GMC SIERRA 1993 Owners Manual

Service
Your General Motors dealer knows your vehicle best and wants you to be
happy with it. We hope you’ll go to your dealer for
all your service needs.
You’ll get genuine GM parts and GM-trained and supported ser\
vice people.
We hope you’ll want to keep your GM vehicle all GM. Genuine
GM parts
have one of theqe marks:
Doing Your
If you want to
proper General
GM
Own Service Work
do some of your own service work, you’ll want to get the
.. Motors Service Manual. It tells you much more about how to
service your vehicle than this manual can.
To order the proper service
manual, see “Service Publications” in the Index.
You should keep a .record with all parts receipts and list the mileage and the
date of any service work you perform. See “Maintenance Record” \
in the
Index.
I CAUTION
AA You can be injured if you try to erv n a vehicle without
knowing enough about it.
I
Be sure you have sufficient knowledge, experience, and the
proper replacement parts and tools before you attempt any
vehicle maintenance task.
Be sure to use the proper nuts, bolts and other fasteners.
“English” and “metric” fasteners can be easily confus\
ed.
If you
use the wrong fasteners, parts can later break or fall
off. You
could be hurt.
I
6-3
ProCarManuals.com

Service & Appearance Care
1 If you try to do your own service work without knowing enough ab\
out it, I
1 your vehicle could be damaged.
Maintenance Schedule
Section 7 of this manual, “Scheduled Maintenance Services”, explains the \
maintenance your new vehicle needs, and when
it -should be done. It also,
has a form that you can use to record the maintenance work done \
on your
vehicle. Be sure to read this ,information.
-I .. >. ’ , .
Fuel (Gasoline Engines)
If your vehicle has a diesel engine, see “Diesel Fuel Requi\
rements and Fuel
System’’ in this Section: For vehicles with gasoline engines, please read this.
Use regular unleaded gasoline rated at 87 octane or’higher.
It should meet
specifications ASTM D4814 in the
U.S. and CGSB 3.592 in Canada. These
fuels should have the proper additives,
so you should not have to add
anything to the fuel.
In the
U.S. and Canada, it’s easy to be sure you get the right kind of
gasoline (unleaded). You’ll see
UNLEADED right on the pump. And only
unleaded nozzles
will fit into your vehicle’s filler neck.
Be sure the posted octane is at least 87. If the octane
is less than 87, you
may get a heavy knocking noise when you drive.
If it’s bad enough, it can
damage your engine.
6-4
ProCarManuals.com

If you’re using fuel rated at 87 octane or higher and you still hear heavy
knocking, your engine needs service. But don’t worry
if you hear a little
pinging noise when you’re accelerating or driving up a hill. That’s normal and
you don’t have
to buy a higher octane fuel to get rid of pinging. It’s the
heavy, constant knock that means you have a problem.
What about gasoline with blending materials that contain oxygen,\
such as MTBE or alcohol?
MTBE is “methyl tertiary-butyl ether.” Fuel that is no more than 15% MTBE is
fine for your vehicle.
Ethanol is ethyl or grain alcohol. Properly-blended fuel that is no more than
10% ethanol is fine for your vehicle.
Methanol is methyl or wood alcohol.
le1 that is more than
5% methanol is bad for your vehicle. Don’t use it.
can corrode metal parts in your fuel system and also damage plastic
and rubber parts. That damage wouldn’t be covered under your warranty
And even at
5% or less, there must be “cosolvents” and corrosion
- ~wenters in this fuel to help avoid these problems.
Gasolines for CIeaner Air
Your use of gasoline with detergent additives will help prevent depo\
sits from
forming in your engine and fuel system. That helps keep your engine in tune
and your emission control system working properly. It’s good \
for your vehicle,
and you’ll be doing your part for cleaner air.
Many gasolines are now blended with materials that called
oxygenates.General Motors recommends that you use gasolines with \
these
blending materials, such as MTBE and ethanol. By doing
so, you can help
clean the air, especially in those parts
of the country that have higher carbon
monoxide levels.
In addition, some gasoline suppliers are now producing reformulated \
gasolines. These gasolines are specially designed to reduce vehicle
emissions. General Motors recommends that you use reformulated g\
asoline.
By doing
so, you can help clean the air, especially in those parts of the
country that have high ozone levels.
You should ask your service station operators
if their gasolines contain
detergents and oxygenates, and
if they have been reformulated to reduce
vehicle emissions.
6-5
ProCarManuals.com

Service & Appearance Care
Diesel Fuel Requirements
and Fuel System
Some states and provinces have restrictions on the purchase of diesel fuel
for light-duty vehicles and require you
to buy permits or pay special taxes.
Some of these restrictions apply only
to residents, and others apply to both
residents and visitors. These restrictions can change.
To learn the current
restrictions in any state or province, contact your auto club, \
the police or
other officials.
Fuel Requirements
1 NOTICE
Diesel fuel or fuel additives not recommended in this manual could
damage your fuel system and engine. Your warranty wouldn’t cover thi
damage. And:
Diesel fuel that has been mixed with engine oil could damage your
engine and emission controls.
Always check with your service station
his
diesel fuel, it can be difficult to restart your
engine. “Running Out of Fuel,” later
in this section, tells you how to
get
it started again. To avoid all this, try never to let. your tank get
What Fuel to Use:
You can use either Number I-D or Number 2-D diesel fuel, but you’ll get
better fuel economy using
2-D.
Diesel fuel may foam when you fill your tank. This can cause the automatic
pump nozzle
to shut off, even though your tank isn’t full. If this happens, just
wait for the foaming to stop and then continue to fill your tank.
1 CAUTION
- Heat coming from the engine may cause the fuel to expand and force
the fuel out of your tank. If something ignites the fuel, a \
fire could start
and people could be burned.
To help avoid this, fill your fuel tank only
until the automatic nozzle shuts
off. Don’t try to “top if off .” I
I
6-6
ProCarManuals.com

