Subaru 2009 IMPREZA, Service Manual

Page: 282 / 3619

ME(H4SO)-64
Cylinder Head
MECHANICAL
20.Cylinder Head
A: REMOVAL
NOTE:
• Perform the work with the engine installed to
body when replacing a single part. Refer to “Valve
Clearance” for preparation procedures. <Ref. to
ME(H4SO)-28, Valve Clearance.>
• When performing the work with the engine in-
stalled to body, the following parts must also be re-
moved/installed.
• Front exhaust pipe <Ref. to EX(H4SO)-6, RE-
MOVAL, Front Exhaust Pipe.> <Ref. to
EX(H4SO)-7, INSTALLATION, Front Exhaust
Pipe.>
1) Remove the V-belts. <Ref. to ME(H4SO)-39,
REMOVAL, V-belt.>
2) Remove the intake manifold. <Ref. to
FU(H4SO)-16, REMOVAL, Intake Manifold.>
3) Remove the crank pulley. <Ref. to ME(H4SO)-
46, REMOVAL, Crank Pulley.>
4) Remove the timing belt cover. <Ref. to
ME(H4SO)-48, REMOVAL, Timing Belt Cover.>
5) Remove the timing belt. <Ref. to ME(H4SO)-49,
REMOVAL, Timing Belt.>
6) Remove the cam sprocket. <Ref. to ME(H4SO)-
54, REMOVAL, Cam Sprocket.>
7) Remove the bolts which secure A/C compressor
bracket to cylinder head.
8) Remove the valve rocker assembly. <Ref. to
ME(H4SO)-57, REMOVAL, Valve Rocker Assem-
bly.>
9) Remove the camshaft. <Ref. to ME(H4SO)-60,
REMOVAL, Camshaft.>
10) Remove the oil level gauge guide. (LH side)
11) Remove the cylinder head bolts in alphabetical
sequence as shown in the figure.
NOTE:
Leave bolts (a) and (c) engaged by three or four
threads to prevent the cylinder head from falling.
12) While tapping the cylinder head with a plastic
hammer, separate it from cylinder block. Remove
the bolts (a) and (c) to remove cylinder head.
13) Remove the cylinder head gasket.
CAUTION:
Be careful not to 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:
Be careful not to scratch the mating surface of
cylinder block and cylinder head.
NOTE:
Use a new cylinder head gasket.
2) Tighten the cylinder head bolts.
(1) Apply a thin coat of engine oil to washer and
bolt thread.
(2) Tighten all bolts to 29 N·m (3.0 kgf-m, 21.4 ft-lb)
in alphabetical order.
(3) Retighten all bolts to 69 N·m (7.0 kgf-m,
50.9 ft-lb) in alphabetical order.
(4) Loosen all the bolts by 180° in the reverse
order of installing, and loosen them further by
180°.
(5) Tighten all bolts to 42 N·m (4.3 kgf-m, 31.0 ft-lb)
in alphabetical order.
(6) Tighten all bolts by 80 to 90° in alphabetical
order.
(7) Tighten all bolts by 40 to 45° in alphabetical
order.
CAUTION:
The tightening angle of the bolt should not ex-
ceed 45°.
ME-02745
( c )
( b )
( f )
( d )
( a )
( e )
ME-02745
( c )
( b )
( f )
( d )
( a )
( e )