engine oil GMC YUKON 2008 Owner's Guide

What Kind of Engine Oil to Use
Look for three things:
GM6094M
Your vehicle’s engine requires oil meeting GM
Standard GM6094M. Look for and use only an oil
that meets GM Standard GM6094M.
SAE 5W-30
As shown in the viscosity chart, SAE 5W-30 is best
for your vehicle.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
have the starburst
symbol on the container.
This symbol indicates
that the oil has
been certied by the
American Petroleum
Institute (API).
Look for this information on the oil container, and use
only those oils that are identied as meeting GM
Standard GM6094M and have the starburst symbol on
the front of the oil container.
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.
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 provide easier
cold starting and better protection for the engine at
extremely low temperatures.
5-17

Engine Oil Additives
Do not add anything to the oil. The recommended oils
with the starburst symbol that meet GM Standard
GM6094M are all you 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 lter. This is
based on engine revolutions and engine temperature,
and not on mileage. Based on driving conditions,
the mileage at which an 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 SOON message
will come on. SeeDIC Warnings and Messages on
page 3-64. Change the oil as soon as possible within the
next 600 miles (1 000 km). It is possible that, if youare driving under the best conditions, the oil life system
might not indicate that an oil change is necessary for
over a year. However, the engine oil and lter must be
changed at least once a year and at this time the
system must be reset. Your dealer/retailer has trained
service people who will perform this work using genuine
parts and reset the system. It is also important to
check the oil regularly and keep it at the proper level.
If the system is ever reset accidentally, you must change
the 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
the engine oil and lter based on vehicle use.
Whenever the oil is changed, reset the system so it can
calculate when the next oil change is required. If a
situation occurs where you change the oil prior
to a CHANGE ENGINE OIL SOON message coming
on, reset the system.
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Always reset the engine oil life to 100% after every oil
change. It will not reset itself. To reset the Engine
Oil Life System:
1. Display the OIL LIFE REMAINING on the DIC. If
your vehicle does not have DIC buttons, the
vehicle must be in PARK (P) to access this display.
SeeDIC Operation and Displays (With DIC
Buttons) on page 3-56orDIC Operation and
Displays (Without DIC Buttons) on page 3-61.
2. Press and hold the SET/RESET button on the DIC,
or the trip odometer reset stem if your vehicle does
not have DIC buttons, for more than ve seconds.
The oil life will change to 100%.
If the CHANGE ENGINE OIL SOON message comes
back on when you start your vehicle, the Engine Oil Life
System has not reset. Repeat the procedure.
What to Do with Used Oil
Used engine oil contains certain elements that can 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
lter 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 used oil, ask your
dealer/retailer, a service station, or a local recycling
center for help.
Engine Air Cleaner/Filter
SeeEngine Compartment
Overview on page 5-14for
the location of the
engine air cleaner/lter and
the air lter restriction
indicator, if the vehicle
has one.
5-19

When to Inspect the Engine Air
Cleaner/Filter
If your vehicle has an air lter restriction indicator, it lets
you know when the engine air cleaner/lter needs to
be replaced. On vehicles with a restriction indicator, you
should inspect the air lter restriction indicator at
every oil change and replace the engine air cleaner/lter
when the indicator tells you to.
On vehicles without an air lter restriction indicator,
inspect the air cleaner/lter at the MaintenanceII
intervals and replace it at the rst oil change after each
50,000 mile (80 000 km) interval. SeeScheduled
Maintenance on page 6-4for more information. If you
are driving in dusty/dirty conditions, inspect the lter
at each engine oil change.
How to Inspect the Engine Air
Cleaner/Filter
Vehicles With an Air Filter Restriction
Indicator
Locate the air lter restriction indicator on the engine air
cleaner/lter cover. When the indicator turns black or
is in the red/orange “change” zone, replace the lter and
reset the indicator. See the steps following to replace
the engine air cleaner/lter and to reset the air lter
restriction indicator.
Vehicles Without an Air Filter Restriction
Indicator
To inspect the air cleaner/lter, remove the engine air
cleaner/lter from the vehicle by following Steps 1
through 6. When you have the engine air cleaner/lter
removed, lightly shake it to release loose dust and dirt. If
the engine air cleaner/lter remains caked with dirt, a
new lter is required.
Replacing the Engine Air Cleaner/Filter
and Resetting the Air Filter Restriction
Indicator
1. Locate the air
cleaner/lter assembly.
SeeEngine
Compartment Overview
on page 5-14.
2. Loosen the four screws on the cover of the housing
and lift up the cover.
5-20

