1994 GMC SIERRA Owners Manual

NOTICE:
Your engine is designed to work with the electronics in your
vehicle.
If you add electrical parts or accessories, you could
change the
way the fuel injection system operates. Before adding
electrical equipment, check with your dealer.
If you don’t, your
engine might not perform properly.
If you ever have to have your vehicle towed, see the part of this
manual
that tells how to do it without damaging your vehicle.
See “Towing Your Vehicle” in the Index.
Driving Through Deep Standing Water
NOTICE:
If you drive too quickly through deep puddles or standing water,
water can come in through your engine’s air intake and badly
damage your engine.
If you can’t avoid deep puddles or standing
water, drive through them very slowly.
Driving Through Water (Diesel Engines)
NOTICE:
Never drive through standing water more than 8 inches deep if
your vehicle has a diesel engine. Also, don’t drive through any
standing water faster than
5 mph (8 km/h). If you do, water can
be drawn in through the
air intake, and this can severely
damage your engine.
Driving In Snow (Diesel Engines)
When driving in a heavy snowstorm or in swirling snow with a diesel
engine, snow can get into the
air intake system. If you keep driving in these
conditions the air cleaner may get plugged, causing black smoke and loss of
power. In an emergency,
if the air cleaner gets plugged with snow, you can
remove the air cleaner. Then, drive
to a place of safety as soon as possible
and put the air cleaner back on.
2- 15
ProCarManuals.com

Starting Your Diesel Englne
Your diesel engine starts differently than a gasoline engine.
1. Automatic Transmission:
Move your shift lever to “P” (Park) or “N” (Neutral). Your engine
won’t start in any other position
- that’s a safety feature. To restart
when you’re already moving, use “N” (Neutral) only.
NOTICE:
Don’t try to shift to “P” (Park) if your vehicle is moving. If you
do, you could damage the transmission. Shift to
“P” (Park) only
when your vehicle is stopped.
2. Manual Transmission:
Move your shift lever to neutral and hold the clutch pedal to the floor
while starting the engine. Your vehicle won’t start if the clutch pedal is
not
all the way down - that’s a safety feature.
Turn your ignition key to
RUN. Don’t turn it to “Start.”
With
the ignition in RUN, the “GLOW PLUGS” light will come on. If
the engine is already warm, this light may not come on. That’s normal.
During starting, your “GLOW PLUGS” light may
go on and off a few
times. This is normal. This means that part
of your engine is being
warmed
up for better starting. When the light goes off, your engine is
ready to start. Do not start the engine with this light on.
NOTICE:
If the “GLOW PLUGS” light stays on, it means that your
vehicle could have one
of several problems, so you should have it
serviced right
away.
3. If this light does not come on, or the instant the light goes off, turn your
ignition key to “Start.” When the engine starts,
let go of the key.
NOTICE:
Holding your key in “Start” for longer than 15 seconds at a time
will cause your battery to be drained much sooner. And the
excessive heat can damage your starter motor.
2-16
ProCarManuals.com

4. If the engine does not start after 15 seconds of cranking, turn the
ignition key to
OFF. Wait one minute for the starter to. cool, then try
the
same steps again.
If you’re trying
to start your engine after you’ve run out of fuel, follow the
steps in “Running Out of Fuel” (see “Diesel Fuel Requirements and Fuel
System” in the Index).
When your engine
is cold, let it run for a few minutes before you move your
vehicle. This lets oil pressure build up. Your engine will sound louder
when
it’s cold.
I NOTICE:
If you’re not in an idling vehicle and the engine overheats, you
wouldn’t be there to see the coolant temperature gage. This \
could damage your vehicle. Don’t let your engine run when
you’re not
in your vehicle.
Cold Weather Starting (Diesel Engine)
The following tips will help you get good starting in cold weather.
Use
SAE 1OW-30 oil when the outside temperature drops below freezing.
When the outside temperature drops below
0°F (- 1 SOC), use your engine
coolant heater.
If you park your vehicle
in a garage, you shouldn’t need to use the coolant
heater
until the garage temperature goes below 0°F (-18OC), no matter how
cold it is outside.
To use the engine coolant heater, first turn off the engine. Then open the
hood, unwrap the electrical cord and plug it in. It uses normal house voltage
(I 10 volts), but:
2-17
ProCarManuals.com

