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5. For van models, in order to drain the water from the
system, you will have to repeat the operation for the
primary and secondary fuel filters.6. Remove the fuel-resistant container and properly
dispose of the contaminated fuel. To find out how
to properly dispose of contaminated diesel fuel,
see “What to Do With Used Oil” underEngine Oil
on page 5-21.
7. Install the fuel cap.
8. For pickup models, start the engine and let it run for a
few minutes. If the engine stalls, the fuel system may
need to be primed. While draining the water from the
fuel filter, air may enter the fuel system. If air has
entered the fuel system the fuel system will need to
be primed. For van models, start the engine and let it
run for a few minutes.
If the WATER IN FUEL message/warning light comes
on again after driving a short distance or the engine runs
rough or stalls, a large amount of water has probably
been pumped into the fuel tank. The fuel tank should
be purged.
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A. Engine Air Cleaner/Filter
B. Coolant Surge Tank
C. Battery
D. Engine Air Cleaner/Filter Restriction Indicator
(If Equipped)
E. Engine Oil Dipstick
F. Automatic Transmission Dipstick (If Equipped)
G. Engine Oil Fill CapH. Engine Fan
I. Power Steering Fluid Reservoir
J. Remote Negative (−) Terminal
K. Remote Positive (+) Terminal
L. Brake Fluid Reservoir
M. Clutch Fluid Reservoir (If Equipped)
N. Underhood Fuse Block
O. Windshield Washer Fluid Reservoir
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Page 45 of 100

A. Battery
B. Coolant Surge Tank
C. Automatic Transmission Dipstick
D. Engine Fan
E. Engine Air Cleaner/Filter
F. Engine Oil Fill Cap
G. Power Steering Fluid Reservoir
H. Brake Fluid Reservoir
I. Windshield Washer Fluid Reservoir
Engine Oil
Checking Engine Oil
It is a good idea to check your engine oil level every
time you get fuel.
The engine oil dipstick handle is a yellow loop.
SeeEngine Compartment Overview on page 5-18
for the location of the engine oil dipstick.In order to get an accurate reading, the oil must be
warm, at normal operating temperature, and the vehicle
must be on level ground.
1. Turn off the engine and give the oil at least
five minutes to drain back into the oil pan. With a
cool engine, allow 30 minutes. If you do not do this,
the oil dipstick might not show the actual level.
2. Pull out the dipstick and clean it with a paper towel
or a cloth, then push it back in all the way. Remove
it again, keeping the tip down.
When to Add Engine Oil
If the oil is below the cross-hatched area at the tip of the
dipstick, you will need to add at least two quarts/liters of
oil. But you must use the right kind. This section explains
what kind of oil to use. For engine oil crankcase capacity,
seeSpeci cation Charts on page 5-50.
Notice:Do not add too much oil. If the engine
has so much oil that the oil level gets above the
cross-hatched area that shows the proper operating
range, the engine could be damaged.
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SeeEngine Compartment
Overview on page 5-18for
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 these two things:
•CI-4 or CH-4
Oils designated as API CI-4 or CH-4 are
recommended for your vehicle. The CI-4 or CH-4
designations may appear either alone, together, or
in combination with other API designations, such
as API CI-4/SL.
These letters show American Petroleum
Institute (API) levels of quality.
Notice:Use only engine oils that have one of these
designations CI-4 or CH-4 for the DURAMAX
®diesel
engine. Failure to use the recommended oils can
result in engine damage not covered by your
warranty.
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•SAE 15W-40
As shown in the viscosity chart, SAE 15W-40 is
best for your vehicle. However, you can use
SAE 10W-30 at temperatures above 0°F (−18°C).
When it is very cold, below 0°F (−18°C), you should
use SAE 5W-40 to improve cold starting. 5W-40
is not recommended for use at high temperatures,
above 100°F (38°C).
These numbers on the oil container show its
viscosity, or thickness. Do not use other viscosity
oils such as SAE 10W-40 or SAE 20W-50.
This doughnut-shaped logo
(symbol) is used on most
oil containers to help you
select the correct oil. It
means that the oil has been
certified by the American
Petroleum Institute.
You should look for this on the oil container, and use
onlythose oils that display this logo.
GM Goodwrench
®oil of the recommended viscosity
grades meets all the requirements for your vehicle.
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Engine Oil Additives
Do not add anything to your oil. The recommended oils
with the API service symbol are all you will need for
good performance and engine protection.
Engine Oil Life System
When to Change Engine Oil
Your vehicle has a computer system that lets you know
when to change the engine oil and filter. This is based on
engine timing, engine load, and engine temperature, and
not on mileage. Based on driving conditions, the mileage
at which an engine oil change will be indicated can vary
considerably. For the oil life system to work properly, you
must reset the system every time the oil is changed.
When the system has calculated that oil life has been
diminished, it will indicate that an oil change is necessary.
A CHANGE ENGINE OIL message in pickup models
or a change engine oil light in van models will come on.
Change your oil as soon as possible within the next
600 miles (1 000 km). It is possible that, if you are driving
under the best conditions, the oil life system may not
indicate that an oil change is necessary for over a year.
However, your engine oil and filter must be changed at
least once a year and at this time the system must be
reset. Your dealer has GM-trained service people who
will perform this work using genuine GM parts and reset
the system. It is also important to check your oil regularly
and keep it at the proper level.If the system is ever reset accidentally, you must
change your oil at 3,000 miles (5 000 km) since your
last oil change. Remember to reset the oil life system
whenever the oil is changed.
How to Reset the Engine Oil Life
System
The Engine Oil Life System calculates when to change
your engine oil and filter based on vehicle use. Anytime
your oil is changed, reset the system so it can calculate
when the next oil change is required. If a situation occurs
where you change your oil prior to a CHANGE ENGINE
OIL message (pickup models) or a change engine oil light
(van models) being turned on, reset the system.
To reset the Engine Oil Life System, do the following:
1. Turn the ignition key to RUN with the engine off.
2. Fully press and release the accelerator pedal
three times within five seconds.
Pickup Models: If the OIL LIFE RESET message
flashes for 10 seconds, the system is resetting.
Van Models: If the change engine oil light flashes
for five seconds, the system is reset.
3. Turn the key to LOCK.
If the message or light comes back on when you start
your vehicle, the engine oil life system has not reset.
Repeat the procedure. If it still does not reset, see your
dealer for service.
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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 throw away clothing or rags
containing used engine oil. See the manufacturer’s
warning 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.
Engine Air Cleaner/Filter
Pickup Models
The air cleaner/filter
assembly may have an
air cleaner/filter restriction
indicator that lets you
know when the engine air
cleaner/filter is dirty and
needs to be serviced.
The air cleaner/filter restriction indicator is located on
the air cleaner cover.
When to Inspect
Inspect the air cleaner/filter every 15,000 miles
(25 000 km) and replace the filter if necessary.
How to Inspect
When the restriction indicator turns black, or is in
the red/orange “change” zone, replace the filter and
reset the restriction indicator.
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Automatic Transmission Fluid
When to Check and Change
(Pickup Models)
A good time to check your automatic transmission fluid
level is when the engine oil is changed.
Change both the fluid and filter every 25,000 miles
(41 500 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).
SeeScheduled Maintenance 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 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.
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