2004 BUICK REGAL engine

What to Use
Use a mixture of one-halfclean, drinkable waterand
one-half DEX-COOL®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 the proper coolant, you do not
have to add extra inhibitors or additives which claim
to improve the system. These can be harmful.
Checking Coolant
The engine coolant recovery tank is located on the
passenger’s side of the vehicle at the rear of the engine
compartment. SeeEngine Compartment Overview on
page 5-12for more information on location.
The vehicle must be on a
level surface. When the
engine is cold, the coolant
level should be at the
COLD mark or a little
higher. When the engine is
warm, the level should
be up to the HOT mark or
a little higher.
5-27

Adding Coolant
If the vehicle needs more coolant, 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 5-29.
{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 5-32.
5-28

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.
The radiator pressure cap is located near the front of the
engine compartment on the passenger’s side of the
vehicle. SeeEngine Compartment Overview on
page 5-12for more information on location.
Engine Overheating
The coolant temperature gage and the hot engine
warning light on the instrument panel can indicate an
overheated engine condition. SeeEngine Coolant
Temperature Gage on page 3-34andEngine Coolant
Temperature Warning Light on page 3-34.
Overheated Engine Protection
Operating Mode
The emergency operating mode allows the vehicle to be
driven to a safe place in an emergency situation. If an
overheated engine condition exists, this mode alternates
ring groups of cylinders, to help prevent engine
damage. In this mode, there will be a signicant loss in
power and engine performance. The engine coolant
temperature gage will move to the red area and
the engine coolant temperature warning light will come
on, indicating that an overheated engine condition
exists. Driving extended miles (km) and/or towing a
trailer in the overheated engine protection operating
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 5-16.
5-29

If Steam Is Coming From Your Engine
{CAUTION:
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. Just turn it off and get
CAUTION: (Continued)
CAUTION: (Continued)
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 your engine is
overheated, the liquids in it can catch re. You
or others could be badly burned. Stop your
engine if it overheats, and get out of the
vehicle until the engine is cool.
See “Overheated Engine Protection Operating
Mode” underEngine Overheating on page 5-29
for information on driving to a safe place in an
emergency.
Notice:If your engine catches re because you
keep driving with no coolant, your vehicle can
be badly damaged. The costly repairs would not be
covered by your warranty. See “Overheated
Engine Protection Operating Mode” underEngine
Overheating on page 5-29for information on driving
to a safe place in an emergency.
5-30

If No Steam Is Coming From Your
Engine
An overheated engine warning can indicate a serious
problem. SeeEngine Coolant Temperature Warning
Light on page 3-34.
If there is an overheated engine warning, and no steam
is seen or heard, the problem may not be too serious.
Sometimes the engine can get a little too hot when
the vehicles:
Climbs a long hill on a hot day.
Stops after high-speed driving.
Idles for long periods in traffic.
Tows a trailer.
If the overheated engine warning appears with no sign
of steam, try this for a minute or so:
1. In heavy traffic, let the engine idle in NEUTRAL (N)
while stopped. If it is safe to do so, pull off the road,
shift to PARK (P) or NEUTRAL (N) and let the
engine idle.
2. Adjust the heater to the highest temperature and
fan speed settings and open the window as
necessary.If the overheated engine warnings no longer exist, the
vehicle can be driven. Just to be safe, drive slower
for about 10 minutes. If the warning does not come back
on, continue to drive.
If the warning continues, and you have not stopped, pull
over, stop, and park the vehicle right away.
If there is still no sign of steam, idle the engine for three
minutes while parked. If the warning still exists, turn
off the engine and get everyone out of the vehicle until
it cools down. Also, see “Overheated Engine Protection
Operating Mode” listed previously in this section.
You may decide not to lift the hood but to get service
help right away.
5-31

Cooling System
When it is safe to lift the hood, this is what will be seen:
A. Coolant Recovery Tank
B. Electric Cooling Fan
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,
do not 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.
5-32

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, both fans should be
running. If they are not, the vehicle needs service.Notice:Engine damage from running your engine
without coolant is not 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: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.
5-33

How to Add Coolant to the Coolant
Recovery Tank
If no problem has been found yet, but the coolant level
is not at the COLD mark, add a 50/50 mixture of
clean, drinkable water and DEX-COOL
®engine coolant
at the coolant recovery tank. SeeEngine Coolant on
page 5-26for 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 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.
{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
COLD mark, start the vehicle.
5-34