Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel (see
“Fuel” in the Index). Poor fuel quality will cause your
engine not to run as efficiently as designed. You
may
notice this as stalling after start-up, stalling when you
put the vehicle into gear, misfiring, hesitation on
acceleration
or stumbling on acceleration. (These
conditions may go away once the engine is warmed up.)
This will be detected by the system and cause the light
to turn
on.
If you experience one or more of these conditions,
change the
fuel brand you use. It will require at least
one full tank
of the proper fuel to turn the light off.
If none of the above steps have made the light turn off,
have your dealer
or qualified service center check the
vehicle. Your dealer has the proper test equipment and
diagnostic tools
to fix any mechanical or electrical
problems that may have developed.
Oil Pressure Gage
The oil pressure gage shows
the engine oil pressure in
psi (pounds per square inch)
when the engine is running.
Canadian vehicles indicate
pressure in kPa
(kilopascals).
Oil pressure may vary
with engine speed, outside
temperature and oil viscosity, but readings above
the
low pressure zone indicate the normal operating range.
A reading in the low pressure zone may be caused by
a dangerously low oil level or some other problem
causing low oil pressure. Check your oil as soon
as possible.
2-75
ProCarManuals.com
Turn Signals When Towing a Trailer
The arrows on your instrument panel will flash
whenever you signal a turn or lane change. Properly
hooked up, the trailer lamps will also flash, telling other
drivers you’re about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will flash for turns even if the bulbs
on the trailer
are burned out. Thus, you may think drivers behind you
are seeing your signal when they are not. It’s important
to check occasionally to be sure the trailer bulbs are
still working.
Driving On Grades
Reduce speed and shift to a lower gear before you start
down a long or steep downgrade. If you don’t shift
down,
you might have to use your brakes so much that
they would get hot and no longer work well.
On
a long uphill grade, shift down and reduce your
speed
to around 45 mph (70 km/h) to reduce the
possibility of engine and transmission overheating. If you have an automatic transmission, you can tow
in
AUTOMATIC OVERDRIVE (a). You
may want to
shift the transmission to THIRD
(3) or, if necessary, a
lower gear selection if the transmission shifts too often
(e.g., under heavy loads and/or hilly conditions).
If you have a manual transmission and you are towing a
trailer, it’s better not to use
FIFTH (5) gear. Just drive in
FOURTH
(4) gear (or, as you need to, a lower gear).
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a
lower temperature than at normal altitudes. If
you turn
your engine off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar to engine overheating.
To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in
PARK (P) (or the
manual transmission out of gear and the parking brake
applied) for a few minutes before turning the engine
off.
If you do get the overheat warning, see “Engine
Overheating”
in the Index.
4-56
ProCarManuals.com
I a CAUTION:
Rust or dirt on the wheel, or on the parts to
which it is fastened, can make the wheel nuts
become loose after
a time. The wheel could come
off and cause an accident. When you change a
wheel, remove any rust or dirt from the places
where the wheel attaches to the vehicle. In an
emergency, you can use a cloth or a paper towel
to do this; but be sure to use a scraper or wire
brush later, if you need to, to get
all the rust or
dirt
off.
b, CAUTION:
Never use oil or grease on studs or nuts. If you
do, the nuts might come loose. Your wheel could
fall
off, causing a serious accident.
6. Replace the wheel nuts
with the rounded end
of the nuts toward the
wheel. Tighten each wheel
nut by hand using
the wheel wrench until
the wheel is held against
the hub.
5-29
ProCarManuals.com
I 1 What Kind of Oil to Use
I NOTICE: I Oils recommended for your vehicle can be identified by
looking
for the “Starbuk” symbol. This symbol
.I
Don’t add too much oil. If your engine has so indicates that the oil has been certified by the American
much oil that the oil level gets above the upper Petroleum Institute (API). Do not use any oil which
mark that shows the proper operating range, does not carry this Starburst symbol.
The engine oil fill cap
for the “VORTEC”
4300,
5000 and 5700 engines are
located on the driver’s side
engine valve cover.
your engine could be damaged.
I
The engine oil fill cap for the “VORTEC” 7400 engine
is located at the front of the engine.
