Komatsu PC88MR-10 Shop Manual page 1009

No. Cause
Defective contact between
13
valve and valve seat
14 Defective piston ring
PC88MR-10
Point to check, remarks
Measure compression pressure (see
Standard value table).
(Reference: See Testing and adjusting,
"Testing compression pressure".)
Check valve clearance.
(Reference: See Testing and adjusting,
"Testing and adjusting valve clearance".)
Check exhaust gas at KDOC muffler outlet.
(Reference: See Testing and adjusting,
"Testing exhaust gas color".)
Measure compression pressure (see
Standard value table).
(Reference: See Testing and adjusting,
"Testing compression pressure".)
Check piston ring and piston ring groove.
40 Troubleshooting
Troubleshooting of engine (S-mode)
Remedy
Correct contact
between valve and
valve seat or replace
them.
Replace piston ring or
piston.
40-521