1997 GMC SIERRA engine

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

Air Cleaner (Gasoline Engines)
Your air cleaner is located between the battery and
coolant recovery tank. The
air cleaner assembly
has an indicator that lets
you know when the air filter
is dirty and needs to be
serviced. The indicator
is
located in the air intake
tube between the air cleaner
and the engine.
See “Owner Checks and Services” in the Index to
determine when to check the indicator.
If the area inside the clear section of the indicator is
green, no air filter service is required. When the area
inside the indicator is orange and
CHANGE AIR
FILTER appears, the filter should be replaced.
6-19
..
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

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 on the dipstick.
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.
Wait at least 30 minutes before checking the
transmission fluid level if you have been driving:
0 When outside temperatures are above 90°F (32°C).
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).
Checking 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 THIRD (3) until the engine temperature gage
moves and then remains steady for 10 minutes. Then
follow
the hot check procedures.
Checking 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
( 10°C) or
more. If it's colder than
50°F (lO"C), you may have
to idle the engine longer. Should the fluid level be low
during a cold check,
you must perform a hot check
before adding fluid. This will give you a more accurate
reading
of the fluid level.
0 At high speed for quite a while.
0 In heavy traffic -- especially in hot weather.
0 While pulling a trailer.
6-22
ProCarManuals.com

Checking the Fluid Hot or Cold
Park your vehicle on a level place. Keep the
engine running.
With the parking brake applied, place the shift lever
in PARK
(P).
0 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). Then, without shutting
off the engine, follow these steps:
0 Let the
engine run at idle for three minutes or more.
1. The red transmission dipstick handle is located at the
rear
of the engine compartment, on the passenger's
side. Flip the handle
up and then 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.
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

What to Use
Use a mixture of one-half clean water (preferably
distilled) and one-half
DEX-COOL’ coolant which
won’t damage aluminum parts.
If you use this mixture,
you don’t need to add anything else.
A CAUTION:
Adding only plain water to your cooling system
can
be dangerous. Plain water, or some other
liquid like alcohol, can boil before the proper
coolant
mix will. Your vehicle’s coolant warning
system is set for the proper coolant
mix. With
plain water or the wrong
mix, your engine could
get too hot but you wouldn’t get the overheat
warning. Your engine could catch fire and you or
others could be burned. Use a
50/50 mix of clean
water and
DEX-COOL@ coolant.
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.
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 don’t have to
add extra inhibitors or additives which claim to
improve the system. These can be harmful.
6-30
ProCarManuals.com