2021 LINCOLN NAUTILUS coolant reservoir

Engine coolant reservoir. See Checking the Coolant (page 340).
A
Engine oil dipstick.
See Engine Oil Dipstick Overview (page 338).
B
Engine oil filler cap.
See Adding Engine Oil (page 338).
C
Brake fluid reservoir.
See Checking the Brake Fluid (page 218).
D
Battery.
See Changing the 12V Battery (page 345).
E
Power distribution box.
See Accessing the Under Hood Fuse Box (page 316).
F
Air filter.
See Changing the Engine Air Filter (page 344).
G
Windshield washer fluid reservoir.
See Adding Washer Fluid (page 118).
H
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2021 Nautilus (CD9) Canada/United States of America, enUSA, Edition date: 202011, First-Printing Maintenance

Engine coolant reservoir. See Checking the Coolant (page 340).
A
Brake fluid reservoir.
See Checking the Brake Fluid (page 218).
B
Battery.
See Changing the 12V Battery (page 345).
C
Power distribution box.
See Accessing the Under Hood Fuse Box (page 316).
D
Air filter assembly.
See Changing the Engine Air Filter (page 344).
E
Engine oil dipstick.
See Engine Oil Dipstick Overview (page 338).
F
Engine oil filler cap.
See Adding Engine Oil (page 338).
G
Windshield washer fluid reservoir.
See Adding Washer Fluid (page 118).
H
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2021 Nautilus (CD9) Canada/United States of America, enUSA, Edition date: 202011, First-Printing Maintenance

CHECKING THE COOLANT
When the engine is cold, check the
concentration and level of the coolant at the
intervals listed in the scheduled maintenance
information. See Scheduled Maintenance
(page 459).
Note: Make sure that the coolant level is
between the minimum and maximum marks
on the coolant reservoir.
Note: Coolant expands when it is hot. The
level may extend beyond the
MAX mark.
If the coolant level is at or below the
minimum mark, add prediluted coolant
immediately.
Maintain coolant concentration within 48%
to 50%, which equates to a freeze point
between
-29°F (-34°C) and -35°F (-37°C).
Coolant concentration should be checked
using a refractometer. We do not recommend
the use of hydrometers or coolant test strips
for measuring coolant concentration. Adding Coolant 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. WARNING:
Do not add engine
coolant when the engine is on or the
cooling system is hot. Failure to follow this
instruction could result in personal injury. WARNING:
Do not add coolant
further than the MAX mark. WARNING: Do not put coolant in the
windshield washer reservoir. If sprayed on
the windshield, coolant could make it
difficult to see through the windshield. Note:
Do not use stop leak pellets, cooling
system sealants, or non-specified additives
as they can cause damage to the engine
cooling or heating systems. Resulting
component damage may not be covered by
the vehicle Warranty.
Note: Automotive fluids are not
interchangeable.
It is very important to use prediluted coolant
approved to the correct specification in order
to avoid plugging the small passageways in
the engine cooling system.
See Capacities
and Specifications (page 407). Do not mix
different colors or types of coolant in your
vehicle. Mixing of engine coolants or using
an incorrect coolant may harm the engine or
cooling system components and could void
the vehicle Warranty.
Note: If prediluted coolant is not available,
use the approved concentrated coolant
diluting it to 50/50 with distilled water.
See
Capacities and Specifications (page 407).
Using water that has not been deionized
may contribute to deposit formation,
corrosion and plugging of the small cooling
system passageways.
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2021 Nautilus (CD9) Canada/United States of America, enUSA, Edition date: 202011, First-Printing Maintenance

To top up the coolant level do the following:
1. Unscrew the cap slowly. Any pressure
escapes as you unscrew the cap.
2. Add enough prediluted coolant to reach
the correct level.
Note: We do not recommend the use of
recycled coolant.
3. Replace the coolant reservoir cap. Turn the cap clockwise until it contacts the
hard stop.
4. Check the coolant level in the coolant reservoir the next few times you drive
your vehicle. If necessary, repeat step 2.
If you have to add more than 1.1 qt (1 L) of
engine coolant per month, have your vehicle
checked as soon as possible. Operating an
engine with a low level of coolant can result
in engine overheating and possible engine
damage.
In case of emergency, you can add a large
amount of water without engine coolant in
order to reach a vehicle service location.
Service your vehicle as soon as possible. Water alone, without engine coolant, can
cause engine damage from corrosion,
overheating or freezing.
Do not use the following as a coolant
substitute, as they can cause engine damage
from overheating or freezing:
•
Alcohol.
• Methanol.
• Brine.
• Any coolant mixed with alcohol or
methanol antifreeze.
Do not add extra inhibitors or additives to
the coolant. These can be harmful and
compromise the corrosion protection of the
coolant.
Severe Climates
If you drive in extremely cold climates, you
may need to increase the coolant
concentration above 50%. Note:
A coolant concentration of 60%
provides improved freeze point protection.
Coolant concentrations above 60% decrease
the overheat protection characteristics of
the coolant and could cause engine
damage.
If you drive in extremely hot climates, you
may need to decrease the coolant
concentration to 40%.
Note: Coolant concentrations below 40%
decrease the freeze and corrosion protection
characteristics of the coolant and could
cause engine damage.
Coolant Change
Change the coolant at specific mileage
intervals. Refer to the scheduled
maintenance information.
See Normal
Scheduled Maintenance (page 463).
Note: Dispose of used coolant in the
appropriate manner.
Follow your community's regulations and
standards for recycling and disposing of
automotive fluids.
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2021 Nautilus (CD9) Canada/United States of America, enUSA, Edition date: 202011, First-Printing Maintenance

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.
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 could
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.
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2021 Nautilus (CD9) Canada/United States of America, enUSA, Edition date: 202011, First-Printing Maintenance

Multi-Point Inspection
Steering and linkage
Exterior lamps operation
Tires including the spare for wear and proper pressure 2
Fluid levels 1
; fill if necessary
Windshield for cracks, chips or pits
For oil and fluid leaks
Washer spray and wiper operation
Half-shaft dust boots
1 Brake, coolant recovery reservoir, automatic transmission and window washer.
2 If your vehicle has a temporary mobility kit, check the tire sealant exp\
iration Use By date on the canister. Replace as needed.
Be sure to ask your dealership service
advisor or technician about the multi-point
vehicle inspection. It is a comprehensive way
to perform a thorough inspection of your
vehicle. Your checklist gives you immediate
feedback on the overall condition of your
vehicle. NORMAL SCHEDULED
MAINTENANCE
Oil Change Reminder
Your vehicle comes with an oil change
reminder that determines when you should
change the engine oil based on how you use
your vehicle.Your vehicle lets you know when an oil
change is due by displaying a message in
the information display.
The following table provides examples of
vehicle use and its impact on oil change
intervals. It is a guideline only. Actual oil
change intervals depend on several factors
and generally decrease with severity of use.
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2021 Nautilus (CD9) Canada/United States of America, enUSA, Edition date: 202011, First-Printing Scheduled Maintenance