2008 PONTIAC G8 cooling

Notice:If the air cleaner/lter is
off, a backre can cause a
damaging engine re. And, dirt
can easily get into your engine,
which will damage it. Always have
the air cleaner/lter in place
when you are driving.
Automatic Transmission
Fluid
It is not necessary to check the
transmission uid level. A
transmission uid leak is the only
reason for uid loss. If a leak occurs,
take your vehicle to a dealer/retailer
and have it repaired as soon as
possible.
Change the uid and lter at the
intervals listed in the Maintenance
Schedule. SeeScheduled
Maintenance on page 11-4. Be sure
to use the transmission uid
listed inRecommended Fluids and
Lubricants on page 11-12.Notice:Use of the incorrect
automatic transmission uid may
damage your vehicle, and the
damages may not be covered by
your warranty. Always use the
automatic transmission uid
listed inRecommended Fluids
and Lubricants on page 11-12.
Engine Coolant
The cooling system in your vehicle is
lled with DEX-COOL®engine
coolant. This coolant is designed to
remain in your vehicle for ve years
or 150,000 miles (240 000 km),
whichever occurs rst, if you add
only DEX-COOL
®extended life
coolant.
The following explains your cooling
system and how to add coolant
when it is low. If you have a problem
with engine overheating, see
Engine Overheating on page 9-16.A 50/50 mixture of clean, drinkable
water and DEX-COOL
®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
®can 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
the vehicle warranty. Always
use DEX-COOL
®(silicate-free)
coolant in the vehicle.
Vehicle Service and Care 9-13
2008 - Pontiac G8 Owner Manual

What to Use
Use a mixture of one-half clean,
drinkable water and one-half
DEX-COOL
®coolant which will not
damage aluminum parts. If you
use this coolant mixture, you do not
need to add anything else.
{CAUTION
Adding only plain water to the
cooling system can be
dangerous. Plain water, or
some other liquid such as
alcohol, can boil before the
proper coolant mixture will.
(Continued)
CAUTION (Continued)
The vehicle’s coolant warning
system is set for the proper
coolant mixture. With plain
water or the wrong mixture, the
engine could get too hot but
would not get the overheat
warning. The 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 an improper coolant
mixture is used, the engine could
overheat and be badly damaged.
The repair cost would not be
covered by the vehicle warranty.
Too much water in the mixture
can freeze and crack the engine,
radiator, heater core, and
other parts.If you have to add coolant more
than four times a year, have
your dealer/retailer check your
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 11-12for
more information.
9-14 Vehicle Service and Care
2008 - Pontiac G8 Owner Manual

Checking Coolant
The coolant reservoir and dipstick is
located in the engine compartment
on the passenger side of the vehicle.
SeeEngine Compartment Overview
on page 9-6for more information
on location.
1. Turn off the ignition.
2. Turn the coolant dipstick
cap one-eighth of a turn
counterclockwise and slowly
pull the dipstick straight up.3. When the engine is cold, the
coolant level should be at or
above the Min mark on the
dipstick.
After the vehicle has been driven
and the engine is at normal
operating temperature, the level
should be somewhere between
half full and the Max mark.
4. If the coolant level is correct,
replace the dipstick and turn
the cap one-eighth of a
turn clockwise.
Adding Coolant
If you need more coolant, add the
proper DEX-COOL
®coolant mixture
at the coolant reservoir, but only
when the engine is cool. If the
coolant reservoir is empty, a special
ll procedure is necessary. See
Engine Overheating on page 9-16
for instructions on “How to Add
Coolant to the Cooling System.”
{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 coolant reservoir
cap, make sure it is hand-tight
and fully seated.
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 cap is
properly closed.
SeeEngine Compartment Overview
on page 9-6for more information
on location.
Vehicle Service and Care 9-15
2008 - Pontiac G8 Owner Manual

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 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 vehicle until it
cools down.
You may decide not to lift the hood
but to get service help right away.Cooling System
When you decide it is safe to lift the hood, this is what you see:
A. Coolant Reservoir and Dipstick
B. Radiator Pressure CapV6 Engine
Vehicle Service and Care 9-17
2008 - Pontiac G8 Owner Manual

A. Coolant Reservoir and Dipstick
B. Radiator Pressure Cap
{CAUTION
An electric engine cooling fan
under the hood can start up
even when the engine is not
running and can cause injury.
Keep hands, clothing, and tools
away from any underhood
electric fan.
The coolant level should be at or
above the top mark on the coolant
reservoir dipstick. If it is not,
you may have a leak at the radiator
pressure cap or in the radiator
hoses, heater hoses, radiator, water
pump, or somewhere else in the
cooling system.
V8 Engine
9-18 Vehicle Service and Care
2008 - Pontiac G8 Owner Manual

{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 the engine without
coolant is not covered by the
warranty.Notice:Using coolant other than
DEX-COOL
®can 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
the vehicle warranty. Always
use DEX-COOL
®(silicate-free)
coolant in the vehicle.
How to Add Coolant to the
Cooling System
Notice:This vehicle has a
specic coolant ll procedure.
Failure to follow this procedure
could cause the engine to
overheat and be severely
damaged.If no coolant is visible in the coolant
reservoir, add coolant as follows:
{CAUTION
Adding only plain water to the
cooling system can be
dangerous. Plain water, or
some other liquid such as
alcohol, can boil before the
proper coolant mixture will.
The vehicle’s coolant warning
system is set for the proper
coolant mixture. With plain
water or the wrong mixture, the
engine could get too hot but
you would not get the overheat
warning. The engine could
catch re and you or others
could be burned. Use a 50/50
mixture of clean, drinkable
water and DEX-COOL
®coolant.
Vehicle Service and Care 9-19
2008 - Pontiac G8 Owner Manual

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.
1. Check the engine coolant
reservoir (A) level and, if
required, top with coolant. See
Engine Coolant on page 9-13.2. Locate the radiator pressure
cap (B).
{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
(Continued)
CAUTION (Continued)
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.
3. Cover the cap with a thick
cloth and turn it slowly
counterclockwise and remove.
4. If there is no coolant or the level
is low, slowly ll the system
through the radiator pressure cap
opening with a 50/50 mixture
of clean, drinkable water and
a DEX-COOL
®coolant until full.
Wait 30 seconds for coolant
to settle and top off if the
level drops.
Do not spill coolant on the
accessory drive belts.
If a spill occurs, rinse the belt
with fresh water.
9-20 Vehicle Service and Care
2008 - Pontiac G8 Owner Manual

Fuses UsageFL1 Spare
FL2 Rear Defog
FL3 ABS Motor
FL4 Battery Main 3
FL5 Battery Main 1
FL6 Spare
FL7 Battery Main 2
FL8 Starter
FL9 HVAC Blower Motor
FL10 Fan 1 Engine
Cooling (Right)
FL11 Spare
FL12 Fan 2 Engine
Cooling (Left)
F1 Comm Enable
F2 HVAC Battery
F3 Back-up Lamp
F4 Fog Lamps (Front)
F5 ABS Valves
F6 Spare
F8 Horn
F9 Transmission
Control Module
Engine Compartment Fuse Block - Fuse Puller Shown
9-36 Vehicle Service and Care
2008 - Pontiac G8 Owner Manual