Service manual

G420F(FE) Service Manual Chapter 3. Engine Mechanical System
112
3. Calculate the difference between the cylinder
bore diameter and the piston diameter.
Piston-to-cylinder clearance
0.02 ~ 0.04 mm (0.0008 ~ 0.0016 in.)
4. Inspect the piston ring side clearance. Using a
feeler gauge, measure the clearance between
new piston ring and the wall of the ring groove.
Piston ring side clearance
No.1: 0.04 ~ 0.08 mm (0.0016 ~ 0.0031in.)
No.2: 0.03 ~ 0.07 mm (0.0012 ~ 0.0028in.)
Limit
No.1: 0.1 mm (0.004in.)
No.2: 0.1 mm (0.004in.)
If the clearance is greater than maximum, replace
the piston.
5. Inspect piston ring end gap. To measure the
piston ring end gap, insert a piston ring into the
cylinder bore. Position the ring at right angles to
the cylinder wall by gently pressing it down with a
piston. Measure the gap with a feeler gauge. If the
gap exceeds the service limit, replace the piston
ring. If the gap is too large, recheck the cylinder
bore diameter against the wear limits, If the bore
is over the service limit, the cylinder block must be
rebored.
Piston ring end gap
Standard
No.1: 0.23~0.38 mm (0.0091~0.0150in.)
No.2: 0.33~0.48 mm (0.0130~0.0189in.) [2.0L]
Limit
No.1,2,oil ring:1.0mm(0.039in.)