engine CHEVROLET ASTRO 2003 Service Manual

Hydroplaning
Hydroplaning is dangerous. So much water can build up
under your tires that they can actually ride on the
water. This can happen
if the road is wet enough and
you’re going fast enough. When your vehicle is
hydroplaning, it has little or no contact with the road.
Hydroplaning doesn’t happen often. But it can
if
your tires do not have much tread or if the pressure in
one or more is low. It can happen
if a lot of water is
standing on the road. If you can see reflections
from trees, telephone poles or other vehicles, and
raindrops “dimple” the water’s surface, there could be
hydroplaning.
Hydroplaning usually happens at higher speeds.
There just isn’t a hard and fast rule about hydroplaning.
The best advice is to slow down when it is raining.
Driving Through Deep Standing Water
Notice: If you drive too quickly through deep
puddles or standing water, water can come
in
through your engine’s air intake and badly damage your engine. Never drive through water that
is
slightly lower than the underbody of your vehicle.
If you can’t avoid deep puddles or standing
water, drive through them very slowly.
Driving Through Flowing Water
Flo..,ng or rushing water cr,,tes strong forces.
If you try to drive through flowing water, as you
might at a low water crossing, your vehicle
can be carried away.
As little as six inches of
flowing water can carry away a smaller vehicle.
If this happens, you and other vehicle
occupants could drown. Don’t ignore police
warning signs, and otherwise be very cautious
about trying to drive through flowing water.
Some Other Rainy Weather Tips
Besides slowing down, allow some extra following
distance. And be especially careful when you
pass another vehicle. Allow yourself more clear
room ahead, and be prepared to have your
view restricted by road spray.
See
Tires on page 5-63.
Have good tires with proper tread depth.
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The exit ramp can be curved, sometimes quite sharply.
The exit speed is usually posted.
Reduce your speed according to your speedometer, not
to your sense of motion. After driving for any distance
at higher speeds, you
may tend to think you are
going slower than you actually are.
Before Leaving on a Long Trip
Make sure you’re ready. Try to be well rested. If you
must start when you’re not fresh
- such as after a day’s
work
- don’t plan to make too many miles that first
part of the journey. Wear comfortable clothing and shoes
you can easily drive in.
Is your vehicle ready for a long trip? If you keep it
serviced and maintained, it’s ready to go.
If it needs
service, have it done before starting out. Of course,
you’ll find experienced and able service experts
in dealerships all across North America. They’ll be
ready and willing to help
if you need it. Here
are some things you can check before a trip:
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Windshield Washer Fluid: Is the reservior full?
Are
all windows clean inside and outside?
Wiper Blades: Are they in good shape?
Fuel, Engine Oil, Other Fluids: Have you checked
all levels?
Lamps: Are they all working? Are the lenses clean?
Tires: They are vitally important to a safe,
trouble-free trip.
Is the tread good enough for
long-distance driving? Are the tires all inflated
to the recommended pressure?
Weather Forecasts: What’s the weather outlook
along your route? Should you delay your trip a
short time to avoid a major storm system?
Maps: Do you have up-to-date maps?
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Highway Hypnosis
Is there actually such a condition as “highway hypnosis”?
Or
is it just plain falling asleep at the wheel? Call it
highway hypnosis, lack of awareness, or whatever.
There is something about an easy stretch of road with
the same scenery, along with the hum of the tires on
the road, the drone
of the engine, and the rush of
the wind against the vehicle that can make you sleepy.
Don’t let it happen to you!
If it does, your vehicle can
leave the road in
less than a second, and you could
crash and be injured.
What can you do about highway hypnosis?
First, be aware that it can happen.
Then here are some tips:
Make sure your vehicle is well ventilated, with a
comfortably cool interior.
Keep your eyes moving. Scan the road ahead and
to the sides. Check your mirrors and your
instruments frequently.
If you get sleepy, pull off the road into a rest,
service or parking area and take a nap, get some
exercise, or both. For safety, treat drowsiness
on the highway as an emergency.
