engine overheat CHEVROLET EXPRESS 2007 User Guide

Service............................................................6-3
Accessories and Modifications..........................6-3
California Proposition 65 Warning.....................6-4
California Perchlorate Materials Requirements.....6-4
Doing Your Own Service Work.........................6-4
Adding Equipment to the Outside of
the Vehicle.................................................6-5
Fuel................................................................6-5
Gasoline Octane............................................6-6
Gasoline Specifications....................................6-6
California Fuel...............................................6-6
Additives.......................................................6-7
Fuel E85 (85% Ethanol)..................................6-8
Fuels in Foreign Countries...............................6-9
Filling the Tank............................................6-10
Filling a Portable Fuel Container.....................6-12
Checking Things Under the Hood....................6-12
Hood Release..............................................6-13
Engine Compartment Overview.......................6-14
Engine Oil...................................................6-15
Engine Oil Life System..................................6-18
Engine Air Cleaner/Filter................................6-20
Automatic Transmission Fluid
(4-Speed Transmission)..............................6-21
Automatic Transmission Fluid
(6-Speed Transmission)..............................6-24Cooling System............................................6-28
Engine Coolant.............................................6-29
Engine Overheating.......................................6-35
Engine Fan Noise.........................................6-37
Power Steering Fluid.....................................6-38
Windshield Washer Fluid................................6-39
Brakes........................................................6-40
Battery........................................................6-43
Jump Starting...............................................6-44
All-Wheel Drive.............................................
.6-49
Rear Axle.......................................................6-50
Front Axle......................................................6-50
Noise Control System.....................................6-51
Tampering with Noise Control System
Prohibited.................................................6-51
Bulb Replacement..........................................6-53
Halogen Bulbs..............................................6-53
Headlamps..................................................6-53
Front Turn Signal, Sidemarker and
Parking Lamps..........................................6-55
Center High-Mounted Stoplamp (CHMSL).........6-56
Taillamps.....................................................6-56
License Plate Lamp......................................6-58
Replacement Bulbs.......................................6-58
Windshield Wiper Blade Replacement..............6-59
Section 6 Service and Appearance Care
6-1

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 32°C (90°F).
•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 82°C to 93°C
(180°F to 200°F).
Get the vehicle warmed up by driving about 24 km
(15 miles) when outside temperatures are above 10°C
(50°F). If it is colder than 10°C (50°F), drive the vehicle in
D (DRIVE) 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 10°C (50°F), 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.
6-22

How to Check Automatic Transmission
Fluid
Because this operation can be difficult, it is recommended
to have this check done at the dealer/retailer service
department, which can monitor the transmission
temperature. The transmission fluid level increases
with temperature. To obtain a highly accurate fluid level
check, the transmission temperature must be measured.
If it is decided to check the fluid level, be sure to follow
all the instructions here, or a false reading on the
dipstick may occur.
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 with the engine Off, before
checking the transmission fluid level if the vehicle has
been driven:
•In hot weather, when outside temperatures are
above 32°C (90°F).
•The vehicle is heavily loaded.
•At high speed for quite a while in hot weather.
•In heavy traffic and hot weather.
•While pulling a trailer.
After driving under these conditions, a hot check can
be performed. The fluid should be Hot, which is
71°C to 93°C (160°F to 200°F).
A cold fluid level check can be performed 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 is
between 15°C to 32°C (60°F to 90°F). Should the fluid
level be low during this cold check, the fluid must be
checked Warm or Hot before adding fluid. If the outside
temperature is colder than 15°C (60°F) or hotter than
32°C (90°F), a cold check cannot be performed.
A warm fluid level check can be performed by driving
the vehicle under lightly loaded conditions and outside
temperatures between 10°C to 27°C (50°F to 80°F).
The vehicle should be driven for at least 15 miles before
performing a warm check. Checking the fluid Warm or
Hot will give a more accurate reading of the fluid level
than a cold check.
Because the vehicle is equipped with a high-efficiency
air-to-oil cooler, the transmission fluid temperature
may not reach the required Hot fluid level checking
temperature under normal lightly loaded driving vehicle
conditions.
6-25

