2008 PONTIAC G8 open hood

When the engine starts, let go of
the key and accelerator. If the
vehicle starts briey but then
stops again, do the same thing.
This clears the extra gasoline
from the engine. Do not race
the engine immediately
after starting it. Operate the
engine and transmission gently
until the oil warms up and
lubricates all moving parts.
Notice:The engine is designed
to work with the electronics
in the vehicle. If you add electrical
parts or accessories, you could
change the way the engine
operates. Before adding electrical
equipment, check with your
dealer/retailer. If you do not,
the engine might not perform
properly. Any resulting damage
would not be covered by the
vehicle warranty.Engine Coolant Heater
The engine coolant heater, if
available, can help in cold weather
conditions at or below 0°F (−18°C)
for easier starting and better fuel
economy during engine warm-up.
Plug in the coolant heater at least
four hours before starting your
vehicle. An internal thermostat in the
plug-end of the cord will prevent
engine coolant heater operation at
temperatures above 0°F (−18°C).
To Use The Engine Coolant
Heater
1. Turn off the engine.
2. Open the hood and unwrap the
electrical cord.
The electrical cord is located on
the driver side of the engine
compartment, behind the
air cleaner for V8 models.
The electrical cord is located on
the passenger side of the
engine compartment, behind the
engine compartment fuse
block for V6 models.3. Plug it into a normal, grounded
110-volt AC outlet.
{CAUTION
Plugging the cord into an
ungrounded outlet could cause
an electrical shock. Also, the
wrong kind of extension cord
could overheat and cause a
re. You could be seriously
injured. Plug the cord into a
properly grounded three-prong
110-volt AC outlet. If the cord
will not reach, use a heavy-duty
three-prong extension cord
rated for at least 15 amps.
4. Before starting the engine, be
sure to unplug and store the
cord as it was before to keep it
away from moving engine
parts. If you do not it could be
damaged.
Driving and Operating 8-5
2008 - Pontiac G8 Owner Manual

Gasoline Octane
If your vehicle has a V8 engine, use
regular unleaded gasoline with a
posted octane rating of 87 or higher.
If the octane rating is less than 87,
you might notice an audible
knocking noise when you drive,
commonly referred to as spark
knock. If this occurs, use a gasoline
rated at 87 octane or higher as
soon as possible. If you are using
gasoline rated at 87 octane or higher
and you hear heavy knocking, the
engine needs service.
If your vehicle has the 3.6L V6
engine (VIN Code 7), use regular
unleaded gasoline with a posted
octane rating of 87 or higher.
For best performance or trailer
towing, you could choose to
use middle grade 89 octane
unleaded gasoline. If the octane
rating is less than 87, you might
notice an audible knocking noise
when you drive, commonly referred
to as spark knock.If this occurs, use a gasoline rated
at 87 octane or higher as soon
as possible. If you are using
gasoline rated at 87 octane or higher
and you hear heavy knocking, the
engine needs service.
Gasoline Specications
At a minimum, gasoline should
meet ASTM specication D 4814
in the United States or
CAN/CGSB-3.5 or 3.511 in Canada.
Some gasolines contain an
octane-enhancing additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT). We recommend
against the use of gasolines
containing MMT. SeeAdditives on
page 8-34for additional information.
California Fuel
If your vehicle is certied to meet
California Emissions Standards, it is
designed to operate on fuels that
meet California specications.
See the underhood emission control
label. If this fuel is not available
in states adopting California
emissions standards, your vehicle
will operate satisfactorily on
fuels meeting federal specications,
but emission control system
performance might be affected.
The malfunction indicator lamp could
turn on and your vehicle might fail
a smog-check test. SeeMalfunction
Indicator Lamp on page 4-18.
If this occurs, return to your
authorized dealer/retailer for
diagnosis. If it is determined that the
condition is caused by the type of
fuel used, repairs might not be
covered by the vehicle warranty.
Driving and Operating 8-33
2008 - Pontiac G8 Owner Manual

Owner Checks
{CAUTION
An electric fan under the hood
can start up and injure you
even when the engine is not
running. Keep hands, clothing,
and tools away from any
underhood electric fan.
{CAUTION
Things that burn can get on hot
engine parts and start a re.
These include liquids like fuel,
oil, coolant, brake uid,
windshield washer and other
uids, and plastic or rubber.
You or others could be burned.
Be careful not to drop or spill
things that will burn onto a hot
engine.
Hood Release
To open the hood:
1. Pull the release handle with the
above symbol on it. It is located
below the instrument panel to
the left of the steering wheel.2. Pull up on the secondary hood
release. The lever is located
near the middle of the hood.
3. Lift the hood.
4. Release the hood prop rod from
its retainer and put it into the
slot in the hood. To insert
the hood prop rod into the slot.
Before closing the hood, be sure all
the ller caps are on properly.
Make sure to return the hood prop
rod carefully back to its retainer
to avoid damaging the vehicle.
Vehicle Service and Care 9-5
2008 - Pontiac G8 Owner Manual

