2007 CHEVROLET TAHOE 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, if necessary,
a lower gear selection if the transmission shifts too
often (e.g., under heavy loads and/or hilly
conditions).
You may also want to activate the tow/haul mode
if the transmission shifts too often. See “Tow/Haul
Mode” earlier in this section for more information.
When towing at high altitude on steep uphill
grades, consider the following: Engine coolant at
higher altitudes will boil at a lower temperature
than at or near sea level. 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 473.
435

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 473.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.
470

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 458for more
information on location.
Engine Overheating
You will nd a coolant temperature gage on your
vehicle’s instrument panel. SeeEngine Coolant
Temperature Gage on page 252.
In addition, you will nd an ENGINE
OVERHEATED STOP ENGINE, ENGINE
OVERHEATED IDLE ENGINE, and an ENGINE
POWER IS REDUCED message in the Driver
Information Center (DIC) on the instrument panel.
SeeDIC Warnings and Messages on page 270.
473

5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
6. Verify coolant level after engine is shut off
and the coolant is cold. If necessary, repeat
coolant ll procedure steps 1 through 6.
Engine Fan Noise
If 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 fan is
spinning slower and the clutch is not fully engaged.
This improves fuel economy and reduces fan
noise. Under heavy vehicle loading, trailer towing,
and/or high outside temperatures, the fan speed
increases as the clutch more fully 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
partially disengages.
If your vehicle has electric cooling fans, you may
hear the fans spinning at low speed during most
everyday driving. The fans may turn off if no cooling
is required. Under heavy vehicle loading, trailer
towing, and/or high outside temperatures, or if you
are operating your air conditioning system, the fans
may change to high speed and you may hear an
increase in fan noise. This is normal and indicates
that the cooling system is functioning properly. The
fans will change to low speed when additional
cooling is no longer required.
483

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
Your vehicle has a low washer uid message in
the DIC that comes on when the washer uid
is low. The message is displayed for 15 seconds
at the start of each ignition cycle. When the
WASHER FLUID LOW ADD FLUID message is
displayed, you will need to add washer uid to the
windshield washer uid reservoir.Open the cap with the
washer symbol on it.
Add washer uid until
the tank is full. See
Engine Compartment
Overview on page 458
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.
485

(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)Check vent hose at transfer case for 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 470 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.
585

Cleaning (cont.)
Weatherstrips........................................... 556
Windshield, Backglass, and
Wiper Blades........................................ 558
Climate Control System............................... 227
Dual Automatic......................................... 231
Outlet Adjustment..................................... 238
Rear Air Conditioning and Heating
System................................................. 239
Rear Air Conditioning and Heating
System, Electronic................................ 240
Clock.........................................291, 292, 293
Collision Damage Repair............................. 610
Comfort Guides, Rear Safety Belt................. 56
Compass............................................162, 166
Content Theft-Deterrent............................... 135
Control of a Vehicle..................................... 360
Coolant
Engine Temperature Gage........................ 252
Heater, Engine......................................... 143
Surge Tank Pressure Cap........................ 473
Cooling System........................................... 477
Cruise Control............................................. 211
Cruise Control Light.................................... 258
Cupholder(s)................................................ 190Customer Assistance Information
Courtesy Transportation........................... 607
Customer Assistance for Text
Telephone (TTY) Users ......................... 602
Customer Assistance Offices.................... 602
Customer Satisfaction Procedure.............. 598
GM Mobility Reimbursement Program...... 603
Reporting Safety Defects to
General Motors..................................... 615
Reporting Safety Defects to the
Canadian Government.......................... 615
Reporting Safety Defects to the
United States Government.................... 615
Roadside Assistance Program.................. 604
Service Publications Ordering
Information........................................... 616
D
Daytime Running Lamps............................. 216
Defensive Driving........................................ 356
Delayed Locking.......................................... 123
Disc, MP3..........................................321, 327
Doing Your Own Service Work.................... 445
622

Dome Lamp Override.................................. 219
Dome Lamps............................................... 219
Door
Delayed Locking...................................... 123
Locks....................................................... 122
Power Door Locks................................... 123
Programmable Automatic Door Locks....... 123
Rear Door Security Locks........................ 124
Driver
Position, Safety Belt................................... 43
Driver Information Center (DIC)................... 260
DIC Operation and Displays............261, 267
DIC Vehicle Customization....................... 280
DIC Warnings and Messages................... 270
Driving
At Night................................................... 389
City.......................................................... 393
Defensive................................................. 356
Drunken................................................... 357
Freeway................................................... 394
Hill and Mountain Roads.......................... 398
In Rain and on Wet Roads...................... 390
Off-Road.................................................. 372
Recovery Hooks....................................... 406
Rocking Your Vehicle to Get it Out.......... 405
Winter...................................................... 400Dual Automatic Climate Control System....... 231
DVD
Rear Seat Entertainment System............. 337
E
Electrical System
Add-On Equipment................................... 563
Center Instrument Panel Fuse Block........ 566
Fuses and Circuit Breakers...................... 564
Instrument Panel Fuse Block................... 565
Power Windows and Other Power
Options................................................. 564
Underhood Fuse Block............................. 567
Windshield Wiper Fuses........................... 564
Engine
Air Cleaner/Filter...................................... 464
Check and Service Engine Soon Light..... 253
Coolant.................................................... 470
Coolant Heater......................................... 143
Coolant Temperature Gage...................... 252
Drive Belt Routing.................................... 593
Engine Compartment Overview................ 458
Exhaust................................................... 160
Fan Noise................................................ 483
Oil ........................................................... 459
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