2005 PONTIAC BONNEVILLE engine coolant

If you have to add coolant more than four times a year,
have your dealer check your 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 surge tank is located toward the
rear of the engine compartment on the passenger’s side
of the vehicle. SeeEngine Compartment Overview on
page 5-12for more information on location.The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at the FULL
COLD mark which is located on the side of the surge
tank that faces the engine.
If the LOW ENGINE COOLANT message comes on and
stays on, it means you are low on engine coolant.
SeeDIC Warnings and Messages on page 3-62for
more information.
Adding Coolant
If you need more coolant, add the proper DEX-COOL®
coolant mixtureat the surge tank,but only when the
engine is cool.
{CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. Never turn the surge tank pressure
cap — even a little — when the engine and
radiator are hot.
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{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 replacing the pressure cap, make sure the arrow
lines up with the tube.
Radiator Pressure Cap
(3.8L V6 Engine)
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 5-12
for more information on location.
Coolant Surge Tank Pressure Cap
(4.6L V8 Engine)
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 5-12for
more information on location.
Engine Overheating (3.8L V6 Engine)
You will nd a coolant temperature gage or a DIC
warning message about a hot engine on your vehicle’s
instrument panel. SeeEngine Coolant Temperature
Gage (V6 Engine) on page 3-45orEngine Coolant
Temperature Gage (V8 Engine) on page 3-46and
DIC Warnings and Messages on page 3-62.
5-36

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
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.
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.
If No Steam Is Coming From
Your Engine
If you get an engine overheat warning but see or hear
no steam, the problem may not be too serious.
Sometimes the engine can get a little too hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer.
If you get the overheat warning 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. Turn on your heater to full hot at the highest fan
speed and open the windows as necessary.
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning does not come back on, you can drive
normally.
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If the warning continues and you have not stopped, pull
over, stop, and park your vehicle right away.
If there is still no sign of steam, you can idle the engine
for three minutes while you are parked. If you still
have the warning,turn off the engine and get everyone
out of the vehicleuntil it cools down.
You may decide not to lift the hood but to get service
help right away.
Engine Overheating (4.6L V8 Engine)
You will nd an ENGINE HOT, IDLE ENGINE message
or an ENGINE HOT, STOP ENGINE message
displayed in the Driver Information Center (DIC).
There is also an engine coolant temperature gage on
the instrument panel cluster. SeeDIC Warnings
and Messages on page 3-62andEngine Coolant
Temperature Gage (V6 Engine) on page 3-45orEngine
Coolant Temperature Gage (V8 Engine) on page 3-46.
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
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.
SeeOverheated Engine Protection Operating
Mode (4.6L V8 Engine) on page 5-40for
information on driving to a safe place in an
emergency.
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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. SeeOverheated Engine
Protection Operating Mode (4.6L V8 Engine) on
page 5-40for information on driving to a safe place
in an emergency.
If No Steam Is Coming From Your
Engine
An overheat warning, along with a low coolant message,
can indicate a serious problem. SeeDIC Warnings
and Messages on page 3-62.
If you get an engine overheat warning with no low
coolant message, but see or hear no steam, the problem
may not be too serious. Sometimes the engine can
get a little too hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.If you get the overheat warning 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 safe to do so, pull off the road,
shift to PARK (P) or NEUTRAL (N) and let the
engine idle.
2. Set the climate controls to the highest heat setting
and fan speed and open the windows as necessary.
If you no longer have the overheat warning, you
can drive. Just to be safe, drive slower for about
10 minutes. If the warning does not come back on,
you can drive normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there is still no sign of steam, idle the engine for
three minutes while you are parked. If you still have the
warning,turn off the engine and get everyone out of
the vehicleuntil it cools down. Also, see “Overheated
Engine Protection Operating Mode” later in this section.
You may decide not to lift the hood but to get service
help right away.
5-39

Overheated Engine Protection
Operating Mode (4.6L V8 Engine)
If an overheated engine condition exists and the
message ENGINE HOT, STOP ENGINE is displayed,
an overheat protection mode which alternates ring
groups of cylinders helps prevent engine damage. In this
mode, you will notice a loss in power and engine
performance. This operating mode allows your vehicle
to be driven to a safe place in an emergency. Driving
extended miles (km) 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 5-16.
Cooling System (3.8L V6 Engine)
When you decide it is safe to lift the hood, here is what
you will see:
A. Coolant Recovery Tank
B. Radiator Pressure Cap
C. Electric Engine Cooling Fans
5-40

{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.
SeeEngine Compartment Overview on page 5-12for
more information on location.
The coolant level should be at or above the FULL
COLD mark when the engine is cold. The coolant
level should be at the FULL HOT 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.
5-41

How to Add Coolant to the Coolant
Recovery Tank
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 (3.8L V6 Engine) on page 5-31orEngine
Coolant (4.6L V8 Engine) on page 5-34for 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
FULL COLD mark, start your vehicle.
5-42