| Cooling system parts malfunction |
Poor heat transfer |
Water pump malfunction |
Worn or loose drive belt |
- |
| Thermostat stuck closed |
- |
| Damaged fins |
Dust contamination or paper clogging |
| Physical damage |
| Clogged radiator cooling tube |
Excess foreign material (rust, dirt, sand, etc.) |
| Reduced air flow |
Cooling fan does not operate |
Fan assembly |
- |
| High resistance to fan rotation |
| Damaged fan blades |
| Damaged radiator shroud |
- |
- |
- |
| Improper engine coolant mixture ratio |
- |
- |
- |
| Poor engine coolant quality |
- |
Engine coolant density |
- |
| Insufficient engine coolant |
Engine coolant leakage |
Cooling hose |
Loose clamp |
| Cracked hose |
| Water pump |
Poor sealing |
| Radiator cap |
Loose |
| Poor sealing |
| Radiator |
O-ring for damage, deterioration or improper fitting |
| Cracked radiator tank |
| Cracked radiator core |
| Reservoir tank |
Cracked reservoir tank |
| Overflowing reservoir tank |
Exhaust gas leakage into cooling system |
Cylinder head deterioration |
| Cylinder head gasket deterioration |
| Except cooling system parts malfunction |
- |
Overload on engine |
Abusive driving |
High engine RPM under no load |
| Driving in low gear for extended time |
| Driving at extremely high speed |
| Powertrain system malfunction |
- |
| Installed improper size wheels and tires |
| Dragging brakes |
| Improper ignition timing |
| Blocked or restricted air flow |
Blocked bumper |
- |
- |
| Blocked radiator grille |
Installed car brassiere |
| Mud contamination or paper clogging |
| Blocked radiator |
- |
| Blocked condenser |
Blocked air flow |
| Installed large fog lamp |