Be sure to fill it enough to put the level somewhere
in
the proper operating range. Push the dipstick all the way
back
in when you’re through. If you
change your own oil,
be sure
you use oil that has
the Starburst symbol on
the
front of the oil container.
If you have your oil changed for you, be sure the oil put
into your engine
is American Petroleum Institute
certified for gasoline engines.
You should also use the proper viscosity oil for your
vehicle, as shown
in the following chart:
ProCarManuals.com
Engine Oil Additives
Don’t add anything to your oil. Your GM dealer is ready
to advise if you think something should be added.
When to Change Engine Oil
If any one of these is true for you, use the short tripkity
maintenance schedule:
0
0
0
0
0
Most trips are less than 5 to 10 miles (8 to 16 km).
This is particularly important when outside
temperatures
are below freezing.
Most trips include extensive idling (such as frequent
driving in stop-and-go traffic).
You operate your vehicle in dusty areas or
off-road frequently.
You frequently tow a trailer.
The vehicle is used for delivery service, police, taxi
or other commercial application.
Driving under these conditions causes engine oil to
break down sooner. If any one of these is true for your
vehicle, then you need to change your oil and filter
every
3,000 miles (5 000 km) or 3 months -- whichever
occurs first. If
none
of them is true, use the long triphighway
maintenance schedule. Change the oil and filter
every
7,500 miles (12 500 km) or 12 months -- whichever
occurs first. Driving
a vehicle with a fully warmed
engine under highway conditions causes engine oil to
break down slower.
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 properly 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.
6-18
ProCarManuals.com
Refer to the Maintenance Schedule to determine when to
replace the air filter. See “Owner Checks and Services”
in
the Index.
Operating the engine with the
air cleaner off
can cause you OF others to be burned. The air
cleaner not only cleans the air,
it stops flame if
the engine backfires.
If it isn’t there, and the
engine backfires, you could be burned. Don’t
drive with it
off, and be careful working on the
engine with the air cleaner
off.
I 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.
Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmission fluid
level is
when the engine oil is changed.
Change both the fluid and filter every
50,000 miles
(83
000 km) if the vehicle’s CVWR is over 8,600 or
if the vehicle is mainly driven under one or more
of
these conditions:
In heavy city traffic where the outside temperature
regularly reaches
90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery service.
If your vehicle’s GVWR is not over
8,600 and you do
not use your vehicle under any
of these conditions, the
fluid and filter do
not require changing.
See “Scheduled Maintenance Services’’
in the Index.
ProCarManuals.com
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 a little difficult, you may
choose to have this done at your
GM 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 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 parts, starting
a fire. Be
sure to get an accurate reading if
you check your
transmission fluid.
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
3. If the fluid level is good, install the plug and be sure
the
filler plug hole.
it
is fully seated. If the fluid level is low, add more
fluid as described
in the next steps.
ProCarManuals.com
If the differential is at operating temperature (warm),
add enough lubricant to raise the level to the bottom of
the filler plug hole.
If the differential is cold, add enough lubricant to raise
the level to 1/2 inch (12 mm) below the filler plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See “Recommended Fluids and
Lubricants” in the Index.
Engine Coolant
The cooling system in your vehicle is filled with
new DEX-COOL@ engine coolant. This coolant is
designed to remain in your vehicle for
5 years or
150,000 miles (240
000 km), whichever occurs first,
if
you add only DEX-COOL@ extended life coolant.
The following explains your cooling system and how to
add coolant when
it is low. If you have a problem with
engine overheating, see “Engine Overheating” in
the Index.
A 50/50 mixture of water and the proper coolant for
your vehicle will:
0 Give freezing protection down to -34°F (-37°C).
0 Give boiling protection up to 265 “F (1 29°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
0 Let the warning gages work as they should.
NOTICE:
When adding coolant, it is important that you use
only
DEX-COOL@(silicate-free) coolant.
If coolant other than DEX-COOL@ is added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the
engine coolant will require change sooner
-- at
30,000 miles (50 000 km) or 24 months,
whichever occurs first. Damage caused by the use
of coolant other than DEX-COOL@ is not
covered by your new vehicle warranty.
ProCarManuals.com