —24.0 kgf, 46.1 —52.8 lb)/
36.0 mm (1.417 in)
Lift 426 —490 N (43.4 —50.0 kgf, 95.8 —110 lb)/
26.5 mm (1.043 in)
Cylinder
block
Surface warpage limit (mating with cylinder head) 0.05 mm (0.0020 in)
Surface grinding limit 0.1 mm (0.004 in)
Cylinder bore STD A 92.005 —92.015 mm (3.6222 —3.6226 in)
B 91.995 —92.005 mm (3.6218 —3.6222 in)
Taper STD 0.015 mm (0.0006 in)
Limit 0.050 mm (0.0020 in)
Out-of-roundness STD 0.010 mm (0.0004 in)
Limit 0.050 mm (0.0020 in)
Piston clearance STD 0.010 —0.030 mm (0.0004 —0.0012 in)
Limit 0.050 mm (0.0020 in)
Enlarging (boring) limit 0.5 mm (0.020 in)
Piston Outer diameter
STD A 91.985 —91.995 mm (3.6214 —3.6218 in)
B 91.975 —91.985 mm (3.6211 —3.6214 in)
0.25 mm (0.0098 in)
OS 92.225 —92.235 mm (3.6309 —3.6313 in)
0.50 mm (0.0197 in)
OS 92.475 —92.485 mm (3.6407 —3.6411 in)
Piston pin
Standard clearance between piston
pin and hole in piston
STD 0.004 —0.008 mm (0.0002 —0.0003 in)
Limit 0.020 mm (0.0008 in)
Degree of fit Piston pin must be fitted into position with thumb at 20°C
(68°F).

ME(H4DOTC)-4
MECHANICAL
General Description
Piston ring
Piston ring gap
Top ring STD 0.20 —0.25 mm (0.0079 —0.0098 in)
Limit 1.0 mm (0.039 in)
Second
ring
STD 0.40 —0.50 mm (0.016 —0.020 in)
Limit 1.0 mm (0.039 in)
Oil ring STD 0.20 —0.50 mm (0.0079 —0.020 in)
Limit 1.5 mm (0.059 in)
Clearance between piston
ring and piston ring
groove
Top ring STD 0.04 —0.08 mm (0.0016 —0.0031 in)
Limit 0.15 mm (0.0059 in)
Second
ring
STD 0.030 —0.070 mm (0.0012 —0.0028 in)
Limit 0.15 mm (0.0059 in)
Connecting
rod
Bend or twist per 100 mm (3.94 in) in
length Limit 0.10 mm (0.0039 in)
Side clearance STD 0.070 —0.330 mm (0.0028 —0.0130 in)
Limit 0.4 mm (0.016 in)
Connecting
rod bearing
Oil clearance STD 0.020 —0.046 mm (0.0008 —0.0018 in)
Limit 0.05 mm (0.0020 in)
Thickness at center portion
STD 1.486 —1.498 mm (0.0585 —0.0590 in)
0.03 mm
(0.0012
in) US
1.504 —1.512 mm (0.0592 —0.0595 in)
0.05 mm
(0.0020
in) US
1.514 —1.522 mm (0.0596 —0.0599 in)
0.25 mm
(0.0098
in) US
1.614 —1.622 mm (0.0635 —0.0639 in)
Connecting
rod bushing
Clearance between piston pin and
bushing
STD 0 —0.022 mm (0 —0.0009 in)
Limit 0.030 mm (0.0012 in)

