Probable Cause:
1. Restriction To Air Flow Through Radiator Or Restriction To Flow Of Coolant Through The Heat Exchanger
Remove all restrictions of flow.
2. Not Enough Coolant In System
Add coolant to cooling system.
3. Pressure Cap Has A Defect
Check operations of pressure cap. Install a new pressure cap if necessary.
4. Combustion Gases In Coolant
Find out where gases get into the cooling system. Make repairs as needed.
5. Water Temperature Regulators (Thermostats) Or Temperature Gauge Has A Defect
Check water temperature regulators for correct operation. Check temperature gauge operation. Install new parts as necessary.
6. Water Pump Has A Defect
Install a new water pump.
7. Too Much Load On The System
Make a reduction to the load.
8. Wrong Fuel Injection Timing
Make adjustment to timing.
9. Shunt Line Has A Defect
Make repairs as needed.
10. Drive Belts Loose
Adjust drive belts.