engine overheat CHEVROLET AVALANCHE 2007 2.G User Guide

Then, shut the engine off and close the window
almost all the way to preserve the heat. Start
the engine again and repeat this only when you
feel really uncomfortable from the cold. But do it as
little as possible. Preserve the fuel as long as
you can. To help keep warm, you can get out of
the vehicle and do some fairly vigorous exercises
every half hour or so until help comes.
If Your Vehicle is Stuck in Sand,
Mud, Ice, or Snow
In order to free your vehicle when it is stuck, you
need to spin the wheels, but you do not want to spin
the wheels too fast. The method known as rocking
can help you get out when you are stuck, but you
must use caution.
{CAUTION:
If you let your vehicle’s tires spin at
high speed, they can explode, and
you or others could be injured.
CAUTION: (Continued)
CAUTION: (Continued)
And, the transmission or other parts of
the vehicle can overheat. That could
cause an engine compartment re or
other damage. When you are stuck, spin
the wheels as little as possible. Do not
spin the wheels above 35 mph (55 km/h)
as shown on the speedometer.
Notice:Spinning the wheels can destroy parts
of your vehicle as well as the tires. If you
spin the wheels too fast while shifting the
transmission back and forth, you can destroy
the transmission.
For information about using tire chains on your
vehicle, seeTire Chains on page 514.
Rocking Your Vehicle to Get It Out
First, turn the steering wheel left and right. That
will clear the area around the front wheels.
If you have a four-wheel-drive vehicle, shift into
Four-Wheel High. Turn the StabiliTrak
®System off.
400

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.
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 460.
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.
2. Have someone place chocks under the trailer
wheels.
424

Service........................................................ 432
Accessories and Modications................... 433
California Proposition 65 Warning.............. 433
Doing Your Own Service Work.................. 434
Adding Equipment to the Outside
of Your Vehicle...................................... 435
Fuel............................................................. 435
Gasoline Octane........................................ 436
Gasoline Specications.............................. 436
California Fuel........................................... 436
Additives................................................... 437
Fuel E85 (85% Ethanol)............................ 438
Fuels in Foreign Countries........................ 439
Filling the Tank......................................... 440
Filling a Portable Fuel Container............... 442
Checking Things Under the Hood.............. 442
Hood Release........................................... 443
Engine Compartment Overview.................. 444
Engine Oil................................................. 446
Engine Oil Life System.............................. 449Engine Air Cleaner/Filter............................ 451
Automatic Transmission Fluid.................... 454
Engine Coolant.......................................... 457
Coolant Surge Tank Pressure Cap............ 460
Engine Overheating................................... 460
Overheated Engine Protection
Operating Mode..................................... 463
Cooling System......................................... 464
Engine Fan Noise..................................... 469
Power Steering Fluid ................................. 469
Windshield Washer Fluid........................... 470
Brakes...................................................... 472
Battery...................................................... 475
Jump Starting............................................ 476
Rear Axle.................................................... 482
Four-Wheel Drive........................................ 483
Front Axle................................................... 484
Headlamp Aiming........................................ 485
Section 5 Service and Appearance Care
429

Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
A good time to check your automatic transmission
uid level is when the engine oil is changed.
Change the uid and lter at the intervals listed in
Additional Required Services on page 566, and
be sure to use the transmission uid listed in
Recommended Fluids and Lubricants on page 574.
How to Check Automatic
Transmission Fluid
Because this operation can be a little difficult, you
may choose to have this done at the dealership
service department.
If you do it yourself, be sure to follow all the
instructions here, or you could get a false
reading on the dipstick.Notice:Too much or too little uid can
damage your transmission. Too much can
mean that some of the uid could come out
and fall on hot engine parts or exhaust system
parts, starting a re. Too little uid could
cause the transmission to overheat. Be sure to
get an accurate reading if you check your
transmission uid.
Wait at least 30 minutes before checking the
transmission uid level if you have been driving:
When outside temperatures are above
90°F (32°C).
At high speed for quite a while.
In heavy traffic — especially in hot weather.
While pulling a trailer.
To get the right reading, the uid should be
at normal operating temperature, which is
180°F to 200°F (82°C to 93°C).
454

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 460.
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.
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.
458

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.
SeeRecommended Fluids and Lubricants
on page 574for more information.
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 444for 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.
If your vehicle is equipped with a low coolant
sensor and the LOW COOLANT LEVEL message
comes on and stays on, it means you are low
on engine coolant. See “LOW COOLANT LEVEL”
underDIC Warnings and Messages on page 267.
459

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. SeeCooling
System on page 464.
{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.
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 444for 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 249.
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 267.
460

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 463for
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 463for information on driving to a
safe place in an emergency.
461

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 414.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.
462

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 446.
463