ME(H4DOTC)-5
MECHANICAL
General Description
Crankshaft
Bend limit 0.035 mm (0.0014 in)
Crank pin and crank jour-
nal
Out-of-roundness 0.005 mm (0.0002 in) or less
Grinding limit 0.25 mm (0.0098 in)
Crank pin outer diameter
STD 51.984 —52.000 mm (2.0466 —2.0472 in)
0.03 mm
(0.0012
in) US
51.954 —51.970 mm (2.0454 —2.0461 in)
0.05 mm
(0.0020
in) US
51.934 —51.950 mm (2.0447 —2.0453 in)
0.25 mm
(0.0098
in) US
51.734 —51.750 mm (2.0368 —2.0374 in)
Crank journal outer diam-
eter
#1, #3, #5
STD 59.992 —60.008 mm (2.3619 —2.3625 in)
0.03 mm
(0.0012
in) US
59.962 —59.978 mm (2.3607 —2.3613 in)
0.05 mm
(0.0020
in) US
59.942 —59.958 mm (2.3599 —2.3605 in)
0.25 mm
(0.0098
in) US
59.742 —59.758 mm (2.3520 —2.3527 in)
#2, #4
STD 59.992 —60.008 mm (2.3619 —2.3625 in)
0.03 mm
(0.0012
in) US
59.962 —59.978 mm (2.3607 —2.3613 in)
0.05 mm
(0.0020
in) US
59.942 —59.958 mm (2.3599 —2.3605 in)
0.25 mm
(0.0098
in) US
59.742 —59.758 mm (2.3520 —2.3527 in)
Thrust clearance STD 0.030 —0.115 mm (0.0012 —0.0045 in)
Limit 0.25 mm (0.0098 in)
Oil clearance
#1 STD 0.010 —0.030 mm (0.0004 —0.0012 in)
Limit 0.040 mm (0.0016 in)
#2 STD 0.010 —0.030 mm (0.0004 —0.0012 in)
Limit 0.045 mm (0.0018 in)
#3 STD 0.010 —0.030 mm (0.0004 —0.0012 in)
Limit 0.040 mm (0.0016 in)
#4 STD 0.010 —0.030 mm (0.0004 —0.0012 in)
Limit 0.045 mm (0.0018 in)
#5 STD 0.010 —0.030 mm (0.0004 —0.0012 in)
Limit 0.040 mm (0.0016 in)

ME(H4DOTC)-6
MECHANICAL
General Description
2. STi MODEL
NOTE:
STD: Standard I.D.: Inner Diameter O.D.: Outer Diameter OS: Oversize US: Undersize
Crankshaft
bearing
Crankshaft bearing thick-
ness
#1, #3
STD 1.998 —2.011 mm (0.0787 —0.0792 in)
0.03 mm
(0.0012
in) US
2.017 —2.020 mm (0.0794 —0.0795 in)
0.05 mm
(0.0020
in) US
2.027 —2.030 mm (0.0798 —0.0799 in)
0.25 mm
(0.0098
in) US
2.127 —2.130 mm (0.0837 —0.0839 in)
#2, #4, #5
STD 2.000 —2.013 mm (0.0787 —0.0793 in)
0.03 mm
(0.0012
in) US
2.019 —2.022 mm (0.0795 —0.0796 in)
0.05 mm
(0.0020
in) US
2.029 —2.032 mm (0.0799 —0.0800 in)
0.25 mm
(0.0098
in) US
2.129 —2.132 mm (0.0838 —0.0839 in)
Engine
Type Horizontally opposed, liquid cooled, 4-cylinder,
4-stroke gasoline engine
Valve arrangement Belt driven, double overhead camshaft, 4-valve/cylinder
Bore ×Stroke mm (in) 92 ×75 (3.62 ×2.95)
Piston displacement cm3(cu in) 1,994 (121.67)
Compression ratio 8.0
Compression pres-
sure (at 200 —300
rpm)
kPa (kgf/cm2, psi) 981 —1,177 (10 —12, 142 —171)
Number of piston rings Pressure ring: 2, Oil ring: 1
Intake valve timing
Opening Max. retard ATDC 6°
Min. advance BTDC 24°
Closing Max. retard ABDC 68°
Min. advance ABDC 38°
Exhaust valve timing Opening BBDC 58°
Closing ATDC 10°
Valve clearance Intake mm (in) 0.20±0.02 (0.0079±0.0008)
Exhaust mm (in) 0.35±0.02 (0.0138±0.0008)
Idling speed
[At neutral position on MT] rpm 700±100 (No load) 800±150 (A/C switch ON)
Firing order 1 →3 →2 →4
Ignition timing BTDC/rpm 12°±10°/700

