Diagnosis - Isuzu 4JA1 Workshop Manual

DIAGNOSIS

Engine Cooling Trouble
Symptom
Engine overheating
Engine overcooling
Engine slow to warm–up
Possible Cause
Low Engine Coolant level
Thermo meter unit faulty
Faulty thermostat
Faulty Engine Coolant temperature
sensor
Clogged radiator
Faulty radiator cap
Low engine oil level or use of
improper engine oil
Clogged exhaust system
Faulty Throttle Position sensor
Open or shorted Throttle Position
sensor circuit
Damaged cylinder head gasket
Faulty thermostat
Faulty thermostat
Thermo unit faulty
ENGINE COOLING 6B – 7
Action
Replenish
Replace
Replace
Repair or replace
Clean or replace
Replace
Replenish or change oil
Clean exhaust system or replace
faulty parts
Replace throttle valve assembly
Repair or replace
Replace
Replace
Replace
Replace