1996 GMC SIERRA engine overheat

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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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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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.
- -. ..
;. ;
- - - -
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: I
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.
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Front Axle
When to Check and Change Lubricant
Refer to the Maintenance Schedule to determine how
often
to check the lubricant and when to change it. See
"Scheduled Maintenance Services"
in the Index.
How to Check Lubricant
If the level is below the bottom of the filler plug hole.
you'll
need to add some lubricant.
If the differential is at operating temperature (warm),
add enough lubricant
to raise the level to the bottom of
the filler plug hole.
If the differential is cold, add enough lubricant to raise
the level
to 1/2 inch (1 2 mm) below the filler plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind
of lubricant to use. See "Recommended Fluids and
Lubricants"
in the Index.
Engine Coolant
The cooling system in your vehicle is filled with new
DEX-COOL
TM (orange-colored, silicate-free) engine
coolant. This coolant is designed
to remain in your
vehicle for
5 years or 100,000 miles (1 66 000 km),
whichever occurs first.
The following explains
your cooling system and how
to add coolant when it is low. If you have a problem
with engine overheating, see "Engine Overheating"
in
the Index.
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A 50/50 mixture of water and the proper coolant for
your vehicle
will:
Give freezing prorecrlon down to -34°F (-37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning gages work as they should.
NOTICE:
When adding coolant it is important that you use
DEX-COOL TM (orange-colored, silicate-free)
coolant meeting
GM Specification 6277M.
If silicated coolant 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. use
a mixture
of one-half dum wwter (preferably
distilled) and one-half
DEX-COOL” (orange-colored.
silicate-free) antifreeze that meets
GM Specification
6277M. which
won‘t damage aluminum parts. Use
GM Engine Coolant Supplement (sealer) (GM Part
No. 363462 1 ) with any complete coolant change. If you
use this mixture.
you don’t need to add anything else.
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
50150 mix of clean
water and
DEX-COOL TM (orange-colored,
silicate-free) antifreeze.
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NOTICE:
If you use an improper coolant mix, your engine
could overheat and be badly damaged. The
repair cost wouldn't be covered by your
warranty.
Too much water in the mix can freeze
and crack the engine, radiator, heater core and
other parts.
If you have to add coolant more than four times 8 year,
have
your dealer check your cooling system.
NOTICE:
If you use the proper coolant, you don't have to
add extra inhibitors or additives which claim to
improve the system. These can be harmful.
Checking Coolant
If your vehicle has a diesel engine, see "Clwcking
Coolant"
in the Diesel Engine Supplement.
d
The coolant recovery tank is located on the passenger
side at the rear corner of the engine compartment.
When your engine
is cold, the coolant level should be at
the
COLD mark, or a little higher. When your engine is
warm. the level sho~~ld be up to the HOT mark, or a
little higher.
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Radiator Pressure Cap
(Gasoline Engine)
The radiator pressure cap must be tightly installed with
the arrows on the cap lined LIP with the overflow tube on
the radiator filler neck.
NOTICE:
Your radiator cap is a 15 psi (105 kPa)
pressure-type cap and must be tightly installed
to prevent coolant
loss and possible engine
damage from overheating. Be sure the arrows
on the
cap line up with the overflow tube on the
radiator filler neck.
Thermostat
Engine coolant temperature is controlled by a thermostat
in the engine coolant system. The thermostat stops the
flow of coolant through the radiator until the coolant
reaches
a preset temperature.
When you replace your thermostat, an AC@ thermostat
is recommended.
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