2003 GMC YUKON DENALI cooling

Steam and scalding liquids f I hl 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.
5-30

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 catch fire 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. You can be burned
if you spill coolant on tist
engine parts. Coolant contains ethylene glycol
and
it will burn if the engine parts are hot
enough. Don't
spill coolant on a hot engine.
1. Park the vehicle on a
level surface.
SURGE RESERVOIR
15 PSI
TANK - 105 kPa
D'EXPANSION I
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
(left) about one full turn. If you hear a hiss, wait for
that
to stop. A hiss means there is still some
pressure left.
5-31

4. With the coolant surge tank pressure cap off, start
the engine and let it run until you can feel the upper
radiator hose getting hot. Watch out for the
engine cooling fan.
By this time, the coolant level inside the coolant
surge tank may be lower. If the level
is lower, add
more of the proper mixture to the coolant surge tank
until the level reaches
FULL COLD mark.
5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch
is engaged, the fan spins faster to provide
more air
tu cool the engine. In most everyday driving
conditions, the fan is spinning slower and the clutch is
not fully engaged. This improves fuel economy and
reduces fan noise. Under heavy vehicle loading, trailer
towing and/or high outside temperatures, the fan
speed increases as the clutch more fully engages.
So
you may hear an increase in fan noise. This is
normal and should not be mistaken as the transmission
slipping or making extra shifts. It is merely the cooling
system functioning properly. The fan will slow down
when additional cooling is not required and the clutch
disengages.
You may also hear this fan noise when you start the
engine.
It will go away as the fan clutch partially
disengages.
5-33

Wheel Alignment and Tire Balance
The wheels on your vehicle were aligned and balanced
carefully at the factory
to give you the longest tire life
and best overall performance.
Scheduled wheel alignment and wheel balancing are
not needed. However,
if you notice unusual tire wear or
your vehicle pulling one way or the other, the alignment
may need
to be reset. If you notice your vehicle
vibrating when driving on a smooth road, your wheels
may need
to be rebalanced.
Wheel Replacement
Replace any wheel that is bent, cracked, or badly rusted
or corroded.
If wheel nuts keep coming loose, the
wheel, wheel bolts and wheel nuts should be replaced.
If the wheel leaks air, replace it (except some
aluminum wheels, which can sometimes be repaired).
See your dealer
if any of these conditions exist.
Your dealer will know the kind of wheel you need.
Each new wheel should have the same load-carrying
capacity, diameter, width, offset and be mounted
the same way as the one it replaces.
If you need to replace any of your wheels, wheel bolts
or wheel nuts, replace them only with new
GM
original equipment parts. This way, you will be sure to
have the right wheel, wheel bolts and wheel nuts
for your vehicle. Using the wrong replacement wheels, wheel
bolts or wheel nuts on your vehicle can be
dangerous. It could affect the braking and handling
of your vehicle, make your tires lose
air and make you lose control. You could have
a collision in which you or others could be
injured. Always use the correct wheel, wheel
bolts and wheel nuts for replacement.
Notice: The wrong wheel can also cause problems
with bearing life, brake cooling, speedometer or
odometer calibration, headlamp aim, bumper height,
vehicle ground clearance and
tire clearance to the
body and chassis.
See
Changing a Flat Tire on page 5-63 for more
information.
5-6 1

Capacities and Specifications
Please refer to Part D: Recommended Fluids and Lubricants on page 6-15 for more information.
All capacities are approximate.
Engine Specifications
Engine VIN Code 1 Spark Pluq GaD - I t -
VORTECTM 6000 V8 U I 0.060 inches (1.52 mm)
Capacities and Specifications
Capacities
Application Metric
English
After refill, the level must be rechecked. See Cooling System on page 5-28.
Cooling System 19.0 quarts 18.0 L
After refill, the level must be rechecked. Add enough engine oil so that the fluid is within the proper operating
range. See Engine Oil on page
5-13.
Engine Oil with Filter
Fuel Tank
5.7 L 6.0 quarts
Yukon Denali
Yukon
XL Denali
26.0 gallons
31 .O gallons
98.0 L
117.0 L
5-96

