
Black plate (23,1)Buick Lucerne Owner Manual - 2011
Engine Air Cleaner/Filter
SeeEngine Compartment Overviewon page 6‑14for
the location of the engine air cleaner/filter.
When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/filter at the scheduled
maintenance intervals and replace it at the first oil
change after each 50,000 mile (80 000 km) interval.
See Scheduled Maintenance
on page 7‑3for more
information. If you are driving in dusty/dirty conditions,
inspect the filter at each engine oil change.
How to Inspect the Engine Air
Cleaner/Filter
To inspect the air cleaner/filter, remove the filter from
the vehicle and lightly shake the filter to release loose
dust and dirt. If the filter remains covered with dirt, a
new filter is required. To inspect or replace the filter:1. Remove the two screws on the top of the engine
air cleaner/filter cover.
2. Lift up the outboard side of the cover at an angle while pulling toward you. This is necessary due to
the two hinges located on the inboard side of the
cover.
3. Remove the engine air cleaner/filter and any loose debris that may be found in the air cleaner base.
4. Inspect or replace the air filter element.
6-23

Black plate (24,1)Buick Lucerne Owner Manual - 2011
To reinstall the cover:1. Align the two hinges located on the inboard side of the cover.
2. Push the cover slightly down and towards the engine to engage the tabs in the hinges and align
the two screws.
3. Tighten the two screws on the top of the engine air cleaner/filter cover.
{WARNING:
Operating the engine with the air cleaner/filter off
can cause you or others to be burned. The air
cleaner not only cleans the air; it helps to stop
flames if the engine backfires. Use caution when
working on the engine and do not drive with the
air cleaner/filter off.
Notice: If the air cleaner/filter is off, dirt can easily
get into the engine, which could damage it. Always
have the air cleaner/filter in place when you are
driving.
Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
A good time to check the automatic transmission fluid
level is when the engine oil is changed.
Change the fluid and filter at the intervals listed in
Scheduled Maintenance
on page 7‑3and be sure
to use the transmission fluid listed in Recommended
Fluids and Lubricants on page 7‑8.
How to Check Automatic Transmission
Fluid (3.9L Engine)
Because this operation can be a little difficult, you
may choose to have this done at the dealer service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
Notice: Too much or too little fluid can damage
the transmission. Too much can mean that some
of the fluid could come out and fall on hot engine
parts or exhaust system parts, starting a fire. Too
little fluid could cause the transmission to overheat.
Be sure to get an accurate reading if checking the
transmission fluid.
6-24

Black plate (29,1)Buick Lucerne Owner Manual - 2011
The following explains the cooling system and how
to check and add coolant when it is low. If there is a
problem with engine overheating, seeEngine
Overheating on page 6‑35.
What to Use
{WARNING:
Adding only plain water or some other liquid to
the cooling system can be dangerous. Plain water
and other liquids, can boil before the proper
coolant mixture will. The coolant warning system
is set for the proper coolant mixture. With plain
water or the wrong mixture, the engine could
get too hot but you would not get the overheat
warning. The engine could catch fire and you or
others could be burned. Use a 50/50 mixture of
clean, drinkable water and DEX-COOL coolant.
Use a 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant. If using this mixture, nothing else
needs to be added. This mixture:
.Gives freezing protection down to −34°F (−37°C),
outside temperature.
.Gives boiling protection up to 265°F (129°C),
engine temperature.
.Protects against rust and corrosion.
.Will not damage aluminum parts.
.Helps keep the proper engine temperature.
Notice: If an improper coolant mixture is used, the
engine could overheat and be badly damaged. The
repair cost would not be covered by the vehicle
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core, and
other parts.
Notice: If extra inhibitors and/or additives are used
in the vehicle's cooling system, the vehicle could be
damaged. Use only the proper mixture of the engine
coolant listed in this manual for the cooling system.
See Recommended Fluids and Lubricants
on
page 7‑8for more information.
Never dispose of engine coolant by putting it in
the trash, pouring it on the ground, or into sewers,
streams or bodies of water. Have the coolant changed
by an authorized service center, familiar with legal
requirements regarding used coolant disposal. This will
help protect the environment and your health.
6-29

Black plate (30,1)Buick Lucerne Owner Manual - 2011
Checking Coolant
The vehicle must be on a level surface when checking
the coolant level.
Check to see if coolant is visible in the coolant recovery
tank. If the coolant inside the coolant recovery tank is
boiling, do not do anything else until it cools down.
If coolant is visible but the coolant level is not at or
above the FULL COLD mark, add a 50/50 mixture of
clean, drinkable water and DEX-COOL
®coolant at
the coolant recovery tank, but be sure the cooling
system is cool before this is done. See Engine
Coolant (4.6L Engine)
on page 6‑28or Engine
Coolant (3.9L Engine)on page 6‑31for more
information.
If no coolant is visible in the surge tank, add coolant as
follows:
How to Add Coolant to the Surge Tank
{WARNING:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol
and it will burn if the engine parts are hot enough.
Do not spill coolant on a hot engine. Notice:
This vehicle has a specific coolant fill
procedure. Failure to follow this procedure could
cause the engine to overheat and be severely
damaged.
{WARNING:
An electric engine cooling fan under the hood can
start up even when the engine is not running and
can cause injury. Keep hands, clothing, and tools
away from any underhood electric fan.
{WARNING:
Steam and scalding liquids from a hot cooling
system can blow out and burn you badly. They
are under pressure, and if you turn the surge tank
pressure cap —even a little —they can come
out at high speed. Never turn the cap when the
cooling system, including the surge tank pressure
cap, is hot. Wait for the cooling system and surge
tank pressure cap to cool if you ever have to turn
the pressure cap.
6-30

