engine coolant BUICK LUCERNE 2009 User Guide

If the uid level is low, add only enough of the proper
uid to bring the level into the cross-hatched area on the
dipstick.
1. Pull out the dipstick.
2. Using a long-neck funnel, add enough uid at the
dipstick hole to bring it to the proper level.
It does not take much uid, generally less than
one pint (0.5 L). Do not overll.
Notice:Use of the incorrect automatic transmission
uid may damage the vehicle, and the damages may
not be covered by the vehicle’s warranty. Always
use the automatic transmission uid listed in
Recommended Fluids and Lubricants on page 6-12.
3. After adding uid, recheck the uid level as
described under “How to Check Automatic
Transmission Fluid,” earlier in this section.
4. When the correct uid level is obtained, push the
dipstick back in all the way.
How to Check Automatic Transmission
Fluid (4.6L Engine)
For the 4.6L V8 engine, it is not necessary to check the
transmission uid level. A transmission uid leak is the
only reason for uid loss. If a leak occurs, take your
vehicle to the dealer/retailer service department and
have it repaired as soon as possible.
Cooling System
The Cooling System allows the engine to maintain the
correct working temperature.
A. Coolant Recovery Tank
B. Radiator Pressure Cap
C. Electric Engine Cooling Fans3.9L Engine
5-26

A. Coolant Surge Tank with Pressure Cap
B. Electric Engine Cooling Fans
{CAUTION:
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.
{CAUTION:
Heater and radiator hoses, and other engine parts,
can be very hot. Do not touch them. If you do, you
can be burned.
Do not run the engine if there is a leak. If you run
the engine, it could lose all coolant. That could
cause an engine re, and you could be burned.
Get any leak xed before you drive the vehicle.
Notice:Using coolant other than DEX-COOL
®can
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant could
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by the vehicle warranty.
Always use DEX-COOL
®(silicate-free) coolant
in the vehicle. 4.6L Engine
5-27

Engine Coolant (4.6L Engine)
The cooling system in the vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in the vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst.
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 5-35.
What to Use
{CAUTION:
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
CAUTION: (Continued)
CAUTION: (Continued)
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 re 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.
5-28

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. SeeRecommended Fluids and
Lubricants on page 6-12for more information.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 Engine Coolant
for more information.
5-29

If no coolant is visible in the surge tank, add coolant as
follows:
How to Add Coolant to the Surge Tank
{CAUTION:
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 specic coolant ll
procedure. Failure to follow this procedure could
cause the engine to overheat and be severely
damaged.
{CAUTION:
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.
{CAUTION:
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.
5-30

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.
3. Fill the coolant surge
tank 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.
5-31

Engine Coolant (3.9L Engine)
The cooling system in the vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in the vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst.
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 5-35.
What to Use
{CAUTION:
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
CAUTION: (Continued)
CAUTION: (Continued)
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 re 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.
5-32

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.
SeeRecommended Fluids and Lubricants on
page 6-12for more information.
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 abovethe 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
{CAUTION:
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 specic coolant ll
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.
5-33

How to Add Coolant to the Radiator
{CAUTION:
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.
{CAUTION:
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.
If you hear a hiss, wait for that to stop. A hiss means that
there is still some pressure left.
2. Keep turning the pressure cap and remove it.
3. Fill the cooling system with the proper DEX-COOL
coolant mixture, up to the base of the ller neck.
SeeEngine Coolant (4.6L Engine) on page 5-28
orEngine Coolant (3.9L Engine) on page 5-32.
4. Then ll 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, rell it to the COLD FILL line.
5-34

If the coolant in the recovery tank is constantly low, you
should have a dealer/retailer 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.
Radiator Pressure Cap
Notice:The radiator cap on your vehicle is a
pressure-type cap and must be tightly installed to
prevent coolant loss and possible engine damage
from overheating. Be sure the arrows on the cap line
up with the overow tube on the radiator ller neck.
SeeEngine Compartment Overview on page 5-14for
more information on location.
Coolant Surge Tank Pressure Cap
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.
SeeEngine Compartment Overview on page 5-14for
more information on location.
Engine Overheating
The vehicle has several indicators to warn of engine
overheating.
You will nd a warning light about a hot engine as well
as an engine coolant temperature gage on your
vehicle’s instrument panel cluster.
You may decide not to lift the hood when this warning
appears, but instead get service help right away.
SeeRoadside Assistance Program on page 7-7.
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 re while driving with
no coolant, the vehicle can be badly damaged.
The costly repairs would not be covered by
the vehicle warranty. SeeOverheated Engine
Protection Operating Mode on page 5-37for
information on driving to a safe place in an
emergency.
5-35