engine GMC SIERRA 1993 Repair Manual

If your vehicle has the four-wheel-drive option and the transfer c\
ase is
engaged, a dolly must be used under the rear wheels when towi\
ng from the
front.
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.
If Steam Is Coming From Your Engine:
K2509
I CAUTION
A
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.
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Problems on the Road
If your engine catches fire because you keep driving with no cool\
ant, your
vehicle can be bac"lI damaged.
T- ! costly rep; 1 would not be Iverec
by your warranty.
If No Steam Is Coming From Your Engine:
If you get the overheat warning but see or hear no steam, th\
e 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.
Idle for long periods in traffic.
Tow a trailer.
If you get the overheat warning with no sign of steam, try t\
his 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
3. If you're in a traffic jam, shift to N (Neutral).
window as necessary.
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 vehic\
le 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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Cooling System
PO21 0
When you decide it’s safe to lift the hood, here’s what you’ll see:
A. Coolant recovery tank
B. Radiator pressure cap
C. Engine fan
CAUTION
‘4
An electric fan under the hood can start up even when the engine\
is
not running and can injure you. Keep hands, clothing, and tool\
s
away from any electric fan.
m
If the coolant inside the coolant recovery tank is boiling, don’t do anything
else until it cools down.
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I
I
‘4
!b P4
LL
1
PO593
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.
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 cou
lose all coolant. That could cause an engine fire, and you could be
burned. Get any leak fixed before you drive the vehicle.
I I
NOTICE
Engine damage from running your engine without coolant isn’t covered by
I your warranty.
If there seems to be no leak, check to see if the electric engine fan (if you
have one) is running.
If the engine is overheating, the fan should be running.
If it isn’t, your vehicle needs service.
Start the engine again to see
if the regular fan runs when the engine does.
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
COLD, add a 50hO mixture of clean water (preferably distilled) and a proper
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antifreeze at the coolant recovery tank. (See “Coolant” in the Index for more
information about the proper coolant mix.)
* 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
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
7 50/50 mix of clean water and a proper antifreeze.
I ln cold weather, water can freeze and crack the engine, radiator, heate\
r
:ore and other parts. Use the recommended coolant.
PO206
I * You can be burned if you spill coolant on hot engine parts. CoolQni
A contains ethylene glycol and it will burn if the engine parts are hut
enough. Don’t spill coolant on a hot engine.
When the coolant in the coolant recovery is at
or above COLD, start your
vehicle.
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Prob/ems on the Road
t
e;
K2550
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 m\
ay be
lower.
If the level is lower, add more of the proper mix through the f\
iller
neck until the level reaches the base of the filler neck.
K2515
8. Then replace the pressure cap. Be sure the arrows on the pressure cap
line up like this.
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Engine Fan Noise
This vehicle has a clutched engine cooling fan. When the clutch is engaged,
the fan spins faster to provide more air to
cool the engine. In most every day
driving conditions the clutch is not engaged. This improves fue\
l economy and
reduces fan noise. Under heavy vehicle loading, trailer towing andlor high
outside temperatures, the fan speed increases when the clutch e\
ngages.
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 disengages.
You may also hear this fan noise when you start the engine. It will go away
as the fan clutch disengages.
If a Tire Goes Fiat
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. Take your foot off the accelerator pedal and grip \
the steering wheel
firmly. Steer to maintain lane position, 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 may
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 your tire goes flat, the next part shows how to use your jacking equipment
to change a flat tire safely.
Changing a Flat Tire
If a tire goes flat, avoid further tire and wheel damage by driv\
ing slowly to a
level place. Turn on your hazard warning flashers.
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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. The method known as “rocking” can help you get o\
ut when you’re
stuck, but you must use caution.
CAUTION - --
I * If you let your tires spin at high speed, they can explode and you or
,A 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 krnlh) as shown
I on the speedometer.
;pinning your wheels can destroy parts of your vehicle as well as the
res.
If you spin the wheels too fast while shifting your transmission back
.nd forth, you can destroy your transmission.
NOTICE 1
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
R and a forward gear
(or with a manual transmission, between First or Second 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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Service & Appearance Care
.....
Here you will find information about the care of your vehicle . This Section
begins with service and fuel information. and then it shows how to check
important fluid and lubricant levels
. There is also technical information about
your vehicle. and a section devoted to its appearance care
.
Service ........................................................................\
........................................... 6-3
Fuel (Gasoline Engines)
........................................................................\
............... 6-4
Diesel Fuel Requirements and Fuel System
...................................................... 6-6
Checking Things Under the Hood
..................................................................... 6-17
Hood Release
........................................................................\
.......................... 6-18
Cleaning Your Diesel Engine
........................................................................\
.. 6-19
Noise Control System
........................................................................\
............. 6-19
Engine Oil (Except Diesel)
........................................................................\
..... 6.20
Engine Oil (Diesel Engines)
........................................................................\
... 6-26
Air Cleaner
........................................................................\
............................... 6-31
Automatic Transmission Fluid
........................................................................\
. 6-33
Manual Transmission Fluid
........................................................................\
..... 6-36
Hydraulic Clutch
........................................................................\
....................... 6-37
Transfer Case
........................................................................\
.......................... 6-39
Front Axle ........................................................................\
................................. 6-40
Rear Axle
........................................................................\
................................. 6-41
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Service & Appearance Care
Engine Coolant ........................................................................\
........................ 6-42
Power Steering Fluid
........................................................................\
............... 6-46
Windshield Washer Fluid
........................................................................\
......... 6-48
Brake Master Cylinder
........................................................................\
............. 6-49
Replacing Brake System Parts
........................................................................\
.. 6-50
Other Maintenance Items ........................................................................\
........... 6-51
Lubrication
........................................................................\
.................................... 6-52
Electrical System
........................................................................\
......................... 6-54
Battery
........................................................................\
...................................... 6-54
Fuses and Circuit Breakers
........................................................................\
.... 6-64
Bulb Replacement
........................................................................\
.................... 6-54
Exhaust System
........................................................................\
........................... 6-65
Loading Your Vehicle
........................................................................\
.................. 6-67
Tires
........................................................................\
.............................................. 6-72
Inflation-Tire Pressure
........................................................................\
........... 6-73
Tire Inspection and Rotation
........................................................................\
.. 6-78
When It's Time for New Tires
........................................................................\
6-80
Buying New Tires
........................................................................\
.................... 6-81
Wheel Alignment and Tire Balance
............................................................... 6-82
Wheel Replacement
........................................................................\
................. 6-83
Tire Chains
........................................................................\
............................... 6-84
Appearance Care
........................................................................\
........................ 6-84
Cleaning the Inside Of Your Vehicle
............................................................. 6-85
Cleaning the Outside Of Your Vehicle
.......................................................... 6-88
Appearance Care Materials
.r.ikl...rr.r.n.....lr. ........ ... .. 6-91
Vehicle Identification Number
........................................................................\
..... 6-92
Service Parts Identification Label
...................................................................... 6-94
Specification Charts
....++t....,.,.*,..-".,,. .............. , ........... .................... 6-95
Uniform Tire Quality Grading
........................................................................\
.. 6-81
..................................................
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