2003 GMC SONOMA check oil

Notice:Yourvehicle was not designed for fuel that
contains methanol. Don’t use fuel containing
methanol. It can corrode metal parts in your fuel
system and also damage the plastic and rubber parts.
That damage wouldn’t be covered under your
warranty.
Some gasolines that are not reformulated for low
emissions may contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. General Motors does
not recommend the use of such gasolines. Fuels
containing MMT can reduce the life of spark plugs and
the performance of the emission control system may
be affected. The malfunction indicator lamp may turn on.
If this occurs, return to your authorized GM dealer for
service.
Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel may be hard
tofind. Never use leaded gasoline or any other fuel
not recommended in the previous text on fuel. Costly
repairs caused by use of improper fuel wouldn’tbe
covered by your warranty.
To check the fuel availability, ask an auto club, or
contact a major oil company that does business in the
country where you’ll be driving.
Filling Your Tank
{CAUTION:
Fuel vapor is highly ammable. It burns
violently, and that can cause very bad injuries.
Don’t smoke if you’re near fuel or refueling
your vehicle. Keep sparks, ames and smoking
materials away from fuel.
The fuel cap is located behind a hinged door on the
driver’s side of your vehicle.
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2003 - Sonoma OM

Filling a Portable Fuel Container
{CAUTION:
Neverll a portable fuel container while it is in
your vehicle. Static electricity discharge from
the container can ignite the gasoline vapor.
You can be badly burned and your vehicle
damaged if this occurs. To help avoid injury
to you and others:
Dispense gasoline only into approved
containers.
Do notll a container while it is inside a
vehicle, in a vehicle’s trunk, pickup bed or
on any surface other than the ground.
Bring thell nozzle in contact with the
inside of thell opening before operating
the nozzle. Contact should be maintained
until thelling is complete.
Don’t smoke while pumping gasoline.
Checking Things Under
the Hood
{CAUTION:
Things that burn can get on hot engine parts
and start are. These include liquids like fuel,
oil, coolant, brakeuid, windshield washer and
otheruids, and plastic or rubber. You or
others could be burned. Be careful not to drop
or spill things that will burn onto a hot engine.
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2003 - Sonoma OM

Engine Oil
Checking Engine Oil
It’s 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 on the
“VORTEC™”4300 V6
engine is a yellow ring.
SeeEngine Compartment Overview on page 5-10for
more information on location.
Turn off the engine and give the oil several minutes to
drain back into the oil pan. If you don’t, the oil
dipstick might not show the actual level.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’ll need to
add at least one quart of oil. But you must use the
right kind. This part explains what kind of oil to use.
For engine oil crankcase capacity, seeCapacities and
Specifications on page 5-94.
Notice:Don’t 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.
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2003 - Sonoma OM

Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmissionfluid
level is when the engine oil is changed.
Change both thefluid andfilter 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 thefluid andfilter every
50,000 miles (83 000 km).
SeePart A: Scheduled Maintenance Services
on page 6-4.
How to Check
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 littleuid can damage
your transmission. Too much can mean that some
of theuid could come out and fall on hot engine
part or exhaust system parts, starting are.
Too littleuid could cause the transmission to
overheat. Be sure to get an accurate reading if you
check your transmissionuid.
Wait at least 30 minutes before checking the
transmissionfluid 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, thefluid should be at normal
operating temperature, which is 180°Fto200°F
(82°Cto93°C)
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2003 - Sonoma OM

Manual Transmission Fluid
When to Check
A good time to have it checked is when the engine oil is
changed. However, thefluid 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 littleuid can damage
your transmission. Too much can mean that some
of theuid could come out and fall on hot engine
part or exhaust system parts, starting are.
Too littleuid could cause the transmission to
overheat. Be sure to get an accurate reading if
you check your transmissionuid.
Check thefluid 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 yourfingers on the
transmission case.Then, follow these steps:
1. Remove thefiller plug.
2. Check that the lubricant level is up to the bottom of
thefiller plug hole.
3. If thefluid level is good, install the plug and be sure
it is fully seated. If thefluid level is low, add more
fluid as described in the next steps.
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2003 - Sonoma OM

How to Check and Add Fluid
The properfluid should be added if the level does not
reach the bottom of the diaphragm when it’s in place
in the reservoir. See the instructions on the
reservoir cap.
Engine Coolant
The cooling system in your vehicle isfilled 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 occursfirst, 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, seeEngine Overheating
on page 5-28.A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
•Give freezing protection down to−34°F(−37°C).
•Give boiling protection up to 265°F (129°C).
•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 occursrst.
Damage caused by the use of coolant other
than DEX-COOL
®is not covered by your new
vehicle warranty.
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2003 - Sonoma OM

What to Use
Use a mixture of one-halfclean, drinkable waterand
one-half DEX-COOL®coolant which won’t damage
aluminum parts. If you use this coolant mixture,
you don’t need to add anything else.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle’s coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you wouldn’t get the overheat warning.
Your engine could catchre and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and the proper coolant.
Notice:If you use an improper coolant mixture, your
engine could overheat and be badly damaged. The
repair cost wouldn’t be covered by your warranty.
Too much water in the mixture 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.
Checking Coolant
The coolant recovery tank is located in the engine
compartment near the passenger side of the vehicle.
SeeEngine Compartment Overview on page 5-10
for more information on location.
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2003 - Sonoma OM

Checking Brake Fluid
You can check the brakefluid without taking off the cap.
Just look at the brakefluid
reservoir. Thefluid level
should be above MIN.
If it isn’t have your brake
system checked to
see if there is a leak.
After work is done on the brake hydraulic system,
make sure the level is above the MIN but not over the
MAX mark.
What to Add
When you do need brakefluid, use only DOT-3 brake
fluid. Use new brakefluid from a sealed container
only. SeePart D: Recommended Fluids and Lubricants
on page 6-33.Always clean the brakefluid reservoir cap and the area
around the cap before removing it. This will help
keep dirt from entering the reservoir.
{CAUTION:
With the wrong kind ofuid in your brake
system, your brakes may not work well, or they
may not even work at all. This could cause a
crash. Always use the proper brakeuid.
Notice:
Using the wronguid can badly damage brake
system parts. For example, just a few drops of
mineral-based oil, such as engine oil, in your
brake system can damage brake system
parts so badly that they’ll have to be replaced.
Don’t let someone put in the wrong kind ofuid.
If you spill brakeuid on your vehicle’s painted
surfaces, the paintnish can be damaged. Be
careful not to spill brakeuid on your vehicle.
If you do, wash it off immediately. See
“Appearance Care”in the Index.
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2003 - Sonoma OM