engine CHEVROLET ASTRO 1996 Workshop Manual

Heater and radiator hoses, and other engine
parts, can be
very hot. Don’t touch them. If you
do, you can be burned.
Don’t 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.
Engine damage from running your engine without coolant isn’t covered by your warranty.
If there seems to be
no leak, start the engine again. See
if the fan speed increases when idle speed
is doubled by
pushing the accelerator pedal down.
If it doesn’t, your
vehicle needs service. Turn off the engine.
How to Add Coolant to the Coolant
Recovery Tank
If you haven’t found a problem yet, but the coolant level
isn’t at the
ADD mark, add a 50/50 mixture of clean
water (preferably distilled) and DEX-COOL TM
(orange-colored, silicate-free) antifreeze at the coolant
recovery tank. (See “Engine Coolant’’
in the Index for
more information.)
Adding only plain water to your cooling system
can be dangerous. Plain water,
or some other
liquid like alcohol, can boil before the proper
coolant mix
will. Your vehicle’s coolant warning
system is set
for the proper coolant mix. With
plain water or the wrong mix, 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 mix of clean
water and
DEX-COOL TM antifreeze.
5-16

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 mix.
I A 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. Don’t spill coolant on
a hot engine.
When the coolant in
the coolant recovery tank is at the
ADD mark, start your vehicle.
If the overheat warning continues, there’s one more
thing
you can try. You can add the proper coolant mix
directly
to the radiator, but be sure the cooling system is
cool before you do
it.

6. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine fan.
filler neck may be lower.
If the level is lower, add
more of the proper
mix through the filler neck until
the level reaches the base of the filler neck.
7. By this time the coolant level inside the radiator
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. Be sure the
arrows on the pressure cap line up like this.
5-21

Engine Fan Noise
This 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 every day driving
conditions, 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 when the clutch
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 disengages.
You may also hear this fan noise when
you start the
engine. It will go away as the fan clutch disengages.
If a Tire Goes Flat
It’s unusual for a tire to “blow out” while you’re driving,
especially if
you maintain your tires properly. If air goes
out of a tire, it’s much more likely to leak out slowly.
But if you should ever have a 4‘blowout,” here are a few
tips about what
to expect and what to do:
If a front tire fails, the flat tire will create a drag that
pulls the vehicle toward that side. Take your foot off the
accelerator pedal and grip the steering wheel firmly.
Steer to maintain lane position, and then gently brake to
a stop well
out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you’d use in a
skid.
In any rear blowout, remove your foot from the
accelerator pedal. Get the vehicle under control by steering the way
you want the vehicle to go. It may be
very bumpy and noisy, but
you can still steer. Gently
brake
to a stop -- well off the road if possible.
If a tire goes flat, the next part shows how to
use your
jacking equipment to change a flat tire safely.
5-22

Changing a Flat Tire
If a tire goes flat, avoid further tire and wheel damage
by driving slowly to a level place. Turn on your hazard
warning flashers.
'!!!h CAUTION:
I
Changing a tire can cause an injury. The vehicle
can slip off the jack and roll over you or other
people. You and they could be badly injured.
Find
a level place to change your tire. To help
prevent the vehicle from moving:
1. Set the parking brake firmly.
2. Put the shift lever in PARK (P).
3. 'hrn off the engine.
4. Put the wheel blocks at the front and
rear of the tire farthest away from the
one being changed. That would be the
tire on the other side of the vehicle, at
the opposite end. The
following steps will tell
you how to use the jack and
change a tire.
5-23

If You’re Stuck: In Sand, Mud, Ice
or Snow
What you don’t want to do when your vehicle is stuck is
to spin your wheels too fast. The method known as
“rocking” can help
you get out when you’re stuck, but
you must use caution.
A CAUTION:’
I
If you let your tires spin at high speed, they can
explode, and you or others could be injured.
And, the transmission or other parts of the
vehicle can overheat. That could cause an engine
compartment fire or other damage. When you’re
stuck, spin the wheels
as little as possible. Don’t
~ spin the wheels above 35 mph (55 km/h) as shown
~ on the speedometer.
I
NOTICE:
Spinning your wheels can destroy parts of your
vehicle
as well as the tires. If you spin the wheels
too fast while shifting your transmission back
and forth, you can destroy your transmission.
For information about using tire chains
on your vehicle,
see “Tire Chains” in
the Index.
Rocking your vehicle to get it out:
First, turn your steering wheel left and right. That will
clear the area around your front wheels. Then shift back
and forth between REVERSE
(R) and a forward gear,
spinning the wheels as little as possible. Release the
accelerator pedal while you shift, and press lightly
on
the accelerator pedal when the transmission is in gear. If
that doesn’t get
you out after a few tries, you may need
to be towed out. If you do need to be towed out, see
“Towing Your Vehicle’’’ in the Index.
5-37

