2003 CHEVROLET ASTRO Owners Manual

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.
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Cooling System
When you decide it’s safe to lift the hood, here’s what
you’ll see: The
coolant level should
be at the
ADD mark.
A. Coolant Recovery Tank
B. Radiator Pressure Cap
C. Engine Cooling Fan
If the coolant inside the coolant recovery tank is boiling,
don’t do anything else until it cools down. The vehicle
should be parked
on a level surface.
A
If it isn’t, you may have a leak at the pressure cap or
in the radiator hoses, heater hoses, radiator, water pump
or somewhere else
in the cooling system.
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.
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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.
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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 mixture.
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.
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If the overheat warning continues, there’s one more
thing you can try.
You can add the proper coolant
mixture directly to the radiator, but be sure the cooling
system is cool before you do it.
1
Steam and scalding liquids from a hot cooling
system can blow out and burn you badly. They
are under pressure, and
if you turn the radiator
pressure cap
- even a little - they can come
out at high speed. Never turn the cap when
the
cooling system, including the radiator pressure
cap, is hot. Wait for the cooling system and
radiator pressure cap to cool if you ever have
to
turn the pressure cap.
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How to Add Coolant to the Radiator
You can remove the
radiator pressure cap
when the cooling system,
including the radiator
pressure cap and
upper radiator hose,
is no longer hot.
1. Turn the pressure cap slowly counterclockwise until
it first stops. (Don't press down while turning the
pressure cap.)
2. Then keep turning the pressure cap, but now
push down as you
turn it. Remove
the pressure cap.
If you hear a hiss, wait for that
to stop. A hiss
means there is still some pressure left.
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3. Fill the radiator with the proper DEX-COOL@
coolant mixture, up to the base of the filler
neck. See
Engine Coolant on page 5-28 for more
information about the proper coolant mixture.
4. Then fill the coolant recovery tank to the ADD mark.
5. Put the cap back on the coolant recovery tank,
but leave the pressure cap
off.
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6. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fan.
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.
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 arrow on the pressure cap lines up.
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 everyday 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.
5-39