2008 PONTIAC G6 engine overheat

Starting Procedure
1. With your foot off the accelerator pedal, turn the
ignition key to START. When the engine starts,
let go of the key. The idle speed will go down as
your engine gets warm. Do not race the engine
immediately after starting it. Operate the engine and
transmission gently to allow the oil to warm up
and lubricate all moving parts.
Your vehicle has a Computer-Controlled Cranking
System. This feature assists in starting the
engine and protects components. If the ignition key
is turned to the START position, and then
released when the engine begins cranking, the
engine will continue cranking for a few seconds or
until the vehicle starts. If the engine does not
start and the key is held in START for many
seconds, cranking will be stopped after 15 seconds
to prevent cranking motor damage. To prevent
gear damage, this system also prevents cranking if
the engine is already running. Engine cranking
can be stopped by turning the ignition switch to the
ACC/ACCESSORY or LOCK/OFF position.
Notice:Cranking the engine for long periods of
time, by returning the key to the START position
immediately after cranking has ended, can overheat
and damage the cranking motor, and drain the
battery. Wait at least 15 seconds between each try,
to let the cranking motor cool down.2. If the engine does not start after 5-10 seconds,
especially in very cold weather (below 0°F or
−18°C), it could be ooded with too much gasoline.
Try pushing the accelerator pedal all the way to
the oor and holding it there as you hold the key in
START for up to a maximum of 15 seconds.
Wait at least 15 seconds between each try, to allow
the cranking motor to cool down. 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 your 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, your
engine might not perform properly. Any resulting
damage would not be covered by your vehicle’s
warranty.
2-24

To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord. On
the 2.4L L4 ECOTEC
®engine, the engine coolant
heater cord is located near the air cleaner box
on the passenger’s side of the engine compartment.
On the 3.5L, 3.6L and 3.9L V6 engines, the
engine coolant heater cord is located on the driver’s
side around the battery box. SeeEngine
Compartment Overview on page 5-14for more
information on location.
3. Plug the cord 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.
How long should you keep the coolant heater plugged
in? The answer depends on the outside temperature, the
kind of oil you have, and some other things. Instead
of trying to list everything here, we ask that you contact
your dealer/retailer in the area where you will be
parking your vehicle. The dealer/retailer can give you
the best advice for that particular area.
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While using the MSM feature the vehicle will have rmer
shifting and sportier performance. You can use this
for sport driving or when climbing hills to stay in gear
longer or to downshift for more power or engine braking.
The transmission will only allow you to shift into gears
appropriate for the vehicle speed and engine revolutions
per minute (RPM):
The transmission will not automatically shift to the
next higher gear if the engine RPM is too high.
The transmission will not allow shifting to the next
lower gear if the engine RPM is too high.
If the vehicle does not respond to a gear change, or
detects a problem with the transmission, the range
of gears may be reduced and the Malfunction Indicator
Lamp will come on. SeeMalfunction Indicator Lamp
on page 3-38for more information.
SECOND (2)/THIRD (3) Gear Start
Feature
Notice:If you attempt a third gear start while
trailering or towing a heavy load, you will notice
reduced engine power. This could overheat
and damage your transmission. Do not attempt a
third gear start while trailering or towing your
vehicle.
If your vehicle has the 6-speed transmission, when
accelerating your vehicle from a stop in snowy and icy
conditions, you may want to shift into SECOND (2),
or THIRD (3) gear. A higher gear, and light application
of the gas pedal, may allow you to gain more traction
on slippery surfaces.
With the MSM, the vehicle can accelerate from a stop in
SECOND (2) or THIRD (3).
1. Move the shift lever from DRIVE (D) into the
MANUAL MODE (M) position.
2. With the vehicle stopped, move the lever forward
towards the plus (+) to select SECOND (2) or
THIRD (3)gear. The vehicle will start from a stop
position in SECOND (2) or THIRD (3) gear.
3. Once the vehicle is moving select the desired
drive gear.
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Leaving Your Vehicle With the Engine
Running (Automatic Transmission)
{CAUTION:
It can be dangerous to leave your vehicle with
the engine running. Your vehicle could move
suddenly if the shift lever is not fully in
PARK (P) with the parking brake rmly set.
And, if you leave the vehicle with the engine
running, it could overheat and even catch re.
You or others could be injured. Do not leave
your vehicle with the engine running.
If you have to leave your automatic transmission vehicle
with the engine running, be sure your vehicle is in
PARK (P) and your parking brake is rmly set before
you leave it. After you have moved the shift lever
into PARK (P), hold the regular brake pedal down. Then,
see if you can move the shift lever away from PARK (P)
without rst pushing the button.
If you can, it means that the shift lever was not fully
locked into PARK (P).
Torque Lock (Automatic Transmission)
If you are parking on a hill and you do not shift your
automatic transmission into PARK (P) properly,
the weight of the vehicle may put too much force on the
parking pawl in the transmission. You may nd it
difficult to pull the shift lever out of PARK (P). This is
called torque lock. To prevent torque lock, set the
parking brake and then shift into PARK (P) properly
before you leave the driver’s seat. To nd out how, see
“Shifting Into Park (P)” previously in the section.
When you are ready to drive, move the shift lever out of
PARK (P) before you release the parking brake.
If torque lock does occur, you may need to have another
vehicle push yours a little uphill to take some of the
pressure from the parking pawl in the transmission, so
you can pull the shift lever out of PARK (P).
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Engine Coolant Temperature Gage
This gage shows the engine coolant temperature. If the
gage pointer moves into the red area, the light comes
on and you hear a chime, the engine is too hot! It means
that your engine coolant has overheated. SeeEngine
Overheating on page 5-33.
Tire Pressure Light
Your vehicle has a tire
pressure light.
This light comes on briey when the engine is started
and provides information about tire pressures and
the Tire Pressure Monitoring System.
When the Light is Solid
This indicates that one or more of your tires are
signicantly underinated.
A tire pressure message in the Driver Information
Center (DIC), may accompany the light. SeeDIC
Warnings and Messages on page 3-46for more
information. Stop and check your tires as soon as it is
safe to do so. If underinated, inate to the proper
pressure. SeeTires on page 5-60for more information. United States
Canada
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Then, shut the engine off and close the window almost all
the way to preserve the heat. Start the engine again and
repeat this only when you feel really uncomfortable from
the cold. But do it as little as possible. Preserve the fuel
as long as you can. To help keep warm, you can get out
of the vehicle and do some fairly vigorous exercises
every half hour or so until help comes.
If Your Vehicle is Stuck in Sand,
Mud, Ice, or Snow
Slowly and cautiously spin the wheels to free your
vehicle when stuck in sand, mud, ice, or snow. See
Rocking Your Vehicle to Get It Out on page 4-20.
If your vehicle has a traction system, it can often help to
free a stuck vehicle. Refer to your vehicle’s traction
system in the Index. If the stuck condition is too severe
for the traction system to free the vehicle, turn the
traction system off and use the rocking method.
{CAUTION:
If you let your vehicle’s tires spin at high
speed, they can explode, and you or others
could be injured. The vehicle can overheat,
causing an engine compartment re or other
damage. Spin the wheels as little as possible
and avoid going above 35 mph (55 km/h) as
shown on the speedometer.
For information about using tire chains on your vehicle,
seeTire Chains on page 5-85.
4-19

