Pontiac Fiero 1988 Service Manual page 280

GENERAL ENGINE MECHANICAL 6 A - 3
_ _ _ G 3 4 1 7 0 6 A B G
Figure 3 Measuring Valve Guide Clearance
Engine(s) Nominal Size
Reamer (Oversize - OS)
1.6 & 2.0L 7mm .19mm (.0075") OS
7mm .381mm (.015") OS
7mm .762mm (.030) OS
2.5L 11/32 .076mm (.003") OS
.127mm (.005") OS
2.8L 11/32 .076mm (.003") OS
.381mm (.015") OS
.762mm (.030") OS
3.0 & 3.8L 11/32 .076mm(003") OS
.152mm (.006") OS
4.3L & 5.0L 11/32 .076mm (.003") OS
.127mm (.005") OS
N O T I C E :
Avoid breaking reamer flutes, or
jamming the reamer into the valve guide, due to
packing of chips or carbon. Clean the valve guides
before reaming. Do not push down on the reamer.
V A L V E S
p | p Measure
• Valve run out. Lift the valve off its seat and apply
a dab of Prussian blue on the valve face. Seat the
valve and carefully rotate it. The Prussian blue
traces, transferred to the valve seat, are an
indication of concentricity of the valve seat.
m Clean all traces of Prussian blue. Apply a dab of
Prussian blue on the valve seat and repeat the
F i
9
u r e
4
R © a
m i n
9
Valve
Guide
check. The traces of Prussian blue transferred to
the valve face indicates valve run out.
Recondition valve seat/face, or replace valves, as
required.
G34357-6A-BG