Knocking; Check Items Before Troubleshooting; Problem: Knocking - Mitsubishi L Series Service Manual

TROUBLESHOOTING

1.3 Knocking

The diesel engine rotates producing unique combustion
noise (diesel knock) due to its combustion system. This
knock noise is normal unless it is especially loud.
1.3.1

Check items before troubleshooting

(1) Clogging of air cleaner element
1.3.2

Problem: Knocking

Is the fuel injection timing normal
(fuel injection timing is early)?
YES
Are fuel injection nozzles normal (drop in
injection-valve opening pressure and faulty)
YES
Is the compression pressure
in cylinders normal?
YES
Is the fuel injection pump normal (variations in injection amount)?
YES
Generation of mechanical noise (wear of and damage to main working parts)
14-4
(2) Use of poor quality fuel (low cetane number fuel such
as kerosene)
NO
NO
NO
Inspecting valves, pistons, piston rings
and cylinder head gasket
Problem: Knocking
Adjust fuel injection timing
Examine fuel injection nozzles