Fuel
Use regular unleaded ‘gasoline rated at 87 octane or
higher. At a minimum, it should meet specifications
\.
ASTM D4814 in the United States and CGSB 3.5-M93
in Canada. Improved gasoline specifications have been
developed by the American Automobile Manufacturers
Association (AAMA) for better vehicle performance
and engine protection. Gasolines meeting the AAMA
specification could provide improved driveability and
emission control system protection compared-to
other gasolines.
Be sure the posted octane is at least
87. If the octane is
less than
87, you may get a heavy knocking noise when
you drive. If it’s bad enough, it can damage your engine.
If you’re using fuel rated at 87 octane or hgher and you
still hear heavy knocking, your engine needs service. But
don’t worry
if you hear a little pinging noise when you’re
accelerating or driving
up a hill. That’s nomal, and you don’t
have to buy a higher octane fuel to get rid of pinging. It’s the
heavy, constant knock that means you have a problem. If
your vehicle is certified’ to meet California Emission
Standards (indicated on the underhood tune-up label),
it is designed to operate on fuels that meet California
I
specifications. If such fuels are not available in states
adopting California emissions standards, your vehicle
will operate satisfactorily on fuels meeting federal
specifications, but emission control system performance
may be affected. The malfunction indicator lamp on
your instrument panel may turn on and/or your vehicle
may fail a smog-check test. If this occurs, return to your
authorized GM dealer for diagnosis to determine the
cause of failure. In the event it is determined that the
cause of the condition is the type of fuels used, repairs
may not be covered by your warranty.
.In Canada, some gasolines contain an octane-enhancing
additive called MMT. If you use such fuels, your
emission control system performance may deteriorate
and the malfunction indicator lamp on your instrument
panel may turn on.
If this happens, return to your
authorized GM dealer for service.
6-3

To provide cleaner air, all gasolines are now required to
Contain additives
that will help prevent deposits from
forming in your engine and
fuel system, allowing your
emission control system
to function properly. Therefore,
you should not have
to add anything to the fuel. In
addition, gasolines containing oxygenates, such as ethers
and ethanol, and reformulated gasolines may be
available in your area to help clean the air. General
Motors recommends that
you use these gasolines if they
comply with the specifications described earlier.
NOTICE:
Your vehicle was not designed for fuel that
contains methanol. Don’t use it. It can corrode
metal parts
in your fuel system and also damage
plastic and rubber parts. That damage wouldn’t
be covered under
your warranty.
Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel may be hard
to find. Never use leaded gasoline or any other fuel not
recommended in the previous
text on fuel. Costly repairs
caused by use
of improper fuel wouldn’t be covered by
your warranty.
To check on fuel availability, ask an auto club, or
contact a major
oil company that does business in the
country where you’ll be driving.
You can also write us at the following address for
advice. Just tell
us where you’re going and give your
Vehicle Identification Number
(VIN).
General Motors Overseas Distribution Corporation, North American Export Sales
(NAES)
1908 Colonel Sam Drive
Oshawa, Ontario
L 1 H 8P7
6-4

When you put the cap back on, turn it to the right until
you hear at least three clicks. Make sure you
fully install
the cap. The diagnostic
system can determine if the fuel
cap has been
left off or improperly installed. This would
allow fuel
to evaporate into the atmosphere. See
“Malfunction Indicator Lamp” in the Index.
NOTICE:
If you need a new cap, be sure to get the right
type. Your dealer can get one for you.
If you get
the wrong type, it may not fit or have proper
venting, and your fuel tank and emissions system
might be damaged.
Checking Things Under the Hood
/1 CAUTION:
Things that burn can get on hot engine parts and
start a fire. These include liquids like gasoline,
oil, coolant, brake fluid, windshield washer and
other fluids, and plastic or rubber. You or others
could be burned. Be careful not
to drop or spill
things that will burn onto a hot engine.
6-7

Engine Oil
CHECK
OIL
If the CHECK OIL light on
the instrument panel comes
on, it means you need to
check your engine oil level
right away. For more information, see “Check Oil
Light” in the Index.
You should check your engine oil level regularly; this is
an added reminder.
It’s a good idea to check your engine oil every time
you
get fuel. In order to get an accurate reading, the oil must
be warm and the vehicle must be
on level ground. The
engine oil dipstick
is a yellow ring.
Turn
off the engine and give the oil a few minutes to
drain back into the oil pan. If you don’t, the oil dipstick
might not show the actual
level.
6-11