2008 PONTIAC GRAND PRIX Tire pressure

{CAUTION:
If you use bias-ply tires on your vehicle,
the wheel rim anges could develop
cracks after many miles of driving. A tire
and/or wheel could fail suddenly, causing a
crash. Use only radial-ply tires with the
wheels on your vehicle.
If you must replace your vehicle’s tires with those
that do not have a TPC Spec number, make sure
they are the same size, load range, speed rating,
and construction type (radial and bias-belted tires)
as your vehicle’s original tires.Vehicles that have a tire pressure monitoring
system could give an inaccurate low-pressure
warning if non-TPC Spec rated tires are installed
on your vehicle. Non-TPC Spec rated tires may
give a low-pressure warning that is higher or lower
than the proper warning level you would get with
TPC Spec rated tires. SeeTire Pressure Monitor
System on page 5-71.
Your vehicle’s original equipment tires are listed
on the Tire and Loading Information Label.
SeeLoading Your Vehicle on page 4-22, for more
information about the Tire and Loading Information
Label and its location on your vehicle.
5-79

Wheel Alignment and Tire Balance
The tires and wheels on your vehicle were aligned
and balanced carefully at the factory to give you the
longest tire life and best overall performance.
Adjustments to wheel alignment and tire balancing will
not be necessary on a regular basis. However, if you
notice unusual tire wear or your vehicle pulling to one
side or the other, 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 your wheels, wheel bolts,
wheel nuts, or Tire Pressure Monitor System (TPMS)
sensors, replace them only with new GM original
equipment parts. This way, you will be sure to have the
right wheel, wheel bolts, wheel nuts, and TPMS sensors
for your vehicle.
5-82

If a Tire Goes Flat (GXP)
GXP models have no spare tire, no tire changing
equipment, and no place for storing a spare or at tire.
If a tire goes at, avoid further tire and wheel damage
by driving slowly to a level place and stopping.
Then do this:
1. Turn on the hazard warning ashers. SeeHazard
Warning Flashers on page 3-6.
2. Park your vehicle. Set the parking brake rmly and
put the shift lever in PARK (P). SeeShifting Into
PARK (P) on page 2-34for additional information.
3. Turn off the engine.
4. Inspect the at tire.
If the tire has been separated from the wheel or has
damaged sidewalls or large tears that allow rapid air
loss, call a tire repair facility. SeeRoadside Assistance
Program on page 7-6.
If the at tire is due to a slow leak caused by a nail or
other similar road hazard, the tire inator kit may be
used to temporarily repair the damaged tire. The kit uses
a liquid tire sealant to seal small punctures in the tread
area of the tire. The at tire is then inated to at least
30 psi (207 kPa) and driven to evenly distribute the tire
sealant. The tire pressure is checked after driving for a
maximum of ve miles (8.0 km) to see if the slow leak has
been stopped. If the tire pressure is 19 psi (131 kPa) or
more, inate the tire up to the standard operatingpressure as shown on the tire and loading information
label. This label is attached to the vehicle’s center-pillar
below the driver’s door latch. SeeInflation - Tire Pressure
on page 5-69.
Notice:If the tire pressure has dropped below
19 psi (131 kPa), the vehicle should not be driven.
Damage to the tire may be severe and the sealant
will not be effective. Contact Roadside Assistance,
seeRoadside Assistance Program on page 7-6.
You should have the damaged tire repaired as soon as
possible. The tire sealant is a temporary repair only.
If the tire has been lled with tire sealant, take the tire to
a GM dealer/retailer for inspection and repair. See
Tire Sealant and Compressor Kit (GXP) on page 5-86
for additional information.
Tire Sealant and Compressor
Kit (GXP)
Your vehicle may have a tire inator kit. The kit uses a
liquid tire sealant and air at the same time to seal small
punctures in the tread area of the tire. Be sure to read
and follow all the tire inator kit instructions.
5-86

The kit includes:
A. Air Compressor
B. Tire Sealant Canister
C. Air Compressor
Accessory Plug
D. On/Off SwitchE. Air Pressure Gage
F. Air Compressor
Inator Hose
G. Sealant Filling HoseIf the at tire is due to a slow leak caused by a nail or
other similar road hazard, the tire inator kit may
be used to temporarily repair the damaged tire.
After temporarily repairing a tire using the tire inator kit,
it is recommended to take your vehicle to your
dealer/retailer within 100 miles (161 kilometers) of
driving to have the tire inspected and repaired. If the
sealant is not removed from the tire within a 100 miles
(161 kilometers) of driving, it is more likely that the
tire and tire pressure monitoring sensor may get
damaged and have to be replaced.
5-87