Hill and Mountain Roads
Driving on steep hills or mountains is different from
driving in flat or rolling terrain.
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If you drive regularly in steep country, or if you’re
planning to visit there, here are some tips that can make
your trips safer and more enjoyable.
Keep your vehicle in good shape. Check all fluid
levels and also the brakes, tires, cooling system
and transmission. These parts can work hard
on mountain roads.
0 Know how to go down hills. The most important
thing to know is this: let your engine do some of
the slowing down. Shift
to a lower gear when you go
down a steep or long
hill.
0
If you don’t shift down, y--. -.-. ces coul, Jet
so hot that they wouldn’t work well. You would
then have poor braking or even none going
down a hill. You could crash. Shift down to let
your engine assist your brakes on a steep
downhill slope. Coasting downh.-.
... .rlEUTL .. _L (N) or wit
ignition
off is dangerous. Your brakes will have
to do all the work
of slowing down. They could
get
so hot that they wouldn’t work well. You
would then have poor braking or even none
going down a hill. You could crash. Always have
your engine running and your vehicle in gear
when you go downhill.
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Know how to go uphill. You may want to shift down to
a lower gear. The lower gears help cool your engine
and transmission, and you can climb the hill better.
Stay in your own lane when driving on two-lane
roads
in hills or mountains. Don’t swing wide or cut
across the center of the road. Drive at speeds that let
you stay in your own lane.
As you go over the top of a hill, be alert. There could
be something in your lane, like a stalled car or an
accident.
You may see highway signs on mountains that warn
of special problems. Examples are long grades,
passing or no-passing zones,
a falling rocks area
or winding roads. Be alert to these and take
appropriate action.
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If You’re Caught in a Blizzard
If you are stopped by heavy snow, you could be in a
serious situation. You should probably stay with
your vehicle unless you know for sure that you are near
help and you can hike through the snow. Here are
some things to do to summon help and keep yourself
and your passengers safe:
Turn on your hazard flashers.
Tie a red cloth to your vehicle to alert police that
you’ve been stopped by the snow.
* Put on extra clothing or wrap a blanket around you.
If you have no blankets or extra clothing, make
body insulators from newspapers, burlap bags, rags,
floor mats
- anything you can wrap around
yourself or tuck under your clothing to keep warm.
You can run the engine
to keep warm, but be careful.
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Snow can trap exhaust gases under your
vehicle. This can cause deadly
CO (carbon
monoxide) gas to get inside.
CO could
overcome you and kill you. You can’t see
it or
smell
it, so you might not know it is in your
vehicle. Clear away snow from around the
base of your vehicle, especially any that is
blocking your exhaust pipe. And check around
again from time to time to be sure snow doesn’t collect there.
Open a window just a little on the side
of the
vehicle that’s away from the wind. This will
help keep
CO out. Run your
engine only as long as you must. This saves
fuel. When you run the engine, make it go a little
faster than just idle. That is, push the accelerator
slightly. This uses less fuel for the heat that you get
and
it keeps the battery charged. You will need a
well-charged battery to restart the vehicle, and possibly
for signaling later on with your headlamps. Let the
heater run for a while.
Then, shut the engine
off and close the window almost
all the way to preserve the heat. Start the engine
again and repeat this only when you feel really
uncomfortable from the cold. But do it as little as
possible. Preserve the fuel as long as you can.
To help keep warm, you can get out of the vehicle and
do some fairly vigorous exercises every half hour or
so until help comes.
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If You Are Stuck: In Sand, Mud,
Ice or Snow
In order to free your vehicle when it is stuck, you will
need to spin the wheels, but you don’t want 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.
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
25 mph
(55 km/h) as shown on the speedometer.
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 on page 5-70.
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. By slowly spinning your wheels in the forward
and reverse directions, you will cause a rocking
motion that may free your vehicle. 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” following.
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If yours was built with trailering options, as many are,
it’s ready for heavier trailers. But trailering is different
than just driving your vehicle by itself. Trailering means
changes in handling, durability and fuel economy.
