PONTIAC G6 2008 Owners Manual
Page 271 of 408
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 might decide not to lift the hood but to get service
help right away.Overheated Engine Protection
Operating Mode
This emergency operating mode lets your vehicle 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,
there is a signi cant loss in power and engine
performance. The temperature gage indicates an
overheat condition exists. Driving extended distances
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 5-21.
5-35
Page 272 of 408
Cooling System
When you decide it is safe to lift the hood, this is what
you see:
A. Engine Cooling Fans
B. Engine Coolant Surge Tank
C. Pressure Cap{CAUTION:
An electric engine cooling fan under the hood
can start up even when the engine is not
running and can injure you. Keep hands,
clothing, and tools away from any underhood
electric fan.
If the coolant inside the coolant surge tank is boiling, do
not do anything else until it cools down. The vehicle
should be parked on a level surface.
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.
3.5L V6 Engine shown, 2.4L L4, 3.6L V6 and 3.9L
V6 Engines similar
5-36
Page 273 of 408
{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
®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 the warranty. Always
use DEX-COOL
®(silicate-free) coolant in the vehicle.
How to Add Coolant to the Coolant
Surge Tank
Notice:This vehicle has a speci c 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. See
Engine Coolant on page 5-30for more information.
5-37
Page 274 of 408
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.
{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.
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.
5-38
Page 275 of 408
{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. 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.2. Then keep turning the
pressure cap slowly,
and remove it.
3. Fill the coolant surge tank with the proper mixture,
to the FULL COLD mark. Wait about ve minutes,
then check to see if the level is below the mark.
If the level is below the FULL COLD mark,
add additional coolant to bring the level up to the
mark. Repeat this procedure until the level remains
constant at the FULL COLD mark for at least
ve minutes.
5-39
Page 276 of 408
4. With the coolant surge tank pressure cap off, start
the engine and let it run until you can feel the upper
radiator hose getting hot. Watch out for the
engine cooling fans.
By this time, the coolant level inside the coolant
surge tank might be lower. If the level is lower than
the FULL COLD mark, add more of the proper
mixture to the coolant surge tank until the level
reaches the FULL COLD mark.
5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
Power Steering Fluid
SeeEngine Compartment
Overview on page 5-14for
reservoir location.
When to Check Power Steering Fluid
Power steering uid is used in all vehicles with
V6 engines. Vehicles with the 4-cylinder engine
have electric power steering and do not use power
steering uid.
It is not necessary to regularly check power steering uid
unless a leak is suspected in the system, or an unusual
noise is heard. A uid loss in this system could indicate a
problem. Have the system inspected and repaired.
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. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a
clean rag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the uid level on
the dipstick
The uid level should be within the crosshatched area
on the dipstick.
If the uid is at or below the ADD mark on the dipstick,
add just enough uid to bring the level within the
crosshatched area.
5-40