NOTICE:
After you’ve used the coolant heater, be sure to store the cord in
the manner it was, to help keep it away from moving engine
parts.
If you don’t, it could be torn and damaged.
How long should you keep the coolant heater plugged in? The answer
depends on the weather,
the kind of oil you have, and some other things.
Follow this chart.
Engine Coolant Heater Usage
Viscosity/ 32°F
to 0°F
Oil Grade
(OOC to -1SOC)
SAE
1 OW-30
SAE
I5W-40
Not
Required
Not
Required
0°F to -10°F
(-18” C to -23 O C)
Two
Hours*
Two
Hours*
Below -10°F
Below -23 ” C
Eight Hours* or Overnight
Eight Hours”: or Overnight
*The times listed are minimum times. It
will not harm either the coolant
heater or the vehicle
to leave the coolant heater plugged in longer than the
times stated.
For best results
in cold weather, use Number I-D diesel fuel or a
“winterized” Number 2-D fuel.
lf Your Diesel Engine Won’t Start
If you’ve run out of fuel, look at “Running Out of Fuel” (see “Diesel Fuel
Requirements and Fuel System” in the Index).
If you’re not out of fuel, and your engine won’t start, do this:
Turn your ignition key to RUN. Make sure that the “GLOW PLUGS” light
is out. Then turn the ignition key to START.
If the light doesn’t go off, wait a few seconds, then try starting your engine
again. And, see
your dealer as soon as you can for a starting system check.
2- 18
ProCarManuals.com

If the light comes on and then goes off and you know your batteries are
charged, but your engine still
won’t start, your vehicle needs service.
If the light does not come on when
the engine is cold, your vehicle needs
service.
If your batteries don’t have enough charge to start your engine, see
“Battery”
in the Index.
Be sure you have the right oil for your engine, and that you’ve changed the
oil at the proper times.
If you use the wrong oil, your engine may be harder
to start.
If
the engine starts, runs a short time, then stops, your vehicle needs service.
1 A CAUTION:
Do not use gasoline or starting “aids,” such as ether, in the air
intake.
They could damage your engine. There could also be a
fire, which could cause serious personal injury.
Engine Coolant Heater (Engine Block Heater)
In very cold weather, 0°F (-I 8°C) or colder, the engine coolant heater can
help. You’ll get easier starting and better fuel economy during engine
warm-up. Usually, the coolant heater should be plugged
in a minimum of
four hours prior to starting your vehicle.
2-19
ProCarManuals.com

To use the coolant heater:
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord.
3. Plug it into a normal, grounded 1 10-volt outlet.
NOTICE:
After you’ve used the coolant heater, be sure to store the \
cord as
it was before to keep it away from moving engine parts. If you
don’t, it could be damaged.
How long should you keep the coolant heater plugged in‘? The answer
depends
on the weather, the kind of oil you have, and some other things.
Instead
of trying to list everything here, we ask that you contact a GM
dealer in the area where you’ll be parking your vehicle. The dealer can give
you the best advice
for that particular area.
2-20
ProCarManuals.com

Automatic Transmission
There are several
different positions for
your shift lever.
P (Park)
This locks your rear wheels. It’s the best position to use when you start
your engine because your vehicle can’t move easily.
2-21
ProCarManuals.com

0 R (Reverse)
Use this gear to back up.
NOTICE:
Shifting into “R” (Reverse) while your vehicle is moving
forward could damage your transmission. Shift to
“R” (Reverse)
only after your vehicle is stopped.
To rock your vehicle back and forth to get out of snow, ice or sand
without damaging your transmission, see
“If Your Stuck: In Sand, Mud,
Ice or Snow”
in the Index.
N (Neutral)
In this position, your engine doesn’t connect with the wheels. To restart
when you’re already
moving, use “N” (Neutral) only. Also, use “N”
(Neutral) when your vehicle is being towed.
NOTICE:
Damage to your transmission caused by shifting out of “P”
(Park) or “N” (Neutral) with the engine racing isn’t covered by
your warranty.
2-22
ProCarManuals.com