2001 Ford F250 Owner's Manual - Page 211

Maintenance and care Refer to the chart on the coolant container to ensure the coolant concentration in your vehicle will provide adequate freeze protection. Never increase the engine coolant concentration above 60% (protection to -60°F). At a level over 60%, your engine could overheat and become damaged. If you drive in extremely hot climates, it is still necessary to maintain the coolant concentration at 50/50 coolant and water. Do not allow the coolant concentration to fall below 40% coolant. At a concentration less than 40%, the corrosion protection to your engine and cooling components may be compromised and permanent damage may result. What you should know about fail-safe cooling (if equipped) If the engine coolant supply is depleted, this feature allows the vehicle to be driven temporarily before incremental component damage is incurred. The "fail-safe" distance depends on ambient temperatures, vehicle load and terrain. How fail-safe cooling works If the engine begins to overheat: • The engine coolant temperature H gauge will move to the red (hot) area. and symbol will • The illuminate. C • The Service Engine Soon indicator light will illuminate. If the engine reaches a preset over-temperature condition, the engine will automatically switch to alternating cylinder operation. Each disabled cylinder acts as an air pump and cools the engine. When this occurs the vehicle will still operate. However: • The engine power will be limited. • The air conditioning system will be disabled. Continued operation will increase the engine temperature and the engine will completely shut down, causing steering and braking effort to increase. Once the engine temperature cools, the engine can be re-started. Take your vehicle to a service facility as soon as possible to minimize engine damage. 211