BUICK LUCERNE 2010 Owner's Manual

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 6‑27or 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.
6-29

{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.
You can remove the
coolant surge tank
pressure cap when the
cooling system, including
the coolant surge tank
pressure cap and upper
radiator hose, is no
longer hot.
1. Turn the pressure cap slowly counterclockwise. If you hear a hiss, wait for that to stop. A hiss
means there is still some pressure left.
2. Then keep turning the cap and remove it.
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3. Fill the coolant surgetank with the proper
mixture to the FULL
COLD mark on the
side of the coolant
surge tank.
4. With the coolant surge tank cap off, start the engine and let it run until you can feel the upper
radiator hose getting hot. Watch out for the engine
cooling fans.
By this time, the coolant level inside the coolant
surge tank may be lower. If the level is lower, add
more of the proper mixture to the coolant surge
tank until the level reaches the FULL COLD mark
on the side of the coolant surge tank.
5. Then replace the cap. Be sure the cap is hand‐tight and fully seated. If coolant is needed, add the proper DEX-COOL®
coolant mixture at the coolant recovery tank.
Notice:
If the pressure cap is not tightly installed,
coolant loss and possible engine damage may
occur. Be sure the cap is properly and tightly
secured.
Engine Coolant (3.9L Engine)
The cooling system in the vehicle is filled with
DEX-COOL®engine coolant. This coolant is designed
to remain in the vehicle for five years or 150,000 miles
(240 000 km), whichever occurs first.
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, see Engine
Overheating on page 6‑35.
6-31

What to Use
{WARNING:
Adding only plain water to the cooling system can
be dangerous. Plain water, or some other liquid
such as alcohol, can boil before the proper
coolant mixture will. The vehicle's 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 7‑9for more information.
6-32

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

How to Add Coolant to the Radiator
{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. If coolant is needed, add the proper mixture directly to
the radiator, but be sure the cooling system is cool
before this is done.
1. You can remove
the pressure cap when
the cooling system,
including the pressure
cap and upper
radiator hose is no
longer hot. Turn the
pressure cap slowly
counterclockwise.
2. If you hear a hiss, wait for that to stop. A hiss means that there is still some pressure left. Keep
turning the pressure cap and remove it.
6-34

3. Fill the cooling system with the proper DEX-COOLcoolant mixture, up to the base of the filler neck.
See Engine Coolant (4.6L Engine)
on page 6‑27orEngine Coolant (3.9L Engine) on page 6‑31.
4. Then fill the coolant recovery tank to the COLD FILL line.
5. Install the coolant recovery tank cap and the pressure cap. After a day or two of driving, when
the engine is cold, check the coolant level in the
recovery tank. If it is low, refill it to the COLD
FILL line.
If the coolant in the recovery tank is constantly low, you
should have a dealer service department inspect the
vehicle for leaks.
Notice: If the pressure cap is not tightly installed,
coolant loss and possible engine damage may
occur. Be sure the cap is properly and tightly
secured.
Engine Overheating
The vehicle has several indicators to warn of engine
overheating.
You will find a warning light about a hot engine as
well as an engine coolant temperature gauge on the
instrument panel cluster.
You may decide not to lift the hood when this warning
appears, but instead get service help right away.
See Roadside Assistance Program on page 8‑8.
If you do decide to lift the hood , make sure the vehicle
is parked on a level surface.
Then check to see if the engine cooling fans are
running. If the engine is overheating, both fans should
be running. If they are not, do not continue to run the
engine and have the vehicle serviced.
Notice: Engine damage from running the engine
without coolant is not covered by the warranty.
Notice: If the engine catches fire while driving with
no coolant, the vehicle can be badly damaged. The
costly repairs would not be covered by the vehicle
warranty. See Overheated Engine Protection
Operating Mode
on page 6‑37for information on
driving to a safe place in an emergency.
6-35

If Steam Is Coming From The Engine
Compartment
{WARNING:
Steam from an overheated engine can burn you
badly, even if you just open the hood. Stay away
from the engine if you see or hear steam coming
from it. Turn it off and get everyone away from
the vehicle until it cools down. Wait until there is
no sign of steam or coolant before you open
the hood.
If you keep driving when the vehicles engine is
overheated, the liquids in it can catch fire. You or
others could be badly burned. Stop the engine if it
overheats, and get out of the vehicle until the
engine is cool.
SeeOverheated Engine Protection Operating
Mode
on page 6‑37for information on driving to
a safe place in an emergency.
If No Steam Is Coming From The
Engine Compartment
If an engine overheat warning is displayed but no steam
can be seen or heard, the problem may not be too
serious. Sometimes the engine can get a little too hot
when the vehicle:
.Climbs a long hill on a hot day.
.Stops after high-speed driving.
.Idles for long periods in traffic.
.Tows a trailer.
If the overheat warning is displayed with no sign of
steam: 1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest fan speed. Open the windows as
necessary.
3. In heavy traffic, let the engine idle in N (Neutral) while stopped. If it is safe to do so, pull off the
road, shift to P (Park) or N (Neutral) and let the
engine idle.
6-36

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 6‑17.
6-37

Power Steering Fluid
SeeEngine 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.
How to Check Power Steering Fluid
To check the power steering fluid:
1. Turn the key off and let the engine compartment cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a clean rag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the fluid level on the dipstick.
The level should be at the FULL COLD mark.
If necessary, add only enough fluid to bring the level
up to the mark.
What to Use
To determine what kind of fluid to use, see
Recommended Fluids and Lubricantson page 7‑9.
Always use the proper fluid.
Notice: Use of the incorrect fluid may damage the
vehicle and the damages may not be covered by the
vehicle's warranty. Always use the correct fluid
listed in Recommended Fluids and Lubricants
on
page 7‑9.
6-38