ME(H4DOTC)-7
MECHANICAL
General Description
Belt
tension
adjuster
Protrusion of adjuster rod 5.2 —6.2 mm (0.205 —0.244 in)
Belt
tensioner
Spacer O.D. 17.955 —17.975 mm (0.7069 —0.7077 in)
Tensioner bush I.D. 18.0 —18.08 mm (0.7087 —0.7118 in)
Clearance between spacer and bush STD 0.025 —0.125 mm (0.0010 —0.0049 in)
Limit 0.175 mm (0.0069 in)
Side clearance of spacer STD 0.2 —0.55 mm (0.0079 —0.0217 in)
Limit 0.81 mm (0.0319 in)
Camshaft
Bend limit 0.020 mm (0.0079 in)
Thrust clearance STD 0.040 —0.080 mm (0.0016 —0.0031 in)
Limit 0.10 mm (0.0039 in)
Cam lobe height
Intake STD 45.25 —45.35 mm (1.781 —1.785 in)
Limit 45.15 mm (1.758 in)
Exhaust STD 45.60 —45.70 mm (1.795 —1.799 in)
Limit 45.50 mm (1.791 in)
Journal O.D. STD
Front 37.946 —37.963 mm (1.4939 —1.4946 in)
Center
rear 29.946 —29.963 mm (1.1790 —1.1796 in)
Oil clearance STD 0.037 —0.072 mm (0.0015 —0.0028 in)
Limit 0.10 mm (0.0039 in)
Cylinder
head
Surface warpage limit 0.05 mm (0.0020 in)
Surface grinding limit 0.3 mm (0.012 in)
Standard height 127.5 mm (5.02 in)
Valve seat
Refacing angle 90°
Contacting width
Intake STD 1.0 mm (0.039 in)
Limit 1.7 mm (0.067 in)
Exhaust STD 1.5 mm (0.059 in)
Limit 2.2 mm (0.087 in)
Valve guide Inner diameter 6.000 —6.012 mm (0.2362 —0.2367 in)
Protrusion above head 15.8 —16.2 mm (0.622 —0.638 in)
Valve
Head edge thickness
Intake STD 1.2 mm (0.047 in)
Limit 0.8 mm (0.031 in)
Exhaust STD 1.5 mm (0.059 in)
Limit 0.8 mm (0.031 in)
Stem diameter Intake 5.955 —5.970 mm (0.2344 —0.2350 in)
Exhaust 5.945 —5.960 mm (0.2341 —0.2346 in)
Stem oil clearance STD Intake 0.030 —0.057 mm (0.0012 —0.0022 in) Exhaust 0.040 —0.067 mm (0.0016 —0.0026 in)
Limit —0.15 mm (0.0059 in)
Overall length Intake 104.4 mm (4.110 in)
Exhaust 104.7 mm (4.122 in)
Valve
spring
Free length 43.89 mm (1.728 in)
Squareness 2.5°, 1.9 mm (0.075 in)
Tension/spring height
Set 205 —237 N (20.9 —24.2 kgf, 46.1 —53.3 lb)/
36.0 mm (1.417 in)
Lift 553 —611 N (56.4 —62.3 kgf, 124 —137 lb)/
26.45 mm (1.041 in)

ME(H4DOTC)-8
MECHANICAL
General Description
Cylinder
block
Surface warpage limit (mating with cylinder head) 0.05 mm (0.0020 in)
Surface grinding limit 0.1 mm (0.004 in)
Cylinder bore STD A 92.005 —92.015 mm (3.6222 —3.6226 in)
B 91.995 —92.005 mm (3.6218 —3.6222 in)
Taper STD 0.015 mm (0.0006 in)
Limit 0.050 mm (0.0020 in)
Out-of-roundness STD 0.010 mm (0.0004 in)
Limit 0.050 mm (0.0020 in)
Piston clearance STD 0.010 —0.030 mm (0.0004 —0.0012 in)
Limit 0.050 mm (0.0020 in)
Enlarging (boring) limit 0.5 mm (0.020 in)
Piston Outer diameter
STD A 91.985 —91.995 mm (3.6214 —3.6218 in)
B 91.975 —91.985 mm (3.6211 —3.6214 in)
0.25 mm (0.0098 in)
OS 92.225 —92.235 mm (3.6309 —3.6313 in)
0.50 mm (0.0197 in)
OS 92.475 —92.485 mm (3.6407 —3.6411 in)
Piston pin
Standard clearance between piston
pin and hole in piston
STD 0.004 —0.008 mm (0.0002 —0.0003 in)
Limit 0.020 mm (0.0008 in)
Degree of fit Piston pin must be fitted into position with thumb at 20°C
(68°F).
Piston ring
Piston ring gap
Top ring STD 0.20 —0.25 mm (0.0079 —0.0098 in)
Limit 1.0 mm (0.039 in)
Second
ring
STD 0.40 —0.50 mm (0.016 —0.020 in)
Limit 1.0 mm (0.039 in)
Oil ring STD 0.20 —0.50 mm (0.0079 —0.020 in)
Limit 1.5 mm (0.059 in)
Clearance between piston
ring and piston ring
groove
Top ring STD 0.040 —0.080 mm (0.0016 —0.0031 in)
Limit 0.15 mm (0.0059 in)
Second
ring
STD 0.030 —0.070 mm (0.0012 —0.0028 in)
Limit 0.15 mm (0.0059 in)
Connecting
rod
Bend or twist per 100 mm (3.94 in) in
length Limit 0.10 mm (0.0039 in)
Side clearance STD 0.070 —0.330 mm (0.0028 —0.0130 in)
Limit 0.4 mm (0.016 in)
Connecting
rod bearing
Oil clearance STD 0.020 —0.046 mm (0.0008 —0.0018 in)
Limit 0.05 mm (0.0020 in)
Thickness at center portion
STD 1.486 —1.498 mm (0.0585 —0.0590 in)
0.03 mm
(0.0012
in) US
1.504 —1.512 mm (0.0592 —0.0595 in)
0.05 mm
(0.0020
in) US
1.514 —1.522 mm (0.0596 —0.0599 in)
0.25 mm
(0.0098
in) US
1.614 —1.622 mm (0.0635 —0.0639 in)
Connecting
rod bushing
Clearance between piston pin and
bushing
STD 0 —0.022 mm (0 —0.0009 in)
Limit 0.030 mm (0.0012 in)

