engine overheat PONTIAC G6 2007 User Guide

Notice:Too much or too little uid can damage
the transaxle. Too much can mean that some of
the uid could come out and fall on hot engine
or exhaust system parts, starting a re. Too
little uid could cause the transaxle to overheat.
Be sure to get an accurate reading if you check
the transaxle uid.
Wait at least 30 minutes before checking the
transaxle uid level if you have been driving:
When outside temperatures are above
90°F (32°C).
At high speed for quite a while.
In heavy traffic — especially in hot weather.
While pulling a trailer.
To get the right reading, the uid should be at
normal operating temperature, which is 180°F to
200°F (82°C to 93°C).
Get the vehicle warmed up by driving about
15 miles (24 km) when outside temperatures are
above 50°F (10°C). If it is colder than 50°F (10°C),
you may have to drive longer.
Checking the Fluid Level
Prepare the vehicle as follows:
1. Park the vehicle on a level place. Keep the
engine running.
2. With the parking brake applied, place the shift
lever in PARK (P).
3. With your foot on the brake pedal, move the
shift lever through each gear, pausing for
about three seconds in each one. Then,
position the shift lever in PARK (P).
4. Let the engine run at idle for three to
ve minutes.
Then, without shutting off the engine, follow
these steps:
The transaxle uid
dipstick handle has this
symbol on it, and is
located near the front of
the engine compartment.
333

Automatic Transaxle Fluid
(3.9L V6 Engine)
When to Check and Change Automatic
Transaxle Fluid
A good time to check the automatic transaxle uid
level is when the engine oil is changed.
Change the uid and lter at the intervals listed
inAdditional Required Services on page 434,
and be sure to use the transaxle uid listed in
Recommended Fluids and Lubricants on page 442.
How to Check Automatic Transaxle
Fluid
Because this operation can be a little difficult, you
may choose to have this done at the dealership
service department.
If you do it yourself, be sure to follow all the
instructions here, or you could get a false
reading on the dipstick.Notice:Too much or too little uid can damage
the transaxle. Too much can mean that some of
the uid could come out and fall on hot engine
or exhaust system parts, starting a re. Too
little uid could cause the transaxle to overheat.
Be sure to get an accurate reading if you check
the transaxle uid.
Wait at least 30 minutes before checking the
transaxle uid level if you have been driving:
When outside temperatures are above
90°F (32°C).
At high speed for quite a while.
In heavy traffic — especially in hot weather.
While pulling a trailer.
To get the right reading, the uid should be at
normal operating temperature, which is 180°F to
200°F (82°C to 93°C).
Get the vehicle warmed up by driving about
15 miles (24 km) when outside temperatures are
above 50°F (10°C). If it is colder than 50°F (10°C),
you may have to drive longer.
335

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, seeEngine
Overheating on page 342.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
®
may 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 your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your
vehicle.
339

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 your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can
boil before the proper coolant mixture will.
Your vehicle’s coolant warning system is
set for the proper coolant mixture. With
plain water or the wrong mixture, your
engine could get too hot but you would
not get the overheat warning. Your 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 you use an improper coolant
mixture, your engine could overheat and be
badly damaged. The repair cost would not be
covered by your 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 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. See
Recommended Fluids and Lubricants on
page 442for more information.
340

Adding Coolant
If you need more coolant, add the proper
DEX-COOL®coolant mixture at the surge tank,
but only when the engine is cool. If the surge tank
is empty, a special ll procedure is necessary.
SeeEngine Overheating on page 342andCooling
System on page 345.
{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 pressure cap, make sure it is
hand-tight and fully seated.
Pressure Cap
Notice:If the pressure cap is not tightly
installed, coolant loss and possible engine
damage may occur. Be sure the cap is properly
and tightly secured.
SeeEngine Compartment Overview on page 318
for more information on location.
Engine Overheating
You will nd an engine coolant temperature gage
on your vehicle’s instrument panel. SeeEngine
Coolant Temperature Gage on page 203.
342

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. 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.
If you keep driving when the vehicles
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.
SeeOverheated Engine Protection
Operating Mode on page 344for
information on driving to a safe place
in an emergency.Notice:If your engine catches re because
you keep driving with no coolant, your vehicle
can be badly damaged. The costly repairs
would not be covered by your warranty. See
Overheated Engine Protection Operating Mode
on page 344for information on driving to a
safe place in an emergency.
If No Steam Is Coming From
Your Engine
If you get an engine overheat 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.
Tow a trailer.
343

If you get the overheat warning with no sign of
steam, try this for a minute or so:
1. In heavy traffic, let the engine idle in
NEUTRAL (N) while stopped. If it is safe to
do so, pull off the road, shift to PARK (P)
or NEUTRAL (N) and let the engine idle.
2. Turn on your heater to full hot at the highest fan
speed and open the windows as necessary.
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, pull over, stop, and park
your vehicle right away.
If there is still no sign of steam, 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.Overheated Engine Protection
Operating Mode
This emergency operating mode allows your
vehicle to be driven to a safe place in an emergency
situation. If an overheated engine condition exists,
an overheat protection mode which alternates ring
groups of cylinders helps prevent engine damage.
In this mode, you will notice a signicant loss in
power and engine performance. The temperature
gage will indicate an overheat condition exists.
Driving extended miles (km) and/or towing a trailer
in the overheat protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine
damage, allow the engine to cool before
attempting any repair. The engine oil will be
severely degraded. Repair the cause of coolant
loss, change the oil and reset the oil life
system. SeeEngine Oil on page 325.
344

The coolant level should be at or above the FULL
COLD mark on the coolant surge tank. If it is
not, you may have a leak at the pressure cap or in
the radiator hoses, heater hoses, radiator, water
pump, or somewhere else in the cooling system.
{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 your
engine without coolant is not covered by your
warranty.
Notice:Using coolant other than DEX-COOL®
may 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 your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your
vehicle.
346

How to Add Coolant to the Coolant
Surge Tank
Notice:This vehicle has a specic coolant ll
procedure. Failure to follow this procedure
could cause your engine to overheat and
be severely damaged.
If you have not found a problem yet, check to see if
coolant is visible in the surge tank. If coolant is
visible but the coolant level is not at or above the
FULL COLD mark, add a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant at the
coolant surge tank, but be sure the cooling system,
including the coolant surge tank pressure cap, is
cool before you do it. SeeEngine Coolant on
page 339for more information.If no coolant is visible in the surge tank, add
coolant as follows:
{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 coolant surge tank pressure
cap — even a little — they can come out at
high speed. Never turn the cap when the
cooling system, including the coolant
surge tank pressure cap, is hot. Wait for
the cooling system and coolant surge
tank pressure cap to cool if you ever have
to turn the pressure cap.
347

{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can
boil before the proper coolant mixture will.
Your vehicle’s coolant warning system is
set for the proper coolant mixture. With
plain water or the wrong mixture, your
engine could get too hot but you would
not get the overheat warning. Your 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: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. You can remove the coolant surge tank
pressure cap when the cooling system,
including the coolant surge tank pressure cap
and upper radiator hose, is no longer hot.
Turn the pressure cap slowly counterclockwise
about two or two and one-half turns.
If you hear a hiss, wait for that to stop. This
will allow any pressure still left to be vented out
the discharge hose.
348