2004 PONTIAC GTO check engine

{CAUTION:
Operating the engine with the air cleaner/lter
off can cause you or others to be burned.
The air cleaner not only cleans the air, it helps
to stop ame if the engine backres. If it is
not there and the engine backres, you could
be burned. Do not drive with it off, and be
careful working on the engine with the air
cleaner/lter off.
Notice:If the air cleaner/lter is off, a backre can
cause a damaging engine re. And, dirt can
easily get into your engine, which will damage it.
Always have the air cleaner/lter in place when you
are driving.
Automatic Transmission Fluid
When to Check and Change
The fluid level should be checked monthly, by looking at
the fluid level on the dipstick. A good time to check
your automatic transmission fluid level is when
the engine oil is changed.
SeeScheduled Maintenance on page 6-4for more
information on when to check and change the fluid
and filter.
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How to Check
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
your transmission. Too much can mean that some
of the uid could come out and fall on hot engine
part or exhaust system parts, starting a re.
Too little uid could cause the transmission to
overheat. Be sure to get an accurate reading if you
check your transmission uid.
Wait at least 30 minutes before checking the
transmission fluid level if you have been driving in the
following conditions:
•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 trailerTo get the right reading, the fluid 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’s colder than 50°F (10°C), drive the vehicle
in DRIVE (D) until the engine temperature gage
moves and then remains steady for 10 minutes.
A cold fluid check can be made after the vehicle has
been sitting for eight hours or more with the engine off,
but this is used only as a reference. Let the engine
run at idle for five minutes if outside temperatures are
50°F (10°C) or more. If it’s colder than 50°F (10°C), you
may have to idle the engine longer. Should the fluid
level be low during this cold check, you must check the
fluid hot before adding fluid. Checking the fluid hot
will give you a more accurate reading of the fluid level.
5-20

Checking the Fluid Level
Prepare your vehicle as follows:
•Park your vehicle on a level place. Keep the engine
running.
•With the parking brake applied, place the shift lever
in PARK (P).
•With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position the shift
lever in PARK (P).
•Let the engine run at idle for three minutes or more.Then, without shutting off the engine, follow these steps:
The automatic transmission dipstick is located at the
rear of the engine compartment, on the right side of the
vehicle. SeeEngine Compartment Overview on
page 5-12for more information on location.
1. Unclip the handle and remove the dipstick; wipe it
clean with a clean rag or paper towel and re-insert
it fully. Remove it again and read the fluid level.
2. Check both sides of the dipstick, and read the lower
level. The fluid level must be in the COLD area for
a cold check or in the cross-hatched HOT area
for a hot check.
3. If the fluid level is in the acceptable range, push the
dipstick back in all the way.
Remember to always replace the dipstick and lock
the handle down.
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Manual Transmission Fluid
When to Check
A good time to have it checked is when the engine oil is
changed. However, the fluid in your manual transmission
doesn’t require changing.
How to Check
Because this operation can be difficult, you may choose
to have this done at your dealership service department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading.
Notice:Too much or too little uid can damage
your transmission. Too much can mean that some
of the uid could come out and fall on hot engine
part or exhaust system parts, starting a re.
Too little uid could cause the transmission to
overheat. Be sure to get an accurate reading if you
check your transmission uid.Check the fluid level only when your engine is off, the
vehicle is parked on a level place and the transmission
is cool enough for you to rest your fingers on the
transmission case.
Then, follow these steps:
1. Remove the reverse light switch.
2. Check that the lubricant level is up to the bottom of
the switch hole.
3. If the fluid level is good, install the switch and be
sure it is fully seated. If the fluid level is low, add
more fluid as described in the next steps.
How to Add Fluid
Here’s how to add fluid. Refer to the Maintenance
Schedule to determine what kind of fluid to use. See
Recommended Fluids and Lubricants on page 6-13.
1. Remove the reverse light switch.
2. Add fluid at the switch hole. Add only enough
fluid to bring the fluid level up to the bottom of
the switch hole.
3. Install the reverse light switch. Be sure the switch is
fully seated.
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Hydraulic Clutch
The clutch fluid level should be checked weekly. A fluid
loss in this system could indicate a problem. If the
clutch fluid requires constant filling up it could indicate a
leak. Have the system inspected and repaired by
your dealer. Adding fluid won’t correct a leak.
When to Check and What to Use
Refer to the Maintenance
Schedule to determine the
proper fluid. SeeOwner
Checks and Services
on page 6-9and
Recommended Fluids and
Lubricants on page 6-13.
How to Check and Add Fluid
To check the fluid level, look at the markings on the
reservoir. If the fluid level is between the MIN and the
MAX line, the fluid level is correct. SeeEngine
Compartment Overview on page 5-12for more
information on location. If the fluid level is between
these marks do not remove the cap, as the fluid
will quickly absorb moisture.
If fluid does need to be added, first turn the vehicle off.
Remove the cap and add the proper fluid. Remember
to replace the cap and clean up any spilled fluid.
5-24

What to Use
Use a mixture of one-halfclean, drinkable waterand
one-half DEX-COOL®coolant which won’t damage
aluminum parts. If you use this coolant mixture,
you don’t 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 the proper 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 the proper coolant, you do not
have to add extra inhibitors or additives which claim
to improve the system. These can be harmful.
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Checking Coolant
The coolant surge tank is located in the engine
compartment on the driver’s side of the vehicle. See
Engine Compartment Overview on page 5-12for more
information on location.
{CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. Never turn the surge tank pressure
cap — even a little — when the engine and
radiator are hot.
The coolant level should be checked at least weekly, by
looking at the level on the coolant reservoir when the
engine is cold. The vehicle must be on a level surface.
When your engine is cold, the coolant level should
be at or slightly above the COLD FILL mark, at
the center weld joint. The level rises when the engine is
running and drops when the engine cools down. If
the level falls below the weld joint, the coolant should
be added to a little over the mark. Do not overfill,
as coolant requires space to expand when warmed up.
If the Low Coolant message on the trip computer
display comes on and stays on, it means you’re low on
engine coolant. You should check the level as soon
as possible. You may have to check the coolant level
when it is hot. SeeEngine Overheating on page 5-28.
5-27

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.
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