Subaru 2009 IMPREZA Service Manual page 1130

MECHANICAL
(4) Set the ST2 on valve spring.
ST2 499718000 VALVE SPRING REMOVER
ST2
ST1
(5) Compress the valve spring and fit the valve
spring retainer key.
(6) After installing, tap the valve spring retainers
lightly with a plastic hammer for better seating.
2) Apply oil to the surfaces of the valve lifter.
3) Install the valve lifter.
E: INSPECTION
1. CYLINDER HEAD
1) Check for cracks or damage. Use liquid pene-
trant tester on the important sections to check for
fissures. Check that there are no marks of gas leak-
ing or water leaking on gasket installing surface.
2) Measure the warping of the cylinder head sur-
face that mates with cylinder block using a straight
edge (A) and thickness gauge (B).
If the warping exceeds the limit, correct the surface
by grinding it with a surface grinder.
Warping limit:
0.035 mm (0.0014 in)
Grinding limit:
0.3 mm (0.012 in)
Standard height of cylinder head:
127.5 mm (5.02 in)
NOTE:
Uneven torque for the cylinder head bolts can
cause warpage. When reinstalling, pay special at-
tention to the torque so as to tighten evenly.
Cylinder Head
2. VALVE SEAT
Inspect the intake and exhaust valve seats, and
correct the contact surfaces with a valve seat cutter
if they are defective or when valve guides are re-
placed.
Contacting width W between valve and valve
seat:
Standard
Intake
Exhaust
ME-03142
3. VALVE GUIDE
1) Check the clearance between valve guide and
valve stem. The clearance can be checked by mea-
suring respectively the outer diameter of valve
stem with a micrometer and the inner diameter of
valve guide with a caliper gauge.
Clearance between the valve guide and valve
stem:
(A)
Standard
Intake
Exhaust
(B)
ME-00126
ME(H4DOTC)-72
0.6 — 1.4 mm (0.024 — 0.055 in)
1.2 — 1.8 mm (0.047 — 0.071 in)
0.030 — 0.057 mm (0.0012 — 0.0022 in)
0.040 — 0.067 mm (0.0016 — 0.0026 in)
ME-00127
ME-00287