How fail-safe cooling works
If the engine begins to overheat:
• The engine coolant temperature
gauge will move to the red (hot)
area.
• The and the symbol
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.
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:
• The engine will completely shut down.
• Steering and braking effort will 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.
2004 Navigator (nav)
Owners Guide (post-2002-fmt)
USA English (fus)Maintenance and Specifications
318
change oil soon warning,
message center .......................308
checking and adding ..............308
dipstick ....................................308
filter, specifications ........310, 348
recommendations ...................310
refill capacities ........................349
specifications ..................351, 354
Exhaust fumes ..........................220
Extended Rear Park Assist ......238
F
Fail safe cooling ........................317
Floor mats .................................149
Fluid capacities .........................349
Foglamps .....................................99
Four-Wheel Drive vehicles .......240
control trac .............................240
description ..............................241
driving off road .......................243
electronic shift ........................242
indicator light .........................240
preparing to drive your
vehicle .....................................227
Fuel ............................................319
calculating fuel
economy ..........................139, 323
cap ...........................................321
capacity ...................................349
choosing the right fuel ...........321
comparisons with EPA fuel
economy estimates .................326
detergent in fuel .....................322
filling your vehicle with
fuel ...........................319, 321, 323
filter, specifications ........323, 348
fuel pump shut-off switch .....263
improving fuel economy ........323
octane rating ...................322, 354 quality ......................................322
running out of fuel .................322
safety information relating to
automotive fuels .....................319
Fuses ..................................265 – 266
G
Garage Door Opener (see
Homelink wireless control
system) ......................................132
Gas cap (see Fuel cap) ............321
Gas mileage (see Fuel
economy) ...................................323
Gauges .........................................14
GAWR (Gross Axle Weight
Rating) .......................................252
calculating ...............................254
definition .................................252
driving with a heavy load ......252
location ....................................252
GVWR (Gross Vehicle Weight
Rating) .......................................252
calculating .......................252, 254
definition .................................252
driving with a heavy load ......252
location ....................................252
H
Hazard flashers .........................263
Headlamps ...................................99
aiming ......................................101
autolamp system .......................99
bulb specifications ..................103
daytime running lights ...........100
flash to pass ............................100
high beam ...............................100
replacing bulbs .......................105
turning on and off ....................99
2004 Navigator (nav)
Owners Guide (post-2002-fmt)
USA English (fus) Index
363
