2007 CHEVROLET EXPRESS CARGO VAN engine overheat

How to Add Automatic
Transmission Fluid
Refer to the Maintenance Schedule to determine
what kind of transmission fluid to use. See
Recommended Fluids and Lubricants on page 415.
Using a funnel, add fluid down the transmission
dipstick tube only after checking the transmission
fluid while it is hot. A cold check is used only
as a reference. If the fluid level is low, add only
enough of the proper fluid to bring the level up to
the HOT area for a hot check. It does not take
much fluid, generally less than one pint (0.5 L).
Do not overfill.
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 415.
•After adding fluid, recheck the fluid level as
described under “How to Check Automatic
Transmission Fluid,” earlier in this section.
•When the correct fluid level is obtained, push
the dipstick back in all the way; then flip the
handle down to lock the dipstick in place.
Engine Coolant
If your vehicle has the DURAMAX®Diesel engine,
see the DURAMAX®Diesel manual for more
information.
The cooling system in your vehicle is filled with
DEX-COOL
®engine coolant. This coolant is
designed to remain in your vehicle for five years
or 150,000 miles (240 000 km), whichever
occurs first, 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 315.
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.
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Notice:Using coolant other than
DEX-COOL®may cause premature engine,
heater core, radiator and fuel operated heater
(FOH) corrosion. In addition, the engine coolant
may require changing sooner, at 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.
CAUTION: (Continued)
CAUTION: (Continued)
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 the proper 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/retailer 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 415for more information.
313

{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 317.
Radiator Pressure Cap
The radiator pressure cap is located near the
center of the engine compartment. SeeEngine
Compartment Overview on page 302for more
information on location.
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.
Engine Overheating
If your vehicle has the DURAMAX®Diesel engine,
see the DURAMAX®Diesel manual for more
information.
You will find an engine coolant temperature gage
on your vehicle’s instrument panel. SeeEngine
Coolant Temperature Gage on page 178for more
information.
315

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. Just
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 your 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.
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.
If No Steam Is Coming From
Your Engine
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. See “Driving on Grades”
underTowing a Trailer on page 269.
If you get the overheat warning with no sign of
steam, try this for a minute or so:
1. 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.
2. Turn on your heater to full hot at the highest
fan speed and open the windows as
necessary.
316

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, and you have not
stopped, pull over, stop, and park your vehicle
right away.
If there is still no sign of steam, push down the
accelerator until the engine speed is about
twice as fast as normal idle speed for at least
three 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.
You may decide not to lift the hood but to
get service help right away.
Cooling System
If your vehicle has a diesel engine, see
“Van Models” under “Cooling System” in
the DURAMAX
®Diesel Supplement.When you decide it is safe to lift the hood, here is
what you will see:
A. Radiator Pressure Cap
B. Coolant Recovery Tank
C. Engine Cooling Fan(s)
If the coolant inside the coolant recovery tank is
boiling, do not do anything else until it cools down.
317

If you have not found a problem yet, but the
coolant level is not at the COLD FILL mark,
add a 50/50 mixture of clean, drinkable water
and DEX-COOL
®engine coolant at the coolant
recovery tank. SeeEngine Coolant on page 312
for more information.
{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:
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 the washer uid tank only
three-quarters full when it is very cold.
This allows for uid 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
the vehicle’s windshield washer system
and paint.
Notice:In cold weather, water can freeze and
crack the engine, radiator, heater core and
other parts. Use the recommended coolant
and the proper coolant mixture.
319

{CAUTION:
You can be burned if you spill coolant
on hot components in the engine
compartment. Coolant contains ethylene
glycol, and it will burn if the engine parts
are hot enough. Do not spill coolant on a
hot engine or components in the engine
compartment.
When the coolant in the coolant recovery tank
is at the COLD FILL mark, start your vehicle.
If the overheat warning continues, there is
one more thing you can try. You can add the
proper coolant mixture directly to the radiator,
but be sure the cooling system is cool before
you do it.
{CAUTION:
Steam and scalding liquids from a hot
cooling system can blow out and burn
you badly. They are under pressure,
and if you turn the radiator pressure
cap — even a little — they can come out
at high speed. Never turn the cap when
the cooling system, including the radiator
pressure cap, is hot. Wait for the cooling
system and radiator pressure cap to cool
if you ever have to turn the pressure cap.
How to Add Coolant to the Radiator
for Gasoline Engines
If your vehicle has a diesel engine, see
“How to Add Coolant to the Radiator” under
“Van Models” in the Cooling System section
of the DURAMAX
®Diesel Supplement for the
proper radiator fill procedure.
320

Radial tires may look properly inflated even when
they’re underinflated. Check the tire’s inflation
pressure when the tires are cold. Cold means your
vehicle has been sitting for at least three hours
or driven no more than 1 mile (1.6 km).
Remove the valve cap from the tire valve stem.
Press the tire gage firmly onto the valve to
get a pressure measurement. If the cold tire
inflation pressure matches the recommended
pressure on the tire and loading information label,
no further adjustment is necessary. If the
pressure is low, add air until you reach the
recommended amount.
If you overfill the tire, release air by pushing on
the metal stem in the center of the tire valve.
Recheck the tire pressure with the tire gage.
Be sure to put the valve caps back on the valve
stems. They help prevent leaks by keeping out
dirt and moisture.
Dual Tire Operation
When the vehicle is new, or whenever a wheel,
wheel bolt or wheel nut is replaced, check
the wheel nut torque after 100, 1,000 and
6,000 miles (160, 1 600 and 10 000 km) of driving.For proper wheel nut tightening information, see
“Removing the Flat Tire and Installing the Spare
Tire” later in this section, underChanging a Flat
Tire on page 366. Also see “Wheel Nut Torque”
underCapacities and Specications on page 398.
The outer tire on a dual wheel setup generally
wears faster than the inner tire. Your tires will wear
more evenly and last longer if you rotate the
tires periodically. SeeTire Inspection and Rotation
on page 356. Also seeScheduled Maintenance
(Gasoline Engine) on page 405.
{CAUTION:
If you operate your vehicle with a tire
that is badly underinated, the tire can
overheat. An overheated tire can lose
air suddenly or catch re. You or
others could be injured. Be sure all tires
(including the spare) are properly inated.
SeeTires on page 346andInation - Tire
Pressure on page 354for more information on
proper tire inflation.
355