WARNING: (Continued)
Do not run the engine if there is a leak. If you run
the engine, it could lose all coolant. That could
cause an engine fire, and you could be burned.
Get any leak fixed before you drive the vehicle.
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.
Engine Coolant
The cooling system in the vehicle is filled with
DEX-COOL®engine coolant. This coolant is designed
to remain in the vehicle for five years or 150,000 miles
(240 000 km), whichever occurs first.
The following explains the cooling system and how to
check and add coolant when it is low. If there is a problem
with engine overheating, seeEngine Overheating on
page 6-35.
6-29

What to Use
{WARNING:
Adding only plain water to the cooling system can
be dangerous. Plain water, or some other liquid
such as alcohol, can boil before the proper coolant
mixture will. The vehicle’s coolant warning system
is set for the proper coolant mixture. With plain
water or the wrong mixture, the engine could get
too hot but you would not get the overheat
warning. The engine could catch fire and you or
others could be burned. Use a 50/50 mixture of
clean, drinkable water and DEX-COOL
®coolant.
Use a 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant. If using this mixture, nothing else
needs to be added. This mixture:
•Gives freezing protection down to−34°F (−37°C),
outside temperature.
•Gives boiling protection up to 265°F (129°C),
engine temperature.
•Protects against rust and corrosion.
•Will not damage aluminum parts.
•Helps keep the proper engine temperature.
Notice:If an improper coolant mixture is used,
the engine could overheat and be badly damaged.
The repair cost would not be covered by the vehicle
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core, and
other parts.
Notice:If extra inhibitors and/or additives are used
in the vehicle’s cooling system, the vehicle could
be damaged. Use only the proper mixture of
the engine coolant listed in this manual for the
cooling system. SeeRecommended Fluids and
Lubricants on page 7-12for more information.
6-30

Checking Coolant
The vehicle must be on a level surface when checking
the coolant level.
Check to see if coolant is visible in the coolant recovery
tank. If the coolant inside the coolant recovery tank is
boiling, do not do anything else until it cools down.
If coolant is visible but the coolant level is not at or above
the COLD FILL mark, add a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant at the coolant
recovery tank, but be sure the cooling system is cool
before this is done.
When the engine is cold, the coolant level should be at
or above the COLD FILL mark. If it is not, there could
be a leak in the cooling system.
If the coolant is low, add the coolant or take the vehicle
to a dealer/retailer for service.
How to Add Coolant to the Recovery
Tank for Gasoline Engines
If your vehicle has a diesel engine, see “How to
Add Coolant to the Coolant Recovery Tank” under
“Van Models” in the Cooling System section of the
DURAMAX
®Diesel Supplement for the proper coolant
fill procedure.
{WARNING:
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.
Notice:This vehicle has a specic coolant ll
procedure. Failure to follow this procedure could
cause the engine to overheat and be severely
damaged.
If coolant is needed, add the proper DEX-COOL
®
coolant mixture at the coolant recovery tank.
6-31

7. By this time, the coolant level inside the radiator
filler neck may be lower. If the level is lower, add
more of the proper DEX-COOL
®coolant mixture
through the filler neck until the level reaches
the base of the filler neck.
8. Then replace the pressure cap. At any time during
this procedure if coolant begins to flow out of the
filler neck, reinstall the 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.
Engine Overheating
If your vehicle has the DURAMAX Diesel engine, see
the DURAMAX Diesel manual for more information.
The vehicle has an indicator to warn of engine
overheating.
You will find an engine coolant temperature gage on
your vehicle’s instrument panel. SeeEngine Coolant
Temperature Gage on page 4-29for more information.You may decide not to lift the hood when this warning
appears, but instead get service help right away.
SeeRoadside Assistance Program on page 8-8.
If you do decide to lift the hood, make sure the vehicle
is parked on a level surface.
Then check to see if the engine cooling fans are
running. If the engine is overheating, both fans should
be running. If they are not, do not continue to run
the engine and have the vehicle serviced.
See if the engine cooling fan speed increases when idle
speed is doubled by pushing the accelerator pedal down.
If it does not, your vehicle needs service. Turn off the
engine.
Notice:Engine damage from running the engine
without coolant is not covered by the warranty.
Notice:If the engine catches re because of being
driven with no coolant, your vehicle can be badly
damaged. The costly repairs would not be covered
by the vehicle warranty.
6-35