Section 6 Maintenance Schedule
Maintenance Schedule ...................................... 6.2
Introduction
................................................... 6.2
Your Vehicle and the Environment
.................... 6-2
Maintenance Requirements
.............................. 6.2
How This Section is Organized
......................... 6-3
Part A: Scheduled Maintenance Services
........... 6-4
Using Your Maintenance Schedule
.................... 6-4
Scheduled Maintenance
................................... 6-5
Part
B: Owner Checks and Sewices ................ 6-10
At Each Fuel Fill
.......................................... 6-10
At Least Once a Month
................................. 6-10
At Least Twice a Year
................................... 6-10
~~
At Least Once a Year ................................... 6.11
Part C: Periodic Maintenance Inspections
......... 6.14
Steering and Suspension Inspection
................ 6.14
Exhaust System Inspection
............................ 6.14
Fuel System Inspection
.................................. 6.14
Engine Cooling System Inspection
................... 6.14
Drive) Inspection
....................................... 6.14
Brake System Inspection
................................ 6.14
Part D: Recommended Fluids and Lubricants
.... 6.15
Part E: Maintenance Record
........................... 6.17
Transfer Case and Front
Axle (All-Wheel
6- 1

100,000 Miles (166 000 km)
0 Inspect spark plug wires. An Emission Control
ii Repiace spark piugs. An Emission Zoniroi Service.
0 Change automatic transmission fluid and filter if
the vehicle is mainly driven under one or more
of these conditions:
Service.
- 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.
Ll If you haven’t used your vehicle under severe service
conditions listed previously and, therefore, haven’t
changed your automatic transmission fluid, change
both the fluid and filter.
150,000 Miles (240 000 km)
0 Drain, flush and refill cooling system (or every
60 months since last service, whichever occurs first). See
Engine Codant on page 5-22 for what to me.
Inspect hoses. Clean radiator, condenser, pressure
cap and neck. Pressure test the cooling system
and pressure cap. An Emission Control Service.
0 Inspect engine accessory drive belt. An Emission
Control Service.
U Inspect Positive Crankcase Ventilation (PCV) valve.
An Emission Control Service.
6-9

Part C: Periodic Maintenance
Inspections
Listed in this part are inspections and services which
should be performed at least twice a year (for instance,
each spring and fall).
You should let your dealer’s
service department or other qualified service center do
these jobs. Make sure any necessary repairs are
completed at once.
Proper procedures
to perform these services may be
found in a service manual. See Service Publications
Ordering Information on page
7- IO.
Steering and Suspension Inspection
Inspect the front and rear suspension and steering
system for damaged, loose or missing parts, signs of
wear or lack of lubrication. Inspect the power steering
lines and hoses for proper hook-up, binding, leaks,
cracks, chafing, etc.
Exhaust System Inspection
Inspect the complete exhaust system. Inspect the body
near the exhaust system. Look for broken, damaged,
missing or out-of-position parts as well as open seams,
holes, loose connections or other conditions which
could cause a heat build-up in the floor pan or could let
exhaust fumes into the vehicle. See Engine Exhaust
on page 2-29.
Fuel System Inspection
Engine Cooling System Inspection
Inspect the complete fuel system for damage or leaks.
Inspect the hoses and have them replaced
if they
are cracked, swollen or deteriorated. Inspect all pipes,
fittings and clamps; replace as needed. Clean the
outside of the radiator and air conditioning condenser.
To help ensure proper operation, a pressure test of
the cooling system and pressure cap is recommended
at least once a year.
Transfer Case and Front Axle
(All-Wheel Drive) Inspection
Every 12 months, or at engine oil change intervals,
check front axle and transfer case and add lubricant
when necessary.
A fluid loss could indicate a problem.
Check and have it repaired,
if needed. Check vent
hose at transfer case for kinks and proper installation.
Brake System Inspection
Inspect the complete system. Inspect brake lines and
hoses for proper hook-up, binding, leaks, cracks,
chafing, etc. Inspect disc brake pads for wear and rotors
for surface condition. Inspect other brake parts,
including calipers, parking brake, etc. You may need
to
have your brakes inspected more often if your driving
habits or conditions result in frequent braking.
6-1 4