2006 BUICK LUCERNE radiator

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 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, both fans should be
running. If they are not, your vehicle needs service.
Notice:Engine damage from running your engine
without coolant is not covered by your warranty.
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 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.
5-30

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.
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.If you have not found a problem yet, but the coolant
level is not at the FULL COLD mark, add a
50/50 mixture ofclean, drinkable waterand
DEX-COOL
®engine coolant at the coolant recovery
tank. SeeEngine Coolant on page 5-23for more
information.
{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 in the coolant recovery tank is at the
FULL COLD mark, start your vehicle.
5-31

If the overheat warning continues, there is one more
thing you can try. You can add the proper coolant
mixture directly to the radiator, but be sure the cooling
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
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.
If you hear a hiss, wait for that to stop. A hiss means
there is still some pressure left.
2. Then keep turning the pressure cap. Remove the
pressure cap.
3. Remove the 3800 Series II V6 engine cover shield
to access the bleed valve.
5-32

3.1. Clean the area around the engine oil ll tube
and cap before removing. Twist the oil ll
tube, with cap attached, counterclockwise
and remove it.
3.2. Lift the engine cover shield at the front, slide
the catch tab out of the engine bracket and
remove the cover shield.
3.3. Put the oil ll tube, with cap attached, in the
valve cover oil ll hole until you are ready to
replace the cover shield.4. After the engine cools,
open the coolant air
bleed valve. There
is one bleed valve. It is
located on the
thermostat housing.
5. Fill the radiator with the proper DEX-COOL
®coolant
mixture, up to the base of the ller neck. See
Engine Coolant on page 5-23for more information
about the proper coolant mixture.
If you see a stream of coolant coming from an air
bleed valve, close the valve. Otherwise, close
the valve after the radiator is lled.
6. Rinse or wipe any spilled coolant from the engine
and the compartment.
7. Replace the 3800 Series II V6 engine cover shield.
7.1. Remove the oil ll tube, with cap attached,
from the valve cover.
7.2. Insert the catch tab on the cover shield
under the bracket on the engine.
7.3. Place the hole in the cover shield over the
hole in the valve cover. Install oil ll tube and
cap by twisting clockwise.
5-33

8. Then ll the coolant recovery tank to the FULL
COLD mark.
9. Put the cap back on the coolant recovery tank, but
leave the radiator pressure cap off.
10. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fans.
11. 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.
12. Then replace the 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 arrow on the pressure cap lines up properly.
Cooling System (4.6L V8 Engine)
When you decide it is safe to lift the hood, here is what
you will see:
A. Coolant Surge Tank with Pressure Cap
B. Electric Engine Cooling Fans
5-34

{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 surge tank is boiling, do
not do anything else until it cools down. The vehicle
should be parked on a level surface.
{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, both fans should be
running. If they are not, your vehicle needs service.
Notice:Engine damage from running your engine
without coolant is not covered by your warranty. See
Overheated Engine Protection Operating Mode
(4.6L V8 Engine Only) on page 5-28for 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 may
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.
5-35

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.
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.
5-37

Additional Required Services (cont’d)
Service and Miles (Kilometers)25,000
(40 000)50,000
(80 000)75,000
(120 000)100,000
(160 000)125,000
(200 000)150,000
(240 000)
Engine cooling system service
(or every ve years, whichever occurs
rst).An Emission Control Service. See
footnote (j).•
Inspect engine accessory drive belt.
An Emission Control Service. See
footnote (n).•
Maintenance Footnotes
†The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to
the completion of the vehicle’s useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the
maintenance be recorded.
(a)Visually inspect brake lines and hoses for proper
hook-up, binding, leaks, cracks, chang, etc. Inspect
disc brake pads for wear and rotors for surface
condition. Inspect other brake parts, including calipers,
parking brake, etc.(b)Visually inspect front and rear suspension and
steering system for damaged, loose, or missing parts or
signs of wear. Inspect power steering lines and hoses
for proper hook-up, binding, leaks, cracks, chang, etc.
(c)Visually inspect hoses and have them replaced if they
are cracked, swollen, or deteriorated. Inspect all pipes,
ttings and clamps; replace with genuine GM parts as
needed. To help ensure proper operation, a pressure test
of the cooling system and pressure cap and cleaning the
outside of the radiator and air conditioning condenser is
recommended at least once a year.
6-7