1995 GMC SIERRA engine overheat

Engine Overheating
YOU will find a coolant temperature gage on your vehicle instrument panel.
If
YOU have a diesel engine, you will also find a low coolant light on your
instrument panel.
lf Steam Is Coming From Your Engine
A CAUTION:
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 opening 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.
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 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 (@) or
DRIVE
(3) for automatic transmissions.
If you no longer have the overheat warning, you can drive. Just to be safe,
drive slower for about ten 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 ofSthe 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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I 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.
I 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.
How to Add Coolant to the Coolant Surge Tank
I NOTICE:
The diesel engine has a specific coolant fill procedure. Failure to
follow this procedure could cause your engine to overheat and be
severely damaged.
If you haven’t found a problem yet, but the coolant level isn’t at the COLD
mark, add a
50/50 mixture of cleun water (preferably distilled) and a proper
antifreeze at the coolant surge tank, but be sure the cooling system,
including the
coolant surge tank pressure cap, is cool before you do it. (See
“Engine Coolant”
in the Index for more information about the proper
coolant mix.)
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A CAUTION:
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 coolant surge tank pressure cap
- even a little - they
can come out at high speed. Never turn the cap when the cooling
system, including the coolant surge tank pressure cap,
is hot.
’ Wait for the cooling system and coolant surge tank pressure cap
to cool
if you ever have to turn the pressure cap.
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 a proper antifreeze.
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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 nlust use caution.
A 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 par\
ts
of the vehicle can overheat. That could cause an engine
compartment fire or other damage. When you’re stuck, spin th\
e wheels
as little as possible. Don’t spin the wheels above 35 mph
(55 km/h) as shown on the speedometer.
I 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”
in the Index.
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 (or
with a manual transmission, between FIRST (1 ) or
SECOND (2) gear and REVERSE), 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. If that doesn’t get you
out after a few tries, you may need
to be towed out. Or, you can use your
recovery hooks,
if your vehicle has them. If you do need to be towed out.
see “Towing Your Vehicle”
in the Index.
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NOTICE:
If there is water in your diesel fuel and the weather is warm or
humid, fungus and bacteria can grow in the fuel. They can
damage your fuel system. You'll need a diesel fuel biocide to
sterilize your fuel system. Your dealer can advise
you if you ever
need this.
If your fuel tank needs to be purged to remove water, see your
dealer or a qualified technician. Improper purging can damage
your fuel system.
Running Out of Fuel (Diesel Engines)
If the engine stalls and you think that you've run out of fuel, do this:
First, open the fuel filter air bleed valve.
Briefly crank the
engine and have
someone watch the
bleed valve. If there is
air, then you are
probably
out of fuel.
To restart your engine:
I. If you're parked on a level surface, add at least two gallons of fuel.
However, if you're parked
on a slope, you may need to add up to five
gallons of fuel.
2. With the air bleed valve open, turn your ignition key to START for 10
to
15 seconds to crank (but not start) your engine. Wait one minute
between intervals
of cranking to allow the starter motor to cool.
Overheating the starter motor could damage it. Keep doing this until
you can just see some clear fuel at the air bleed valve. (If, during this
step, the engine starts, turn the ignition off and close the valve before
restart.)
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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
( 12 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 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.
The proper coolant for your vehicle will:
Give freezing protection down to -34°F (-37°C).
0 Give boiling protection up to 262°F (128°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning gages work as they should.
What to Use
Use a mixture of one-half cleun water (preferably distilled) and one-half
antifreeze that meets “GM Specification 6038-M,” which won’t damage
aluminum parts.
You can also use a recycled coolant conforming to “GM
Specification 6038-M.” Use GM Coolant Supplement (Sealer) with a
complete coolant flush and refill. If you use this mixture. you don’t need to
add anything else.
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
a proper 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.
Some conditions. such as air trapped
in the cooling system. can affect the
coolant level
in thc radiator. Check the coolant level when the engine is cold
and
follow the steps under “Adding Coolant“ for the proper way to add
coolant.
If you have to add coolant more than lour timcs a ycar, 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.
Adding Coolant - Gasoline Engine
The coolant reco\wy
tank is located on the
passenger side
at the
rear comer
of the
engine compartment.
To Check Coolant
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 should be up to the
HOT mark, or a little higher.
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