2003 CHEVROLET ASTRO overheating

Engine Coolant Temperature Gage
This gage shows
the engine coolant
temperature.
If the
gage pointer moves
to the red area, your
engine is too hot!
It means that your engine coolant has overheated.
If you have been operating your vehicle under normal
driving conditions, you should pull
off the road, stop your
vehicle and turn
off the engine as soon as possible.
See
Engine Overheating on page 5-31.
Malfunction Indicator Lamp
Service Engine Soon Light in the
United States
or Check Engine Light
in Canada
SERVICE
ENGINE
SOON
ds
CHECK
United States Canada
Your vehicle is equipped with a computer which
monitors operation of the fuel, ignition and emission
control systems.
3-30

Driving On Grades Parking on Hills
Reduce speed and shift to a lower gear before 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).
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, see
Engine Overheating on
page
5-3 1.
You really shoul tot park your vehicle, ith 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
2. Have someone place chocks under the trailer
3. When the wheel chocks are in place, release the
4. Reapply the regular brakes. Then apply your PARK (P) yet.
wheels. regular brakes until the chocks absorb the load.
parking brake, and shift to PARK (P).
5. Release the regular brakes.
4-39

Section 5 Service and Appearance Care
Service .......................................................... -5-3
Doing Your Own Service Work
......................... 5-3
Adding Equipment to the Outside of
Your Vehicle
.............................................. 5-4
Fuel ................................................................ 5.5
Gasoline Octane ........................................... -5-5
Gasoline Specifications .................................... 5.5
California Fuel ............................................. -56
Additives
....................................................... 5.6
Fuels in Foreign Countries
............................... 5.7
Filling Your Tank
............................................ 5-8
Filling a Portable Fuel Container
..................... 5-10
Checking Things Under the Hood .................... 5-1 1
Hood Release .............................................. 5.11
Engine Compartment Overview
...................... 5.14
Engine Oil
................................................... 5.15
Engine Cover ................. .... ........ 5.20
Engine Air Cleaner/Filter
................. ........ 5.24
Automatic Transmission Fluid
...................... 5.25
Engine Coolant ............................................. 5.28
Radiator Pressure Cap
.................................. 5.30
Engine Overheating
....................................... 5.31
Cooling System
............................................ 5.33
Engine Fan Noise
......................................... 5.39
Power Steering Fluid
..................................... 5.40
Windshield Washer Fluid
................................ 5.41 Brakes
........................................................ 5.42
Battery
........................................................ 5-46
Jump Starting
............................................... 5-47
All-Wheel Drive .............................................. 5-52
Rear Axle ....................................................... 5-53
Front Axle ...................................................... 5-54
Bulb Replacement .......................................... 5-55
Halogen Bulbs .............................. ..... 5-55
Headlamps .................................. ..... 5-55
Front Turn Signal Lamps ............................... 5-59
Replacement Bulbs
....................................... 5-61
Windshield Wiper Blade Replacement .............. 5-62
Tires .............................................................. 5.63
Inflation
- Tire Pressure ................................ 5-64
Tire Inspection and Rotation
........................... 5-64
When It
Is Time for New Tires ....................... 5-66
Buying New Tires
......................................... 5-66
Uniform Tire Quality Grading
.......................... 5-67
Wheel Alignment and Tire Balance
.................. 5-69
Wheel Replacement
...................................... 5-69
Tire Chains
.................................................. 5-70
If a Tire Goes Flat ........................................ 5.70
Changing a Flat Tire ..................................... 5.71
Compact Spare Tire ...................................... 5-82
Taillamps
.................................................... 5-60
5- 1

Engine Coolant
The cooling system in your vehicle is filled with
DEX-COOL@ engine coolant. This coolant is designed
to remain in your vehicle for 5 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, see
Engine Overheating on
page
5-3 I.
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: When adding coolant, it is important that
you use only
DEX-COOL@ (silicate-free) coolant.
If coolant other than DEX-COOL@
is added to the
system, premature engine, heater core or radiator
corrosion may result.
In addition, the engine coolant
will require change sooner
- at 30,000 miles
(50,000 km) or 24 months, whichever occurs first. Damage
caused by the use
of coolant other than
DEX-COOL@
is not covered by your new vehicle
warranty.
What to Use
Use a mixture of one-half clean, drinkable water and
one-half DEX-COOL@ coolant which won’t damage
aluminum parts.
If you use this coolant mixture,
you don’t need to add anything else.
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 wouldn’t get the overheat warning.
Your engine could catch fire and you or others could be burned. Use a
50/50 mixture of clean,
drinkable water and the proper coolant.
5-28

