2008 GMC YUKON DENALI check oil

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 6-12for more information.
5-24

Cooling System
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{CAUTION:
An electric engine cooling fan under the hood
can start up even when the engine is not
running and can injure you. 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. 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.
5-29

How to Add Coolant to the Coolant
Surge Tank
If you have not found a problem yet, check to see if
coolant is visible in the surge tank. If coolant is visible
but the coolant level is not at or above the FULL COLD
mark, add a 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant at the coolant surge tank, but be
sure the cooling system, including the coolant surge tank
pressure cap, is cool before you do it. SeeEngine
Coolant on page 5-23for more information.
If no coolant is visible in the surge tank, add coolant
as follows:
{CAUTION:
Steam and scalding liquids from a hot cooling
system can blow out and burn you badly. They
are under pressure, and if you turn the radiator
pressure cap — even a little — they can come
out at high speed. Never turn the cap when the
cooling system, including the radiator pressure
cap, is hot. Wait for the cooling system and
radiator pressure cap to cool if you ever have
to turn the pressure cap.
{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.
5-31

Checking Brake Fluid
The brake uid can be checked without taking off the
cap by looking at the brake uid reservoir.
The uid level should be
above MIN. If it is not,
have the brake hydraulic
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 brake uid, use only DOT-3 brake
uid. Use new brake uid from a sealed container
only. SeeRecommended Fluids and Lubricants
on page 6-12.Always clean the brake uid reservoir cap and the area
around the cap before removing it. This helps keep dirt
from entering the reservoir.
{CAUTION:
With the wrong kind of uid in the brake
hydraulic system, the brakes might not work
well. This could cause a crash. Always use the
proper brake uid.
Notice:
Using the wrong uid can badly damage brake
hydraulic system parts. For example, just a few
drops of mineral-based oil, such as engine oil, in
the brake hydraulic system can damage brake
hydraulic system parts so badly that they will
have to be replaced. Do not let someone put in
the wrong kind of uid.
If you spill brake uid on your vehicle’s painted
surfaces, the paint nish can be damaged.
Be careful not to spill brake uid on your vehicle.
If you do, wash it off immediately. SeeWashing
Your Vehicle on page 5-102.
5-37

Spare Tire
Your vehicle, when new, had a fully-inated spare tire.
A spare tire may lose air over time, so check its
ination pressure regularly. SeeInflation - Tire Pressure
on page 5-60andLoading Your Vehicle on page 4-34
for information regarding proper tire ination and loading
your vehicle. For instruction on how to remove, install
or store a spare tire, seeRemoving the Flat Tire and
Installing the Spare Tire on page 5-85andStoring a Flat
or Spare Tire and Tools on page 5-94.
After installing the spare tire on your vehicle, you should
stop as soon as possible and make sure the spare is
correctly inated. The spare tire is made to perform well
at speeds up to 70 mph (112 km/h) at the recommended
ination pressure, so you can nish your trip.
Have the damaged or at road tire repaired or replaced
as soon as you can and installed back onto your
vehicle. This way, a spare tire will be available in case
you need it again. Do not mix tires and wheels of different
sizes, because they will not t. Keep your spare tire and
its wheel together.
Appearance Care
Interior Cleaning
Your vehicle’s interior will continue to look its best if it is
cleaned often. Although not always visible, dust and dirt
can accumulate on your upholstery. Dirt can damage
carpet, fabric, leather, and plastic surfaces. Regular
vacuuming is recommended to remove particles from
your upholstery. It is important to keep your upholstery
from becoming and remaining heavily soiled. Soils should
be removed as quickly as possible. Your vehicle’s interior
may experience extremes of heat that could cause stains
to set rapidly.
Lighter colored interiors may require more frequent
cleaning. Use care because newspapers and garments
that transfer color to your home furnishings may also
transfer color to your vehicle’s interior.
When cleaning your vehicle’s interior, only use cleaners
specically designed for the surfaces being cleaned.
Permanent damage may result from using cleaners on
5-98