ME(H4DOTC)-9
MECHANICAL
General Description
Crankshaft
Bend limit 0.035 mm (0.0014 in)
Crank pin and crank jour-
nal
Out-of-roundness 0.005 mm (0.0002 in) or less
Grinding limit 0.25 mm (0.0098 in)
Crank pin outer diameter
STD 51.984 —52.000 mm (2.0466 —2.0472 in)
0.03 mm
(0.0012
in) US
51.954 —51.970 mm (2.0454 —2.0461 in)
0.05 mm
(0.0020
in) US
51.934 —51.950 mm (2.0447 —2.0453 in)
0.25 mm
(0.0098
in) US
51.734 —51.750 mm (2.0368 —2.0374 in)
Crank journal outer diam-
eter
#1, #3, #5
STD 59.992 —60.008 mm (2.3619 —2.3625 in)
0.03 mm
(0.0012
in) US
59.962 —59.978 mm (2.3607 —2.3613 in)
0.05 mm
(0.0020
in) US
59.942 —59.958 mm (2.3599 —2.3605 in)
0.25 mm
(0.0098
in) US
59.742 —59.758 mm (2.3520 —2.3527 in)
#2, #4
STD 59.992 —60.008 mm (2.3619 —2.3625 in)
0.03 mm
(0.0012
in) US
59.962 —59.978 mm (2.3607 —2.3613 in)
0.05 mm
(0.0020
in) US
59.942 —59.958 mm (2.3599 —2.3605 in)
0.25 mm
(0.0098
in) US
59.742 —59.758 mm (2.3520 —2.3527 in)
Thrust clearance STD 0.030 —0.115 mm (0.0012 —0.0045 in)
Limit 0.25 mm (0.0098 in)
Oil clearance
#1 STD 0.010 —0.030 mm (0.0004 —0.0012 in)
Limit 0.040 mm (0.0016 in)
#2 STD 0.010 —0.030 mm (0.0004 —0.0012 in)
Limit 0.045 mm (0.0018 in)
#3 STD 0.010 —0.030 mm (0.0004 —0.0012 in)
Limit 0.040 mm (0.0016 in)
#4 STD 0.010 —0.030 mm (0.0004 —0.0012 in)
Limit 0.045 mm (0.0018 in)
#5 STD 0.010 —0.030 mm (0.0004 —0.0012 in)
Limit 0.040 mm (0.0016 in)

