2004 CHEVROLET CORVETTE service

Doing Your Own Service Work
If you want to do some of your own service work, you
will want to use the proper service manual. It tells
you much more about how to service your vehicle than
this manual can. To order the proper service manual,
seeService Publications Ordering Information on
page 7-11.
Your vehicle may have an air bag system. If it does, see
Servicing Your Air Bag-Equipped Vehicle on page 1-49
before attempting to do your own service work.
You should keep a record with all parts receipts and list
the mileage and the date of any service work you
perform. SeeMaintenance Record on page 6-15.
{CAUTION:
You can be injured and your vehicle could be
damaged if you try to do service work on a
vehicle without knowing enough about it.
Be sure you have sufficient knowledge,
experience, the proper replacement parts
and tools before you attempt any vehicle
maintenance task.
CAUTION: (Continued)
CAUTION: (Continued)

Be sure to use the proper nuts, bolts and
other fasteners. “English” and “metric”
fasteners can be easily confused. If you
use the wrong fasteners, parts can later
break or fall off. You could be hurt.
Adding Equipment to the Outside of
Your Vehicle
Things you might add to the outside of your vehicle can
affect the airflow around it. This may cause wind
noise and affect windshield washer performance. Check
with your dealer before adding equipment to the
outside of your vehicle.
Fuel
Use of the recommended fuel is an important part of the
proper maintenance of your vehicle.
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Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that will help
prevent engine and fuel system deposits from forming,
allowing your emission control system to work
properly. You should not have to add anything to your
fuel. However, some gasolines contain only the
minimum amount of additive required to meet U.S.
Environmental Protection Agency regulations. General
Motors recommends that you buy gasolines that
are advertised to help keep fuel injectors and intake
valves clean. If your vehicle experiences problems due
to dirty injectors or valves, try a different brand of
gasoline.
Gasolines containing oxygenates, such as ethers and
ethanol, and reformulated gasolines may be available in
your area to contribute to clean air. General Motors
recommends that you use these gasolines, particularly if
they comply with the specifications described earlier.
Notice:Your vehicle was not designed for fuel that
contains methanol. Do not use fuel containing
methanol. It can corrode metal parts in your fuel
system and also damage the plastic and rubber
parts. That damage would not be covered under
your warranty.Some gasolines that are not reformulated for
low emissions may contain an octane-enhancing
additive called methylcyclopentadienyl manganese
tricarbonyl (MMT); ask the attendant where you
buy gasoline whether the fuel contains MMT. General
Motors does not recommend the use of such gasolines.
Fuels containing MMT can reduce the life of spark
plugs and the performance of the emission control
system may be affected. The malfunction indicator lamp
may turn on. If this occurs, return to your authorized
GM dealer for service.
Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel may be hard
to find. Never use leaded gasoline or any other fuel
not recommended in the previous text on fuel. Costly
repairs caused by use of improper fuel would not
be covered by your warranty.
To check the fuel availability, ask an auto club, or
contact a major oil company that does business in the
country where you will be driving.
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Your vehicle’s engine is filled at the factory with a
Mobil 1®synthetic oil, which meets all requirements for
your vehicle.
Substitute Engine Oil:When adding oil to maintain
engine oil level, oil meeting GM Standard GM4718M
may not be available. You can add substitute oil
designated SAE 5W-30 with the starburst symbol at all
temperatures. If temperatures are above 0°F (-18°C),
you may substitute SAE 10W-30 with the starburst
symbol. Substitute oil not meeting GM Standard
GM4718M should not be used for an oil change.
Engine Oil Additives
Do not add anything to your oil. The recommended oils
with the starburst symbol that meet GM Standard
GM4718M are all you will need for good performance
and engine protection.
When to Change Engine Oil
(GM Oil Life System)
Your vehicle has a computer that lets you know when to
change your engine oil and filter. This is based on
engine revolutions and engine temperature, and not on
mileage. Based on driving conditions, the mileage at
which an oil change will be indicated can vary
considerably. For the oil life system to work properly,
you must reset the system every time the oil is changed.
When the system has calculated that oil life has been
diminished, it will indicate that an oil change is
necessary. A CHANGE OIL SOON message will come
on. Change your oil as soon as possible within the
next two times you stop for fuel. It is possible that, if you
are driving under the best conditions, the oil life
system may not indicate that an oil change is necessary
for over a year. However, your engine oil and filter
must be changed at least once a year and at this time
the system must be reset. Your dealer has GM-trained
service people who will perform this work using
genuine GM parts and reset the system. It is also
important to check your oil regularly and keep it at the
proper level.
If the system is ever reset accidentally, you must
change your oil at 3,000 miles (5 000 km) since your
last oil change. Remember to reset the oil life system
whenever the oil is changed.
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How to Reset the CHANGE OIL SOON
Message
The GM Oil Life System calculates when to change
your engine oil and filter based on vehicle use. Anytime
your oil is changed, reset the system so it can
calculate when the next oil change is required. If a
situation occurs where you change your oil prior to a
CHANGE OIL SOON message being turned on,
reset the system.
To reset the CHANGE OIL SOON message after an oil
change, do the following:
1. Turn the ignition to ON, with the engine off.
2. Press the TRIP button so the OIL LIFE percentage
is displayed.
3. Press RESET and hold for two seconds. OIL LIFE
REMAIN 100% will appear.
4. Turn the key to OFF.
If the CHANGE OIL SOON message comes back on
when you start your vehicle, the engine oil life system
has not reset. Repeat the procedure.
What to Do with Used Oil
Used engine oil contains certain elements that may be
unhealthy for your skin and could even cause cancer.
Do not let used oil stay on your skin for very long. Clean
your skin and nails with soap and water, or a good
hand cleaner. Wash or properly dispose of clothing or
rags containing used engine oil. See the manufacturer’s
warnings about the use and disposal of oil products.
Used oil can be a threat to the environment. If you
change your own oil, be sure to drain all the oil from the
filter before disposal. Never dispose of oil by putting it
in the trash, pouring it on the ground, into sewers, or into
streams or bodies of water. Instead, recycle it by
taking it to a place that collects used oil. If you have a
problem properly disposing of your used oil, ask
your dealer, a service station or a local recycling center
for help.
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Automatic Transmission Fluid
How to Check
It is not necessary to check the transmission fluid level.
A transmission fluid leak is the only reason for fluid
loss. If a leak occurs, take the vehicle to your dealer
service department and have it repaired as soon
as possible.
There is a special procedure for checking and changing
the transmission fluid. Because this procedure is
difficult, you should have this done at your dealer service
department. Contact your dealer for additional
information or the procedure can be found in the service
manual. To purchase a service manual, seeService
Publications Ordering Information on page 7-11.
Notice:We recommend you use only uid labeled
DEXRON
®-III, because uid with that label is
made especially for your automatic transmission.
Damage caused by uid other than DEXRON
®-III is
not covered by your new vehicle warranty.Change both the fluid and filter every 50,000 miles
(80 000 km) if the vehicle is mainly driven under one of
these conditions:
•In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
•In hilly or mountainous terrain.
•High performance operation.
If you do not use your vehicle under one of these
conditions, change the fluid and filter every
100,000 miles (166 000 km).
SeeScheduled Maintenance on page 6-4for the proper
service intervals for the transmission fluid and filter.
5-20

