Engine Cooling System Overheating

Establish what driving conditions caused the complaint. Abnormal loads on the cooling system such as the following may be the cause:

• Prolonged idle.
• Very high ambient temperature.
• Overloaded Truck.
• Slow traffic.
• Traffic jams.
• High speed or steep grades.
• Snow Plow restricting airflow through cooling module.
• Debris on front of the grill or the cooling module that is restricting airflow.

Driving techniques that avoid overheating are:

• Idle with A/C off when temperature gauge is at end of normal range.