ME(H4DOTC)-10
MECHANICAL
General Description
3. DOHC TURBO MODEL (AUSTRALIA MODEL EXCEPT FOR STi MODEL)
NOTE:
STD: Standard I.D.: Inner Diameter O.D.: Outer Diameter OS: Oversize US: Undersize
Crankshaft
bearing
Crankshaft bearing thick-
ness
#1, #3
STD 1.998 —2.011 mm (0.0787 —0.0792 in)
0.03 mm
(0.0012
in) US
2.017 —2.020 mm (0.0794 —0.0795 in)
0.05 mm
(0.0020
in) US
2.027 —2.030 mm (0.0798 —0.0799 in)
0.25 mm
(0.0098
in) US
2.127 —2.130 mm (0.0837 —0.0839 in)
#2, #4, #5
STD 2.000 —2.013 mm (0.0787 —0.0793 in)
0.03 mm
(0.0012
in) US
2.019 —2.022 mm (0.0795 —0.0796 in)
0.05 mm
(0.0020
in) US
2.029 —2.032 mm (0.0799 —0.0800 in)
0.25 mm
(0.0098
in) US
2.129 —2.132 mm (0.0838 —0.0839 in)
Engine
Type Horizontally opposed, liquid cooled, 4-cylinder,
4-stroke gasoline engine
Valve arrangement Belt driven, double overhead camshaft, 4-valve/cylinder
Bore ×Stroke mm (in) 92 ×75 (3.62 ×2.95)
Piston displacement cm3(cu in) 1,994 (121.67)
Compression ratio 9.0
Compression pres-
sure (at 200 —300
rpm)
kPa (kgf/cm2, psi) 1,108 —1,304 (11 —13, 161 —189)
Number of piston rings Pressure ring: 2, Oil ring: 1
Intake valve timing
Opening Max. retard ATDC 7°
Min. advance BTDC 27°
Closing Max. retard ABDC 67°
Min. advance ABDC 33°
Exhaust valve timing Opening BBDC 53°
Closing ATDC 7°
Valve clearance Intake mm (in) 0.20±0.02 (0.0079±0.0008)
Exhaust mm (in) 0.35±0.02 (0.0138±0.0008)
Idling speed
[At neutral position on MT, or
“P”or “N”position on AT]
rpm
MT 650±50 (No load)
800±50 (A/C switch ON)
AT 700±50 (No load)
820±50 (A/C switch ON)
Firing order 1 →3 →2 →4
Ignition timing BTDC/rpm MT 12°±3°/650
AT 12°±3°/700

ME(H4DOTC)-11
MECHANICAL
General Description
Belt
tension
adjuster
Protrusion of adjuster rod 5.2 —6.2 mm (0.205 —0.244 in)
Belt
tensioner
Spacer O.D. 17.955 —17.975 mm (0.7069 —0.7077 in)
Tensioner bush I.D. 18.0 —18.08 mm (0.7087 —0.7118 in)
Clearance between spacer and bush STD 0.025 —0.125 mm (0.0010 —0.0049 in)
Limit 0.175 mm (0.0069 in)
Side clearance of spacer STD 0.2 —0.55 mm (0.0079 —0.0217 in)
Limit 0.81 mm (0.0319 in)
Camshaft
Bend limit 0.020 mm (0.0079 in)
Thrust clearance STD 0.040 —0.080 mm (0.0016 —0.0031 in)
Limit 0.10 mm (0.0039 in)
Cam lobe height
Intake STD 46.25 —46.35 mm (1.821 —1.825 in)
Limit 46.15 mm (1.817 in)
Exhaust STD 46.15 —46.25 mm (1.817 —1.821 in)
Limit 46.05 mm (1.813 in)
Journal O.D. STD
Front 37.946 —37.963 mm (1.4939 —1.4946 in)
Center
rear 29.946 —29.963 mm (1.1790 —1.1796 in)
Oil clearance STD 0.037 —0.072 mm (0.0015 —0.0028 in)
Limit 0.10 mm (0.0039 in)
Cylinder
head
Surface warpage limit 0.05 mm (0.0020 in)
Surface grinding limit 0.3 mm (0.012 in)
Standard height 127.5 mm (5.02 in)
Valve seat
Refacing angle 90°
Contacting width
Intake STD 1.0 mm (0.039 in)
Limit 1.7 mm (0.067 in)
Exhaust STD 1.5 mm (0.059 in)
Limit 2.2 mm (0.087 in)
Valve guide Inner diameter 6.000 —6.012 mm (0.2362 —0.2367 in)
Protrusion above head 15.8 —16.2 mm (0.622 —0.638 in)
Valve
Head edge thickness
Intake STD 1.2 mm (0.047 in)
Limit 0.8 mm (0.031 in)
Exhaust STD 1.5 mm (0.059 in)
Limit 0.8 mm (0.031 in)
Stem diameter Intake 5.955 —5.970 mm (0.2344 —0.2350 in)
Exhaust 5.945 —5.960 mm (0.2341 —0.2346 in)
Stem oil clearance STD Intake 0.030 —0.057 mm (0.0012 —0.0022 in) Exhaust 0.040 —0.067 mm (0.0016 —0.0026 in)
Limit —0.15 mm (0.0059 in)
Overall length Intake 104.4 mm (4.110 in)
Exhaust 104.7 mm (4.122 in)
Valve
spring
Free length 47.32 mm (1.8630 in)
Squareness 2.5°, 2.1 mm (0.083 in)
Tension/spring height
Set 205 —235 N (20.9 —24.0 kgf, 46.1 —52.8 lb)/
36.0 mm (1.417 in)
Lift 426 —490 N (43.4 —50.0 kgf, 95.8 —110 lb)/
26.5 mm (1.043 in)