Cold Weather Operation
In cold weather (below 20”F, or -7°C)’ use 1-D or “Winterized” Number 2-D
fuel (a blend of 1-D and 2-D). Be sure you get the right fuel. In very cold
temperatures (when it stays below
0°F or -18”C), use Number 1-D.
If you’re driving in very cold temperatures and can’t get\
Number 1-D or a
“winterized” Number 2-D, you can use one gallon of kerosene for every two
gallons of diesel fuel. Once you add the kerosene, run your engine for
several minutes
so the fuels will mix. Add kerosene only when the
temperature falls below
0°F (-18°C)’ because the fuel economy of kerosene
isn’t as good as that of diesel fuel.
NOTICE I
Never use home heatina oil o
I
1
In cold weather, your fuel filter may become clogged, especiall\
y if you use
Number 2-D diesel fuel that hasn’t been “winterized.” To unclog it, just warm the
filter to between 32°F and
50°F (0°C to 10°C). You won’t need to replace it.
Water in Fuel
Sometimes, water can be pumped into your fuel tank along with \
your diesel
fuel. This can happen
if a service station doesn’t regularly inspect and clean
its fuel tanks, or
if it gets contaminated fuel from its suppliers.
If this happens, a WATER IN FUEL light will come on. If it does, the excess
water must be drained. Your dealer can
do this for you.
AT€
PBOlO
6-7
ProCarManuals.com

Service & Appearance Care
This light also should come on when you start your engine, as\
a check. If it
doesn’t, have it fixed
so it will be there to let you know if you ever do get
water in your fuel.
If the light comes on at any other time, use this chart.
“WATER IN FUE
PROBLEM
Light comes on intermittently.
1) Temperatures above freezing.
Light stays on
2) Temperatures below freezing.
3) Immediately after refueling -
Large amounts of water
probably pumped into the
tank.
.” LIGHT CHART
RECOMMENDED ACTION
Drain water from fuel filter.
Drain fuel filter immediately.
If nc
water is drained and light stays on
-
replace fuel filter.
Drain fuel filter immediately.
If no
water can be drained
- water may be
frozen. Open air bleed
to check for
fuel pressure.
If no fuel pressure
replace filter.
Fuel tank purging required. See your
dealer for assistance.
1
iesitation or “flat” performance at high speed or hard acceleration may be an
ndication of premature fuel filter plugging due to dirty
or contaminated fuel.
The filter element may need
to be changed if this happens. See your dealer
or assistance.
f you drive when this warning light is on, you can damage your fuel I
njection system and your engine. If the light comes on right after you
efuel,
it means water was pumped into your fuel tank. Turn off your
mgine immediately. Then, have the water drained at once.
I
To drain water:
1. Remove the fuel tank cap.
2. Connect a hose going from the water drain valve to a fuel-resistant
container.
6-8
ProCarManuals.com

7
F
K2451
..
3. With the engine off, open the water drain valve 2 to 3 turns.
4. Start the engine and allow it to idle for 1 to 2 minutes, or until clear fuel
is observed.
5. Stop the engine and close the water drain valve.
6. Install the fuel tank cap.
If the
WATER IN FUEL light comes on again after driving a short distance or
the engine runs rough or stalls-a large amount of water has probably been
pumped into the fuel tank. The fuel tank should be purged.
~ CAUTION I
A Diesel fuel containing water is still flammable. You could h~ burmi.
If you eve:r try to drain water from your fuel, kee,p sparks mes d.
. smoking materials away from the mixture.
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 service technician. Improper purging can damage your fuel
system.
6-9
ProCarManuals.com

Service & Appearance Care
Running Out of Fuel (Diesel Engines)
If the engine stalls and you think that you’ve run out of fuel, do this:
6.5L Engine
c
F-
P
6.2L Engine
PO228
First, open the fuel filter air bleed valve or remove the scr\
ew. 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.
PO227
6-1 0
ProCarManuals.com

2. Unplug the Shut-Off solenoid wire from the fuel pump to prevent the
engine from starting.
3. With the air bleed valve open, turn your ignition key to Start for 10 to
15 seconds to crank (but not start) your engine. Keep doing this until
you can just see some clear fuel at the air bleed valve.
I A Diesel fuel is flammable. It could start a fire if it gets on hot engine
b parts. You could be burned. Don’t let too much fuel flow from the air
bleed valve or screw, and wipe up any spilled fuel with a cloth.
4. Close the air bleed valve, or replace the screw and reconnect \
the
Shut-Off solenoid wire.
5. Turn the ignition key to Start for 10 to 15 seconds at a time until your
engine starts.
Fuel Filter Replacement (6.5L Diesel Engines)
If you want to change the fuel filter yourself, here’s how \
to do it:
1 CAUTION
A Diesel fuel is flammable. It could start a fire if something ignites it,
-L and you could be burned. Don’t let it get on hot .engine parts, and
I keep matches or other ignition sources away.
1. Turn off your engine and set your parking brake.
2. Take off the fuel tank cap. This releases pressure in the tank.
6-1 1
ProCarManuals.com

Service & Appearance Cave
PO503
3. The filter is behind the air cleaner on the intake manifold. \
Unscrew and take
off the ring nut from the the top of the filter head. Lift the element
out of the filter head.
4. If there is any dirt on the element sealing surface of the filter head,
clean it
off.
...
t
PO212
5. Line up the widest key slot in the top of the new element with the
widest key on the filter head
and push the element in until the mating
surfaces touch.
6-1 2
ProCarManuals.com