overheating GMC YUKON 1999 Owner's Manual

yellowblue
2-76 Engine Coolant Temperature Gage
This gage shows the engine
coolant temperature.
It also provides an indicator of how hard your vehicle is
working. During a majority of the operation, the gage
will read 210
F (100
C) or less. If you are pulling a
load or going up hills, it is normal for the temperature to
fluctuate and approach the 260
F (160
C) mark. If the
gage reaches the 260
F (160
C) mark, it indicates that
the cooling system is working beyond its capacity.
The ªProblems on the Road,º section of this manual
shows what to do. See ªEngine Overheatingº in
the Index.
Malfunction Indicator Lamp
(Service Engine Soon Light)
Your vehicle is equipped
with a computer which
monitors operation of the
fuel, ignition and emission
control systems.
This system is called OBD II (On
-Board
Diagnostics
-Second Generation) and is intended to
assure that emissions are at acceptable levels for the life
of the vehicle, helping to produce a cleaner
environment. The SERVICE ENGINE SOON light
comes on to indicate that there is a problem and service
is required. Malfunctions often will be indicated by the
system before any problem is apparent. This may
prevent more serious damage to your vehicle. This
system is also designed to assist your service technician
in correctly diagnosing any malfunction.

yellowblue
4-51 Making Turns
NOTICE:
Making very sharp turns while trailering could
cause the trailer to come in contact with the
vehicle. Your vehicle could be damaged. Avoid
making very sharp turns while trailering.
When you're turning with a trailer, make wider turns
than normal. Do this so your trailer won't strike soft
shoulders, curbs, road signs, trees or other objects.
Avoid jerky or sudden maneuvers. Signal well
in advance.
Turn Signals When Towing a Trailer
The arrows on your instrument panel will flash
whenever you signal a turn or lane change. Properly
hooked up, the trailer lamps will also flash, telling other
drivers you're about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will flash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind youare seeing your signal when they are not. It's important
to check occasionally to be sure the trailer bulbs are
still working.
Driving On Grades
Reduce speed and shift to a lower gear before you start
down a long or steep downgrade. If you don't shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.
You should tow in AUTOMATIC OVERDRIVE (
).
You may want to shift the transmission to THIRD (3) or,
if necessary, a lower gear selection if the transmission
shifts too often (e.g., under heavy loads and/or
hilly conditions).
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If you turn your
engine off immediately after towing at high altitude on
steep uphill grades, your vehicle may show signs similar to
engine overheating. To avoid this, let the engine run while
parked (preferably on level ground) with the automatic
transmission in PARK (P) for a few minutes before turning
the engine off. If you do get the overheat warning, see
ªEngine Overheatingº in the Index.

5-
yellowblue
5-1
Section 5 Problems On The Road
Here you'll find what to do about some problems that can occur on the road.
5
-2 Hazard Warning Flashers
5
-2 Other Warning Devices
5
-3 Jump Starting
5
-8 Towing Your Vehicle
5
-9 Engine Overheating5
-11 Cooling System
5
-18 Engine Fan Noise
5
-18 If a Tire Goes Flat
5
-19 Changing a Flat Tire
5
-32 If You're Stuck: In Sand, Mud, Ice or Snow

yellowblue
5-9
Engine Overheating
You will find a coolant temperature gage on your
vehicle's instrument panel. See ªEngine Coolant
Temperature Gageº in the Index.
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 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.
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.

yellowblue
6-23
NOTICE:
Your radiator cap is a 15 psi (105 kPa) pressure-type
cap and must be tightly installed to prevent coolant
loss and possible engine damage from overheating.
Be sure the arrows on the cap line up with the
overflow tube on the radiator filler neck.
Thermostat
Engine coolant temperature is controlled by a thermostat
in the engine coolant system. The thermostat stops the
flow of coolant through the radiator until the coolant
reaches a preset temperature.
When you replace your thermostat, an ACDelco


thermostat is recommended.
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.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem with
engine overheating, see ªEngine Overheatingº in
the Index.

