Insufficient Air Flow

INSUFFICIENT AIR FLOW, CAUSES
Fan Clutch Not Engaging - The fan clutch fails to engage, resulting in the fan clutch slipping on the water pump shaft.

Missing Radiator Shroud - The shroud direct air flow from the fan through the radiator. With the shroud missing air is drawn around the radiator rather than through it.

Missing Fan Blades - Results in reduce air flow and an unbalanced fan.

SYMPTOMS
- Excessive/constant electric cooling fan operation.

NOTE: The electric cooling fan is used to assist the belt driven fan during periods of high heat load.

- Engine warms up normally but gradually overheats.
- Cooling system overheats when idling or driving at low speeds, but may operate normally at cruising or highway speeds.

NOTE: With speeds in excess of 25 mph, sufficient air flow is forced across the radiator to cool the engine without the use of the cooling fan (under normal conditions).

- Cooling system overheats when under heavy engine loads.
- Very little air flow is felt flowing over the engine during hot idle.