Capacities and Specications
The following approximate capacities are given in English and metric conversions. SeeRecommended Fluids and
Lubricants on page 6-12for more information.
ApplicationCapacities
English Metric
Air Conditioning RefrigerantFor the air conditioning system refrigerant charge
amount, see the refrigerant caution label located
under the hood. See your dealer/retailer for more
information.
Cooling System 18.1 qt 17.1 L
Engine Oil with Filter 6.0 qt† 5.7 L†
Fuel Tank
Regular 26.0 gal 98.4 L
Extended 31.5 gal 119.2 L
Transmission Fluid (Pan Removal and Filter Replacement) 6.0 qt 5.7 L
Transfer Case Fluid 1.5 qt 1.4 L
Wheel Nut Torque 140 lbft 190Y
†Oil lter should be changed at every oil change.
After rell, the level must be rechecked. Add enough engine coolant so that the uid is within the proper
operating range.
Engine Specications
Engine VIN Code Transmission Spark Plug Gap
6.2L V8 8 Automatic 0.040 in (1.01 mm)
5-114

Maintenance Schedule
Introduction
Important: Keep engine oil at the proper level and
change as recommended.
Have you purchased the GM Protection Plan? The Plan
supplements your new vehicle warranties. See your
Warranty and Owner Assistance booklet or your
dealer/retailer for details.
Maintenance Requirements
Notice:Maintenance intervals, checks, inspections,
replacement parts, and recommended uids and
lubricants as prescribed in this manual are
necessary to keep your vehicle in good working
condition. Any damage caused by failure to follow
scheduled maintenance might not be covered
by warranty.
Your Vehicle and the Environment
Proper vehicle maintenance not only helps to keep your
vehicle in good working condition, but also helps the
environment. All recommended maintenance is
important. Improper vehicle maintenance can even
affect the quality of the air we breathe. Improper uid
levels or the wrong tire ination can increase the level of
emissions from your vehicle. To help protect our
environment, and to keep your vehicle in good condition,
be sure to maintain your vehicle properly.
Using the Maintenance Schedule
We want to help you keep your vehicle in good working
condition. But we do not know exactly how you will
drive it. You might drive very short distances only a few
times a week. Or you might drive long distances all the
time in very hot, dusty weather. You might use your
vehicle in making deliveries. Or you might drive it to work,
to do errands, or in many other ways.
Because of all the different ways people use their
vehicles, maintenance needs vary. You might need more
frequent checks and replacements. So please read the
following and note how you drive. If you have any
questions on how to keep your vehicle in good condition,
see your dealer/retailer.
6-2

Scheduled Maintenance
When the CHANGE ENGINE OIL SOON message
comes on, it means that service is required for your
vehicle. Have your vehicle serviced 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 engine oil
life system may not indicate that vehicle service 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 technicians who will perform this work
using genuine parts and reset the system.
If the engine oil life system is ever reset accidentally,
you must service your vehicle within 3,000 miles
(5 000 km) since your last service. Remember to reset
the oil life system whenever the oil is changed. See
Engine Oil Life System on page 5-16for information on
the Engine Oil Life System and resetting the system.When the CHANGE ENGINE OIL SOON message
appears, certain services, checks, and inspections are
required. Required services are described in the
following for “MaintenanceI” and “MaintenanceII.”
Generally, it is recommended that your rst service be
MaintenanceI, your second service be MaintenanceII,
and that you alternate MaintenanceIand MaintenanceII
thereafter. However, in some cases, MaintenanceII
may be required more often.
MaintenanceI— Use MaintenanceIif the CHANGE
ENGINE OIL SOON message comes on within
10 months since the vehicle was purchased or
MaintenanceIIwas performed.
MaintenanceII— Use MaintenanceIIif the previous
service performed was MaintenanceI. Always use
MaintenanceIIwhenever the message comes on
10 months or more since the last service or if the
message has not come on at all for one year.
6-4