2007 GMC ENVOY DENALI coolant temperature

Turn Signals When Towing a Trailer
The arrows on your instrument panel will
ash whenever you signal a turn or lane change.
Properly hooked up, the trailer lamps will also
ash, telling other drivers you’re about to
turn, change lanes or stop.
When towing a trailer, the arrows on your
instrument panel will ash for turns even if the
bulbs on the trailer are burned out. Thus, you may
think drivers behind you are 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 gearbefore
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 can tow in DRIVE (D). You may want to shift
the transmission to THIRD (3) or a lower gear,
under heavy loads 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, seeEngine Overheating
on page 408.
372

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 inRecommended
Fluids and Lubricants on page 517.
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 408.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
30,000 miles (50 000 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.
405

Add coolant mixture at the recovery tank, but be
careful not to spill it.
{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.
Occasionally check the coolant level in the
radiator. For information on how to add coolant to
the radiator, seeCooling System on page 411.
Radiator 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.
SeeEngine Compartment Overview on page 390
for information on location.
Engine Overheating
You will nd a coolant temperature gage on your
vehicle’s instrument panel. SeeEngine Coolant
Temperature Gage on page 208for more
information.
If your vehicle has a Driver Information Center
(DIC), the display will show an Engine Coolant
Hot/Engine Overheated message. SeeDIC
Warnings and Messages on page 222for more
information.
408

6. Start the engine and let it run until you can
feel the upper radiator hose getting hot.
Watch out for the engine cooling fan.
7. By this time, the coolant level inside the
radiator ller neck may be lower. If the level is
lower, add more of the proper DEX-COOL
®
coolant mixture through the ller neck until the
level reaches the base of the ller neck.8. Then replace the pressure cap. At any time
during this procedure if coolant begins to ow
out of the ller neck, reinstall the pressure
cap. Be sure the pressure cap is hand-tight
and fully seated.
Engine Fan Noise
Your vehicle has a clutched engine cooling fan.
When the clutch is engaged, the fan spins faster to
provide more air to cool the engine. In most
everyday driving conditions the clutch is not
engaged. This improves fuel economy and reduces
fan noise. Under heavy vehicle loading, trailer
towing, and/or high outside temperatures, the fan
speed increases when the clutch engages so
you may hear an increase in fan noise. This is
normal and should not be mistaken as the
transmission slipping or making extra shifts. It is
merely the cooling system functioning properly.
The fan will slow down when additional cooling is
not required and the clutch disengages.
You may also hear this fan noise when you start
the engine. It will go away as the fan clutch
disengages.
416

Windshield Washer Fluid
What to Use
When you need windshield washer uid, be sure
to read the manufacturer’s instructions before
use. If you will be operating your vehicle in an area
where the temperature may fall below freezing,
use a uid that has sufficient protection against
freezing.
Adding Washer Fluid
Open the cap with the
washer symbol on it.
Add washer uid
until the tank is full. See
Engine Compartment
Overview on page 390
for reservoir location.Notice:
When using concentrated washer uid,
follow the manufacturer’s instructions
for adding water.
Do not mix water with ready-to-use washer
uid. Water can cause the solution to
freeze and damage your washer uid tank
and other parts of the washer system.
Also, water does not clean as well
as washer uid.
Fill your washer uid tank only
three-quarters full when it is very cold.
This allows for expansion if freezing
occurs, which could damage the tank if it
is completely full.
Do not use engine coolant (antifreeze) in
your windshield washer. It can damage
your washer system and paint.
418

