GMC C-SERIES 1999 Owners Manual

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6-3 Two Safety Cautions about Engine
Fan Breakage
CAUTION:
Changing the Fan Drive Ratio or Engine
Governed Speed
If you change the fan drive ratio or increase the
governed speed of the engine, you may increase
stress on the engine fan and the fan could
eventually fail. If the fan breaks apart while it is
rotating, the flying pieces can cause severe injury
to anyone
-- such as a service technician -- who is
nearby. And, of course, the pieces can severely
damage the vehicle. Don't change the fan drive
ratio or increase the governed speed of the
vehicle without getting the necessary information
from your dealer.
CAUTION: (Continued)
CAUTION: (Continued)
Winter Fronts, Grille Covers or Obstructions
Winter fronts, grille covers or other add-on
equipment causing obstructions in front or
behind the fan should not be used on this vehicle.
They may increase the stress on the fan as the
blades pass over the covered areas. If this causes
the fan to eventually break apart while it is
rotating, the pieces can cause severe injury to
anyone nearby, such as a service technician
working on the engine, and of course the pieces
can severely damage the vehicle.
If your vehicle is equipped with the optional radiator
shutters, see ªRadiator Shuttersº in the Index.
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6-4
Fuel (Gasoline Engine)
If your vehicle has a diesel engine, see ªDiesel Engine
Fuelº in this section. For vehicles with gasoline engines,
please read this.
Use regular unleaded gasoline rated at 87 octane or
higher. It is recommended that the gasoline meet
specifications which have been developed by the
American Automobile Manufacturers Association
(AAMA) and endorsed by the Canadian Motor Vehicle
Manufacturers Association for better vehicle
performance and engine protection. Gasolines meeting
the AAMA specification could provide improved
driveability and emission control system performance
compared to other gasolines. For more information,
write to: American Automobile Manufacturer's
Association, 7430 Second Ave, Suite 300,
Detroit MI 48202.
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.If you're using fuel rated at 87 octane or higher and you
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.
Some gasolines that are not reformulated for low
emissions may contain an octane
-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask your service station operator whether or not
the fuel contains MMT. General Motors does not
recommend the use of such gasolines. If fuels containing
MMT are used, spark plug life may be reduced and your
emission control system performance may be affected.
The malfunction indicator lamp on your instrument
panel may turn on. If this occurs, return to your
authorized GM dealer for service.
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6-5
To provide cleaner air, all gasolines in the United States
are now required to contain additives that will help
prevent deposits from forming in your engine and fuel
system, allowing your emission control system to
function properly. Therefore, you should not have to add
anything to the fuel. In addition, gasolines containing
oxygenates, such as ethers and ethanol, and
reformulated gasolines may be available in your area to
contribute to clean air. General Motors recommends that
you use these gasolines, particularly if they comply with
the specifications described earlier.
NOTICE:
Your vehicle was not designed for fuel that
contains methanol. Don't use it. 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.
Diesel Fuel Requirements and
Fuel System
Diesel Engine Fuel
See your Caterpillar
Operator & Maintenance Manual
for information concerning fuel usage.
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, water must be drained. Your dealer can
show you how to do this.
CAUTION:
Diesel fuel containing water is still flammable.
You could be burned. If you ever try to drain
water from your fuel, keep sparks, flames and
smoking materials away from the mixture.
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6-6
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.
Diesel engine vehicles that stand unused for several
days or weeks can develop water in the fuel from
condensation. It helps to fill the fuel tank if the
diesel engine vehicle will not be used for a time.
Fuels in Foreign Countries
(Gasoline Engines)
If you plan on driving in another country outside the
United States or Canada, the proper fuel may be hard to
find. Never use leaded gasoline or any other fuel not
recommended in the previous text on fuel. Costly repairs
caused by use of improper fuel wouldn't be covered by
your warranty.
To check on fuel availability, ask an auto club, or
contact a major oil company that does business in the
country where you'll be driving.
You can also write us at the following address for
advice. Just tell us where you're going and give your
Vehicle Identification Number (VIN).
General Motors Overseas Distribution Corporation
1908 Colonel Sam Drive
Oshawa, Ontario L1H 8P7
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6-7
Filling Your Tank
CAUTION:
Fuel vapor is highly flammable. It burns
violently, and that can cause very bad injuries.
Don't smoke if you're near gasoline or diesel fuel,
or if you're refueling your vehicle. Keep sparks,
flames and smoking materials away from
gasoline or diesel fuel.
The fuel cap can be on either or both sides of your
vehicle depending on option content.
To take off the cap, turn it slowly to the left
(counterclockwise).
CAUTION:
Gasoline Engine Vehicles: If you get gasoline on
you and then something ignites it, you could be
badly burned. Gasoline can spray out on you if
you open the fuel filler cap too quickly. This
spray can happen if your tank is nearly full, and
is more likely in hot weather. Open the fuel filler
cap slowly and wait for any ªhissº noise to stop.
Then unscrew the cap all the way.
When you put the cap back on, turn it to the right until
it is tight.
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6-8
NOTICE:
If you need a new cap, be sure to get the right
type. Your dealer can get one for you. If you get
the wrong type, it may not fit or have proper
venting, and your fuel tank and emissions system
might be damaged.
If you have dual tanks, fill the driver's side first. The
fuel gage will give better readings this way. Your gage
will show the average level of both tanks combined.
Filling a Portable Fuel Container
CAUTION:
Never fill a portable fuel container while it is in
your vehicle. Static electricity discharge from the
container can ignite the gasoline vapor. You can
be badly burned and your vehicle damaged if this
occurs. To help avoid injury to you and others:

