FORD 2003 Expedition v.4 - Manual (Page 301)

If you drive in extremely hot climates:
• It is still necessary to maintain the coolant concentration
above 40%.
• NEVER decrease the coolant concentration below 40%.
• Decreased engine coolant concentrations below 40% will
decrease the corrosion protection characteristics of the engine
coolant and may cause engine damage.
• Decreased engine coolant concentrations below 40% will
decrease the freeze protection characteristics of the engine
coolant and may cause engine damage.
• Refer to the chart on the coolant container to ensure the
coolant concentration in your vehicle will provide adequate
protection at the temperatures in which you drive.
Vehicles driven year-round in non-extreme climates should use a 50/50
mixture of engine coolant and distilled water for optimum cooling system
and engine protection.
What you should know about fail-safe cooling
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
gauge will move to the red (hot)
area.
• The HI TEMP/LOW OIL indicator
will illuminate.
• 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.
Maintenance and Specifications
301