2003 BUICK REGAL radiator

Cooling System
When you decide it’s safe to lift the hood, here’s what
you’ll see:
A. Coolant Recovery Tank
B. Electric Cooling Fans
C. Radiator Pressure Cap{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,
don’t do anything else until it cools down. The vehicle
should be parked on a level surface.
When the engine is cold,
the coolant level should be
at or above the COLD
mark on the coolant
recovery tank.
5-28
2003 - Regal OM

If it isn’t, 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. Don’t touch them. If you
do, you can be burned.
Don’t run the engine if there is a leak. If you
run the engine, it could lose all coolant. That
could cause an enginere, and you could be
burned. Get any leakxed 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 aren’t, your vehicle needs service.Notice:Engine damage from running your engine
without coolant isn’t covered by your warranty.
See“Overheated Engine Protection Operating
Mode”in the Index for information on driving to a
safe place in an emergency.
Notice:When adding coolant, it is important that
you use only DEX-COOL
®(silicate-free) coolant.
If coolant other than DEX-COOL®is added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the engine
coolant will require change sooner—at 30,000 miles
(50 000 km) or 24 months, whichever occursrst.
Damage caused by the use of coolant other
than DEX-COOL
®is not covered by your new vehicle
warranty.
5-29
2003 - Regal OM

How to Add Coolant to the Coolant
Recovery Tank
If you haven’t found a problem yet, but the coolant level
isn’t at the COLD mark, add a 50/50 mixture ofclean,
drinkable waterand DEX-COOL
®engine coolant at
the coolant recovery tank. SeeEngine Coolant on
page 5-22for more information.
{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 wouldn’t get the overheat warning.
Your engine could catchre 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.
{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. Don’t spill coolant on a hot engine.
When the coolant in the coolant recovery tank is at the
COLD mark, start your vehicle.
5-30
2003 - Regal OM

If the overheat warning continues, there’s 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
Notice:Your engine has a specic radiator
ll procedure. Failure to follow this procedure could
cause your engine to overheat and be severely
damaged.
Turn the pressure cap slowly counterclockwise until it
first stops. Don’t press down while turning the
pressure cap.
5-31
2003 - Regal OM

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.
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, but now push
down as you turn it. Remove the pressure cap.
{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. Don’t spill coolant on a hot engine.
3. Remove the 3800 Series II V6 engine cover shield
to access the bleed valve.
5-32
2003 - Regal OM

4. After the engine cools,
open the coolant air
bleed valve. The bleed
valve is located on
the thermostat housing.
5. Fill the radiator with the
proper DEX-COOL
®
coolant mixture, up to the
base of thefiller neck.
SeeEngine Coolant
on page 5-22for 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 isfilled.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 oilfill 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 oilfill tube and
cap by twisting clockwise.
7.4. If you have the supercharged engine, install
the nut in the center of the cover shield.
5-34
2003 - Regal OM

8. Thenfill the coolant recovery tank to the COLD
mark on the coolant recovery tank.
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
filler neck may be lower. If the level is lower, add
more of the proper DEX-COOL
®coolant mixture
through thefiller neck until the level reaches
the base of thefiller neck.
5-35
2003 - Regal OM

100,000 Miles (166 000 km)
❑Inspect spark plug wires.An Emission Control
Service.
❑Replace spark plugs.An Emission Control Service.
❑Change automatic transaxleuid andlter if the
vehicle is mainly driven under one or more of
these conditions:
In heavy city traffic where the outside
temperature regularly reaches 90°F (32°C) or
higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
service.
❑If you haven’t used your vehicle under severe service
conditions listed previously and, therefore, haven’t
changed your automatic transaxleuid, change both
theuid andlter.
150,000 Miles (240 000 km)
❑Drain,ush and rell cooling system (or every
60 months since last service, whichever occursrst).
SeeEngine Coolant on page 5-22for what to use.
Inspect hoses. Clean radiator, condenser, pressure
cap and neck. Pressure test the cooling system
and pressure cap.An Emission Control Service.
❑Inspect engine accessory drive belt.An Emission
Control Service.
6-9
2003 - Regal OM