engine coolant GMC YUKON XL 2006 User Guide

Filling a Portable Fuel Container
{CAUTION:
Never ll a portable fuel container while it is in
your vehicle. Static electricity discharge from
the container can ignite the gasoline vapor.
You can be badly burned and your vehicle
damaged if this occurs. To help avoid injury
to you and others:
Dispense gasoline only into approved
containers.
Do not ll a container while it is inside a
vehicle, in a vehicle’s trunk, pickup bed,
or on any surface other than the ground.
Bring the ll nozzle in contact with the
inside of the ll opening before operating
the nozzle. Contact should be maintained
until the lling is complete.
Do not smoke while pumping gasoline.
Checking Things Under
the Hood
{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.
{CAUTION:
Things that burn can get on hot engine parts
and start a re. These include liquids like fuel,
oil, coolant, brake uid, windshield washer
and other uids, 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.
5-10

A. Engine Air Cleaner/Filter. SeeEngine
Air Cleaner/Filter on page 5-20.
B. Coolant Surge Tank and Pressure Cap.
SeeCooling System on page 5-30andCoolant
Surge Tank Pressure Cap on page 5-27.
C. Air Filter Restriction Indicator (If Equipped).
SeeEngine Air Cleaner/Filter on page 5-20.
D. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 5-15.
E. Automatic Transmission Dipstick. See “Checking
the Fluid Level” underAutomatic Transmission
Fluid on page 5-22.
F. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-15.
G. Engine Cooling Fan. SeeCooling System
on page 5-30.H. Remote Negative (−) Terminal (GND).
SeeJump Starting on page 5-42.
I. Power Steering Fluid Reservoir. SeePower
Steering Fluid on page 5-36.
J. Remote Positive (+) Terminal. SeeJump Starting
on page 5-42.
K. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-38.
L. Underhood Fuse Block. SeeUnderhood Fuse
Block on page 5-109.
M. Battery. SeeBattery on page 5-41.
N. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield Washer
Fluid on page 5-37.
5-13

A. Engine Air Cleaner/Filter. SeeEngine
Air Cleaner/Filter on page 5-20.
B. Coolant Surge Tank and Pressure Cap.
SeeCooling System on page 5-30andCoolant
Surge Tank Pressure Cap on page 5-27.
C. Air Filter Restriction Indicator (If Equipped).
SeeEngine Air Cleaner/Filter on page 5-20.
D. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 5-15.
E. Automatic Transmission Dipstick. See “Checking
the Fluid Level” underAutomatic Transmission
Fluid on page 5-22.
F. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-15.
G. Engine Cooling Fan. SeeCooling System
on page 5-30.
H. Remote Negative (−) Terminal (GND).
SeeJump Starting on page 5-42.
I. Remote Positive (+) Terminal. SeeJump Starting
on page 5-42.
J. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-36.
K. Brake Master Fluid Reservoir. See “Brake Fluid”
underBrakes on page 5-38.
L. Underhood Fuse Block. SeeUnderhood Fuse
Block on page 5-109.M. Battery. SeeBattery on page 5-41.
N. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield Washer
Fluid on page 5-37.
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 3-56.
You should check your engine oil level regularly; this is
an added reminder.
Checking Engine Oil
It is 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 handle is a yellow loop.
SeeEngine Compartment Overview on page 5-12
for the location of the engine oil dipstick.
1. Turn off the engine and give the oil several minutes
to drain back into the oil pan. 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 cloth, then push it back in all the way. Remove it
again, keeping the tip down, and check the level.
5-15

How to Add Automatic Transmission
Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission uid to use. SeeRecommended
Fluids and Lubricants on page 6-13.
Add uid only after checking the transmission uid
while it is hot. A cold check is used only as a reference.
If the uid level is low, add only enough of the proper
uid to bring the level up to the HOT area for a hot
check. It does not take much uid, generally less than
one pint (0.5 L). Do not overll.
Notice:Use of the incorrect automatic transmission
uid may damage your vehicle, and the damages
may not be covered by your warranty. Always
use the automatic transmission uid listed in
Recommended Fluids and Lubricants on page 6-13.
After adding uid, recheck the uid level as
described under “How to Check Automatic
Transmission Fluid,” earlier in this section.
When the correct uid level is obtained, push the
dipstick back in all the way; then ip the handle
down to lock the dipstick in place.
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 5-28.
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 25,000 miles (41 500 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.
5-25

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 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.
Checking Coolant
The coolant surge tank is located in the engine
compartment on the passenger’s side of the vehicle.
SeeEngine Compartment Overview on page 5-12
for more information on location.
5-26

{CAUTION:
Turning the surge tank pressure 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 your vehicle is equipped with a low coolant sensor
and the LOW COOLANT LEVEL message comes
on and stays on, it means you are low on engine
coolant. See “LOW COOLANT LEVEL” underDIC
Warnings and Messages on page 3-56.
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.
{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.
When replacing the pressure cap, make sure it is
hand-tight and fully seated.
Coolant Surge Tank Pressure Cap
Notice:If the pressure cap is not tightly installed,
coolant loss and possible engine damage may
occur. Be sure the cap is properly and tightly
secured.
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. SeeEngine
Compartment Overview on page 5-12for more
information on location.
5-27

Engine Overheating
You will nd a coolant temperature gage on your
vehicle’s instrument panel. SeeEngine Coolant
Temperature Gage on page 3-43.
In addition, you will nd an ENGINE OVERHEATED,
and a REDUCED ENGINE POWER message in
the Driver Information Center (DIC) on the instrument
panel. SeeDIC Warnings and Messages on page 3-56.
If Steam Is Coming From
Your Engine
{CAUTION:
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
down. Wait until there is no sign of steam or
coolant before you open the hood.
CAUTION: (Continued)
CAUTION: (Continued)
If you keep driving when your engine is
overheated, the liquids in it can catch re.
You or others could be badly burned. Stop
your engine if it overheats, and get out of
the vehicle until the engine is cool.
SeeOverheated Engine Protection Operating
Mode on page 5-30for information on driving
to a safe place in an emergency.
Notice:If your engine catches re because you
keep driving with no coolant, your vehicle can
be badly damaged. The costly repairs would not be
covered by your warranty. SeeOverheated Engine
Protection Operating Mode on page 5-30for
information on driving to a safe place in an
emergency.
5-28

If No Steam Is Coming From
Your Engine
The ENGINE COOLANT HOT message, along with a
low coolant condition, can indicate a serious problem.
If you get an engine overheat warning, but see or
hear no steam, the problem may not be too serious.
Sometimes the engine can get a little too hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer. SeeTowing a Trailer on page 4-60.
If you get the ENGINE COOLANT HOT message with
no sign of steam, try this for a minute or so:
1. If you have an air conditioner and it is on, turn it off.
2. Turn on your heater to full hot 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 right away.
If there is still no sign of steam and your vehicle is
equipped with 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 three minutes
while you are parked.
If there is still no sign of steam and your vehicle is
equipped with an electric cooling fan, idle the engine
for three minutes while you are 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 may decide not to lift the hood but to get service
help right away.
5-29

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 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.
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 Fan8.1L V8 Engines
5-30

A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan
{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. 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.
All Other Engines
5-31