Cylinder Head Assembly - Subaru Impreza 2002 Service Manual

19.Cylinder Head Assembly

A: REMOVAL
1) Remove the V-belt. <Ref. to ME(STi)-43, RE-
MOVAL, V-belt.>
2) Remove the crankshaft pulley. <Ref. to ME(STi)-
45, REMOVAL, Crankshaft Pulley.>
3) Remove the belt cover. <Ref. to ME(STi)-46,
REMOVAL, Belt Cover.>
4) Remove the timing belt assembly. <Ref. to
ME(STi)-47, REMOVAL, Timing Belt Assembly.>
5) Remove the camshaft sprocket. <Ref. to
ME(STi)-56, REMOVAL, Camshaft Sprocket.>
6) Remove the intake manifold. <Ref. to FU(TUR-
BO)-15, REMOVAL, Intake Manifold.>
7) Remove the bolt which installs A/C compressor
bracket on cylinder head.
8) Remove the camshaft. <Ref. to ME(STi)-59, RE-
MOVAL, Camshaft.>
9) Remove the cylinder head bolts in alphabetical
sequence shown in the figure.
CAUTION:
Leave bolts (A) and (D) engaged by three or
four threads to prevent the cylinder head from
falling.
10) While tapping the cylinder head with a plastic
hammer, separate it from cylinder block.
Remove bolts (A) and (D) to remove the cylinder
head.
11) Remove the cylinder head gasket.
CAUTION:
Do not scratch the mating surface of the cylin-
der head and cylinder block.
CYLINDER HEAD ASSEMBLY
B2M1397C
B2M1397C
ME(STi)-65
12) 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 the cylinder head and cylinder block.
2) Tighten 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-
lb) in alphabetical sequence.
Then tighten all bolts to 69 N·m (7.0 kgf-m, 51 ft-
lb) in alphabetical sequence.
(3) Loosen all bolts by 180° in reverse order,
and then loosen the bolts by 180° again.
(4) Tighten all bolts to 39 N·m (4.0 kgf-m, 29 ft-
lb) in alphabetical sequence.
(5) Tighten all bolts by 80 to 90° in alphabetical
sequence.
(6) Additionally, tighten all bolts by 40 to 45° in
alphabetical sequence.
CAUTION:
Do not tighten the bolts more than 45° ° ° ° .
(7) Tighten bolts (A) and (B) by 45°.
CAUTION:
Ensure that the total "re-tightening angle" [in
the two previous step] does not exceed 90° ° ° ° .
3) Install the camshaft. <Ref. to ME(STi)-60, IN-
STALLATION, Camshaft.>
4) Install the A/C compressor bracket on cylinder
head.
5) Install the intake manifold. <Ref. to FU(TURBO)-
18, INSTALLATION, Intake Manifold.>
6) Install the camshaft sprocket. <Ref. to ME(STi)-
56, INSTALLATION, Camshaft Sprocket.>
7) Install the timing belt assembly. <Ref. to
ME(STi)-49, INSTALLATION, Timing Belt Assem-
bly.>
8) Install the belt cover. <Ref. to ME(STi)-46, IN-
STALLATION, Belt Cover.>
MECHANICAL
B2M1397D