cooling BUICK LACROSSE 2007 User Guide

Engine Coolant
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, if only DEX-COOL
®extended life
coolant is added.
The following explains the cooling system and
how to add coolant when it is low. If there is
a problem with engine overheating or if coolant
needs to be added to the radiator, seeEngine
Overheating on page 367.A 50/50 mixture of clean, drinkable water and
DEX-COOL
®engine coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as
they should.
Notice:Using coolant other than DEX-COOL
®
may cause premature engine, heater core, or
radiator corrosion. In addition, the engine
coolant may require changing sooner, at the rst
maintenance service after each 30,000 miles
(50 000 km) or 24 months, whichever occurs
rst. Any repairs would not be covered by your
warranty. Always use DEX-COOL
®(silicate-free)
coolant in your vehicle.
363

What to Use
Use a mixture of one-half clean, drinkable water
and one-half DEX-COOL®engine coolant which will
not damage aluminum parts. If this coolant mixture
is used, nothing else needs to be added.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can
boil before the proper coolant mixture will.
Your vehicle’s coolant warning system is
set for the proper coolant mixture. With
plain water or the wrong mixture, your
engine could get too hot but you would
not get the overheat warning. Your engine
could catch re and you or others could
be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.Notice:If you use an improper coolant
mixture, your engine could overheat and be
badly damaged. The repair cost would not be
covered by your warranty. Too much water
in the mixture can freeze and crack the engine,
radiator, heater core, and other parts.
If coolant needs to be added more than four times
a year, have your dealer check the cooling
system.
Notice:If you use extra inhibitors and/or
additives in your vehicle’s cooling system,
you could damage your vehicle. Use only the
proper mixture of the engine coolant listed
in this manual for the cooling system.
SeeRecommended Fluids and Lubricants
on page 470for more information.
364

Adding Coolant
If more coolant is needed, add the proper
DEX-COOL®coolant mixture at the coolant
recovery tank, but be careful not to spill it.
If the coolant recovery tank is completely empty,
add coolant to the radiator. SeeEngine
Overheating on page 367.
{CAUTION:
Turning the radiator pressure cap when
the engine and radiator are hot can allow
steam and scalding liquids to blow out
and burn you badly. With the coolant
recovery tank, you will almost never
have to add coolant at the radiator. Never
turn the radiator pressure cap — even
a little — when the engine and radiator
are hot.
{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.
Occasionally check the coolant level in the
radiator. For information on how to add coolant to
the radiator, seeCooling System on page 370.
366

Overheated Engine Protection
Operating Mode
This emergency operating mode allows your
vehicle to be driven to a safe place in an emergency
situation. If an overheated engine condition exists,
an overheat protection mode which alternates ring
groups of cylinders helps prevent engine damage.
In this mode, you will notice a signicant loss in
power and engine performance. The REDUCED
POWER STOP WHEN SAFE message will come
on in the Driver Information Center (DIC), if the
vehicle has one, along with the engine coolant
temperature warning light on the instrument panel,
to indicate the vehicle has entered overheated
engine protection operating mode. The temperature
gage will also indicate an overheat condition exists.
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. SeeEngine Oil on page 353.
Cooling System
When you decide it is safe to lift the hood, this is
what you will see:
A. Coolant Recovery Tank
B. Radiator Pressure Cap
C. Electric Engine Cooling Fans
3.8L V6 Engine
370

A. Coolant Recovery Tank
B. Pressure Cap
C. 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 injure you. Keep
hands, clothing, and tools away from any
underhood electric fan.
If the coolant inside the coolant recovery tank is
boiling, do not do anything else until it cools down.
The vehicle should be parked on a level surface.
3.6L V6 Engine
371

When the engine is cold, the coolant level should
be at or above the cold ll line on the coolant
recovery tank. If it is not, there may be a leak at the
pressure cap or in the radiator hoses, heater hoses,
radiator, water pump, or somewhere else in the
cooling system.
{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.If there seems to be no leak, with the engine on,
check to see if the electric engine cooling fans
are running. If the engine is overheating, the fans
should be running. If the fans are not running,
the vehicle needs service.
Notice:Engine damage from running your
engine without coolant is not covered by your
warranty. SeeOverheated Engine Protection
Operating Mode on page 370for information
on driving to a safe place in an emergency.
Notice:Using coolant other than DEX-COOL®
may 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 your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your
vehicle.
372

How to Add Coolant to the Coolant
Recovery Tank
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can
boil before the proper coolant mixture will.
Your vehicle’s coolant warning system is
set for the proper coolant mixture. With
plain water or the wrong mixture, your
engine could get too hot but you would
not get the overheat warning. Your engine
could catch re and you or others could
be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.If you have not found a problem yet, but the
coolant level is not at the cold ll line, add a
50/50 mixture of clean, drinkable water and
DEX-COOL
®engine coolant at the coolant
recovery tank. SeeEngine Coolant on page 363
for more information.
Notice:In cold weather, water can freeze and
crack the engine, radiator, heater core and
other parts. Use the recommended coolant
and the proper coolant mixture.
{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.
When the coolant level in the coolant recovery
tank is at the cold ll line, start the vehicle.
373

If the overheat warning continues, there is one
more thing you can try. You can add the proper
coolant mixture directly to the cooling system
through the coolant ll neck under the pressure cap,
but be sure the system is cool before you do it.
{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 radiator pressure cap — even a
little — they can come out at high speed.
Never turn the cap when the cooling
system, including the radiator pressure
cap, is hot. Wait for the cooling system
and radiator pressure cap to cool if you
ever have to turn the pressure cap.
How to Add Coolant to the Radiator
(3.8L V6 Engine)
Notice:Your engine has a specic radiator
ll procedure. Failure to follow this procedure
could cause your engine to overheat and
be severely damaged.
1. You can remove the
radiator pressure
cap when the
cooling system,
including the radiator
pressure cap and
upper radiator hose,
is no longer hot.
Turn the pressure cap slowly counterclockwise
until it rst stops. Do not press down while
turning the pressure cap. If you hear a
hiss, wait for that to stop. A hiss means there
is still some pressure left.
374

7. Put the cap back on the coolant recovery tank,
but leave the radiator pressure cap off.
8. Start the engine and let it run until you can
feel the upper radiator hose getting hot.
Watch out for the engine cooling fans.9. By this time, the coolant level inside the
radiator ller neck may be lower. If the level is
lower, add more of the proper DEX-COOL
®
coolant mixture through the ller neck until the
level reaches the base of the ller neck.
10. Then replace the radiator pressure cap.
At any time during this procedure if coolant
begins to ow out of the ller neck, reinstall
the pressure cap. Be sure the pressure cap
is hand-tight and fully seated.
11. Check the coolant in the recovery tank. The
level in the coolant recovery tank should be
at the cold ll line when the engine is cold.
376

How to Add Coolant to the Cooling
System (3.6L V6 Engine)
Notice:Your engine has a specic cooling
system drain and ll procedure. Failure
to follow this procedure could cause your
engine to overheat and be severely damaged.
If your engine’s cooling system needs to
be drained and re-lled, please see your dealer.
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. Then keep turning the pressure cap and
remove it.
{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.
3. Fill the cooling system with the proper
DEX-COOL
®coolant mixture, up to the base
of the ller neck. SeeEngine Coolant on
page 363for more information about
the proper coolant mixture.
4. Rinse or wipe any spilled coolant from the
engine and the compartment.
377