ME(H4DOTC)-12
MECHANICAL
General Description
Cylinder
block
Surface warpage limit (mating with cylinder head) 0.05 mm (0.0020 in)
Surface grinding limit 0.1 mm (0.004 in)
Cylinder bore STD A 92.005 —92.015 mm (3.6222 —3.6226 in)
B 91.995 —92.005 mm (3.6218 —3.6222 in)
Taper STD 0.015 mm (0.0006 in)
Limit 0.050 mm (0.0020 in)
Out-of-roundness STD 0.010 mm (0.0004 in)
Limit 0.050 mm (0.0020 in)
Piston clearance STD 0.010 —0.030 mm (0.0004 —0.0012 in)
Limit 0.050 mm (0.0020 in)
Enlarging (boring) limit 0.5 mm (0.020 in)
Piston Outer diameter
STD A 91.985 —91.995 mm (3.6214 —3.6218 in)
B 91.975 —91.985 mm (3.6211 —3.6214 in)
0.25 mm (0.0098 in)
OS 92.225 —92.235 mm (3.6309 —3.6313 in)
0.50 mm (0.0197 in)
OS 92.475 —92.485 mm (3.6407 —3.6411 in)
Piston pin
Standard clearance between piston
pin and hole in piston
STD 0.004 —0.008 mm (0.0002 —0.0003 in)
Limit 0.020 mm (0.0008 in)
Degree of fit Piston pin must be fitted into position with thumb at 20°C
(68°F).
Piston ring
Piston ring gap
Top ring STD 0.20 —0.25 mm (0.0079 —0.0098 in)
Limit 1.0 mm (0.039 in)
Second
ring
STD 0.40 —0.50 mm (0.016 —0.020 in)
Limit 1.0 mm (0.039 in)
Oil ring STD 0.20 —0.50 mm (0.0079 —0.020 in)
Limit 1.5 mm (0.059 in)
Clearance between piston
ring and piston ring
groove
Top ring STD 0.040 —0.080 mm (0.0016 —0.0031 in)
Limit 0.15 mm (0.0059 in)
Second
ring
STD 0.030 —0.070 mm (0.0012 —0.0028 in)
Limit 0.15 mm (0.0059 in)
Connecting
rod
Bend or twist per 100 mm (3.94 in) in
length Limit 0.10 mm (0.0039 in)
Side clearance STD 0.070 —0.330 mm (0.0028 —0.0130 in)
Limit 0.4 mm (0.016 in)
Connecting
rod bearing
Oil clearance STD 0.020 —0.046 mm (0.0008 —0.0018 in)
Limit 0.05 mm (0.0020 in)
Thickness at center portion
STD 1.486 —1.498 mm (0.0585 —0.0590 in)
0.03 mm
(0.0012
in) US
1.504 —1.512 mm (0.0592 —0.0595 in)
0.05 mm
(0.0020
in) US
1.514 —1.522 mm (0.0596 —0.0599 in)
0.25 mm
(0.0098
in) US
1.614 —1.622 mm (0.0635 —0.0639 in)
Connecting
rod bushing
Clearance between piston pin and
bushing
STD 0 —0.022 mm (0 —0.0009 in)
Limit 0.030 mm (0.0012 in)

