2004 PONTIAC GTO engine

Adding Coolant
If you need more coolant, add the proper DEX-COOL®
coolant mixtureat the surge tank, but only when the
engine is cool.
{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 the level is correct, replace the cap and turn
clockwise until secure.
Engine Overheating
Immediate action is required if your engine overheats.
This is indicated by the coolant temperature gage
and the Engine Temp Hot message on the trip computer
display.Engine Coolant Temperature Gage on
page 3-28.
If Steam Is Coming From Your Engine
5-28

{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.
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 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.
If No Steam Is Coming From Your
Engine
An overheat warning, along with an Engine Temp Hot
message can indicate a serious problem.
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
do the following:
•Climb a long hill on a hot day
•Stop after high-speed driving
•Idle for long periods in traffic
•Tow a trailer
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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,
with the parking brake applied, shift to PARK (P)
or NEUTRAL (N) and let the engine idle while
you get out and check that the cooling fan is
working.
2. If the fan is working and the temperature gauge
needle has not returned to its normal position
within a few minutes, stop the engine and remove
the ignition key.
Look for leaks at the radiator hoses and
connections, heater hoses and connections,
radiator, and water pump. Be careful when checking
these areas as they will probably still be hot. If
you find a major leak or other problems that may
have caused the engine to overheat, do not run the
engine until these problems have been corrected.
If you do not find anything wrong, you should check
the engine coolant level. SeeEngine Coolant on
page 5-25. You should also check the air intake
area below the front bumper to ensure that it is clear
of leaves and road grime.3. Turn off your air conditioning and turn on your
heater to full hot at the highest fan speed and
open the window 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 doesn’t come back on, you can drive
normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there’s still no sign of steam, you can idle the engine
for three minutes while you’re parked. If you still
have the warning,turn off the engine and get everyone
out of the vehicleuntil it cools down.
You may decide not to lift the hood but to get service
help right away.
5-30

Cooling System
When you decide it’s safe to lift the hood, you’ll see the
electric engine cooling fan (A) and the engine coolant
reservoir (B).
{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,
don’t do anything else until it cools down. The vehicle
should be parked on a level surface.
5-31

The coolant level should be at or above the COLD FILL
mark. If it isn’t, 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 fan is running. If
the engine is overheating, the fan should be running.
If it isn’t, your vehicle needs service.Notice:If you operate the engine without coolant
or fail to maintain the cooling system properly,
you could damage the engine. The repairs would not
be covered by your warranty. Always follow the
maintenance schedule in this manual for
maintaining your cooling system. SeeCooling
System on page 5-31for more information.
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 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.
5-32

{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. Park the vehicle on a level surface.
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 (left) 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. Keep turning the pressure cap slowly, and
remove it.
5-34

3. Then fill the coolant surge tank with the proper
mixture to the COLD FILL mark.
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 fan.
By this time, the coolant level inside the coolant
surge tank may be lower. If the level is lower than
the COLD FILL mark, add more of the proper
mixture to the coolant surge tank until the level
reaches the mark.
5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
See your dealer, if necessary.
5-35

Power Steering Fluid
When to Check Power Steering Fluid
SeeEngine Compartment Overview on page 5-12
for reservoir location.
It is not necessary to regularly check power steering
fluid unless you suspect there is a leak in the system or
you hear an unusual noise. A fluid loss in this system
could indicate a problem. Have the system inspected
and repaired.
How to Check Power Steering Fluid
The fluid level should be checked after the vehicle has
been driven for at least 20 minutes, so that the fluid
is warm. A convenient time is when stopping for
gas. The cold level check should only be used after the
engine has not been running for at least five hours.
However, the hot level check is always recommended.
The fluid level can be viewed through the reservoir.
The level markings are next to the fluid window. When
the fluid is cold the level should be between the
COLD MIN and MAX marks; when the vehicle has been
driven for awhile and the fluid is hot the level should
be between the HOT MIN and MAX marks. If fluid must
be added, undo the cap counterclockwise to the
stop; then the cap can be lifted off. Do not overfill and
remember to replace the cap tightly. If you often need to
add fluid, you should see your dealer. Remember to
secure the cap when the level is correct and clean up
any spillage.
What to Use
To determine what kind of fluid to use, see
Recommended Fluids and Lubricants on page 6-13.
Always use the proper fluid. Failure to use the proper
fluid can cause leaks and damage hoses and seals.
5-36