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 filler plug.
2. Check that the lubricant level is up to the bottom of
the filler plug hole.
3. If the fluid level is good, install the plug and be sure
it is fully seated. If the fluid level is low, add more
fluid as described in the next steps.
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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 6-11.
1. Remove the filler plug.
2. Add fluid at the filler plug hole. Add only enough
fluid to bring the fluid level up to the bottom of the
filler plug hole.
3. Install the filler plug. Be sure the plug is fully
seated.
4. Tighten the plug to 20 lb ft (27Y).
Hydraulic Clutch
The hydraulic clutch linkage in your vehicle is
self-adjusting. The master cylinder reservoir is filled with
hydraulic fluid.
It is not necessary to regularly check the fluid unless
you suspect there is a leak in the system. Adding fluid
won’t correct a leak.
A fluid loss in this system could indicate a problem.
Have the system inspected and repaired.
When to Check and What to Use
The clutch master cylinder reservoir is located at the
rear of the engine compartment on the driver’s side. See
Engine Compartment Overview on page 5-12for
more information on location.
Refer to the Maintenance Schedule to determine how
often you should check the fluid level in your master
cylinder reservoir and for the proper fluid. SeeOwner
Checks and Services on page 6-8andRecommended
Fluids and Lubricants on page 6-11.
5-22

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.
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 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 does not come back on, you can drive
normally.
If the warning continues and you are not stopped, pull
over, stop, and park your vehicle right away.
If there is still no sign of steam, you can 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 vehicleuntil it cools down. Also, see
“Overheated Engine Protection Operating Mode” listed
previously in this section.
You may decide not to lift the hood but to get service
help right away.
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