Black plate (32,1)Buick Lucerne Owner Manual - 2011
What to Use
{WARNING:
Adding only plain water or some other liquid to the
cooling system can be dangerous. Plain water
and other liquids, can boil before the proper
coolant mixture will. The coolant warning system
is set for the proper coolant mixture. With plain
water or the wrong mixture, the engine could
get too hot but you would not get the overheat
warning. The engine could catch fire and you or
others could be burned. Use a 50/50 mixture of
clean, drinkable water and DEX-COOL coolant.
Use a 50/50 mixture of clean, drinkable water and
DEX-COOL coolant. If using this mixture, nothing else
needs to be added. This mixture:
.Gives freezing protection down to −34°F (−37°C),
outside temperature.
.Gives boiling protection up to 265°F (129°C),
engine temperature.
.Protects against rust and corrosion.
.Will not damage aluminum parts.
.Helps keep the proper engine temperature.
Notice: If an improper coolant mixture is used, the
engine could overheat and be badly damaged. The
repair cost would not be covered by the vehicle
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core, and
other parts.
Notice: If extra inhibitors and/or additives are
used in the vehicle's cooling system, the vehicle
could be damaged. Use only the proper mixture
of the engine coolant listed in this manual for the
cooling system. See Recommended Fluids and
Lubricants
on page 7‑8for more information.
Never dispose of engine coolant by putting it in
the trash, pouring it on the ground, or into sewers,
streams or bodies of water. Have the coolant changed
by an authorized service center, familiar with legal
requirements regarding used coolant disposal. This will
help protect the environment and your health.
6-32

Black plate (33,1)Buick Lucerne Owner Manual - 2011
Checking Coolant
The vehicle must be on a level surface when checking
the coolant level.
The coolant level should be at or above the FULL
COLD mark when the engine is cold. The coolant level
should be above the FULL COLD mark under normal
operating conditions. If it is not, you may have a leak in
the cooling system.
Check to see if coolant is visible in the coolant recovery
tank. If the coolant inside the coolant recovery tank is
boiling, do not do anything else until it cools down.
If coolant is visible but the coolant level is not at or
above the FULL COLD mark, add a 50/50 mixture of
clean, drinkable water and DEX-COOL coolant at the
coolant recovery tank, but be sure the cooling system is
cool before this is done. See Engine Coolant for more
information.
How to Add Coolant to the
Recovery Tank
{WARNING:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol
and it will burn if the engine parts are hot enough.
Do not spill coolant on a hot engine.
Notice: This vehicle has a specific coolant fill
procedure. Failure to follow this procedure could
cause the engine to overheat and be severely
damaged.
If coolant is needed, add the proper DEX-COOL coolant
mixture at the coolant recovery tank.
6-33

Black plate (37,1)Buick Lucerne Owner Manual - 2011
If the temperature overheat gauge is no longer in
the overheat zone or an overheat warning no longer
displays, the vehicle can be driven. Continue to drive
the vehicle slow for about 10 minutes. Keep a safe
vehicle distance from the car in front of you. If the
warning does not come back on, continue to drive
normally.
If the warning continues, pull over, stop, and park the
vehicle right away.
If there is no sign of steam, idle the engine for
three minutes while parked. If the warning is still
displayed, turn off the engine until it cools down. Also,
see“Overheated Engine Protection Operating Mode”
next in this section.
Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
message ENGINE OVERHEATED STOP ENGINE
is displayed, an overheat protection mode which
alternates firing groups of cylinders helps prevent
engine damage. In this mode, you will notice a loss in
power and engine performance. This operating mode
allows the vehicle to be driven to a safe place in an
emergency. Driving extended miles (km) and/or towing
a trailer in the overheat protection mode should be
avoided. Notice:
After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any
repair. The engine oil will be severely degraded.
Repair the cause of coolant loss, change the oil
and reset the oil life system. See Engine Oil
on
page 6‑18.
Power Steering Fluid
See Engine Compartment
Overviewon page 6‑14for information on the
location of the power
steering fluid reservoir.
When to Check Power Steering Fluid
It is not necessary to regularly check power steering
fluid unless you suspect there is a leak in the system or
you hear an unusual noise. A fluid loss in this system
could indicate a problem. Have the system inspected
and repaired.
6-37

Black plate (40,1)Buick Lucerne Owner Manual - 2011
Do not top off the brake fluid. Adding fluid does not
correct a leak. If fluid is added when the linings are
worn, there will be too much fluid when new brake
linings are installed. Add or remove brake fluid, as
necessary, only when work is done on the brake
hydraulic system.
{WARNING:
If too much brake fluid is added, it can spill on the
engine and burn, if the engine is hot enough. You
or others could be burned, and the vehicle could
be damaged. Add brake fluid only when work is
done on the brake hydraulic system.
When the brake fluid falls to a low level, the brake
warning light comes on. See Brake System Warning
Light on page 4‑32.
What to Add
Use only new DOT 3 brake fluid from a sealed
container. See Recommended Fluids and Lubricantson
page 7‑8. Always clean the brake fluid reservoir cap and the area
around the cap before removing it. This helps keep dirt
from entering the reservoir.
{WARNING:
With the wrong kind of fluid in the brake hydraulic
system, the brakes might not work well. This could
cause a crash. Always use the proper brake fluid.
Notice:
.Using the wrong fluid can badly damage
brake hydraulic system parts. For example,
just a few drops of mineral-based oil, such
as engine oil, in the brake hydraulic system
can damage brake hydraulic system parts so
badly that they will have to be replaced. Do
not let someone put in the wrong kind of
fluid.
.If brake fluid is spilled on the vehicle's
painted surfaces, the paint finish can be
damaged. Be careful not to spill brake
fluid on the vehicle. If you do, wash it off
immediately. See Washing Your Vehicle
on
page 6‑102
.
6-40