2004 GMC SONOMA Owner's Manual

A. Battery. SeeBattery on page 5-40for more
information.
B. Coolant Recovery Tank. SeeEngine Coolant on
page 5-23for more information.
C. Engine Oil Dipstick. SeeEngine Oil on page 5-13for
more information.
D. Engine Oil Fill. SeeEngine Oil on page 5-13for
more information.
E. Automatic Transmission Dipstick. SeeAutomatic
Transmission Fluid on page 5-19for more
information.
F. Power Steering Reservoir. SeePower Steering Fluid
on page 5-35for more information.
G. Brake Master Cylinder Reservoir. SeeBrakes on
page 5-37for more information.
H. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-18for more information.
I. Engine Compartment Fuse Block. SeeFuses
and Circuit Breakers on page 5-95for more
information.
J. Windshield Washer Fluid Reservoir. SeeWindshield
Washer Fluid on page 5-36for more information.Engine Oil
Checking Engine Oil
It is a good idea to check your engine oil every time you
get fuel. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.
The engine oil dipstick handle is a yellow loop. See
Engine Compartment Overview on page 5-12for
the location of the engine oil dipstick.
Turn off the engine and give the oil several minutes to
drain back into the oil pan. If you do not do this, the
oil dipstick might not show the actual level.
5-13

Pull out the dipstick and clean it with a paper towel or
cloth, then push it back in all the way. Remove it again,
keeping the tip down, and check the level.
When to Add Engine Oil
If the oil is at or below the ADD line, then you will need
to add at least one quart of oil. But you must use the
right kind. This section explains what kind of oil to use.
For engine oil crankcase capacity, seeCapacities
and Specications on page 5-101.
Notice:Do not add too much oil. If your engine has
so much oil that the oil level gets above the
cross-hatched area that shows the proper operating
range, your engine could be damaged.SeeEngine Compartment
Overview on page 5-12for
the location of the
engine oil fill cap.
Be sure to add enough oil to put the level somewhere in
the proper operating range. Push the dipstick all the
way back in when you are through.
What Kind of Engine Oil to Use
Look for two things:
•GM6094M
Your vehicle’s engine requires oil meeting GM
Standard GM6094M. You should look for and use
only an oil that meets GM Standard GM6094M.
5-14

•SAE 5W-30
As shown in the viscosity chart, SAE 5W-30 is best
for your vehicle. However, if it is going to be 0°F
(–18°C) or above and SAE 5W-30 is not available,
you may use SAE 10W-30.
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 information on the oil container,
and useonlythose oils that are identified as meeting
GM Standard GM6094M and have the starburst symbol
on the front of the oil container.
5-15

Notice:Use only engine oil identied as meeting
GM Standard GM6094M and showing the American
Petroleum Institute Certied 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 of extreme cold, where the
temperature falls below−20°F (−29°C), it is
recommended that you use 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
Do not add anything to your oil. The recommended oils
with the starburst symbol that meet GM Standard
GM6094M 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 miles (8 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 frequently tow a trailer or use a carrier on top
of your vehicle.
•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 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 will cause engine oil to
break down slower.
5-16

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.
Turn 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
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
more information on the location of the engine air
cleaner/filter.
When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/filter every 15,000 miles (25 000
km) and replace every 30,000 miles (50 000 km). If
you are driving in dusty/dirty conditions, inspect the filter
at each engine oil change.
How to Inspect the Engine Air
Cleaner/Filter
To remove either engine air cleaner/filter, do the
following:
1. Remove the fasteners that hold the cover on and
remove the cover
2. Lift out the engine air cleaner/filter, if needed.
3. Insert a new air filter. SeeNormal Maintenance
Replacement Parts on page 6-34to determine
which filter to use.
4. Reinstall the engine air cleaner/filter cover. Tighten
the fasteners to hold the cover in place.
5-18

{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.
Automatic Transmission Fluid
When to Check and Change the
Automatic Transmission Fluid
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 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 you do not use your vehicle under any of these
conditions, change the fluid and filter every 50,000 miles
(83 000 km).
SeePart A: Scheduled Maintenance Services on
page 6-4.
5-19

How to Check the Automatic
Transmission Fluid
Because this operation can be a little difficult, you may
choose to have this done at the 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 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.
Wait at least 30 minutes before checking the
transmission fluid level if you have been driving:
•When outside temperatures are above 90°F (32°C).
•At high speed for quite a while.
•In heavy traffic–especially in hot weather.
•While pulling a trailer.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)
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.
A cold fluid check can be made after the vehicle has
been sitting for eight hours or more with the engine off,
but this 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 (10°C), you
may have to idle the engine longer. Should the fluid
level be low during this cold check, you must check the
fluid hot before adding fluid. Checking the fluid hot
will give you a more accurate reading of the fluid level.
5-20