yellowblue
6-39
Replacement blades come in different types and are
removed in different ways. For proper type and length,
see ªNormal Maintenance Replacement Partsº in the
Index. Here's how to remove the Shephard's Hook type.
To replace the windshield wiper blade assembly:
1. Lift the wiper arm and rotate the blade until it is
facing away from the windshield.
2. Push the release lever and slide the wiper assembly
toward the driver's side of the vehicle.
3. Install a new blade by reversing Steps 1 and 2.
Tires
Your new vehicle comes with high-quality tires made by
a leading tire manufacturer. If you ever have questions
about your tire warranty and where to obtain service, see
your GMC Warranty booklet for details.
CAUTION:
Poorly maintained and improperly used tires
are dangerous.

Overloading your tires can cause overheating
as a result of too much friction. You could
have an air
-out and a serious accident. See
ªLoading Your Vehicleº in the Index.

Underinflated tires pose the same danger as
overloaded tires. The resulting accident
could cause serious injury. Check all tires
frequently to maintain the recommended
pressure. Tire pressure should be checked
when your tires are cold.

Overinflated tires are more likely to be cut,
punctured or broken by a sudden impact
--
such as when you hit a pothole. Keep tires
at the recommended pressure.

Worn, old tires can cause accidents. If your
tread is badly worn, or if your tires have
been damaged, replace them.

yellowblue
9-4
Electronic Compass 2-51 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine 6-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air Cleaner/Filter 6-15, 6-64 . . . . . . . . . . . . . . . . . . . . . . . .
Coolant 6-23, 7-41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant Heater 2-24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant Level Check 7-35 . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant Temperature Gage 2-76 . . . . . . . . . . . . . . . . . . . . .
Cooling System 6-64 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust 2-36, 4-41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Identification 6-55 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil Level Check 7-35 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overheating 5-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Running While Parked 2-37 . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications 6-63 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starting Your 2-22 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Oil 6-11, 6-65, 7-41 . . . . . . . . . . . . . . . . . . . . . . . . . .
Adding 6-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Additives 6-13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking 6-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Gage 2-79 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Used 6-14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
When to Change 6-14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equipment, Adding to the Outside of Your Vehicle 6-3 . . . . . .
Ethanol 6-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust, Engine 2-36, 4-41 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exit Lighting and Delayed Illumination 2-49 . . . . . . . . . . . . .
Exterior Lamps 2-46 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fabric Cleaning 6-47 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Feature Customization 2-16 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Driver's Door Alarm Delay 2-19 . . . . . . . . . . . . . . . . . . . . .
Keyless Entry Verification 2-17 . . . . . . . . . . . . . . . . . . . . . .
Leaving Programming Mode 2-19 . . . . . . . . . . . . . . . . . . . .
Lockout Prevention 2-17 . . . . . . . . . . . . . . . . . . . . . . . . . . . Theft
-Deterrent Arming Method 2-18 . . . . . . . . . . . . . . . . .
Theft-Deterrent Arming Verification 2-19 . . . . . . . . . . . . . .
Filling a Portable Fuel Container 6-8 . . . . . . . . . . . . . . . . . . . .
Filling Your Tank 6-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Filter, Air Cleaner 6-15, 6-64 . . . . . . . . . . . . . . . . . . . . . . . . .
Filter, Engine Oil 6-14, 6-64 . . . . . . . . . . . . . . . . . . . . . . . . . .
Finish Care 6-51 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Finish Damage 6-53 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
First Gear, Automatic Transmission 2-27 . . . . . . . . . . . . . . . .
Flashers, Hazard Warning 5-2 . . . . . . . . . . . . . . . . . . . . . . . . .
Flat Tire, Changing 5-19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Capacities 6-63 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Leak Check 6-33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluids and Lubricants 7-41 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fog Lamps 2-48, 6-36, 6-61 . . . . . . . . . . . . . . . . . . . . . . . . . .
Folding the Rear Seat 1-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Foreign Countries, Fuel 6-5 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Four-Wheel Drive 2-28, 6-21 . . . . . . . . . . . . . . . . . . . . . . . . .
French Language Manual ii. . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Axle 6
-22, 7-42 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Axle Locking Feature 2-28 . . . . . . . . . . . . . . . . . . . . . . .
Front Park/Turn Signal Bulb Replacement 6-36, 6-61 . . . . . .
Front Sidemarker Lamp Bulb Replacement 6-36, 6-61 . . . . . .
Front Towing 5-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel 6-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Canada 6-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Filling a Portable Container 6-8 . . . . . . . . . . . . . . . . . . . . . .
Filling Your Tank 6-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gage 2-82 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
In Foreign Countries 6-5 . . . . . . . . . . . . . . . . . . . . . . . . . . .
System Capacity 6-64 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuses and Circuit Breakers 6-57 . . . . . . . . . . . . . . . . . . . . . . .

