2004 CHEVROLET CORVETTE Owners Manual

•SAE 5W-30
As shown in the viscosity chart, SAE 5W-30 is best
for your vehicle. However, you can use SAE
10W-30 if it is going to be 0°F (-18°C) or above.
These numbers on an oil container show its
viscosity, or thickness. Do not use other viscosity
oils such as SAE 20W-50.
Oils meeting these
requirements should also
have the starburst
symbol on the container.
This symbol indicates
that the oil has been
certified by the American
Petroleum Institute (API).
You should look for this on the oil container, and use
onlythose oils that are identified as meeting GM
Standard GM4718M and have the starburst symbol on
the front of the oil container.
5-15

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.
5-16

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.
5-17

Engine Air Cleaner/Filter
SeeEngine Compartment Overview on page 5-12for
location of the engine air cleaner/filter.
When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/filter at every oil change and
replace at the first oil change after 25,000 miles
(40 000 km).
How to Inspect the Engine Air
Cleaner/Filter
To inspect the air cleaner/filter, remove the filter from
the vehicle and lightly shake the filter to release
loose dust and dirt. If the filter remains caked with dirt, a
new filter is required.
To inspect or replace the filter, do the following:
1. Pull up on the clips on each side to release the
assembly.
5-18

2. Pull the assembly out.
3. Replace the filter. SeeNormal Maintenance
Replacement Parts on page 6-13.
4. Push the assembly back into place.
5. Fasten the clips.
{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.
5-19

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.
5-21

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