Automatic Transmission Fluid
(4-Speed Transmission)
When to Check and Change Automatic
Transmission Fluid
A good time to check your automatic transmission uid
level is when the engine oil is changed.
Change the uid and lter at the intervals listed in
Additional Required Services on page 6-6, and be sure
to use the transmission uid listed inRecommended
Fluids and Lubricants on page 6-13.
How to Check Automatic
Transmission Fluid
Because this operation can be a little difficult, you may
choose to have this done at the dealer/retailer 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
parts 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 uid 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 uid 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 is 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 uid 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 ve minutes if outside temperatures are
50°F (10°C) or more. If it is colder than 50°F (10°C), you
may have to idle the engine longer. Should the uid
level be low during this cold check, you must check the
uid hot before adding uid. Checking the uid hot
will give you a more accurate reading of the uid level.
5-22

Consistency of Readings
Always check the uid level at least twice using the
procedures described. Consistency (repeatable
readings) is important to maintaining proper uid level. If
uid is added, it may take 15 minutes or longer to
obtain an accurate reading because of residual uid
draining down the dipstick tube. If inconsistent readings
persist, check the transmission breather to be sure it
is clean and not clogged. If readings are still
inconsistent, contact your dealer/retailer.
Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst, 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 5-31.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:Using coolant other than DEX-COOL
®may
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at the rst maintenance
service after each 30,000 miles (50 000 km) or
24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
5-28

What to Use
Use a mixture of one-half clean, drinkable water and
one-half DEX-COOL®coolant which will not damage
aluminum parts. If you use this coolant mixture, you do
not 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 would not get the overheat warning.
Your engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.Notice:If you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost would not 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/retailer check your cooling system.
Notice:If you use extra inhibitors and/or additives
in your vehicle’s cooling system, you could
damage your vehicle. Use only the proper mixture
of the engine coolant listed in this manual for
the cooling system. SeeRecommended Fluids and
Lubricants on page 6-13for more information.
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If you get the ENGINE OVERHEATED STOP ENGINE or
the ENGINE OVERHEATED IDLE ENGINE message
with no sign of steam, try this for a minute or so:
1. If the vehicle has an air conditioner and it is on,
turn it off.
2. Turn on the heater to the highest temperature and
at the highest fan speed and open the windows as
necessary.
3. In heavy traffic, let the engine idle in NEUTRAL (N)
while stopped. If it is safe to do so, pull off the road,
shift to PARK (P) or NEUTRAL (N) and let the
engine idle.
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning does not come back on, you can drive
normally.
If the warning continues, pull over, stop, and park your
vehicle immediately.
If there is still no sign of steam and your vehicle has an
engine-driven cooling fan, push down the accelerator
until the engine speed is about twice as fast as normal
idle speed for at least ve minutes while parked.
If there is still no sign of steam and your vehicle has an
electric cooling fan, idle the engine for ve minutes
while parked.If you still have the warning, turn off the engine and get
everyone out of the vehicle until it cools down. Also,
see “Overheated Engine Protection Operating Mode”
later in this section.
You might decide not to lift the hood but to get service
help right away.
Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
ENGINE POWER IS REDUCED message is displayed,
an overheat protection mode which alternates ring
groups of cylinders helps prevent engine damage. In this
mode, you will notice a loss in power and engine
performance. This operating mode allows your vehicle
to be driven to a safe place in an emergency. Driving
extended miles (km) and/or towing a trailer in the
overheat protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any
repair. The engine oil will be severely degraded.
Repair the cause of coolant loss, change the oil and
reset the oil life system. SeeEngine Oil on
page 5-15.
5-33

Cooling System
If your vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
When you decide it is safe to lift the hood, here is what
you will see:
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan(s){CAUTION:
An electric fan under the hood can start up
and injure you even when the engine is not
running. Keep hands, clothing, and tools away
from any underhood electric fan.
If the coolant inside the coolant surge tank is boiling, do
not do anything else until it cools down. If possible,
the vehicle should be parked on a level surface. Check
the coolant level after the system cools down. Some
amount of coolant may be lost due to overheating.
5.3L Engine (4.8L and 6.0L Similar)
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{CAUTION:
Adding only plain water to the cooling system
can be dangerous. Plain water, or some other
liquid such as alcohol, can boil before the
proper coolant mixture will. The vehicle’s
coolant warning system is set for the proper
coolant mixture. With plain water or the wrong
mixture, the engine could get too hot but you
would not get the overheat warning. The
engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.
Notice:In cold weather, water can freeze and crack
the engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.
1. You can remove the
coolant surge tank
pressure cap when the
cooling system,
including the coolant
surge tank pressure
cap and upper radiator
hose, is no longer hot.
Turn the pressure cap slowly counterclockwise
about one full turn. If you hear a hiss, wait for that to
stop. A hiss means there is still some pressure left.
2. Then keep turning the pressure cap slowly, and
remove it.
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