2008 CHEVROLET EXPRESS PASSANGER engine overheat

Driving On Grades
Reduce speed and shift to a lower gearbeforeyou 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 a lower gear under heavy
loads and/or hilly conditions.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. 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 5-27.
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. Then turn your wheels into the curb if
facing downhill or into traffic if facing uphill.
2. Have someone place chocks under the trailer
wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your
parking brake and then shift to PARK (P).
5. Release the regular brakes.
4-40

Service............................................................5-3
Accessories and Modifications..........................5-3
California Proposition 65 Warning.....................5-4
California Perchlorate Materials Requirements.....5-4
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of
Your Vehicle..............................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-6
Gasoline Specifications....................................5-6
California Fuel...............................................5-6
Additives.......................................................5-7
Fuel E85 (85% Ethanol)..................................5-8
Fuels in Foreign Countries...............................5-9
Filling the Tank............................................5-10
Filling a Portable Fuel Container.....................5-12
Checking Things Under the Hood....................5-12
Hood Release..............................................5-13
Engine Compartment Overview.......................5-14
Engine Oil (Gasoline Engine)..........................5-15
Engine Oil Life System..................................5-18
Engine Air Cleaner/Filter................................5-20
Automatic Transmission Fluid.........................5-21
Engine Coolant.............................................5-24
Radiator Pressure Cap..................................5-27Engine Overheating.......................................5-27
Cooling System............................................5-29
Engine Fan Noise.........................................5-34
Power Steering Fluid.....................................5-35
Windshield Washer Fluid................................5-36
Brakes........................................................5-37
Battery........................................................5-40
Jump Starting...............................................5-41
All-Wheel Drive..............................................5-46
Rear Axle.......................................................5-47
Front Axle......................................................5-48
Noise Control System.....................................5-48
Tampering with Noise Control System
Prohibited.................................................5-48
Bulb Replacement..........................................5-50
Halogen Bulbs..............................................5-50
Headlamps..................................................5-50
Front Turn Signal, Sidemarker and
Parking Lamps..........................................5-52
Center High-Mounted Stoplamp (CHMSL).........5-52
Taillamps.....................................................5-53
Replacement Bulbs.......................................5-54
Windshield Wiper Blade Replacement..............5-54
Section 5 Service and Appearance Care
5-1

How to Check Automatic
Transmission Fluid
Because this operation can be a little difficult, you may
choose to have this done at the dealer/retailer 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 fluid 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 fluid should be at
normal operating temperature, which is 180°F to 200°F
(82°C to 93°C).
Get the vehicle warmed up by driving about
15 miles (24 km) when outside temperatures are above
50°F (10°C). If it is colder than 50°F (10°C), drive
the vehicle in DRIVE (D) until the engine temperature
gage moves and then remains steady for 10 minutes.
A cold fluid check can be made after the vehicle
has been sitting for eight hours or more with the engine
off, but this is used only as a reference. Let the
engine run at idle for five minutes if outside
temperatures are 50°F (10°C) or more. If it is colder
than 50°F (10°C), you may have to idle the engine
longer. Should the fluid level be low during this cold
check, you must check the fluid hot before adding fluid.
Checking the fluid hot will give you a more accurate
reading of the fluid level.
5-22

How to Add Automatic
Transmission Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission fluid to use. SeeRecommended
Fluids and Lubricants on page 6-13.
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 in
Recommended Fluids and Lubricants on page 6-13.
•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 5-27.
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.
5-24

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 6-13for more information.
5-25

{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 5-29.
Radiator Pressure Cap
The radiator pressure cap is located near the
center of the engine compartment. SeeEngine
Compartment Overview on page 5-14for 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 3-36for more information.
5-27

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” under
Towing a Trailer on page 4-28.
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.
5-28

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.
5-29