engine coolant CHEVROLET TAHOE 2007 3.G User Guide

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

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

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. 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 the vehicles
engine is overheated, the liquids in it can
catch re. You or others could be badly
burned. Stop your engine if it overheats,
and get out of the vehicle until the engine
is cool.
CAUTION: (Continued)
CAUTION: (Continued)
SeeOverheated Engine Protection
Operating Mode on page 476for
information on driving to a safe place in
an emergency.
Notice:If your engine catches re because
you keep driving with no coolant, your vehicle
can be badly damaged. The costly repairs
would not be covered by your warranty. See
Overheated Engine Protection Operating Mode
on page 476for information on driving to a
safe place in an emergency.
474

If No Steam Is Coming From Your
Engine
The ENGINE OVERHEATED STOP ENGINE or
the ENGINE OVERHEATED IDLE ENGINE
message, along with a low coolant condition, can
indicate a serious problem.
If you get an engine overheat warning, but see or
hear no steam, the problem may not be too
serious. Sometimes the engine can get a little too
hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer. SeeTowing a Trailer on
page 422.If you get the ENGINE OVERHEATED STOP
ENGINE or the ENGINE OVERHEATED IDLE
ENGINE message with no sign of steam, try this
for a minute or so:
1. If you have an air conditioner and it is on, turn
it off.
2. Turn on your heater to full hot at the highest
fan speed and open the windows as
necessary.
3. In heavy traffic, let the engine idle in
NEUTRAL (N) while stopped. If it is safe to do
so, pull off the road, shift to PARK (P) or
NEUTRAL (N) and let the engine idle.
If you no longer have the overheat warning, you
can drive. Just to be safe, drive slower for
about 10 minutes. If the warning does not come
back on, you can drive normally.
If the warning continues, pull over, stop, and park
your vehicle immediately.
475

If there is still no sign of steam and your vehicle is
equipped with an engine-driven cooling fan,
push down the accelerator until the engine speed
is about twice as fast as normal idle speed for
at least ve minutes while you are parked.
If there is still no sign of steam and your vehicle is
equipped with an electric cooling fan, idle the
engine for ve minutes while you are parked.
If you still have the warning, turn off the engine
and get everyone out of the vehicle until it
cools down. Also, see “Overheated Engine
Protection Operating Mode” later in this section.
You may decide not to lift the hood but to get
service help right away.Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is
displayed, an overheat protection mode which
alternates ring groups of cylinders helps prevent
engine damage. In this mode, you will notice a
loss in power and engine performance. This
operating mode allows your vehicle to be driven to
a safe place in an emergency. Driving extended
miles (km) and/or towing a trailer in the overheat
protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine
damage, allow the engine to cool before
attempting any repair. The engine oil will be
severely degraded. Repair the cause of coolant
loss, change the oil and reset the oil life
system. SeeEngine Oil on page 459.
476