engine overheat LINCOLN NAVIGATOR 2021 User Guide

Coolant Change
At specific mileage intervals, as listed in the
scheduled maintenance information, the
coolant should be changed. Add prediluted
coolant approved to the correct specification.
See Capacities and Specifications (page
440).
Fail-Safe Cooling
Fail-safe cooling allows you to temporarily
drive your vehicle before any incremental
component damage occurs. The fail-safe
distance depends on ambient temperature,
vehicle load and terrain.
How Fail-Safe Cooling Works If the engine begins to overheat,
the coolant temperature gauge
moves toward the red zone:
A warning lamp illuminates and a
message may appear in the
information display. If the engine reaches a preset
over-temperature condition, the engine
automatically switches to alternating cylinder
operation. Each disabled cylinder acts as an
air pump and cools the engine.
When this occurs, your vehicle still operates,
however:
•
Engine power is limited.
• The air conditioning system turns off.
Continued operation increases the engine
temperature, causing the engine to
completely shut down. Your steering and
braking effort increases in this situation.
When the engine temperature cools, you can
re-start the engine. Have your vehicle
checked as soon as possible to minimize
engine damage. When Fail-Safe Mode Is Activated WARNING: Fail-safe mode is for use
during emergencies only. Operate your
vehicle in fail-safe mode only as long as
necessary to bring your vehicle to rest in
a safe location and seek immediate repairs.
When in fail-safe mode, your vehicle will
have limited power, will not be able to
maintain high-speed operation, and may
completely shut down without warning,
potentially losing engine power, power
steering assist, and power brake assist,
which may increase the possibility of a
crash resulting in serious injury. WARNING:
Do not remove the
coolant reservoir cap when the engine is
on or the cooling system is hot. Wait 10
minutes for the cooling system to cool
down. Cover the coolant reservoir cap with
a thick cloth to prevent the possibility of
scalding and slowly remove the cap.
Failure to follow this instruction could result
in personal injury.
386
Navigator (TB9) Canada/United States of America, enUSA, First-Printing Maintenance

Your vehicle has limited engine power when
in the fail-safe mode, drive your vehicle with
caution. Your vehicle does not maintain
high-speed operation and the engine may
operate poorly.
Remember that the engine is capable of
automatically shutting down to prevent
engine damage. In this situation:
1. Pull off the road as soon as safely
possible and switch the engine off.
2. If you are a member of a roadside assistance program, we recommend that
you contact your roadside assistance
service provider.
3. If this is not possible, wait a short period
for the engine to cool.
4. Check the coolant level. If the coolant level is at or below the minimum mark,
add prediluted coolant immediately.
5. When the engine temperature cools, you
can re-start the engine. Have your vehicle
checked as soon as possible to minimize
engine damage.
Note: Driving your vehicle without repair
increases the chance of engine damage. Engine Coolant Temperature
Management (If Equipped) WARNING:
To reduce the risk of
crash and injury, be prepared that the
vehicle speed may reduce and the vehicle
may not be able to accelerate with full
power until the coolant temperature
reduces.
If you tow a trailer with your vehicle, the
engine may temporarily reach a higher
temperature during severe operating
conditions, for example ascending a long or
steep grade in high ambient temperatures.
At this time, you may notice the coolant
temperature gauge moves toward the red
zone and a message may appear in the
information display. You may notice a reduction in vehicle speed
caused by reduced engine power in order
to manage the engine coolant temperature.
Your vehicle may enter this mode if certain
high-temperature and high-load conditions
take place. The amount of speed reduction
depends on vehicle loading, grade and
ambient temperature. If this occurs, there is
no need to stop your vehicle. You can
continue to drive.
The air conditioning may automatically turn
on and off during severe operating
conditions to protect the engine from
overheating. When the coolant temperature
decreases to the normal operating
temperature, the air conditioning turns on.
If the coolant temperature gauge moves fully
into the red zone, or if the coolant
temperature warning or service engine soon
messages appear in your information display,
do the following:
1.
Stop your vehicle as soon as it is safe to
do so. Fully apply the parking brake, shift
into park (P) or neutral (N).
387
Navigator (TB9) Canada/United States of America, enUSA, First-Printing Maintenance

Your vehicle is equipped with the Intelligent
Oil-Life Monitor system, which displays a
message in the information display at the
proper oil change interval. This interval may
be up to one year or 10,000 mi (16,000 km).
When the oil change message appears in
the information display, it is time for an oil
change. Make sure you perform the oil
change within two weeks or 500 mi (800 km)
of the message appearing. Make sure you
reset the Intelligent Oil-Life Monitor after
each oil change. See Oil Change Indicator
Reset
(page 381).
If your information display resets prematurely
or becomes inoperative, you should perform
the oil change interval at six months or
5,000 mi (8,000 km)
from your last oil
change. Never exceed one year or 10,000 mi
(16,000 km)
between oil change intervals.
Your vehicle is very sophisticated and built
with multiple, complex, performance systems.
Every manufacturer develops these systems
using different specifications and
performance features. That is why it is
important to rely upon your dealership to
properly diagnose and repair your vehicle. The Lincoln Motor Company has
recommended maintenance intervals for
various parts and component systems based
upon engineering testing. The Lincoln Motor
Company relies upon this testing to
determine the most appropriate mileage for
replacement of oils and fluids to protect your
vehicle at the lowest overall cost to you and
recommends against maintenance schedules
that deviate from the scheduled maintenance
information.
We strongly recommend the use of only
genuine Lincoln, Motorcraft or Lincoln
authorized re-manufactured replacement
parts engineered for your vehicle.
Additives and Chemicals
This owner's manual and the Lincoln
Workshop Manual list the recommended
additives and chemicals for your vehicle. We
do not recommend using chemicals or
additives not approved by us as part of your
vehicle
’s normal maintenance. Please consult
your warranty information. Oils, Fluids and Flushing
In many cases, fluid discoloration is a normal
operating characteristic and, by itself, does
not necessarily indicate a concern or that the
fluid needs to be changed. However, a
qualified expert, such as the factory-trained
technicians at your dealership, should
inspect discolored fluids that also show signs
of overheating or foreign material
contamination immediately.
Make sure to change your vehicle
’s oils and
fluids at the specified intervals or in
conjunction with a repair. Flushing is a viable
way to change fluid for many vehicle
sub-systems during scheduled maintenance.
It is critical that systems are flushed only with
new fluid that is the same as that required
to fill and operate the system or using a
Lincoln approved flushing chemical.
Owner Checks and Services
Make sure you perform the following basic
maintenance checks and inspections every
month or at six-month intervals.
540
Navigator (TB9) Canada/United States of America, enUSA, First-Printing Scheduled Maintenance