Engine Compartment Overview
When you open the hood, this is what you will see:A. Engine Compartment Fuse
Block. See Engine Compartment
Fuse Block on page 9-35 .
B. Coolant Reservoir and Dipstick. See Cooling System on
page 9-17 .
C. Engine Oil Fill Cap. See “When to Add Engine Oil” under Engine
Oil on page 9-8 .
D. Engine Oil Dipstick (Out of View). See “Checking Engine Oil” under
Engine Oil on page 9-8 .
E. Brake Master Cylinder Reservoir. See “Brake Fluid” under Brakes
on page 9-24 .
F. Power Steering Reservoir. See Power Steering Fluid on
page 9-21 .
G. Engine Air Cleaner/Filter. See Engine Air Cleaner/Filter
on page 9-11 .
H. Windshield Washer Fluid Reservoir. See Windshield
Washer Fluid on page 9-22 .
I. Radiator Pressure Cap. See Cooling System on page 9-17 .
V6 Engine
9-6 Vehicle Service and Care
2008 - Pontiac G8 Owner Manual

How to Inspect the Engine Air
Cleaner/Filter
To inspect the air cleaner/lter,
remove the lter from the vehicle
and lightly shake the lter to release
loose dust and dirt. If the lter
remains caked with dirt, a new lter
is required.
To inspect or replace the engine air
cleaner/lter:
1. Open the hood. SeeHood
Release on page 9-5.
2. Locate the air lter housing on
the front of the driver side of
the engine compartment.
SeeEngine Compartment
Overview on page 9-6.
3. On the V8 engine, remove the
airow sensor connector by
pushing in the tab and pulling
straight back.
4. Remove the ve retaining clips
on the air lter housing.5. Pull straight up on cover, while
holding the cover remove the
air lter.
6. Install the air lter.
7. Close the air lter housing cover
and clip the ve retaining clips.
8. On the V8 engine push in the
airow sensor connector.
{CAUTION
Operating the engine with the
air cleaner/lter off can cause
you or others to be burned. The
air cleaner not only cleans the
air; it helps to stop ames if the
engine backres. If it is not
there and the engine backres,
you could be burned. Do not
drive with it off, and be careful
working on the engine with the
air cleaner/lter off.
9-12 Vehicle Service and Care
2008 - Pontiac G8 Owner Manual

Engine Overheating
There is an engine coolant
temperature warning light on your
vehicle’s instrument panel. See
Engine Coolant Temperature Gage
on page 4-17.
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.
(Continued)
CAUTION (Continued)
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 the engine catches re
because of being driven with
no coolant, your vehicle can be
badly damaged. The costly
repairs would not be covered by
the vehicle warranty.
If No Steam Is Coming From
Your Engine
An engine coolant temperature
warning can indicate a serious
problem. SeeEngine Coolant
Temperature Gage on page 4-17.If you get an engine coolant
temperature 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.
If you get the engine coolant
temperature warning with no sign of
steam, try this for a minute or so:
1. If your air conditioner is on, turn
it off.
2. In heavy traffic, let the engine idle
in N (Neutral) while stopped. If it
is safe to do so, pull off the road,
shift to P (Park) or N (Neutral) and
let the engine idle.
3. Turn on your heater to full hot at
the highest fan speed and open
the windows as necessary.
9-16 Vehicle Service and Care
2008 - Pontiac G8 Owner Manual

Headlamp Aiming
The optical headlamp aiming system
has been preset at the factory
and should need no further
adjustment.
However, if the vehicle is damaged
adjustment may be necessary.
If oncoming vehicles ash their high
beams at you, this may also mean
the vertical aim needs to be adjusted.
It is recommended that the vehicle
is taken to your dealer/retailer
for service if the headlamps need to
be re-aimed. It is possible however,
to re-aim the headlamps as
described.
The vehicle should:
Be placed so the headlamps
are 25 ft. (7.6 m) from a light
colored wall.
Have all four tires on a perfectly
level surface which is level all
the way to the wall.
Be placed so it is at a right angle
to the wall.
Not have any snow, ice, or
mud on it.
Be fully assembled and all other
work stopped while headlamp
aiming is being done.
Have a full tank of fuel and one
person or 160 lbs (75 kg) on
the driver seat.
Have all tires properly inated.
Headlamp aiming is done with
the vehicle’s low-beam headlamps.
The high-beam headlamps will
be correctly aimed if the low-beam
headlamps are aimed properly.To adjust the vertical aim on the
headlamps:
1. Open the hood.Hood Release
on page 9-5.
2. Locate the aim dot on the lens of
the low-beam headlamp.
3. Record the distance from the
ground to the aim dot on the
low-beam headlamp.
Vehicle Service and Care 9-27
2008 - Pontiac G8 Owner Manual

Bulb Replacement
For the proper type of replacement
bulbs, seeReplacement Bulbs
on page 9-32.
For any bulb changing procedure
not listed in this section, contact
your dealer/retailer.
Halogen Bulbs
{CAUTION
Halogen bulbs have
pressurized gas inside and can
burst if you drop or scratch the
bulb. You or others could be
injured. Be sure to read and
follow the instructions on the
bulb package.
Headlamps and Parking
Lamps
To replace one of these bulbs:
If the front turn signal lamp
or parking lamp needs to be
changed, see your dealer/retailer.
A. Front Turn Signal Lamp/
Parking Lamp
B. Low Beam Headlamp
C. High Beam Headlamp1. Open the hood. SeeHood
Release on page 9-5.
2. Remove the radiator support by
turning the head screws
counterclockwise and then
pulling them straight out.
3. For the passenger side pull up
on the coolant bottle ller neck
to remove it and place it to
one side.
Let the ller neck drain before
pulling it all the way out. Place a
clean towel over the opening
of the coolant bottle after
removing it.
Vehicle Service and Care 9-29
2008 - Pontiac G8 Owner Manual