1995 CHEVROLET SUBURBAN engine overheat

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.
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.
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:
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 (a) 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.
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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
NOTICE:
The diesel engine has a specific coolant fill procedure. Failur\
e 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 clean 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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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:
1. 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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How to Check Lubricant
P
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
(I 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 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).
Give boiling protection up to 262°F (128°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they should.
What to Use
Use a mixture of one-half chi? wcmr (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
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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.
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 the 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 four times
a year, have your dealer
check
your cooling system.
I 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.
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To Add Coolant
If you need more coolant, add the proper mix crt the surge tunk, but only
when the engine
is cool. If the surge tank is empty, see “Engine
Overheating”
in the Index for the proper fill procedure.
A 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 replacing the pressure
cap, make sure it is tight.
Radiator Pressure Cap - Gasoline Engine
The radiator pressure
cap
must be tightly
installed
with the
arrows on the cap
lined up with the
overflow tube
on the
radiator filler neck.
U
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.
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Surge Tank Pressure Cap - Diesel Engine
The surge tank
pressure cap must
be
tightly installed with
the arrows on the cap
lined up with the top
tube
of the coolant
surge tank.
NOTICE:
Your surge tank pressure cap is a unique 15 psi (105 kPa)
pressure-type cap for use with surge tank cooling systems only.
It 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 top tube of the coolant surge tank.
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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E
Eiectrical System
Engine Add-On
Equipment
........................................... 6-74
Adding Coolant
. Diesel Engine ........................... 5.18, 636
Adding Coolant
- Gasoline Engine .... , .................... 5-1 1’6-35 .
Air Cieaner
Coolant
.........................
Coolant Heater ...................
Coolant Temperature Gage (See “Gages‘
Diesel Heater Output
...............
.
......................
Control Module System ............
........................... 6-25
........................... 6-53
........................... 6-33
.................. 2-19.3-4. 6-19
1
............................ 3-4
Exhaust
..................................................... 2-31
FanNoise
................................................... 5-24
Identification .................................. 6-72.6-73.6-76. 6-77
Oil (See “Oil”)
Overheating
................................................... 5-9
RunningWhileParked ......................................... 2-32
Starting Your Gasoline Engine
................................... 2-13
Starting Your Diesel Engine
..................................... 2-15
Exhaust System
............................................... 6-53
F
Filter Replacement Chart (See “Service-Replacement Parts and Filter
Recommendations’’)
Fluid Capacities (See “Capacities and Specification”)
Fluid Leak Check
..................................... ........ 6-45
Fluids (See “Scheduled Maintenance Services”)
Four-WheelDrive
............................................... 2-33
Front Axle Locking Feature
..................................... 2-35
Transfer Case
........................................... 2-33. 6-32
Canadian
..................................................... 6-5
Diesel
....................................................... 6-4
Filling Your Tank ............................................. 6-11
Foreign Countries (Gasoline Engines)
............................. 6-11
Filter Replacement (Diesel Engines)
............................... 6-9
Gage (See “Gages”)
Gasoline
..................................................... 6-2
Gasolines for Cleaner Air
........................................ 6-3
Running Out of Fuel (Diesel Engines) .............................. 6-8
Tankcapacity ................................................ 6-78
Water in Fuel (Diesel Engines) ............................... 2-70. 6-5
Fuses and Circuit Breakers ................................... 6-75. 6-81
FuseBlock
............................................. 6-766-80
Fuel
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