4. Attach the sealant lling hose (A) onto the tire valve
stem. Turn it clockwise until it is tight.
Make sure the inator kit on/off switch (B) is in the
O (off) position.
5. Plug the air compressor accessory plug (C) into an
accessory power outlet in the vehicle. See
Accessory Power Outlet(s) on page 3-26for more
information.
{CAUTION:
Idling the engine in a closed-in place or with
the climate control system off can cause
deadly carbon monoxide (CO). SeeEngine
Exhaust on page 2-36.
6. Start the vehicle. SeeStarting the Engine on
page 2-25for more information. The vehicle must be
running while using the air compressor.
{CAUTION:
Inating something too much can make it
explode, and you or others could be injured.
Be sure to read the inator instructions, and
inate the tire to its recommended pressure.
Do not exceed 36 psi (248 kPa).
7. Move the inator kit switch to the I (on) position.
The inator kit will force sealant and air into the
tire. Sealant may leak from the puncture hole until
the vehicle is driven and the hole has sealed.
5-90

8. Make sure there is a proper connection between
the tire valve stem and the sealant lling hose by
looking at the air pressure gage. If there is not a
pressure reading while the compressor is running,
the connection between the inator kit and the
tire is bad.
Check the attachment between the sealant lling
hose and the tire valve stem.
9. Inate the tire up to the recommended ination
pressure, found on the Tire and Loading Information
label located on the vehicle’s center pillar (B-pillar)
below the vehicle’s door latch, using the air pressure
gage on the top of the unit as a guide.
The pressure gage reading is slightly high while the
compressor is on. Turn the compressor off to get
an accurate pressure reading.
Notice:If the recommended pressure cannot be
reached after 15 minutes, the vehicle should not be
driven. The tire is too severely damaged and
cannot be inated or sealed with the tire sealant
and compressor kit. Remove the air compressor
accessory plug from the accessory power outlet and
unscrew the sealant/air hose from the tire valve or
tire pressure monitoring sensor valve. SeeRoadside
Assistance Program on page 7-6.10. Move the inator kit switch to the O (off) position
once the correct tire pressure is obtained.
11. Turn off the engine.
12. Unplug the air compressor accessory plug from the
accessory power outlet in the vehicle.
13. Disconnect the sealant lling hose from the tire
valve stem, by turning it counterclockwise, and
replace the tire valve stem cap.
Be careful when handling the tire inator
components as they may be hot after usage.
14. Wrap the sealant lling hose around the air
compressor channel to stow it in its original location.
5-91

15. Stow the air compressor accessory plug back in the
air compressor. To do this, wrap the air compressor
accessory plug, snap in the plug, and then push in
the bottom and then the top of the wrapped air
compressor accessory plug.
16. If the at tire was able
to inate to the
recommended ination
pressure, remove the
maximum speed label
from the sealant
canister.
Place it in a highly visible location such as the
inside of the upper left corner of the windshield or
to the face of the radio/clock.
The maximum speed label reminds you to drive
cautiously and not to exceed 55 mph (90 km/h) until
you have the damaged tire inspected and repaired.
{CAUTION:
Storing the tire sealant and compressor kit or
other equipment in the passenger
compartment of the vehicle could cause injury.
In a sudden stop or collision, loose equipment
could strike someone. Store the tire sealant
and compressor kit in the proper place.
17. Return the equipment to the proper storage location
in the trunk of your vehicle.
18. Immediately drive the vehicle 5 miles (8 km) to
distribute the sealant evenly in the tire. Stop at a
safe location and check the tire pressure. Refer to
Steps 1 through 8 under “Using the Air Compressor
without Sealant” next in this section. If the tire
pressure has fallen more than 10 psi (68 kPa) below
the recommended ination pressure, stop driving
the vehicle. The tire is too damaged for the sealant to
work. SeeRoadside Assistance Program on
page 7-6.
If the tire pressure has not dropped more than
10 psi (68 kPa) from the recommended ination
pressure, you can inate the tire back up to the
recommended ination pressure.
5-92

5. Plug the air compressor accessory plug into an
accessory power outlet in the vehicle. See
Accessory Power Outlet(s) on page 3-26for more
information.
{CAUTION:
Idling the engine in a closed-in place or with
the climate control system off can cause
deadly carbon monoxide (CO). SeeEngine
Exhaust on page 2-36.
6. Start the vehicle. SeeStarting the Engine on
page 2-25for more information. The vehicle must be
running while using the air compressor.
{CAUTION:
Inating something too much can make it
explode, and you or others could be injured.
Be sure to read the inator instructions, and
inate the tire to its recommended pressure.
Do not exceed 36 psi (248 kPa).
7. Move the inator kit switch to the I (on) position.
8. Make sure there is a proper connection between the
tire valve stem and the air compressor hose by
looking at the air pressure gage. If there is not a
pressure reading while the compressor is running,
the connection between the inator kit and the
tire is bad.
Check the attachment between the air compressor
hose and the tire valve stem.
5-94