yellowblue
9-7
Mirrors 2-51 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Convex Outside 2
-55 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrochromic Day/Night Rearview with
Compass/Temperature Display/Headlamp Delay 2
-51 . . . . .
Electrochromic Heated Outside Rearview 2-54, 3-7 . . . . . .
Inside Rearview 2-51 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Remote Control 2-54 . . . . . . . . . . . . . . . . . . . . . . . . .
MMT 6-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Model Reference vi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mountain Roads 4
-36 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Multifunction Lever 2-40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Net, Convenience 2-58 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Neutral, Automatic Transmission 2-26 . . . . . . . . . . . . . . . . . .
New Vehicle Break-In 2-20 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Night Vision 4-29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Normal Maintenance Replacement Parts 6-65 . . . . . . . . . . . . .
Odometer 2-71 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Odometer, Trip 2-71 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Off-Road Driving 4-14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Off-Road Recovery 4-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil, Engine 6-11, 6-65, 7-41 . . . . . . . . . . . . . . . . . . . . . . . . . .
OnStar
System 2-67 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overdrive, Automatic Transmission 2-27 . . . . . . . . . . . . . . . .
Overheating Engine 5-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Owner Checks and Services 7-35 . . . . . . . . . . . . . . . . . . . . . . .
Owner Publications, Ordering 8-12, 8-13 . . . . . . . . . . . . . . . .
Paint Spotting, Chemical 6-53 . . . . . . . . . . . . . . . . . . . . . . . .
Park
Automatic Transmission 2
-25 . . . . . . . . . . . . . . . . . . . . . . .
Shifting Into 2-33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shifting Out of 2-35 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parking
At Night 2
-13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake 2-32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake Mechanism Check 7-38 . . . . . . . . . . . . . . . . . . . . . . .
Lots 2-13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Over Things That Burn 2-36 . . . . . . . . . . . . . . . . . . . . . . . .
With a Trailer 4-52 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Passenger Position 1-23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Passing 4-12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Passlock
2-20, 2-80 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Periodic Maintenance Inspections 7-39 . . . . . . . . . . . . . . . . . .
Power
Auxiliary Outlet 2
-62 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Door Locks 2-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lumbar Adjustment 1-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Option Fuses 6-56 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Remote Control Mirror 2-54 . . . . . . . . . . . . . . . . . . . . . . . .
Seat 1-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steering 4-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steering Fluid 6-27, 7-41 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Windows 2-38 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Lumbar Adjustment 1-3 . . . . . . . . . . . . . . . . . . . . . . . .
Pregnancy, Use of Safety Belts 1-22 . . . . . . . . . . . . . . . . . . . .
Problems on the Road 5-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Protecting Exterior Bright Metal Parts 6-52 . . . . . . . . . . . . . . .
Publications, Service and Owner 8-12, 8-13 . . . . . . . . . . . . . .