39
Reason of failure Troubleshooting
5. Abnormal noise
The fuel supply advanced angle is too
large and there are noises inside the
cylinder sound like knock on the
metal.
The fuel injection nozzle is dripping
oil and meshed with the needle valve,
causing noises sound like “da,da,da”.
Too large valve clearance will cause
clear and uniform knocking noise.
The collision between piston and
valve will cause strong and uniform
knocking noise (You will feel
vibration of piston if putting your
hands slightly on the nuts of cylinder
head ).
Strong knocking noises can be head if
piston is hitting the bottom of cylinder
head.
There will be slight knocking noises
for the valve mechanism when valve
spring is broken, valve pushing rod is
bent or valve tappet is abrasive.
Noises because of the large clearance
between piston and cylinder liner will
be relieved after the diesel engine is
warming up.
In case of great clearance between
connecting rod bearing, strong
knocking noise can be heard when the
speed is abruptly dropped.
Large clearance between connecting
rod liner and piston pin will result in
slight and sharp noise that can be
especially heard at idle speed.
If the thrust plate of crankshaft is
greatly worn with large clearance, the
noise caused by the knock of
crankshaft at idle speed can be heard.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Adjust the fuel supply advanced
angle.
Clean, repair or replace needle valve
parts.
Adjust the valve clearance.
Increase the valve clearance
properly;correct the clearance for
connecting rod bearing or replace the
connecting rod bearing shell.
Replace the cylinder head liner.
Replace spring, push rod or tappet and
adjust the valve clearance.
Replace the cylinder liner and piston
in line with the abrasion.
Replace the connecting rod bearing.
Replace the connecting rod liner.
Replace the thrust plate of crankshaft.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
To Next Page
Loading...
