Causes Of Faults And Troubleshooting - Doosan DX22 Operation & Maintenance Manual

6. Cooling System

Causes of Faults and Troubleshooting

Symptom
Overheated engine
Overcooled engine
Insufficient coolant
Abnormal noise in cooling
system
Possible Cause
Insufficient coolant
Loose radiator cap spring
Loose or broken fan belt
Fan belt contaminated with oil
Malfunctioning thermostat
Faulty coolant pump
Resistance due to contamination of coolant
passage
Incorrect injection timing
Contaminated or clogged radiator air passage
Coolant leakage due to damaged cylinder
head gasket
Malfunctioning thermostat
Excessively low ambient temperature
Coolant leaking from radiator
Loose or damaged radiator coolant connection Retighten the hose clamp or replace the hose
Loose radiator cap valve spring
Leaky coolant pump
Loose or damaged heater hose connection
Leaky cylinder head gasket
Cracked cylinder head or block
Faulty coolant pump bearing
Loose or bent cooling fan
Uneven rotation of cooling fan
Faulty fan belt
Add coolant
Replace the cap
Adjust or replace the fan belt
Replace the fan belt
Replace the thermostat
Repair or replace
Clean the radiator and coolant passage
Adjust the injection timing
Clean the outside of the radiator
Replace the cylinder head gasket
Replace the thermostat
Cover the radiator
Repair or replace
Replace the cap
Repair or replace
Tighten or replace the hose
Replace the cylinder head gasket
Replace the cylinder head or block
Replace the bearing
Retighten or replace the fan
Replace the fan
Replace the fan belt
92
Troubleshooting