Dispense gasoline only into
approved containers.

Do not fill a container while it is inside a
vehicle, in a vehicle's trunk, pickup bed or
on any surface other than the ground.

Bring the fill nozzle in contact with the
inside of the fill opening before operating
the nozzle. Contact should be maintained
until the filling is complete.

Don't smoke while pumping gasoline.
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6-9
Checking Things Under the Hood
To tilt the hood forward, pull out on each of the hood
latches. If the hood is equipped with hood access panels,
make sure the panel latches are locked down before
rotating the hood open.
Then take the hand holds and pull the hood forward.
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6-10
When you rotate the hood far enough, the cables will
support it.If your vehicle has the optional hood access panels, you
can easily get to one side of the engine or the other as
you need to.
Pull out on the top of each hood latch. Then push the
latch down and swing the bottom out.
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6-11
Then place the prop rod,
located on the panel, where
the arrow is pointing.
CAUTION:
Things that burn can get on hot engine parts and
start a fire. These include liquids like gasoline or
diesel fuel, oil, coolant, brake fluid, windshield
washer and other fluids, and plastic or rubber. You
or others could be burned. Be careful not to drop
or spill things that will burn onto a hot engine.
Before closing the hood or access panels, be sure all the
filler caps are on properly.
Noise Control System
The following information relates to compliance with
Federal noise emission standards for vehicles with a
Gross Vehicle Weight Rating (GVWR) of more than
10,000 lbs. (4 536 kg). The Maintenance Schedule
provides information on maintaining the noise control
system to minimize degradation of the noise emission
control system during the life of your vehicle. The
noise control system warranty is given in your
Warranty booklet.
These standards apply only to vehicles sold in the
United States.
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6-12 Tampering With Noise Control
System Prohibited
Federal law prohibits the following acts or the
causing thereof:
1. The removal or rendering inoperative by any person,
other than for purposes of maintenance, repair or
replacement, of any device or element of design
incorporated into any new vehicle for the purpose of
noise control, prior to its sale or delivery to the
ultimate purchaser or while it is in use; or
2. The use of the vehicle after such device or element
of design has been removed or rendered inoperative
by any person.
Among those acts presumed to constitute tampering are
the acts listed below.
Insulation:

Removal of the noise shields or any
underhood insulation.Engine:

Removal or rendering engine speed governor (if
equipped) inoperative so as to allow engine speed to
exceed manufacturer specifications.
Fan and Drive:

Removal of fan clutch (if equipped) or rendering
clutch inoperative.

Removal of the fan shroud (if equipped).
Air Intake:

Removal of the air cleaner silencer.

Reversing the air cleaner cover.
Exhaust:

Removal of the muffler and/or resonator.

Removal of the exhaust pipes and exhaust
pipe clamps.
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