CHEVROLET CORVETTE 1994 4.G Owners Manual

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I
NOTICE:
If you use oils that don’t have the
GM4718M Standard designation,
you can cause engine damage not
covered by your warranty.
0 SAE 5W-30
As shown in the viscosity chart,
SAE 5W-30 is best for your
vehicle. However, you can use
SAE 1OW-30 if it’s 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.
. .I80
Recommended SAE Viscosity
Grade Engine Oils
For best fuel economy and cold starting,
.select the lowest SAE viscosity grade oil
for the expected temperature range.
HOT
WEATHER
/
WEATHER
r
COLD
WOK FOR
LABELS
ONE OFTHESE @
1
-r
SAEZ-30
PREFERRED
Oils meeting these requirements should
also have either one or both of these
symbols
on the container.
You should look for these
on the oil
container, and use
o& those oils that
are identified as meeting GM Standard
4718M and have either the “starburst”
symbol or the
API doughnut symbol
with either the
SH or the SG designation.
Your Corvette engine is filled at the
factory with a Mobil
l@ synthetic oil,
which meets all requirements for your
vehicle.

Downloaded from www.Manualslib.com manuals search engine Substitute Oil (LT1 Only): When adding
oil to maintain engine oil level, if an oil
meeting GM Standard GM4718M is not
available, you can use oil designated
either
SAE 5W-30 API Service SH or SG
at all temperatures, or
SAE 1OW-30 API
Service
SH or SG at temperatures above
0°F (-18°C). This oil should not be used
for an oil change.
Substitute Oil (LT5 Only): When adding
oil to maintain engine oil level, if an oil
meeting
GM Standard GM4718M is not
available, you can use oil designated SAE
1OW-30 API Service SH or
SG at all
temperatures. This oil should not be used
for an oil change.
Engine Oil Additives
Don’t add anything to your oil. Your
Chevrolet dealer is ready to advise if you
think something should be added.
When to Change Engine Oil
See if any one of these is true for you:
Most trips are less than 4 miles
It’s below freezing outside and most
trips are less than
10 miles (16 km).
(6 km).
The engine is at low speed most of
the time (as
in stop-and-go traffic).
Most trips are through dusty places.
If any one of these is true for your
vehicle, you need to change your oil and
filter every 3,000 miles
(5 000 km) or
3 months
- whichever comes first.
(See “Engine Oil Life Monitor” in the
Index.)
If none of them is true, change the oil
every 7,500 miles
( 12 500 km) or 12
months
- whichever comes first. Change
the filter at the first oil change and at
every other oil change after that. (See
“Engine Oil Life Monitor” in the Index.)
Engine Coolant Heater (Engine Block
Heater)
An engine coolant heater can be a big
help if you have to park outside in very
cold weather,
0 “F (- 18 “C) or colder. If
your vehicle has this feature, see “Engine
Coolant Heater” in the Index.
What to Do with Used Oil
Did you know that used engine oil
contains certain elements that may be
unhealthy for your skin and could even
cause cancer? Don’t 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 throw away
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 real threat to the
environment. If you change your own oil,
be sure to drain all free-flowing oil from
the filter before disposal. Don’t ever
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. L 1
181 ...

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5.7L LT1 (Code P)
Air Cleaner
Refer to the Maintenance Schedule to
determine when to replace the air filter.
See “Scheduled Maintenance Services” in
the Index.
. . .182
5.7L LT5 (Code J)
NOTICE:
If the air cleaner is off, a backfire can
cause a damaging engine fire. And,
dirt can easily get into your engine,
which will damage it. Always have
the air cleaner in place when you’re
driving.

Downloaded from www.Manualslib.com manuals search engine Air Filter Replacement
To remove the air filter:
1. Unscrew the three knobs.
1. Pull the air cleaner straight up. ?,
1. ODen the air cleaner and remove the
fiiter.
183..
C I

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5.
0
0
Reverse the steps.
Align the tabs
to the slots in the
bottom of the assembly before you
replace it.
Install the short knob into the middle
hole first. Then install the longer
knobs into the outer holes.
Automatic Transmission Fluid
When to Check and Change
4 good time to check your automatic
:ransmission fluid level is when the
mgine oil is changed. Refer to the
Maintenance Schedule to determine when
co change your fluid. See “Scheduled
Maintenance Services” in the Index.
How to Check
Because this operation can be a little
iifficult, you may choose to have this
done at a Chevrolet dealership Service
Department.
[f 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 fluid can dam-
age your transmission.
Too much can
mean that some of the fluid could
come out and fall
on hot engine parts
or exhaust system, starting a fire. Be
sure to get an accurate reading if you
check your transmission fluid. Wait
at least 30 minutes before checking
the transmission fluid level if you have
been driving:
0 When outside temperatures are above
0 At high speed for quite a while.
0 In heavy traffic - especially in hot
To get the right reading, the fluid should
be at normal operating temperature, which is
180°F to 200°F (82°C to 93°C).
To check transmission fluid hot: 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
“D’ (Third Gear) until the
engine temperature gage moves and then
remains steady for ten minutes. Then follow the hot check procedures.
To check transmission fluid cold: A cold
check is made after the vehicle has been sitting for eight hours or more with the
engine
off and is used only as a reference.
Let the engine run at idle for five minutes
if outside temperatures are 50” F ( 1 OOC)
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 a
90°F (32°C).
weather.
. . .184