Maximum trailer weight is calculated assuming only the
driver is in the tow vehicle and it has all the required
trailering equipment. The weight of additional optional
equipment, passengers and cargo in the tow vehicle
must be subtracted from the maximum trailer weight.
When towing a trailer on long uphill grades and
the outside temperature is above 85°F (29°C), reduce
your vehicle speed to 45 mph (72 km/h) to avoid
overheating the engine cooling system.
Ask your dealer/retailer for additional trailering
information or advice, or write us at our Customer
Assistance Offices. SeeCustomer Assistance Offices on
page 7-5for more information.
Weight of the Trailer Tongue
The tongue load (A) of any trailer is an important weight
to measure because it affects the total or gross weight of
your vehicle. The Gross Vehicle Weight (GVW) includes
the curb weight of the vehicle, any cargo you may carry in
it, and the people who will be riding in the vehicle. If you
have a lot of options, equipment, passengers or cargo in
your vehicle, it will reduce the tongue weight your vehicle
can carry, which will also reduce the trailer weight your
vehicle can tow. And if you tow a trailer, you must include
the tongue load in the GVW because your vehicle will be
carrying that weight, too. SeeLoading Your Vehicle on
page 4-20for more information about your vehicle’s
maximum load capacity.If you are using a weight-carrying hitch, the trailer
tongue (A) should weigh 10 to 15 percent of the total
loaded trailer weight (B).
After you have loaded your trailer, weigh the trailer and
then the tongue, separately, to see if the weights are
proper. If they are not, you may be able to get them right
simply by moving some items around in the trailer.
Total Weight on Your Vehicle’s Tires
Be sure your vehicle’s tires are inated to the upper limit
for cold tires. You will nd these numbers on the
Tire-Loading Information label at the rear edge of the
driver’s door or seeLoading Your Vehicle on page 4-20.
Then be sure you do not go over the GVW limit for
your vehicle, including the weight of the trailer tongue.
4-30

Driving On Grades
When towing a trailer on long uphill grades and the
outside temperature is above 85°F (29°C), reduce your
vehicle speed to 45 mph (72 km/h) to avoid overheating
the engine cooling system.
Reduce speed and shift to a lower gearbeforeyou start
down a long or steep downgrade. If you do not shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.
Parking on Hills
{CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.But if you ever have to park your rig on a hill, here is
how to do it:
1. Apply your regular brakes, but do not shift into
PARK (P) for an automatic transmission or into
gear for a manual transmission. When parking
uphill, turn your wheels away from the curb. When
parking downhill, turn your wheels into the curb.
2. Have someone place chocks under the trailer
wheels.
3. When the chocks are in place, release the regular
brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your
parking brake and shift into PARK (P).
5. Release the regular brakes.
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