SECTION 10 - ENGINE - CHAPTER 1
5
84176561
- 03-2008
ENGINE TROUBLESHOOTING
(cont)
Problems
Possible Causes
Solutions
8.
Fuel supply pump damaged.
Replace fuel supply pump.
9.
Incorrect valve - rocker arm
clearances.
Adjust the clearance between the
rocker arms and the valves.
10. Cylinder compression low.
Test compression and overhaul en‐
gine if necessary.
11. Air filter clogged.
Clean filter unit and replace filter el‐
ement if necessary.
12. Tie-rod in linkage between accel‐
erator and injection pump incor‐
rectly adjusted.
Adjust to correct length.
13. Fast idling speed screw on injec‐
tion pump incorrectly adjusted.
Adjust fast idling speed screw.
Engine produces abnormal
knocking noises.
1.
Injectors partially obstructed or
damaged.
Clean and overhaul injectors and ad‐
just pressure setting.
2.
Impurities accumulating in fuel
lines.
Clean fuel lines and replace severely
dented pipes; clean injection pump if
necessary.
3.
Injection pump timing incorrect.
Adjust injection pump timing.
4.
Crankshaft knocking due to ex‐
cessive play in one or more main
or big-end bearings or excessive
endfloat.
Re-grind crankshaft journals and
crankpins. Fit oversize shell bearings
and thrust washers.
5.
Crankshaft out of balance.
Check crankshaft alignment and bal‐
ance; replace if necessary.
6.
Flywheel bolts loose.
Replace any bolts that have worked
loose and tighten all bolts to the speci‐
fied preliminary and angular torque
values.
7.
Connecting rod axes not parallel. Straighten connecting rods, check
axes parallelism; replace con rods if
necessary.
8.
Pistons knock due to excessive
wear.
Rebore cylinder liners and fit oversize
pistons.
9.
Noise caused by excessive play
of gudgeon pins in small-end and
piston bushings. Loose fit of
small-end bushing.
Fit oversize gudgeon pin, rebore pis‐
ton seats and small-end bushings.
Replace with new bushings.
10. Excessive tappet / valve noise.
Check for broken springs or excess‐
ive play between valve stems and
guides, cam followers and bores; ad‐
just valve clearances.
(continued)
