engine GMC SAVANA 1997 Workshop Manual

Engine Overheating
(Gasoline Engine)
You will find a coolant temperature gage on your vehicle’s
instrument panel.
If you have a diesel engine, you will also
find a low coolant light on your instrument panel.
If your vehicle has a diesel engine, see “Engine
Overheating” in the Diesel Engine Supplement.
If Steam Is Coming From Your Engine
Steam from 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.
I 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.
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If No Steam Is Coming From Your Engine
If you get the 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:
0 Climb a long hill on a hot day.
0 Stop after high-speed driving.
0 Idle for long periods in traffic.
Tow a trailer. See “Driving on Grades” in the Index.
If you get the overheat warning with no sign of steam,
try this for a minute or
so:
1. If you have an air conditioner, turn it off.
2. Turn on your heater to full hot at the highest fan
3. If you’re in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to
the highest gear while
driving
-- AUTOMATIC OVERDRIVE (a)
or DRIVE (D). speed and
open the window as necessary. 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, pull over, stop, and park your
vehicle right away.
If there’s still no sign of steam, you can idle the engine
for two or three minutes while you’re parked, to push
the accelerator until the engine speed is about twice as
fast as normal idle speed. Bring the engine speed back
to normal idle speed after two or three minutes. Now
see if the warning stops. But then, if you still have the
warning,
turn ofithe 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.
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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 or above the
FULL
COLD mark.
A. Radiator pressure cap
B. Coolant recovery tank
C. Engine fan(s)
If the coolant inside the coolant recovery tank is boiling,
don’t do anything else until it cools down.
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If it isn’t, you may have a leak in the radiator hoses,
heater hoses, radiator, water pump or somewhere else in
the cooling system.
A CAUTION:
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 a11 coolant. That could
cause an engine fire, and
you could be burned.
Get any leak fixed before
you drive the vehicle.
NOTICE:
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.
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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
FULL COLD mark, add a 50/50 mixture of
clean water (preferably distilled) and DEX-COOL@
(silicate-free) antifreeze
at the coolant recovery tank. (See
“Engine Coolant” in the Index for more information.)
Adding only plain
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.
CAUTION: (Continued) JAUTION:
(Continu
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@ coolant.
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.
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’ 1 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
FULL COLD 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.
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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 fan.
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.
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.
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Engine Fan Noise
Your 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 fan
is spinning slower and 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 as the
clutch more fully 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 partially disengages.
You may
also hear this fan noise when you start the engine.
It will go away as the fan clutch partially 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 “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.
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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.
A
/! CAUTION:
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. Turn off the engine.
To be even more certain the vehicle won’t move,
you can put 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.
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5. Put the flat end of the extension on an angle through
the hole in
the rear door frame, above the bumper.
Turn the ratchet clockwise until the tire is against the
underside
of the vehicle.
You will hear two “clicks” when the tire
is up all the
way. Try
to move the tire with your hands to make
sure
it is securely in place.
Return the jacking equipment
to the proper location.
Secure the items and replace the jack cover.
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.
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 kmh) as shown
on the speedometer.
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