If Steam Is Coming From The Engine
Compartment
{WARNING:
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 fire. You or
others could be badly burned. Stop your engine if
it overheats, and get out of the vehicle until the
engine is cool.
If No Steam Is Coming From The
Engine Compartment
If an engine overheat warning is displayed but no steam
can be seen or heard, the problem may not be too
serious. Sometimes the engine can get a little too
hot when the vehicle:
•Climbs a long hill on a hot day.
•Stops after high-speed driving.
•Idles for long periods in traffic.
•Tows a trailer. See “Driving on Grades” under
Towing a Trailer on page 5-30.
If the overheat warning is displayed with no sign of
steam:
1. Turn the air off.
2. Turn the heater on to the highest temperature and
to the highest fan speed. Open the windows as
necessary.
3. In heavy traffic, let the engine idle in N (Neutral)
while stopped. If it is safe to do so, pull off the
road, shift to P (Park) or N (Neutral) and let
the engine idle.
6-36

If the temperature overheat gage is no longer in the
overheat zone or an overheat warning no longer
displays, the vehicle can be driven. Continue to drive
the vehicle slow for about 10 minutes. Keep a safe
vehicle distance from the car in front of you. If the
warning does not come back on, continue to drive
normally.
If the warning continues, pull over, stop, and park the
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 until it cools down.
You may decide not to lift the hood but to get service
help right away.Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When the
clutch is engaged, the fan spins faster to provide more air
to cool the engine. In most everyday driving conditions,
the fan is spinning slower and the clutch is not fully
engaged. This improves fuel economy and reduces fan
noise. Under heavy vehicle loading, trailer towing, and/
or high outside temperatures, the fan speed increases
as the clutch more fully engages, so you may hear an
increase in fan noise. This is normal and should not be
mistaken as the transmission slipping or making extra
shifts. It is merely the cooling system functioning properly.
The fan will slow down when additional cooling is not
required and the clutch partially disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch partially
disengages.
6-37

The vehicle has an airbag system. Before attempting
to add anything electrical to the vehicle, seeServicing
Your Airbag-Equipped Vehicle on page 2-78andAdding
Equipment to Your Airbag-Equipped Vehicle on
page 2-79.
Headlamp Wiring
The headlamp wiring is protected by fuses in the engine
compartment fuse block. An electrical overload will cause
the lamps to flicker on and off, or in some cases to remain
off. If this happens, have your headlamp wiring checked
right away.
Windshield Wiper Fuses
The windshield wiper motor is protected by a circuit
breaker and a fuse. If the motor overheats due to heavy
snow, etc., the wiper will stop until the motor cools.Although the circuit is protected from electrical overload,
overload due to heavy snow, etc., may cause wiper
linkage damage. Always clear ice and heavy snow from
the windshield before using the windshield wipers. If the
overload is caused by some electrical problem and not
snow, etc., be sure to get it fixed.
Fuses and Circuit Breakers
The wiring circuits in the vehicle are protected from
short circuits by a combination of fuses and circuit
breakers. This greatly reduces the chance of fires
caused by electrical problems.
Look at the silver-colored band inside the fuse. If the
band is broken or melted, replace the fuse. Be sure
you replace a bad fuse with a new one of the identical
size and rating.
6-110