ME(H4DOTC)-13
MECHANICAL
General Description
Crankshaft
Bend limit 0.035 mm (0.0014 in)
Crank pin and crank jour-
nal
Out-of-roundness 0.005 mm (0.0002 in) or less
Grinding limit 0.25 mm (0.0098 in)
Crank pin outer diameter
STD 51.984 —52.000 mm (2.0466 —2.0472 in)
0.03 mm
(0.0012
in) US
51.954 —51.970 mm (2.0454 —2.0461 in)
0.05 mm
(0.0020
in) US
51.934 —51.950 mm (2.0447 —2.0453 in)
0.25 mm
(0.0098
in) US
51.734 —51.750 mm (2.0368 —2.0374 in)
Crank journal outer diam-
eter
#1, #3, #5
STD 59.992 —60.008 mm (2.3619 —2.3625 in)
0.03 mm
(0.0012
in) US
59.962 —59.978 mm (2.3607 —2.3613 in)
0.05 mm
(0.0020
in) US
59.942 —59.958 mm (2.3599 —2.3605 in)
0.25 mm
(0.0098
in) US
59.742 —59.758 mm (2.3520 —2.3527 in)
#2, #4
STD 59.992 —60.008 mm (2.3619 —2.3625 in)
0.03 mm
(0.0012
in) US
59.962 —59.978 mm (2.3607 —2.3613 in)
0.05 mm
(0.0020
in) US
59.942 —59.958 mm (2.3599 —2.3605 in)
0.25 mm
(0.0098
in) US
59.742 —59.758 mm (2.3520 —2.3527 in)
Thrust clearance STD 0.030 —0.115 mm (0.0012 —0.0045 in)
Limit 0.25 mm (0.0098 in)
Oil clearance
#1 STD 0.010 —0.030 mm (0.0004 —0.0012 in)
Limit 0.040 mm (0.0016 in)
#2 STD 0.010 —0.030 mm (0.0004 —0.0012 in)
Limit 0.045 mm (0.0018 in)
#3 STD 0.010 —0.030 mm (0.0004 —0.0012 in)
Limit 0.040 mm (0.0016 in)
#4 STD 0.010 —0.030 mm (0.0004 —0.0012 in)
Limit 0.045 mm (0.0018 in)
#5 STD 0.010 —0.030 mm (0.0004 —0.0012 in)
Limit 0.040 mm (0.0016 in)

ME(H4DOTC)-14
MECHANICAL
General Description
Crankshaft
bearing
Crankshaft bearing thick-
ness
#1, #3
STD 1.998 —2.011 mm (0.0787 —0.0792 in)
0.03 mm
(0.0012
in) US
2.017 —2.020 mm (0.0794 —0.0795 in)
0.05 mm
(0.0020
in) US
2.027 —2.030 mm (0.0798 —0.0799 in)
0.25 mm
(0.0098
in) US
2.127 —2.130 mm (0.0837 —0.0839 in)
#2, #4, #5
STD 2.000 —2.013 mm (0.0787 —0.0793 in)
0.03 mm
(0.0012
in) US
2.019 —2.022 mm (0.0795 —0.0796 in)
0.05 mm
(0.0020
in) US
2.029 —2.032 mm (0.0799 —0.0800 in)
0.25 mm
(0.0098
in) US
2.129 —2.132 mm (0.0838 —0.0839 in)

ME(H4DOTC)-15
MECHANICAL
General Description
B: COMPONENT
1. TIMING BELT
•EXCEPT FOR STi AND AUSTRALIA MODEL
(1) Timing belt cover No. 2 (RH) (10) Intake camshaft sprocket (LH) Tightening torque: N·m (kgf-m, ft-lb)
(2) Timing belt guide (MT model) (11) Exhaust camshaft sprocket (LH) T1: 5 (0.5, 3.6)
(3) Crankshaft sprocket (12) Timing belt T2: 6.4 (0.65, 4.7)
(4) Timing belt cover No. 2 (LH) (13) Belt idler No. 2 T3: 25 (2.5, 18.1)
(5) Tensioner bracket (14) Belt idler T4: 39 (4.0, 28.9)
(6) Automatic belt tension adjuster
ASSY
(15) Timing belt cover (LH) T5: 98 (10, 72.4)
(16) Front belt cover T6: <Ref. to ME(H4DOTC)-56,
INSTALLATION, CRANKSHAFT
PULLEY.>
(7) Belt idler (17) Timing belt cover (RH)
(8) Exhaust camshaft sprocket (RH) (18) Crankshaft pulley
(9) Intake camshaft sprocket (RH) T7: 10 (1.0, 7.2)
ME-00601
T5
T1
T6
(7)
(6)
(10)
(18)
(5)
(14)
(2)
(3)
T7
(4)
(1)
(2)
(2)
T2
T4
T3
T4
T4
T4
T5 T1
T2
(11)
(15)
(17)
(2)
(9)
(8)
(13)
(14)
(12)
(16)
T1
T1
T2
T1
T1

