1999 GMC ENVOY overheating

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2-70 Engine Coolant Temperature Gage
This gage shows the engine
coolant temperature. If the
gage pointer moves into the
red area, your engine is
too hot!
It means that your engine coolant has overheated. If you
have been operating your vehicle under normal driving
conditions, you should pull off the road, stop your
vehicle and turn off the engine as soon as possible.
The ªProblems on the Roadº section of this manual
shows you what to do. See ªEngine Overheatingº in
the Index.
Malfunction Indicator Lamp
(Service Engine Soon Light)
United States Canada
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.
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4-52 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 use THIRD (3) when towing a trailer.
Operating your vehicle in THIRD (3) when towing a
trailer will minimize heat buildup and extend the life of
your transmission.
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.
Parking on Hills
CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People can
be injured, and both your vehicle and the trailer
can be damaged.
But if you ever have to park your rig on a hill, here's
how to do it:
1. Apply your regular brakes, but don't shift into
PARK (P) yet. Then turn your wheels into the curb if
facing downhill or into traffic if facing uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your parking
brake, and then shift into PARK (P).
5. Release the regular brakes.
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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
-7 Towing Your Vehicle
5
-8 Engine Overheating5
-18 Engine Fan Noise
5
-18 If a Tire Goes Flat
5
-19 Changing a Flat Tire
5
-30 If You're Stuck: In Sand, Mud, Ice or Snow
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5-8
Engine Overheating
You will find a coolant temperature gage on your
vehicle's instrument panel. See ªGagesº 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.
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6-21
Radiator Pressure Cap
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.
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.
A 50/50 mixture of clean, drinkable water and
DEX
-COOL coolant will:

Give freezing protection down to
-34F (-37C).

Give boiling protection up to 265F (129C).

Protect against rust and corrosion.

Help keep the proper engine temperature.

