Cylinder Head Assembly - Subaru IMPREZA 2002 Service Manual

CYLINDER HEAD ASSEMBLY
MECHANICAL
20.Cylinder Head Assembly
A: REMOVAL
1) Remove the V-belt. <Ref. to ME(S0HC)-43, RE-
MOVAL, V-belt.>
2) Remove the crankshaft pulley. <Ref. to ME(S0-
HC)-45, REMOVAL, Crankshaft Pulley.>
3) Remove the belt cover. <Ref. to ME(S0HC)-46,
REMOVAL, Belt Cover.>
4) Remove the timing belt assembly. <Ref. to
ME(S0HC)-47, REMOVAL, Timing Belt Assem-
bly.>
5) Remove the camshaft sprocket. <Ref. to
ME(S0HC)-52, REMOVAL, Camshaft Sprocket.>
6) Remove the intake manifold. <Ref. to FU(S0-
HC)-15, REMOVAL, Intake Manifold.>
7) Remove the bolt which installs the N C compres-
sor bracket on cylinder head.
8) Remove the valve rocker assembly. <Ref. to
ME(S0HC)-55, REMOVAL, Valve Rocker Assem-
bly.>
.
9) Remove the camshaft. <Ref. to ME(S0HC)-57,
REMOVAL, Camshaft.>
10) Remove the cylinder head bolts in alphabetical
sequence shown in figure.
CAUTION:
Leave bolts (a) and (c) engaged by three or four
threads to prevent the cylinder head from fall-
ing.
11) While tapping the cylinder head with a plastic
hammer, separate it from cylinder block.
12) Remove the bolts (a) and (b) to remove the cyl-
inder head.
13) Remove the cylinder head gasket.
CAUTION:
Do not scratch the mating surface of cylinder
head and cylinder block.
14) Similarly, remove the right side cylinder head.
B: INSTALLATION
1) Install the cylinder head and gaskets on cylinder
block.
CAUTION:
Use new cylinder head gaskets.
Be careful not to scratch the mating surface
of cylinder block and cylinder head.
2) Tighten the cylinder head bolts.
(1) Apply a coat of engine oil to washers and
bolt threads.
(2) Tighten all bolts to 29 N.m (3.0 kgf-m, 22 ft-
Ib) in alphabetical sequence.
Then tighten all bolts to 69 N.m (7.0 kgf-m, 51 ft-
Ib) in alphabetical sequence.
(3) Back off all bolts by 180" first; back them off
by 180" again.
(4) Tighten the bolts (a) and (b) to 34 N-m (3.5
kgf-m, 25 ft-lb).
(5) Tighten the bolts (c), (d), (e) and (f) to 15
N.m (1.5 kgf-m, 11 ft-lb).
(6) Tighten all bolts by 80 to 90" in alphabetical
sequence.
CAUTION:
Do not tighten the bolts more than 90".
(7) Further tighten all bolts by 80 to 90" in al-
phabetical sequence shown in the figure below.
CAUTION:
Ensure the total "re-tightening angle" [in the
former two steps], do not exceed 180".
( C )
S2M1589B
3) Install the camshaft. <Ref. to ME(S0HC)-58, IN-
STALL AT1 0 N
,
Cams haft. >
4) Install the valve rocker assembly. <Ref. to
ME(S0HC)-55, INSTALLATION, Valve Rocker As-
sembly.>
5 ) Install the N C compressor bracket on cylinder
head.
ME(S0HC)-61