ME(H4DOTC)-16
MECHANICAL
General Description
•STi AND AUSTRALIA MODEL
(1) Timing belt cover No. 2 (RH) (10) Intake camshaft sprocket (LH) Tightening torque: N·m (kgf-m, ft-lb)
(2) Timing belt guide (11) Exhaust camshaft sprocket (LH) T1: 5 (0.5, 3.6)
(3) Crankshaft sprocket (12) Timing belt T2: 6.4 (0.65, 4.7)
(4) Timing belt cover No. 2 (LH) (13) Belt idler No. 2 T3: 25 (2.5, 18.1)
(5) Tensioner bracket (14) Belt idler T4: 39 (4.0, 28.9)
(6) Automatic belt tension adjuster
ASSY
(15) Timing belt cover (LH) T5: 98 (10, 72.4)
(16) Front belt cover T6: <Ref. to ME(H4DOTC)-56,
INSTALLATION, CRANKSHAFT
PULLEY.>
(7) Belt idler (17) Timing belt cover (RH)
(8) Exhaust camshaft sprocket (RH) (18) Crankshaft pulley
(9) Intake camshaft sprocket (RH)
ME-00704
T5
T1
T6
(7)
(6)
(10)
(18)
(5)
(14)
(2)
(3)
T2
(4)
(1)
(2)
(2)
T2
T3
T3
T4
T4
T5
T4
T5 T1
T2
(11)
(15)
(17)
(2)
(9)
(8)
(13)
(14)
(12)
(16)
T1
T1
T2
T1
T1
T5

ME(H4DOTC)-17
MECHANICAL
General Description
2. CYLINDER HEAD AND CAMSHAFT
•EXCEPT FOR STi AND AUSTRALIA MODEL
ME-00756
T2
T4
T3
T5
T4
T2
T2
T1
(7)
(6)
(14)
(9)
(8)
(10) (15)
(16)
(13)
(12)
(32)
(29)
(30)
(31)
(3)
(4)
(27)
(23)
(24)
(21)
(32)
(18)
(19)
(14)
(26)
(28)
(25)
(20)
(22)
(17)
(16)
(11)
(5)
(4)
(1)
(3)
(2)
T1
T3
T3
T5
T5
T3
T4
T5
(13)

ME(H4DOTC)-18
MECHANICAL
General Description
(1) Rocker cover (RH) (15) Cylinder head (RH) (29) Gasket
(2) Rocker cover gasket (RH) (16) Cylinder head gasket (30) Oil filler duct
(3) Oil separator cover (17) Cylinder head (LH) (31) O-ring
(4) Gasket (18) Intake camshaft (LH) (32) Stud bolt
(5) Intake camshaft cap (Front RH) (19) Exhaust camshaft (LH)
(6) Intake camshaft cap (Center RH) (20) Intake camshaft cap (Front LH) Tightening torque: N·m (kgf-m, ft-lb)
(7) Intake camshaft cap (Rear RH) (21) Intake camshaft cap (Center LH) T1: <Ref. to ME(H4DOTC)-78,
INSTALLATION, CYLINDER
HEAD ASSEMBLY.>
(8) Intake camshaft cap (RH) (22) Intake camshaft cap (Rear LH)
(9) Exhaust camshaft cap (Front RH) (23) Exhaust camshaft cap (Front LH)
(10) Exhaust camshaft cap (Center
RH)
(24) Exhaust camshaft cap (Center
LH)
T2: 5 (0.5, 3.6)
T3: 20 (2.0, 14.5)
(11) Exhaust camshaft cap (Rear RH) (25) Exhaust camshaft cap (Rear LH) T4: 6.4 (0.65, 4.7)
(12) Exhaust camshaft (RH) (26) Rocker cover gasket (LH) T5: 10 (1.0, 7.2)
(13) Cylinder head bolt (27) Rocker cover (LH)
(14) Oil seal (28) Oil filler cap

ME(H4DOTC)-19
MECHANICAL
General Description
•STi AND AUSTRALIA MODEL
ME-00705
T2
T3
T4
T2
T2
T1
(1)
(3)
(7) (6)
(9)
(8) (10) (12)
(13)
(28)
(24)
(25)
(26)
(23)
(19)
(20)
(28)
(15)
(16)
(11)
(17)
(22)
(27)
(21)
(18)
(10)
(14)
(13)
(11)
(5)
(4)
T3
T3
T5
(2)
T3
T5
T5
T5