2007 CHEVROLET TAHOE engine coolant

ENGINE OVERHEATED STOP ENGINE
Notice:If you drive your vehicle while the
engine is overheating, severe engine damage
may occur. If an overheat warning appears on
the instrument panel cluster and/or DIC, stop
the vehicle as soon as possible. SeeEngine
Overheating on page 473for more information.
This message displays and a chime sounds if the
engine cooling system reaches unsafe
temperatures for operation. Stop and turn off the
vehicle as soon as it is safe to do so to avoid
severe damage. This message clears when the
engine has cooled to a safe operating temperature.
ENGINE POWER IS REDUCED
This message displays and a chime sounds when
the cooling system temperature gets too hot
and the engine further enters the engine coolant
protection mode. SeeEngine Overheating on
page 473for further information.This message also displays when the vehicle’s
engine power is reduced. Reduced engine power
can affect the vehicle’s ability to accelerate. If
this message is on, but there is no reduction in
performance, proceed to your destination. The
performance may be reduced the next time the
vehicle is driven. The vehicle may be driven at a
reduced speed while this message is on, but
acceleration and speed may be reduced. Anytime
this message stays on, the vehicle should be taken
to your dealer for service as soon as possible.
FUEL LEVEL LOW
This message displays and a chime sounds if the
fuel level is low. Refuel as soon as possible.
SeeFuel Gage on page 259andFuel on page 446
for more information.
HOOD OPEN
This message displays and a chime sounds if the
hood is not fully closed. Stop and turn off the
vehicle, check the hood for obstructions, and close
the hood again. Check to see if the message
still appears on the DIC.
273

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

Service........................................................ 444
Accessories and Modications................... 444
California Proposition 65 Warning.............. 445
Doing Your Own Service Work.................. 445
Adding Equipment to the Outside of
Your Vehicle.......................................... 446
Fuel............................................................. 446
Gasoline Octane........................................ 447
Gasoline Specications.............................. 447
California Fuel........................................... 447
Additives................................................... 448
Fuel E85 (85% Ethanol)............................ 449
Fuels in Foreign Countries........................ 450
Filling the Tank......................................... 451
Filling a Portable Fuel Container............... 455
Checking Things Under the Hood.............. 456
Hood Release........................................... 457
Engine Compartment Overview.................. 458
Engine Oil................................................. 459
Engine Oil Life System.............................. 462
Engine Air Cleaner/Filter............................ 464
Automatic Transmission Fluid.................... 466
Engine Coolant.......................................... 470Coolant Surge Tank Pressure Cap............ 473
Engine Overheating................................... 473
Overheated Engine Protection
Operating Mode..................................... 476
Cooling System......................................... 477
Engine Fan Noise..................................... 483
Power Steering Fluid ................................. 484
Windshield Washer Fluid........................... 485
Brakes...................................................... 486
Battery...................................................... 490
Jump Starting............................................ 491
Rear Axle.................................................... 496
Four-Wheel Drive........................................ 497
Front Axle................................................... 498
Headlamp Aiming........................................ 499
Bulb Replacement....................................... 502
Halogen Bulbs........................................... 502
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps...................................... 502
License Plate Lamp................................... 504
Replacement Bulbs................................... 504
Section 5 Service and Appearance Care
441

Checking Things Under
the Hood
{CAUTION:
An electric fan under the hood can start up
and injure you even when the engine is not
running. Keep hands, clothing, and tools
away from any underhood electric fan.
{CAUTION:
Things that burn can get on hot engine
parts and start a re. These include
liquids like fuel, oil, coolant, brake uid,
windshield washer and other uids, and
plastic or rubber. You or others could be
burned. Be careful not to drop or spill
things that will burn onto a hot engine.
456

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 464.
B. Air Filter Restriction Indicator (If Equipped).
SeeEngine Air Cleaner/Filter on page 464.
C. Coolant Surge Tank and Pressure Cap.
SeeCooling System on page 477andCoolant
Surge Tank Pressure Cap on page 473.
D. Remote Positive (+) Terminal. SeeJump
Starting on page 491.
E. Battery. SeeBattery on page 490.
F. Engine Oil Fill Cap. See “When to Add Engine
Oil” underEngine Oil on page 459.
G. Automatic Transmission Dipstick. See
“Checking the Fluid Level” underAutomatic
Transmission Fluid on page 466.
H. Remote Negative (−) Terminal (Out of View).
SeeJump Starting on page 491.
I. Engine Oil Dipstick (Out of View). See
“Checking Engine Oil” underEngine Oil on
page 459.
J. Engine Cooling Fan. SeeCooling System on
page 477.
K. Power Steering Fluid Reservoir. SeePower
Steering Fluid on page 484.L. Brake Master Cylinder Reservoir. See “Brake
Fluid” underBrakes on page 486.
M. Underhood Fuse Block. SeeUnderhood Fuse
Block on page 567.
N. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield
Washer Fluid on page 485.
Engine Oil
If the CHECK OIL LEVEL message in the Driver
Information Center (DIC) comes on, check the
engine oil level right away. For more information,
see CHECK OIL LEVEL underDIC Warnings and
Messages on page 270. You should check the
engine oil level regularly; this is an added reminder.
Checking Engine Oil
It is a good idea to check the engine oil every time
you get fuel. In order to get an accurate reading,
the oil must be warm and the vehicle must be
on level ground.
459

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

What to Use
Use a mixture of one-half clean, drinkable water
and one-half DEX-COOL®coolant which will
not damage aluminum parts. If you use this coolant
mixture, you do not need to add anything else.
{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 would
not get the overheat warning. Your engine
could catch re 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 would not 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 extra inhibitors and/or
additives in your vehicle’s cooling system, you
could damage your vehicle. Use only the
proper mixture of the engine coolant listed in
this manual for the cooling system. See
Recommended Fluids and Lubricants on
page 590for more information.
471

Checking Coolant
The coolant surge tank is located in the engine
compartment on the passenger’s side of the
vehicle. SeeEngine Compartment Overview on
page 458for more information on location.
{CAUTION:
Turning the surge tank pressure cap when
the engine and radiator are hot can allow
steam and scalding liquids to blow out
and burn you badly. Never turn the surge
tank pressure cap — even a little — when
the engine and radiator are hot.
The vehicle must be on a level surface. When
your engine is cold, the coolant level should be at
the FULL COLD mark.
Adding Coolant
If you need more coolant, add the proper
DEX-COOL®coolant mixture at the surge tank,
but only when the engine is cool.
{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.
When replacing the pressure cap, make sure it is
hand-tight and fully seated.
472