(e)Make sure the safety belt reminder light and all
your belts, buckles, latch plates, retractors, and
anchorages are working properly. Look for
any other loose or damaged safety belt system
parts. If you see anything that might keep a safety
belt system from doing its job, have it repaired.
Have any torn or frayed safety belts replaced. Also
look for any opened or broken airbag coverings,
and have them repaired or replaced. The
airbag system does not need regular maintenance.
(f)Lubricate all key lock cylinders, hood latch
assembly, secondary latch, pivots, spring anchor,
release pawl, rear compartment hinges, outer
liftgate handle pivot points, rear door detent link,
roller mechanism, liftgate handle pivot points, latch
bolt, fuel door hinge, cargo door hinge, locks,
and folding seat hardware. More frequent
lubrication may be required when exposed to a
corrosive environment. Applying silicone grease on
weatherstrips with a clean cloth will make them
last longer, seal better, and not stick or squeak.
(g)Inspect hoses for cracks, chang, leaks, kinks,
and proper installation.(h)Change automatic transmission uid and lter
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.
(i)Drain, ush, and rell cooling system. This
service can be complex; you should have
your dealer perform this service. See Engine
Coolant on page 405 for what to use. Inspect
hoses. Clean radiator, condenser, pressure cap,
and ller neck. Pressure test the cooling
system and pressure cap.
(j)A uid loss in any vehicle system could indicate
a problem. Have the system inspected and
repaired and the uid level checked. Add uid if
needed.
512

Cleaning (cont.)
Weatherstrips........................................... 485
Windshield, Backglass, and
Wiper Blades........................................ 487
Climate Control System
Dual......................................................... 186
Dual Automatic......................................... 189
Outlet Adjustment..................................... 194
Rear........................................................ 195
Collision Damage Repair............................. 539
Comfort Guides, Rear Safety Belt................. 38
Compass..........................134, 136, 138, 140
Content Theft-Deterrent............................... 110
Control of a Vehicle..................................... 306
Convenience Net......................................... 162
Coolant
Engine Temperature Gage........................ 208
Heater, Engine......................................... 116
Cooling System........................................... 411
Cruise Control............................................. 176
Cruise Control Light.................................... 215
Customer Assistance Information
Courtesy Transportation........................... 535
Customer Assistance for Text Telephone
(TTY) Users.......................................... 530
Customer Assistance Offices.................... 530
Customer Satisfaction Procedure.............. 526Customer Assistance Information (cont.)
GM Mobility Reimbursement Program...... 531
Reporting Safety Defects to
General Motors..................................... 544
Reporting Safety Defects to the
Canadian Government.......................... 544
Reporting Safety Defects to the
United States Government.................... 544
Roadside Assistance Program.................. 532
Service Publications Ordering
Information........................................... 545
D
Daytime Running Lamps............................. 180
Defensive Driving........................................ 302
Delayed Locking.......................................... 102
Disc, MP3................................................... 271
Doing Your Own Service Work.................... 381
Dome Lamp Override.................................. 183
Dome Lamps............................................... 182
Door
Delayed Locking...................................... 102
Locks....................................................... 100
Power Door Locks................................... 101
Programmable Automatic Door Locks....... 102
Rear Door Security Locks........................ 105
550

Driver
Position, Safety Belt................................... 26
Driver Information Center (DIC)................... 218
DIC Operation and Displays..................... 219
DIC Vehicle Customization....................... 229
DIC Warnings and Messages................... 222
Driving
At Night................................................... 334
City.......................................................... 338
Defensive................................................. 302
Drunken................................................... 303
Freeway................................................... 339
Hill and Mountain Roads.......................... 342
In Rain and on Wet Roads...................... 335
Off-Road.................................................. 319
Rocking Your Vehicle to Get it Out.......... 348
Winter...................................................... 344
Dual Automatic Climate Control System....... 189
Dual Climate Control System....................... 186
DVD
Rear Seat Entertainment System............. 280E
Electric Power Management........................ 184
Electrical System
Add-On Equipment................................... 492
Engine Compartment Fuse Block............. 493
Fuses and Circuit Breakers...................... 493
Headlamps............................................... 492
Power Windows and Other Power
Options................................................. 492
Rear Underseat Fuse Block..................... 499
Windshield Wiper Fuses........................... 492
Electronically Controlled Air Suspension
System.................................................... 360
Engine
Air Cleaner/Filter...................................... 400
Battery..................................................... 422
Change Engine Oil Light.......................... 214
Check and Service Engine Soon Light..... 210
Coolant.................................................... 405
Coolant Heater......................................... 116
Coolant Temperature Gage...................... 208
551