2008 PONTIAC G8 check engine

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

{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

5. Start the engine.
6. With the engine idling, top off the
coolant through the radiator
pressure cap opening until full.
Wait 30 seconds for the
coolant to settle and top off, if
the level drops.
7. Once the system is full, put the
radiator pressure cap back on
by turning clockwise.
8. Turn off the ignition.
9. Check the coolant level in the
reservoir and ll it until the
level is at the top of the dipstick.Power Steering Fluid
Power Steering Fluid Level
Power steering uid is used in
all vehicles.
Check the level after the vehicle has
been driven for at least twenty
minutes so the uid is warm.
How to Check Power Steering
Fluid
To check the power steering uid,
do the following:
1. Turn the key off and let the
engine compartment cool down.
2. The power steering uid reservoir
is located on the driver side
toward the front of the engine
compartment. SeeEngine
Compartment Overview on
page 9-6.3. Wipe the cap and the top of the
reservoir clean.
V6 Engine
Vehicle Service and Care 9-21
2008 - Pontiac G8 Owner Manual

Any time you notice unusual
wear, rotate the tires as soon
as possible and check wheel
alignment. Also check for
damaged tires or wheels.
SeeWhen It Is Time for New
Tires on page 9-56andWheel
Replacement on page 9-61.
When rotating the vehicle’s tires,
always use the correct rotation
pattern shown here.The compact spare tire, if the
vehicle has one, is not included
in the tire rotation.
After the tires have been rotated,
adjust the front and rear ination
pressures as shown on the Tire
and Loading Information label.
SeeInflation - Tire Pressure on
page 9-46andLoading the
Vehicle on page 8-28.
Reset the Tire Pressure Monitor
System. SeeTire Pressure
Monitor Operation on page 9-51.
Make certain that all wheel
nuts are properly tightened.
See “Wheel Nut Torque” under
Capacities and Specifications
on page 10-2.{CAUTION
Rust or dirt on a wheel, or
on the parts to which it is
fastened, can make wheel
nuts become loose after
time. The wheel could come
off and cause an accident.
When you change a wheel,
remove any rust or dirt from
places where the wheel
attaches to the vehicle. In an
emergency, you can use a
cloth or a paper towel to do
this; but be sure to use a
scraper or wire brush later,
if needed, to get all the rust
or dirt off. SeeChanging a
Flat Tire (V6 Engine) on
page 9-71.
Vehicle Service and Care 9-55
2008 - Pontiac G8 Owner Manual

the alignment might need to be
checked. If you notice your vehicle
vibrating when driving on a
smooth road, the tires and wheels
might need to be rebalanced.
See your dealer/retailer for proper
diagnosis.
Wheel Replacement
Replace any wheel that is bent,
cracked or badly rusted or corroded.
If wheel nuts keep coming loose,
the wheel, wheel bolts and
wheel nuts should be replaced. If
the wheel leaks air, replace it
(except some aluminum wheels,
which can sometimes be repaired).
See your dealer/retailer if any of
these conditions exist.
Your dealer/retailer will know the
kind of wheel you need.
Each new wheel should have the
same load-carrying capacity,
diameter, width, offset and be
mounted the same way as the one
it replaces.If you need to replace any of the
wheels, wheel bolts or wheel
nuts, replace them only with new
GM original equipment parts.
This way, you will be sure to have
the right wheel, wheel bolts and
wheel nuts for the vehicle.
{CAUTION
Using the wrong replacement
wheels, wheel bolts, or wheel
nuts on your vehicle can be
dangerous. It could affect the
braking and handling of your
vehicle, make your tires lose air
and make you lose control. You
could have a collision in which
you or others could be injured.
Always use the correct wheel,
wheel bolts, and wheel nuts for
replacement.Notice:The wrong wheel can
also cause problems with bearing
life, brake cooling, speedometer
or odometer calibration,
headlamp aim, bumper height,
vehicle ground clearance, and tire
or tire chain clearance to the
body and chassis.
SeeChanging a Flat Tire (V6
Engine) on page 9-71for more
information.
Used Replacement Wheels
{CAUTION
Putting a used wheel on the
vehicle is dangerous. You
cannot know how it has been
used or how far it has been
driven. It could fail suddenly
and cause a crash. If you have
to replace a wheel, use a new
GM original equipment wheel.
Vehicle Service and Care 9-61
2008 - Pontiac G8 Owner Manual

Tire Sealant and
Compressor Kit
(V8 Engine)
This vehicle has a tire sealant and
compressor kit in place of a jack or
spare tire. It is located in a foam
container in the trunk. The tire
sealant and compressor kit can be
used to repair a at tire by sealing
small punctures in the tread of the
tire. It can also be used to inate an
underinated tire. The vehicle must
be driven for ve miles (8 kilometers)
after the tire is sealed and inated to
the recommended pressure to
ensure the sealant is distributed
evenly. For detailed instructions see
“Using the Tire Sealant and
Compressor Kit to Temporarily
Repair a Punctured Tire” later in this
section.The kit includes:
A. On/Off Switch
B. Air Compressor Accessory Plug
C. Air Compressor
D. Sealant Canister
E. Sealant/Air Hose
F. Air-only Hose
G. Pressure Gage
Tire Sealant
The sealant can temporarily seal a
small puncture up to 6 mm in
the tread area of the tire. The
sealant cannot seal sidewall
damage, large punctures, or a wheel
that has unseated from the wheel.
Read and follow the safe handling
instructions on the label adhered to
the sealant canister.
Check the tire sealant expiration
date on the sealant canister.
The sealant canister should be
replaced before its expiration date.
There is only enough sealant to
seal one tire. After usage, the
sealant canister and sealant/air hose
assembly must be replaced.
Replacement sealant canisters are
available from a dealer/retailer.
See “Removal and Installation of
Sealant Canister” later in this
section.
9-64 Vehicle Service and Care
2008 - Pontiac G8 Owner Manual