1996 GMC SIERRA engine

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:
Climb a long hill on a hot day.
0 Stop after high-speed driving.
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:
I. If you have an air conditioner, turn it off.
2. Turn on your heater to full hot at the highest fan
speed and open the window
as necessary.
3. If you’re in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving
-- AUTOMATIC OVERDRIVE (0)
or THIRD (3) for automatic transmissions.
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, 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 of
the engine nrzd get everyone nut 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 -- Gasoline Engines
When you decide it's safe to lift the hood, here's what
you'll see:
A. Coolant Recovery Tdnk
B. Radiator Pressure Cap
C. Engine Fan(s)
A CAUTION:
If your vehicle has air conditioning, the auxiliary
electric fan under the hood can start up even when the engine is not running and can injure
you. Keep hands, clothing and tools away from
any underhood electric fan.
If the coolant inside the coolant recovery tank is boiling,
don't do anything else
until it cools down.
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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 all coolant. That could
cause an engine fire, and you could be burned.
Get any leak fixed before you drive the vehicle.
The coolant level should be at or above the
COLD mark.
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.
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NOTICE:
I
I
I
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 or above the
COLD mark, add a SO/SO mixture
of ciecu? wter (preferably distilled) and DEX-COOL”
(orange-colored, silicate-free) antifreeze at the coolant
recovery tank.
(See (‘Engine Coolant” in the Index for
more information.)
I A CAUTION:
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.
I 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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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 hat engine.
When the coolant in the coolant recovery tank is at or
above
the 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(s).
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 mix through the filler neck until
the level reaches the base of the filler neck.
I
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 fdster to provide more air
to cool the engine.
In most every day 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 andor
high outside temperatures, the
fm 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
fm 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. Fake 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
ITMY 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 tlat, 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.
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 an automatic transmission shift lever in
PARK (P) or shift a manual transmission to
FIRST (1) or REVERSE: (K).
3. If you have a four-wheel-drive vehicle,
be sure the transfer case is
in a drive
gear
-- not in NEUTRAL (N).
4. Turn off the engine.
CAUTION: (Continued)
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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