2003 CHEVROLET ASTRO engine overheat

Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmission fluid
level is when the engine oil is changed.
Change both the fluid and filter every
15,000 miles
(25
000 km) if the vehicle is mainly driven under one or
more of these conditions:
In heavy city traffic where the outside temperature
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
If you do not use your vehicle under any of these
conditions, change the fluid and filter every
50,000 miles (83 000 km).
See
Part A: Scheduled Maintenance Services on
page
6-4.
regularly reaches 90°F (32°C) or higher.
service.
How to Check
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.
Notices Too much or too little fluid can damage
your transmission.
Too much can mean that some
of the fluid could come out and fall on hot engine
part or exhaust system parts, starting a fire.
Too little fluid could cause the transmission to
overheat. Be sure to get an accurate reading if you
check your transmission fluid.
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).
0 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).
5-25

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

Notice: If you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost wouldn’t 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 the proper coolant, you don’t
have to add extra inhibitors or additives which claim
to improve
the system. These can be harmful.
Checking Coolant
r
The engine coolant tank is
located in the engine
compartment on the
passenger’s side at the
front. See Engine
Compartment Overview
on page
5-14 for more
information on location. The
vehicle must be on a level surface. When your
engine is cold, the coolant level should be at
ADD,
or a little higher. When your engine is warm, the level
should be up to
FULL HOT, or a little higher.
Adding Coolant
If you need more coolant, add the proper DEX-COOL@
coolant mixtureat the coolant recovery tank.
Lvrl DEX-COOL@
L
A
A
Turning the radiato ressure cap when the
engine and radiator are hot can allow steam and
scalding
liquids to blow out and burn you badly.
With the coolant recovery tank, you will almost
never have to add coolant at the radiator.
Never
turn the radiator pressure cap - even a
little -when the engine and radiator are hot.
5-29

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

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” in Towing a
Trailer on page 4-3 I.
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.
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about
10 minutes.
If the warning doesn’t 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’s still no sign of steam, you can push down the
accelerator until the engine speed is about twice as
fast as normal idle speed for at least three minutes while
you’re 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.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.
5-32

If there seems to be no leak, start the engine again. How to Add Coolant to the Coolant
The engine cooling fan speed should increase when idle
speed is doubled by pushing the accelerator pedal
Recovery Tank
down. If it doesn’t, your vehicle needs service. Turn off If you haven’t found a problem yet, but the coolant level
the engine. isn’t at the
ADD mark, add a 50/50 mixture of clean
Nofice: Engine damage from running your engine
without coolant isn’t covered by your warranty.
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.
drinkable wafer, and DEX-COOL@ engine coolant at
the coolant recovery tank. See
Engine Coolant on
page 5-28 for more information.
Adding only p.,,n water to your coG...rg
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 DEX COOL@ coolant.
5-34

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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