Service manual
ENGINE
TROUBLESHOOTING
PROBLEM
PROBABLE
CAUSE
VERIFICATION/REMEDY
SMOKY
EXHAUST
(coni.)
WHITISH
OR
PURPLISH
(coni.)
d.
Worn
valve
stem
and
valve
guide.
d.
Replace.
e.
Low
engine
oil
viscosity.
e.
Replace.
r.
Excessive
oil
pressure.
r.
Correct.
3.
Injection
timing
is
too
late.
3.
Adjust.
4.
Insufficient
compression.
4.
See
LOW
COMPRESSION;
HARD
STARTING.
BLACKISH
OR
DARK
GRAYISH
1.
Engine
body
troubles.
a.
Poor
compression.
a.
See
LOW
COMPRESSION;
HARD
STARTING.
b.
Improper
valve
clearance.
b.
Adjust.
2.
Insufficient
intake
air.
2.
Clear
intake.
3.
Improper
fuel.
3.
Replace
with
proper
fuel.
ABNORMAL
SOUND
CRANKSHAFT
AND
MAIN
BEARING
OR
NOISE
1.
Badly
worn
bearing.
1.
Replace
bearing
and
grind
crankshaft.
2.
Badly
worn
crankshaft.
2.
Grind
crankshaft.
3.
Melted
bearing.
3.
Replace
bearing
and
check
lubrication
system.
CONNECTING
ROD
AND
CONNECTING
ROD
BEARING
1.
Worn
connecting
rod
big
end
bearing.
1.
Replace
bearing.
2.
Worn
crankpin.
2.
Grind
crankshaft.
3.
Bent
connecting
rod.
3.
Correct
bend
or
replace.
PISTON,
PISTON
PIN,
AND
PISTON
RING
1.
Worn
cylinder.
1.
Rebore
cylinder
to
oversize
and
replace
piston.
2.
Worn
piston
pin.
2.
Replace
piston.
3.
Piston
seized.
3.
Replace
piston
and
rebore
cylinder.
4.
Piston
seized
and
ring
worn
or
damaged.
4.
Replace
piston
and
rings.
VALVE
MECHANISM
1.
Worn
camshaft.
1.
Replace.
2.
Excessive
valve
clearance.
2.
Adjust.
3.
Worn
timing
gear.
3.
Replace.
ROUGH
OPERATION
INJECTION
PUMP
SYSTEM
1.
Uneven
injection.
1.
Adjust
injection
or
replace
parts.
2.
Worn
delivery
valve.
2.
Replace.
3.
Inadequate
injection
nozzle
spray.
3.
Replace
injection
nozzle.
(continued)
Engines
&
Generators
5