FORD 1998 Expedition - Manual (Page 162)

container to ensure the coolant
concentration in your vehicle is
such that the coolant will not
freeze at the temperature level in
which you drive during winter
months. Never increase the engine
coolant concentration above 60%.
Leave a 50/50 mixture of engine
coolant and water in your vehicle
year-round in non-extreme
climates.
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 overheats, the engine
will automatically switch from
eight to alternating four cylinder
operation. Each disabled cylinder
acts as an air pump and cools the
engine.
When this occurs, the engine
coolant temperature gauge will
move into the red area and the
light illuminates.
The check engine light will
illuminate, indicating that vehicle
service is required.
The vehicle will still operate, but
will have limited engine power and
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Maintenance and care
162