Add coolant mixture at the recovery tank, but be careful
not to
mill it.
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
Radiator Pressure Cap
Occasionally check the coolant level in the radiator.
For information on how to add coolant to the radiator,
see
Cooling System on page 5-33.
A L
The radiator pressure cap is located in the engine
compartment on the
passenger's side of
the vehicle.
Notice: Your radiator cap is a 15.6 psi (1 10 kPa)
pressure-type cap and must be tightly installed
to prevent coolant
loss and possible engine damage
from overheating. Be sure the arrows on the cap
line up with the overflow tube on the radiator filler.
5-30

Engine Overheating
You will find an engine coolant temperature gage on
your vehicle’s instrument panel. See Engine Coolant
Temperature Gage on page 3-30.
If Steam Is Coming From Your Engine
Sean, ,ram 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.
Notice: If your engine catches fire because you
keep driving with no coolant, your vehicle can
be badly damaged. The costly repairs would not
be covered by your warranty.
5-31

Tires
Your new vehicle comes with high-quality tires made by
a leading tire manufacturer.
If you ever have questions
about your tire warranty
and where to obtain service,
see your GMC Warranty booklet for details.
Poorl! lail -Jned anc. ..nproy-. ly used tires
are dangerous.
Overloading your tires can cause
overheating as a result of too much
friction. You could have an air-out and a
serious accident. See “Loading Your
Vehicle” in the Index.
CAUTION: (Continued)
0 Underinflated tires pose the same danger
as overloaded tires. The resulting accident
could cause serious injury. Check
all tires
frequently to maintain the recommended pressure. Tire pressure should be checked
when your tires are cold.
Overinflated tires are more likely to be
cut, punctured or broken by
a sudden
impact
- such as when you hit a pothole.
Keep tires at the recommended pressure.
Worn, old tires can cause accidents.
If your tread
is badly worn, or if your tires
have been damaged, replace them.
5-63

Daytime Running Lamps (DRL) ...................... 3-14
Defensive Driving
............................................. 4-2
Defogging and Defrosting
................................. 3-1 9
Directing the Airflow
........................................ 3-20
Disabling the Theft-Deterrent Feature
................. 3-49
Doing Your Own Service Work
........................... 5-3
Dome Lamps
.......................................... ~ ~~~ 3-16
Door Front Doors
............................................... 2-8
Locks
.......................................................... 2-7
Power Door Locks
......................................... 2-8
Programmable Automatic Door Locks
............... 2-9
Rear Doors
................................................. 2-13
Sliding Side Door
........................................ 2-10
Position, Safety Belt
..................................... 1-1 8
Driver Information System
................................ 2-42
At Night
..................................................... 4-14
City
........................................................... 4-19
Defensive
..................................................... 4-2
Drunken
....................................................... 4-3
Freeway
..................................................... 4-20
Hill and Mountain Roads
.............................. 4-22
In Rain and on Wet Roads ........................... 4-16
Winter
........................................................ 4-24
Driving On Grades
.......................................... 4-39
Driving on Snow or Ice
.................................... 4-24
Driver
Driving Driving
Through Deep Standing Water
............... 4-18
Driving Through Flowing Water
......................... 4-18
Driving with a Trailer
....................................... 4-37
E
Electrical System
Add-on Equipment
...................................... 5-92
Headlamp Wiring
......................................... 5-92
Fuses and
Circuit Breakers
........................... 5-93
Power Windows and Other Power Options
......... 5-92
Windshield Wiper Fuses
............................... 5-92
Emissions Inspection and
Engine Maintenance Programs
................................. 3-33
Air Cleaner/Filter
......................................... 5-24
Battery
....................................................... 5-46
Check and Service Engine Soon Light
............ 3-30
Coolant
...................................................... 5-28
Coolant Heater
............................................ 2-22
Coolant Temperature Gage
........................... 3-30
Cooling System Inspection
............................ 6-30
Cover
........................................................ 5-20
Engine Compartment Overview
...................... 5-14
Exhaust
..................................................... 2-30
Fan Noise
.................................................. 5-39
Oil
............................................................. 5-15
Starting
...................................................... 2-21
Overheating
................................................ 5-31
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