Subaru 2009 IMPREZA Service Manual page 1131

2) If the clearance between valve guide and valve
stem exceeds the standard, replace the valve
guide or valve itself, whichever shows the greater
amount of wear or damage. See the following pro-
cedure for valve guide replacement.
Valve guide inner diameter:
6.000 — 6.012 mm (0.2362 — 0.2367 in)
Valve stem outer diameters:
Intake
5.955 — 5.970 mm (0.2344 — 0.2350 in)
Exhaust
5.945 — 5.960 mm (0.2341 — 0.2346 in)
(1) Place the cylinder head on ST1 with the
combustion chamber upward so that valve
guides fit the holes in ST1.
(2) Insert the ST2 into valve guide and press it
down to remove the valve guide.
ST1 498267600 CYLINDER HEAD TABLE
ST2 499767200 VALVE GUIDE REMOVER
ST2
(3) Turn the cylinder head upside down and
place the ST as shown in the figure.
ST 18251AA020 VALVE GUIDE ADJUSTER
(4) Before installing a new valve guide, make
sure that neither scratches nor damages exist
on the inner surface of valve guide holes in cyl-
inder head.
Cylinder Head
ST1 499767200
ST2 18251AA020 VALVE GUIDE ADJUSTER
Valve guide protrusion L:
15.8 — 16.2 mm (0.622 — 0.638 in)
NOTE:
• Apply engine oil to the ST when reaming.
• If the inner surface of valve guide is damaged,
ST1 the edge of ST should be slightly ground with oil
stone.
• If the inner surface of valve guide becomes lus-
ME-00128
trous and the ST does not chip, use a new ST or
remedy the ST.
ST 499767400
ST
ME-00757
ME(H4DOTC)-73
(5) Put a new valve guide, coated with sufficient
oil, in the cylinder head, and insert the ST1 into
valve guide. Press in until the valve guide upper
end is flush with the upper surface of ST2.
VALVE GUIDE REMOVER
ST1
ST2
(6) Check the valve guide protrusion.
(7) Ream the inside of valve guide using ST.
Put the ST in valve guide, and rotate the ST
slowly clockwise while pushing it lightly. Bring
the ST back while rotating it clockwise.
VALVE GUIDE REAMER
(8) After reaming, clean the valve guide to re-
move chips.
(9) Recheck the contact condition between
valve and valve seat after replacing the valve
guide.
MECHANICAL
ME-00130
ME-00294