Abnormal Engine Noise; Engine Knocking - Isuzu A-4JA1 Workshop Manual

Checkpoint
Check to see that the engine has been thoroughly warmed up before beginning the troubleshooting procedure.
Fuel
OK
Fuel injection timing
OK
Injection nozzle
OK
Compression pressure
Exhaust pipes
OK
Injection nozzles and/or glow
plugs
Continued on the next page
10.

ABNORMAL ENGINE NOISE

1.

Engine Knocking

Trouble Cause
NG
Fuel unsuitable
NG Fuel injection timing improperly
adjusted
NG Improper injection nozzle starting
pressure and spray condition
Blown out head gasket
NG
Broken piston ring
2. Gas Leakage Noise
NG Loosely connected exhaust pipes
Broken exhaust pipes
NG Loose injection nozzles and/or
glow plugs
TROUBLESHOOTING
Countermeasure
NG
Replace the fuel
NG
Adjust the fuel injection timing
NG Adjust or replace the injection
nozzle
Replace the head gasket or the
NG
piston ring
Tighten the exhaust pipe
NG
connections
Replace the exhaust pipes
Replace the washers
NG
Tighten the injection nozzles
and/or the glow plugs
197