Successful, safe trailering takes correct equipment,
and it has to be used properly.
That’s the reason for this part. In it are many time-tested,
important trailering tips and safety rules. Many of these
are important for your safety and that of your passengers.
So please read this section carefully before you pull
a trailer.
If You Do Decide To Pull A Trailer
If you do, here are some important points:
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There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
your rig will
be legal, not only where you live
but also where you’ll be driving.
A good source for
this information can be state or provincial police.
Consider using
a sway control if your trailer will
weigh 2,000 Ibs
(900 kg) or less. You should
always use a sway control
if your trailer will weigh
more than 2,000
Ibs (900 kg). You can ask a
hitch dealer about sway controls.
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Don’t tow a trailer at all during the first 500 miles
(800 km) your new vehicle is driven. Your engine,
axle or other parts could be damaged.
Then, during the first
500 miles (800 km) that you
tow a trailer, don’t drive over
50 mph (80 km/h)
and don’t make starts at full throttle. This helps your
engine and other parts of your vehicle wear in at
the heavier loads.
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).
Three important considerations have to do with weight:
the weight of the trailer,
the weight of the trailer tongue
and the weight on your vehicle’s tires.
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Tow/Haul Mode
The tow/haul mode is a feature that assists when pulling
a heavy trailer. The purpose of the tow/haul mode is:
e to reduce the frequency of shifts when pulling a
heavy trailer.
to provide the same shift feel when pulling a heavy
trailer as when the vehicle is unloaded.
to reduce the need to change throttle position when
pulling a heavy trailer.
This feature is turned on or off by pressing a button on
the column shift lever. When the feature
is on, a
light on the instrument panel will illuminate to indicate
that the tow/haul mode has been selected.
See
Tow/Haul Mode Light on page 3-36. The tow/haul
mode is automatically turned
off each time the vehicle
is started.
The tow/haul mode is most effective when the vehicle
and trailer combined weight is at least
75% of the Gross
Vehicle Weight Rating (GVWR) and the maximum
trailer weight rating for the vehicle. The tow/haul
mode for hauling a heavy trailer is most
useful under the following conditions:
When driving through hilly terrain at speeds below
55 mph
(88 km/h).
When driving in low speed or stop and go traffic
below
55 mph (88 km/h).
When driving in parking lots.
Operating in the tow/haul mode when not pulling a
heavy trailer will not cause damage to the vehicle,
but you may experience reduced fuel economy
and undesirable petformance from the engine and
transmission. The tow/haul mode should be used only
when pulling a heavy trailer.
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how you plan to use your rig. For example,
speed, altitude, road grades, outside temperature and
how much your vehicle is used to pull a trailer are all
important. And, it can also depend on any special
equipment that you have on your vehicle.
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Driving with a Trailer
If you ~ ve a rear-most window open and
you pull a trailer with your vehicle, carbon monoxide (CO) could come into your vehicle.
You can’t see or smell
CO. It can cause
unconsciousness or death. See “Engine
Exhaust” in the Index.
To maximize your safety
when towing a trailer:
Have your exhaust system inspected for
leaks, and make necessary repairs before
starting on your trip.
Keep the rear-most windows closed.
If exhaust does come into your vehicle
through a window
in the rear or another
opening, drive with your front, main
heating or cooling system on and with the
fan on any speed. This will bring fresh,
outside air into your vehicle.
Do not use
the climate control setting for maximum air because
it only recirculates the air inside
your vehicle. See “Climate Controls” in
the Index. Towing
a trailer requires a certain amount of experience.
Before setting out for the open road, you’ll want to get
to know your rig. Acquaint yourself with the feel of
handling and braking with the added weight of the trailer.
And always keep in mind that the vehicle you are
driving is now a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check the trailer hitch and platform
(and attachments), safety chains, electrical connector,
lamps, tires and mirror adjustment. If the trailer has
electric brakes, start your vehicle and trailer moving and
then apply the trailer brake controller by hand to be
sure the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally
to be sure that
the load
is secure, and that the lamps and any trailer
brakes are still working.
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