engine overheat GMC YUKON 2003 User Guide

Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmissionfluid
level is when the engine oil is changed.
Change both thefluid andfilter every 50,000 miles
(83 000 km) if the vehicle’s GVWR is over 8,600 or if
the vehicle is mainly driven under one or more of these
conditions:
•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.
If your vehicle’s GVWR is not over 8,600 and you do
not use your vehicle under any of these conditions,
change thefluid andfilter every 100,000 miles
(166 000 km).
SeePart A: Scheduled Maintenance Services on
page 6-4.
How to Check
Because this operation can be a little difficult, you may
choose to have this done at the dealership 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 littleuid can damage
your transmission. Too much can mean that some
of theuid could come out and fall on hot engine
part or exhaust system parts, starting are.
Too littleuid could cause the transmission to
overheat. Be sure to get an accurate reading if you
check your transmissionuid.
Wait at least 30 minutes before checking the
transmissionfluid 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, thefluid should be at normal
operating temperature, which is 180°Fto200°F
(82°Cto93°C).
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Engine Coolant
The cooling system in your vehicle isfilled 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 occursfirst, 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 5-29.
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: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 occursrst.
Damage caused by the use of coolant other
than DEX-COOL
®is not covered by your new vehicle
warranty.
What to Use
Use a mixture of one-halfclean, drinkable waterand
one-half DEX-COOL®coolant which won’t damage
aluminum parts. If you use this coolant mixture,
you don’t need to add anything else.
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2003 - Yukon/Yukon XL

{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 wouldn’t get the overheat warning.
Your engine could catchre 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 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.
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.
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Coolant Surge Tank Pressure Cap
SeeEngine Compartment
Overview on page 5-12for
more information on
location.
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank.
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 Specications”for more
information.
Engine Overheating
You willfind a coolant temperature gage on your
vehicle’s instrument panel. SeeEngine Coolant
Temperature Gage on page 3-46. In addition, you will
find a LOW COOLANT LEVEL, ENGINE OVERHEATED
and a REDUCED ENGINE POWER message in the
DIC on the instrument panel. SeeDriver Information
Center (DIC) on page 3-53.
Overheated Engine Protection
Operating Mode (V8 Engines Only)
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternatesfiring
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.
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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.
If you keep driving when your engine is
overheated, the liquids in it can catchre. 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 catchesre 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.
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If No Steam Is Coming From Your
Engine
An overheat warning, along with a low coolant message,
can indicate a serious problem. SeeLow Coolant
underDIC Warnings and Messages on page 3-64.
If you get an engine overheat warning with no low
coolant message, 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 4-61.
If you get the overheat warning with no sign of steam, try
this for a minute or so:
1. In heavy traffic, let the engine idle in neutral while
stopped. If it is safe to do so, pull off the road. Shift
to park or neutral and let the engine idle.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning doesn’t come back on, you can drive
normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there’s still no sign of steam, you can push down the
accelerator until the engine speed is about twice as
fast as normal idle speed for at least three minutes while
you’re parked. If you still have the warning,turn off
the engine and get everyone out of the vehicleuntil it
cools down. Also, seeOverheated Engine Protection
Operating Modelisted previously in this section.
You may decide not to lift the hood but to get service
help right away.
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The coolant level should
be at or above the FULL
COLD mark. If it isn’t,
you may have a leak at the
pressure cap or in the
radiator hoses, heater
hoses, radiator, water
pump or somewhere else
in the cooling system.
{CAUTION:
Heater and radiator hoses, and other engine
parts, can be very hot. Don’t touch them. If you
do, you can be burned.
Don’t run the engine if there is a leak. If you
run the engine, it could lose all coolant. That
could cause an enginere, and you could be
burned. Get any leakxed before you drive the
vehicle.If there seems to be no leak, start the engine again.
The engine cooling fan speed should increase when idle
speed is doubled by pushing the accelerator pedal
down. If it doesn’t, your vehicle needs service. Turn off
the engine.
Notice:Engine damage from running your engine
without coolant isn’t covered by your warranty.
See“Overheated Engine Protection Operating
Mode”in the Index for information on driving to a
safe place in an emergency.
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 occursrst.
Damage caused by the use of coolant other
than DEX-COOL
®is not covered by your new vehicle
warranty.
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2003 - Yukon/Yukon XL