Let the warning lights and gages work as
they should.
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6-37
6. Put the blade assembly pivot in the wiper arm hook.
Pull up until the pivot locking tab locks in the
hook slot.
7. Carefully lower the wiper arm and blade assembly
onto the windshield.
Backglass Wiper Blade Replacement
See ªWindshield Wiper Blade Replacementº in this
section for instructions on how to change the backglass
wiper blade. The backglass wiper blade will not lock in
a vertical position like the windshield wiper blade, so
care should be used when pulling it away from
the vehicle.
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.
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9-3
Compact Disc Care 3-27 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Console Mounted CD Changer 3-18 . . . . . . . . . . . . . . . . . . . .
Content Theft-Deterrent 2-11 . . . . . . . . . . . . . . . . . . . . . . . . .
Control of a Vehicle 4-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Convenience Net 2-51 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Convex Outside Mirror 2-45 . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant 5-12, 6-21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant Heater, Engine 2-17 . . . . . . . . . . . . . . . . . . . . . . . . . .
Courtesy Transportation 8-8 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cruise Control 2-37 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Customer Assistance Information 8-1 . . . . . . . . . . . . . . . . . . .
Customer Satisfaction Procedure 8-2 . . . . . . . . . . . . . . . . . . . .
Damage, Finish 6-52 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Damage, Sheet Metal 6-51 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Daytime Running Lamps 2-41 . . . . . . . . . . . . . . . . . . . . . . . . .
Dead Battery 5-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Defects, Reporting Safety 8-10 . . . . . . . . . . . . . . . . . . . . . . . .
Defensive Driving 4-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Defogging 3-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Defrosting 3-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dimensions, Vehicle 6-61 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disabilities, GM Mobility Program for Persons with 8-5 . . . .
Dome Lamps 2-43 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Door Locks 2-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Drive 2-20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Drive Axle Service 7-44 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Driver Information System 2-47 . . . . . . . . . . . . . . . . . . . . . . .
Driver Position 1-12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Driving
City 4
-31 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Defensive 4-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Drunken 4-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Foreign Countries 6
-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Freeway 4-32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Guidelines 4-14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hill and Mountain Roads 4-34 . . . . . . . . . . . . . . . . . . . . . . .
In a Blizzard 4-38 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Night 4-27 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Off-Road 4-15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
On Curves 4-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rainy Conditions 4-28 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Snowy and Icy Conditions 4-36 . . . . . . . . . . . . . . . . . . . . . .
Through Deep Standing Water 4-30 . . . . . . . . . . . . . . . . . . .
Wet Roads 4-28 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Winter 4-36 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
With a Trailer 4-50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Driving On Grades While Towing a Trailer 4-52 . . . . . . . . . . .
Driving Through Water 4-30 . . . . . . . . . . . . . . . . . . . . . . . . . .
Drunken Driving 4-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical Equipment, Adding 3-25, 6-55 . . . . . . . . . . . . . . .
Electrical System 6-54 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrochromic Inside Day/Night Rearview Mirror 2-44 . . . .
Electronic Level Control 4-43 . . . . . . . . . . . . . . . . . . . . . . . . .
Engine 6-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant Heater 2-17 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant Level Check 7-39 . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant Temperature Gage 2-70 . . . . . . . . . . . . . . . . . . . . .
Exhaust 2-30 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fan Noise 5-18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Identification 6-54 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil Level Check 7-39 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overheating 5-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Running While Parked 2-30 . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications 6-61 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starting 2-16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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9-7
OnStar
System 2-57 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Your Vehicle Off Paved Roads 4-15 . . . . . . . . . . . .
Ordering Owner and Service Publications 8-12, 8-13 . . . . . . .
Outside Mirror
Convex 2
-45 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heated 2-45 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Folding 2-46 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Remote Control 2-45 . . . . . . . . . . . . . . . . . . . . . . . . .
Overhead Console 2-46 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overheating Engine 5-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Owner Checks and Services 7-39 . . . . . . . . . . . . . . . . . . . . . . .
Owner Publications 8-12, 8-13 . . . . . . . . . . . . . . . . . . . . . . . .
Paint Spotting, Chemical 6-52 . . . . . . . . . . . . . . . . . . . . . . . .
Park 2-18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shifting Into 2-26 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shifting Out of 2-28 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parking
At Night 2
-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake 2-25 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake Mechanism Check 7-42 . . . . . . . . . . . . . . . . . . . . . . .
Lots 2-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
On Hills with a Trailer 4-52 . . . . . . . . . . . . . . . . . . . . . . . . .
Over Things That Burn 2-29 . . . . . . . . . . . . . . . . . . . . . . . .
Passing 4-12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Passlock
2-12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Payload 4-43 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Periodic Maintenance Inspections 7-43 . . . . . . . . . . . . . . . . . .
Power
Accessory Outlets 2
-57 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Door Locks 2-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Remote Control Mirror 2-45 . . . . . . . . . . . . . . . . . . . . . . . .
Seat 1-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Steering 4
-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steering Fluid 6-24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Windows 2-31 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Folding Mirrors 2-46 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pregnancy, Use of Safety Belts 1-19 . . . . . . . . . . . . . . . . . . . .
Problems on the Road 5-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Publications, Service and Owner 8-12, 8-13 . . . . . . . . . . . . . .
Radiator, Adding Coolant 5-15 . . . . . . . . . . . . . . . . . . . . . . .
Radiator Pressure Cap 6-21 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Radio Reception 3-24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Radios
Cassette Tape Player 3
-8 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cassette Tape Player Care 3-25, 7-39 . . . . . . . . . . . . . . . . .
CD Changer 3-18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Compact Disc Player 3-12 . . . . . . . . . . . . . . . . . . . . . . . . . .
Compact Disc Player Care 3-27 . . . . . . . . . . . . . . . . . . . . . .
Rear Seat Audio 3-16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting the Clock 3-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Theft-Deterrent Feature 3-21 . . . . . . . . . . . . . . . . . . . . . . . .
Rain, Driving 4-28 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RAP 2-15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear
Axle 6
-18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Door Security Locks 2-5 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Safety Belt Comfort Guides 1-31 . . . . . . . . . . . . . . . . . . . . .
Seat Outside Passengers 1-28 . . . . . . . . . . . . . . . . . . . . . . . .
Seats 1-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Window Defogger 3-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Window Washer/Wiper 2-36 . . . . . . . . . . . . . . . . . . . . . . . .
Rear Seat Audio 3-16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rearview Mirror 2-45 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reclining Front Seatbacks 1-5 . . . . . . . . . . . . . . . . . . . . . . . . .
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