Downloaded from www.Manualslib.com manuals search engine cold check, you must perform a hot check
before adding fluid. This will give you a
more accurate reading
of the fluid level.
To check the fluid hot or cold
0
Park your vehicle on a level place.
With the parking brake applied, place
the shift lever in “P” (Park).
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 “P’ (Park).
Let the engine run at idle for three
minutes or more. Then, without shutting off the engine,
Follow these steps:
1. Pull out the dipstick and wipe it with a
clean rag or paper towel.
2. Push it back in all the way, wait three
seconds and then pull
it back out
again.
3. 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
“HOT” area or
cross-hatched area for a hot check.
range, push the dipstick back in all
the way.
4. If the fluid level is in the acceptable
How to Add Fluid
Refer to the Maintenance Schedule to
determine what kind of transmission fluid to use. See “Recommended Fluids and
Lubricants” in the Index.
If the fluid level
is low, add only enough
of the proper fluid to bring the level up
to the cold area for a cold check or the
“HOT” area for a hot check. It doesn’t

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;ake much fluid, generally less than a pint.
Don’t overfill. We recommend you use
mly fluid labeled DEXRON@-111 or
DEXRON@-IIE, because fluids with that
label are made especially for your
automatic transmission. Dama e caused
by fluid other than DEXRON -111 or
DEXRON@-IIE is not covered by your
new vehicle warranty.
0 After adding fluid, recheck the fluid
level as described under “How to
Check.”
obtained, push the dipstick back in all
the way.
D
0 When the correct fluid level is
Manual Transmission Fluid
How to Check:
Because this operation can be difficult,
you may choose to have this done at a
Chevrolet dealership Service Department.
If you do it yourself, be sure to follow all
the instructions here, or you could get a
false reading.
. . .I86
NOTICE:
Too much or too little fluid can
damage your transmission.
Too much
can mean that some of the fluid could
come out and fall on hot engine parts
or exhaust system, starting a fire. Be
sure to get an accurate reading if
you
check your transmission fluid.
:heck the fluid level only when your
mgine is
off, the vehicle is parked on a
eve1 place and the transmission is cool
:nough for you to rest your fingers on
he 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.
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”
in the Index.
1. Remove the filler plug.

Downloaded from www.Manualslib.com manuals search engine 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.
Hydraulic Clutch
The clutch linkage in your vehicle is
self-adjusting. The clutch master cylinder
reservoir is filled with hydraulic clutch
fluid.
It isn’t a good idea to “top
off’ your
clutch fluid. 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
Refer to the Maintenance Schedule to
determine how often you should check
the fluid level in your clutch master
cylinder reservoir and for the proper fluid. See
“Owner Checks and Services’’ and
“Recommended Fluids and Lubricants”
in the Index.
How to Check and Add Fluid
The clutch master cylinder is under the
Engine Control Module
(ECM) in the left
rear area of the engine compartment.
To check the fluid, look at the area
between the
ECM and the battery.
To add fluid, remove the ECM unit.
187 ...

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Remove the nut on the outboard side
of the unit. Then loosen the front and
inboard nuts. For the LT5 engine, loosen
the two inboard nuts. Move the ECM unit
to either side.
Fluid should be added if the fluid level
is at or below the “ADD” mark on the
reservoir. There are additional instructions
on the reservoir cap.
When returning the ECM to its proper
position, make sure the bolts are aligned
with the slots in the bracket. Then gently
push down on the unit. When replacing
the unit, be careful not to over-tighten the
nuts -just tighten them until they are
snug.
. . * 188
Rear Axle
When to Check Lubricant
Refer to the Maintenance Schedule
to determine how often to check the
lubricant. See “Periodic Maintenance
Inspections” in the Index.
How to Check Lubricant
If the level is below the bottom of the
filler plug hole, you’ll need to add some
lubricant. Add enough lubricant to raise
the level to the bottom of the filler plug
hole.
What to Use:
To add lubricant when the level is low, use
Axle Lubricant (GM Part
No. 12345977)
or
SAE 8OW-90 GL-5 gear lubricant.
To completely refill after draining,
add 4 ounces (1 18 ml) of Limited-Slip
Differential Lubricant Additive (GM Part
No. 1052358). Then fill to the bottom of
the filler plug hole with Axle Lubricant
(GM Part
No. 12345977) or SAE 8OW-90
GL-5 gear lubricant.
Engine Coolant
The following explains your cooling
system and how to add coolant when
it
is low. If you have a problem with
engine overheating or
if you need to add
coolant to your high fill reservoir, see
“Engine Overheating” in the Index.
The proper coolant for your Corvette will:
0
0
0
0
0
Give freezing protection down to -34°F (-37°C).
Give boiling protection up to 262°F
(128°C).
Protect against rust and corrosion.
Help keep the proper engine
temperature.
Let the warning lights work as they
should.

Downloaded from www.Manualslib.com manuals search engine What to Use:
Use a mixture of one-half clean water
(preferably distilled) and one-half
antifreeze that meets “GM Specification
1825-M,” which won’t damage aluminum
parts.
You can also use a recycled coolant
conforming to GM Specification 1825-M
with a complete coolant flush and refill.
If you use this mixture, you don’t need to
add anything else.
NOTICE:
If you use an improper coolant mix,
your engine could overheat and be
badly damaged. The repair cost wouldn’t be covered by your
warranty.
Too much water in the mix
can freeze and crack the engine,
radiator, heater core and other parts.
Adding Coolant
I’o Check Coolant When your engine is
;old, check the dipstick on the cap of the
;oolant recovery tank. The coolant level
should be at “COLD,” or a little higher.
When your engine is warm, the level on
the dipstick should be up to “HOT,” or a
little higher.
Your Corvette also has a coolant high fill
reservoir located at the right rear of the
engine compartment.
189 ...