How fail-safe cooling works
If the engine begins to overheat:
•The engine coolant temperature
gauge will move to the red (hot)
area.
•The message center will indicate
the engine is overheating.
•TheCheck engineindicator
(
) 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.
When fail-safe mode is activated
You have limited engine power when in the fail-safe mode, so drive the
vehicle with caution. The vehicle will not be able to maintain high-speed
operation and the engine will run rough. Remember that the engine is
capable of completely shutting down automatically to prevent engine
damage, therefore:
1. Pull off the road as soon as safely possible and turn off the engine.
2. Arrange for the vehicle to be taken to a service facility.
3. If this is not possible, wait a short period for the engine to cool.
4. Check the coolant level and replenish if low.
Never remove the coolant reservoir cap while the engine is
running or hot.
5. Re-start the engine and take your vehicle to a service facility.
2008 F-250/350/450/550(f23)
Owners Guide (post-2002-fmt)
USA(fus)
Maintenance and Specifications
329
4. Latch the gearshift lever in P (Park) and leave the engine running.
5. Remove the dipstick, wiping it clean with a clean, dry lint free rag. If
necessary, refer toIdentifying components in the engine compartment
in this chapter for the location of the dipstick.
6. Install the dipstick making sure it is fully seated in the filler tube.
7. Remove the dipstick and inspect the fluid level. The fluid should be in
the designated area for normal operating temperature or ambient
temperature.
Low fluid level
Do not drive the vehicle if the fluid
level is at the bottom of the dipstick
and the ambient temperature is
above 50°F (10°C).
Correct fluid level
The transmission fluid should be checked at normal operating
temperature 150°F-170°F (66°C-77°C) on a level surface. The normal
operating temperature can be reached after approximately 20 miles
(30 km) of driving.
You can check the fluid without driving if the ambient temperature is
above 50°F (10°C). However, if fluid is added at this time, an overfill
condition could result when the vehicle reaches normal operating
temperature.
The transmission fluid should be in
this range if at normal operating
temperature (150°F-170°F
[66°C-77°C]).
The transmission fluid should be in
this range if at ambient temperature
(50°F-95°F [10°C-35°C]).
High fluid level
Fluid levels above the safe range
may result in transmission failure.
An overfill condition of transmission
fluid may cause shift and/or
engagement concerns and/or possible damage.
High fluid levels can be caused by an overheating condition.
2008 F-250/350/450/550(f23)
Owners Guide (post-2002-fmt)
USA(fus)
Maintenance and Specifications
344
