Abnormal Noise Is Made - Komatsu PC130-7 Shop Manual

TROUBLESHOOTING
S-15 Abnormal noise is made
a Judge if the noise is an internal noise or an external
noise.
General causes why abnormal noise is made
• Abnormality due to defective parts
• Abnormal combustion
• Air sucked in from intake system
Confirm recent repair history
Degree of use of machine
Condition of abnormal
noise
Non-specified fuel is being used
Engine oil must be added more frequently
Color of exhaust gas
Metal particles are found in oil filter
Blow-by gas is excessive
Noise of interference is heard from around turbocharger
Engine pickup is poor and combustion is abnormal
When exhaust manifold is touched immediately after starting
engine, temperature of some cylinders is low
Seal on injection pump has come off
Abnormal noise is loud when accelerating engine
Clanging sound is heard from around cylinder head
Leakage of air between turbocharger and cylinder head, loose clamp
Vibrating noise is heard from around muffler
When compression pressure is measured, it is found to be low
When turbocharger is rotated by hand, it is found to be heavy
Remove gear cover and inspect directly
Speed does not change when operation of certain cylinders is
stopped
When control rack is pushed, it is found to be heavy, or does
not return
Injection pump test shows that injection amount is incorrect
Fan is deformed, belt is loose
When valve clearance is checked, it is found to be outside
standard value
Remove cylinder head cover and inspect directly
When muffler is removed, abnormal noise disappears
PC130-7
Operated for long period
Gradually occurred
Suddenly occurred
Blue under light load
Black
Remedy
Causes
20-623
S-15
(1)