2003 GMC YUKON DENALI engine coolant

Section 5 Service and Appearance Care
Service ............................................................ 5.3
Doing Your Own Service Work
......................... 5-3
Adding Equipment
to the Outside of Your
Vehicle
.................................................. 5-4
................................................................ Fuel 5.5
Gasoline Octane ............................................ 5.5
Gasoline Specifications ................................... 5-5
California Fuel ............................................... 5-6
Additives
....................................................... 5.6
Fuels in Foreign Countries
............................... 5-6
Filling Your Tank
............................................ 5-7
Filling a Portable Fuel Container ....................... 5.9
the Hood .................... , .................... 5.10
Hood Release ...................... ................ 5-10
Engine Compartment Overview ....... ......... 5-12
Engine Oil ....................................... ..... 5.13
Engine Air Cleaner/Filter ............................. 5.17
Automatic Transmission Fluid ......................... 5-20
Engine Coolant ......................................... 5-22
Checking Things Under
~~
Coolant Surge Tank Pressure Cap ............... 5-25
Engine Overheating ....................................... 5-25
Cooling System ............................................ 5.28
Engine Fan Noise ......................................... 5.33
Power Steering Fluid
..................................... 5-34
Windshield Washer Fluid
................................ 5.34
Brakes
........................................................ 5.36
Battery
........................................................ 5-39
Jump Starting
............................................... 5.40
All-Wheel Drive .............................................. 5.46
Rear Axle .................................. .......... 5-48
Bulb Replacement .......................................... 5-49
Halogen Bulbs .............................................. 5-49
Headlamps
.................................................. 5-49
Running Lamps
......................................... 5-50
Center High-Mounted Stoplamp (CHMSL) ......... 5-52
Taillamps ..................................................... 5-52
Replacement Bulbs ................................... 5.53
Front Turn Signal, Sidemarker and Daytime
5- 1

Checking Things Under
the
Hood
- .lings It burn can get c hot engine parts
and start a fire. These include liquids like fuel,
oil, coolant, brake fluid, windshield washer and
other fluids, 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.
Hood Release
To open the hood, do the following:
1. Pull the handle located
inside the vehicle
to
the lower left of
the steering wheel.
5-1 0

A. Engine Air CleanedFilter
B. Coolant Surge Tank
C. Air Filter Restriction Indicator
D. Engine Qii Dipstick
E. Engine Oil Fill
F. Automatic Transmission Dipstick
G. Fan
H. Remote Negative (-) Terminal (GND)
I. Remote Positive (+) Terminal
J. Power Steering Fluid Reservoir (Out of View)
K. Brake Master Cylinder Reservoir
L. Underhood Fuse Block
M. Battery
N. Windshield Washer Fluid Reservoir
Before closing the hood, be sure all filler caps are on
properly. Pull down the hood and close
it firmly.
Engine Oil
If the CHECK OIL LEVEL message appears on the
instrument cluster, it means you need to check
your engine oil level right away.
For more information, see “CHECK OIL LEVEL” under
DIC Warnings and Messages on page 3-52.
You should check your engine oil level regularly; this is
an added reminder.
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 has a yellow loop handle and
is located in the engine
compartment on the
passenger’s side of the
vehicle. See Engine
Compartment Overview on
page
5- 12 for 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.
5-1 3

See Engine Compartment Overview on page 5-12 for
more information on location.
1. Flip the handle up and then pull out the dipstick
and wipe it with a clean rag or paper towel.
2. Push it back in all the way, wait three seconds and
then pull it back out again.
3. Check both sides of the dipstick, and read the lower
level. The fluid level must be in the COLD area,
below the cross-hatched area, for a cold check or in
the HOT area or cross-hatched area for a
hot check.
4. If the fluid level is in the acceptable range, push the
dipstick back in all the way; then flip the handle
down
to lock the dipstick in place.
How to Add Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission fluid
to use. See Part D:
Recommended Fluids and Lubricants on page 6-15.
Add fluid only after checking the transmission fluid while
it is hot. (A cold check is used only as
a reference.) If
the fluid level is low, add only enough of the proper fluid
to bring the level up to the HOT area for a hot check.
It doesn't take much fluid, generally less than one
pint (0.5 L). Don't overfill.
Notice: We recommend you use only fluid labeled
DEXRON@
-111, because fluid with that label is
made especially for your automatic transmission.
Damage caused by fluid other than DEXRON@
-111 is
not covered by your new vehicle warranty.
After adding fluid, recheck the fluid level as
described under How to Check.
When the correct fluid level is obtained, push the
dipstick back in all the way; then flip the handle
down
to lock the dipstick in place.
Engine Coolant
The cooling system in your vehicle is filled 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 occurs first, if you add
only DEX-COOL@ extended life coolant.
5-22

The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, see Engine Overheating
on
page 5-25.
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.
e 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 occurs first.
Damage caused by the use of coolant other than
DEX-COQL.@ is not covered by your new vehicle
warranty.
What to Use
Use a mixture of one-half clean, drinkable water and
one-half DEX-COOL@ coolant which won’t damage
aluminum parts.
!f YOU uss this coolant mixture,
you don’t need
to add anything else.
Adding c..ly
c 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-COQL@ 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.
5-23

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 surge tank is
located in the engine
compartment on the
passenger’s side of the
vehicle.
.
1 ~ ---lg the surge tanl- ,xessure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you badly. Never turn the surge tank pressure
cap
- even a little - when the engine and
radiator are hot.
The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at the FULL
COLD mark.
If the LOW COOLANT
LEVEL message comes on and
stays on, it means you’re low on engine coolant.
See “Low Coolant Level” under
DIC Warnings and
Messages on page
3-52.
See Engine Compartment Overview on page 5-12 for
more information on location.
5-24

Adding Coolant
If you need more coolant, add the proper DEX-COOL@
coolant mixture
at the surge tank, but only when the
engine
is cool.
1 “J can be burned if you sb... coolant on hot
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.
When replacing the pressure cap, make sure it is
hand-tight.
Coolant Surge Tank Pressure Cap
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. See Engine
Compartment Overview on page
5-12 for more
information on location.
Notice: Your pressure cap is a pressure-type cap
and must be tightly installed to prevent coolant
loss
and possible engine damage from overheating.
See “Capacities and Specifications” for more
information.
Engine Overheating
You will find a coolant temperature gage on your
vehicle’s instrument panel. See Engine Coolant
Temperature Gage
on page 3-36. in addition, yoti ill
find a LOW COOLANT, ENGINE COOLANT HOT,
ENGINE OVERHEATED and a REDUCED ENGINE
POWER message in the DIC on the instrument panel.
See DIC Warnings and Messages on page
3-52.
Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternates firing
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. See “Engine Oil” in the Index.
5-25

If Steam Is Coming From Your Engine
L
Steam from an overheated engine can burn
you badly, even if you just open the hood. Stay
away from the engine if you see or hear steam
coming from
it. Just turn it off and get
everyone away from the vehicle until
it cools
CAUTION: (Continued) down. Wait until there
is no sign of steam or
coolant before you open the hood.
If you
keep driving when your engine is
overheated, the liquids in it can catch fire. You
or others could be badly burned. Stop your
engine if
it overheats, and get out of the
vehicle until the engine is cool.
See “Overheated Engine Protection Operating
Mode” in the Index for information on driving
to a safe place
in an emergency.
Notice: If your engine catches fire because you
keep driving with no coolant, your vehicle can
be badly damaged. The costly repairs would not be
covered by your warranty. See “Overheated
Engine Protection Operating Mode” in the Index for
information on driving to a safe place in an
emergency.
5-26