POTENTIAL CAUSE
1. Dirt, debris blocking air flow through coolers, condenser, and radiator.
2. Low coolant level.
3. Serpentine belt loose, worn, or tensioner inoperative.
4. Prolonged idling/slow speed operation in heavy traffic when ambient temperatures are high.
5. Failed thermostat or radiator cap.
6. Fan clutch inoperative.
7. Water pump inoperative.
8. Blown head gasket.
9. Crack in block, or leaking freeze plug.
10. Coolant temperature gauge or sensor faulty.
CORRECTION
1. Remove and clear fins with compressed air, soft bristle brush, or water stream.
2.Add coolant and check for leaks (hoses, surge tank, hose connections, water pump, radiator).
3.Replace belt and/or tensioner if either part has failed or is worn beyond limit.
4. If this type operation cannot be avoided, have driver turn on heater and “rev” engine when stopped in traffic. This will help dissipate some heat and get more air through radiator (from fan).
5. Check thermostat and cap operation. Replace either part if inoperative.
6. Replace clutch.
7. Check coolant flow and replace pump if necessary.
8. Verify that coolant is leaking into combustion chamber and replace gasket.
9. Replace corroded freeze plugs. Replace block if cracked.
10. Test and replace gauges or sensors as needed.
