CHECK THESE NEXT:

9. COLLAPSED LOWER RADIATOR HOSE
Replace lower radiator hose.

10. RETARDED IGNITION TIMING
Have ignition timing professionally advanced.

11. DEFECTIVE PUMP IMPELLER OR CLOGGED WATER PUMP
Have water pump professionally replaced.

12. BROKEN OR MISSING FAN SHROUD
Have fan shroud professionally replaced.

13. FAULTY ELECTRIC FAN MOTOR, RELAY, FUSE OR COOLANT TEMPERATURE SENSOR
Replace appropriate fuse.
Otherwise, have fan system professionally repaired.

14. EXCESSIVE USE OF AIR CONDITIONER DURING IDLE
Avoid air conditioner use at idle.
Alter driving habits.

15. WORN ENGINE FAN DRIVE CLUTCH OR DAMAGED FAN
Have fan drive clutch or fan professionally replaced.

16. EXHAUST MANIFOLD HEAT CONTROL VALVE (HEAT RISER) STUCK CLOSED
Have heat riser professionally serviced.