1994 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.
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 “N” (Neutral).
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 OFF THE 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 NOTICE:
In cold weather, water can freeze and crack the engine, radiator, \
heater core and other parts. Use the recommended coolant.
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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~ 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.
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 "Sta\
rt" for 10
to 15 seconds to crank (but not start) your engine. Wait one minut\
e
between intervals of cranking to allow the starter motor to cool.
Overheating the starter could damage it. Keep doing this until you can
just see some clear fuel at the air bleed valve. (If, during this ste\
p, the
engine starts, turn the ignition
off and close the valve before restart.)
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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 -20 OF (-29”C), or -34°F (-37°C) in
Canada and for vehicles with the cold climate option.
Give boiling protection up to 258 OF ( 125 O 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 clean wuter (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” with a complete coolant flush and refill. If you use
this mixture, you don’t need to add anything else.
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I 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.
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 -Gas Engines
To Check Coolant
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 COLD, or a little
higher. When
your engine is warm, the level should be up to HOT, or a little
higher.
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Radiator Pressure Cap-Gas Engines
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.
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.
Surge Tank Pressure Cap- Diesel Engines
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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.
Power Steering Fluid
NOTICE:
Always turn the engine off before checking or adding power
steering fluid. The power steering pump cap is close to the fan
and other moving parts.
How To Check Power Steering Fluid
Unscrew the cap and
wipe the dipstick
with
a clean rag. Replace
the cap and completely
tighten it. Then
remove the cap again
and
look at the fluid
level on the dipstick.
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Driving (continued) AtNight
............................................... 4-24. 4.38
BackingUp
.................................................. 4-42
Defensive
.................................................... 4-2
Downhill
.................................................... 4-19
Freeway
...................................................... 4-29
Highway Hypnosis
............................................ 4-30
Hydroplaning
................................................ 4-27
InBlizzard
................................................... 4-35
InCity
...................................................... 4-28
InRain
...................................................... 4-26
In Sand, Mud, Ice, Or Snow
........................... 2-15,4-22, 5-40
InWater
..................................................... 4-23
Nightvision
................................................. 4-25
Off-Roading
................................................. 4-13
OnGrades
................................................... 4-43
On Hill and Mountain Roads .................................... 4-31
On Off-Road Hills
............................................ 4-16
On Snow or Ice
..................................... 2-15,433, 4-55
Skidding
.................................................... 4-12
Stuck in Deep Snow
...................................... 4-40, 5-40
Throughwater
.......................................... 2-15, 4-23
Uphill
...................................................... 4-17
Winter
...................................................... 4-33
WithaTrailer
................................................ 4-41
DrunkenDriving ................................................. 4-2
E
Electronic Heating/Air Conditioning (See “Heating”) Engine Adding Coolant
..................................... 5.14.5.17. 6-41
Coolant (Block) Heater
................................ 2.19.3-4. 6.23
Cold Weather Starting (Diesel)
................................... 2-17
Coolant
...................................... 5.13.5.20.6-92. 6.98
Coolant Temperature Gage
...................................... 2-79
Diesel
.................................................. 2.16. 6-5
Crankcase .............................................. 2.96. 6.93
Exhaust
................................................ 2.33. 6.64
FanNoise
................................................... 5-25
Identification
................................................. 6-89
Oil (See “Oil”)
RunningWhileParked
......................................... 2-33
Aircleaner
.................................................. 6-29
Noise Control System
.......................................... 6-16
Overheating
.................................................. 5-11
starting ................................................ 2.12. 2.16
Equipment. Add-on
............................................. 6-68
Exhaustsystem
............................................ 2.33. 6-64
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