{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 wouldn’t get the overheat warning.
Your engine could catchre 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. Don’t spill coolant on a hot engine.
1. Park the vehicle on a
level surface. 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.
2. 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.
3. Then keep turning the pressure cap slowly, and
remove it.
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E
Easy Exit Seat...............................................2-60
Electrical System
Add-On Equipment......................................5-97
Fuses and Circuit Breakers...........................5-98
Power Windows and Other Power Options......5-97
Windshield Wiper Fuses...............................5-97
Electrochromic Mirror Operation................2-41, 2-43
Emissions Inspection and Maintenance
Programs...................................................3-50
Engine
Air Cleaner/Filter.........................................5-21
Battery.......................................................5-43
Check and Service Engine Soon Light............3-48
Compartment Overview................................5-12
Coolant......................................................5-26
Coolant Heater............................................2-21
Coolant Temperature Gage...........................3-46
Cooling System Inspection............................6-16
Exhaust.....................................................2-38
Fan Noise..................................................5-37
Oil .............................................................5-16
Overheating................................................5-29
Starting
......................................................2-20
ENGINE COOLANT HOT
.................................3-64
Engine Coolant Level Check
.............................6-11
Engine Hour Meter Display
...............................3-39Engine Oil Additives........................................5-19
Engine Oil Level Check...................................6-11
ENGINE OVERHEATED..................................3-65
Entering or Exiting the Third Row Seats.............. 1-8
Entertainment System
Cleaning the Video Screen..........................3-125
DVD Distortion..........................................3-123
Entry Lighting.................................................3-18
Environmental Concerns..................................4-26
Erasing HomeLink
®Buttons..............................2-53
Exit Lighting...................................................3-18
Express-Down Windows...................................2-15
Extender, Safety Belt.......................................1-43
Exterior Lamps...............................................3-14
F
Filter
Engine Air Cleaner......................................5-21
Finding a PTY Station
(RDS and XM™) .......................3-78, 3-88, 3-101
Finding a Station....................3-73, 3-76, 3-86, 3-99
Finish Care....................................................5-92
Finish Damage...............................................5-94
Fixed Mast Antenna.......................................3-125
Flash-To-Pass.................................................. 3-9
Flat Tire........................................................5-69
Flat Tire, Changing.........................................5-69
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2003 - Yukon/Yukon XL

Mirrors (cont.)
Outside Manual Mirrors................................2-45
Outside Power Camper-Type.........................2-47
Outside Power Foldaway Mirrors....................2-47
Outside Power Mirrors..................................2-46
Model Reference................................................ vi
MyGMLink.com................................................ 7-3
N
New Vehicle Break-In......................................2-18
Normal Maintenance Replacement Parts...........5-109
O
Odometer......................................................3-39
Off-Road Recovery..........................................4-19
Oil
Engine.......................................................5-16
Pressure Gage............................................3-51
OIL PRESSURE LOW .....................................3-65
Older Children, Restraints................................1-44
Online Owner Center........................................ 7-3
OnStar
®Personal Calling.................................2-49
OnStar®Services............................................2-49
OnStar®Steering Wheel Controls......................2-50
OnStar®System.............................................2-48
OnStar®Virtual Advisor....................................2-49
Operating Your All-Wheel-Drive Vehicle Off
Paved Roads..............................................4-22Other Warning Devices...................................... 3-7
Outlet Adjustment...................................3-25, 3-31
Outside
Automatic Dimming Mirror.............................2-47
Camper-Type Mirrors....................................2-46
Convex Mirror.............................................2-48
Curb View Assist Mirrors..............................2-47
Heated Mirrors............................................2-48
Manual Mirrors............................................2-45
Power Foldaway Mirrors...............................2-47
Power Mirrors.............................................2-46
Outside Power Camper-Type Mirror...................2-47
Overheated Engine Protection Operating Mode
(V8 Engines Only).......................................5-29
Owners, Canadian............................................... ii
Owner’s Information........................................7-11
P
Panel Doors...................................................2-13
Park (P)
Shifting Out of............................................2-37
Parking
Brake........................................................2-34
Over Things That Burn.................................2-38
Parking Brake and Automatic Transmission Park
(P) Mechanism Check..................................6-14
Parking on Hills..............................................4-71
Park(P)
Shifting Into................................................2-35
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2003 - Yukon/Yukon XL