Cylinder Bores-Inspect; Checking Connecting Rod Side Clearance; Cylinder Ring Ridge; Checking Crankshaft End Play - Pontiac Grand Prix Service Manual

SIX CYLINDER ENGINE 6-27
with pin and bosses clean and dry.
NOTE: Piston and pin must be at room temperature
when checking fit and pin must be able to fall from
piston by its own weight (Fig. 6-55).
Piston pins are available separately in .001 and .003
oversizes. If the pin fit becomes loose it should be
replaced with a new oversized pin.
CYLINDER BORES-INSPECT
Inspect cylinder bores for out-of-round or excessive
taper, with an accurate cylinder gauge J 8087 or
comparable, at top, middle and bottom of bore. (Fig.
6-56). Measure cylinder bore parallel and at right
angles to the centerline of the engine to determine
out-of-round. Variation in measure from top to bottom
of cylinder indicates the taper in cylinder. Fig. 6-57,
Fig. 6-50 Checking Connecting Rod Side Clearance
Step B (Fig. 6-54)
1. Remove J 95 10-2 and spring from support J 95 10- 1.
2. Press piston pin rest of way out of piston.
CONNECTING ROD AND PISTON-CLEAN AND
INSPECT
1. Clean carbon, varnish, and gum from piston surfaces,
including underside of piston head. Clean ring grooves,
and oil holes in oil ring groove, using suitable cleaning
tools and solvent.
Fig. 6-51 Cylinder Ring Ridge
2. Clean piston pin, rod, cap, bolts and nuts in suitable
solvent. Reinstall cap on connecting rod to assure
against subsequent mixing of caps and connecting
rods.
3. Carefully examine piston for rough or scored
bearing surfaces; cracks in skirt or head; cracked,
broken, or worn ring lands; and scored, galled, or
worn piston bosses. Damaged or faulty pistons should
be replaced.
4. Inspect piston pin for scoring, roughness, or uneven
wear and proper fit.
5. Inspect bearing shells to see that they are service-
able. Fit of bearings should be checked when engine is
assembled.
PISTON PIN FIT
RIDGE CAUSED BY CYLINDER WEAR
CYLINDER WALL
The piston pin fit in piston is .0003" to .0005" loose
Fig.
6-52 Checking Crankshaft End Play