1999 GMC SONOMA oil change

5-25
6. Remove any rust or dirt
from the wheel bolts,
mounting surfaces and
spare wheel.
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.
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.
7. Place the spare on the wheel mounting surface.
8. Put the nuts on by
hand. Make sure
the cone
-shaped
end is toward
the wheel.

6-15 What Kind of Engine Oil to Use
Oils recommended for your vehicle can be identified by
looking for the starburst symbol.
This symbol indicates that the oil has been certified by
the American Petroleum Institute (API). Do not use any
oil which does not carry this starburst symbol.
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:

6-16
As shown in the chart, SAE 5W-30 is best for your
vehicle. However, you can use SAE 10W
-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.
NOTICE:
Use only engine oil with the American Petroleum
Institute Certified For Gasoline Engines
starburst symbol. Failure to use the
recommended oil can result in engine damage not
covered by your warranty.
GM Goodwrench oil meets all the requirements for
your vehicle.
If you are in an area where the temperature falls below
-20F (-29C), consider using either an SAE 5W-30
synthetic oil or an SAE 0W
-30 oil. Both will provide
easier cold starting and better protection for your engine
at extremely low temperatures.
Engine Oil Additives
Don't add anything to your oil. The recommended oils
with the starburst symbol are all you will need for good
performance and engine protection.
When to Change Engine Oil
If any one of these is true for you, use the short trip/city
maintenance schedule:

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).

Your vehicle has a 2200 L4 (Code 5) flexible fuel
engine and you have used E
-85 ethanol fuel.

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.

6-17
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 trip/highway
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.
Remote Oil Filter (Four
-Wheel Drive)
The access door for the
remote oil filter is in the
steering linkage shield
assembly located under the
radiator support. Twist the
screw to unlock or lock the
door. Make sure if you open
the door, it is securely
closed when you
are finished.
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.

6-19
CAUTION:
Operating the engine with the air cleaner/filter
off can cause you or 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/filter off.
NOTICE:
If the air cleaner/filter 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/filter 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 15,000 miles
(25 000 km) if the vehicle is mainly driven under one or
more of these conditions:

In heavy city traffic where the outside temperature
regularly reaches 90F (32C) or higher.

In hilly or mountainous terrain.

When doing frequent trailer towing.

Uses such as found in taxi, police or delivery service.
If you do not use your vehicle under any of these
conditions, change the fluid and filter every
50,000 miles (83 000 km).
See ªScheduled Maintenance Servicesº in the Index.

6-23
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
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.

6-27
When the differential is cold, add enough lubricant to raise
the level to 1/2 inch (12 mm) below the filler plug hole.
When the differential is at operating temperature
(warm), add enough lubricant to raise the level to the
bottom of the filler plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See ªRecommended Fluids and
Lubricantsº in the Index.
Engine Coolant
The cooling system in your vehicle is filled with
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 ªEngine Overheatingº in the Index.A 50/50 mixture of clean, drinkable water and
DEX
-COOL coolant will:

Give freezing protection down to
-34F (-37C).

Give boiling protection up to 265F (129C).

Protect against rust and corrosion.

Help keep the proper engine temperature.

Let the warning lights and 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.

6-54
Don't use any of these unless this manual says you can.
In many uses, these will damage your vehicle:

Alcohol

Laundry Soap

Bleach

Reducing Agents
Cleaning the Inside of Your Vehicle
Use a vacuum cleaner often to get rid of dust and loose
dirt. Wipe vinyl, leather, plastic and painted surfaces
with a clean, damp cloth.
Cleaning of Fabric and Carpet
Your dealer has two cleaners, Multi-Purpose Interior
Cleaner and Capture Non
-Solvent Dry Spot and
Soil Remover for cleaning fabric and carpet. They will
clean normal spots and stains very well. You can get
GM
-approved cleaning products from your dealer.
(See ªAppearance Care and Materialsº in the Index.)Here are some cleaning tips:

Always read the instructions on the cleaner label.

Clean up stains as soon as you can
-- before they set.

Carefully scrape off any excess stain.

Use a clean cloth or sponge, and change to a clean area
often. A soft brush may be used if stains are stubborn.

If a ring forms on fabric after spot cleaning, clean the
entire area immediately or it will set.
Using Multi-Purpose Interior Cleaner
on Fabric
1. Vacuum and brush the area to remove any loose dirt.
2. Always clean a whole trim panel or section. Mask
surrounding trim along stitch or welt lines.
3. Mix powdered cleaner following the directions on
the container label to form thick suds.
4. Use suds only and apply with a clean sponge.
Don't saturate the material and don't rub it roughly.
5. As soon as you've cleaned the section, use a sponge
to remove the suds.
6. Wipe cleaned area with a clean, damp towel or cloth.
7. Wipe with a clean cloth and let dry.