2002 CHEVROLET C3500 HD engine

6-10
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.
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.

Modification of the air cleaner.
Exhaust:

Removal of the muffler and/or resonator.

Removal of the exhaust pipes and exhaust pipe clamps.

6-11
Engine Oil (Gasoline Engine)
If your vehicle has a diesel engine, see ªEngine Oil
(Diesel Engine)º in the Diesel Engine Supplement.
Checking Engine Oil
It's a good idea to check your engine oil every time you
get fuel. In order to get an accurate reading, the oil must
be warm and the vehicle must be on level ground.
The engine oil dipstick
has a yellow ring handle
and is located in the
engine compartment on
the passenger's side of
the vehicle. See ªEngine
Compartment Overviewº
in the Index for more
information on location.
Turn off the engine and give the oil several minutes to
drain back into the oil pan. If you don't, the oil dipstick
might not show the actual level.Pull out the dipstick and clean it with a paper towel or
cloth, then push it back in all the way. Remove it again,
keeping the tip down, and check the level.
When to Add Engine Oil
If the oil is at or below the ADD mark, then you'll need
to add at least one quart of oil. But you must use the
right kind. This part explains what kind of oil to use.
For engine oil crankcase capacity, see ªCapacities and
Specificationsº in the Index.

6-12
NOTICE:
Don't add too much oil. If your engine has so
much oil that the oil level gets above the upper
mark that shows the proper operating range,
your engine could be damaged.
The engine oil fill cap is
located at the front of
the engine. See ªEngine
Compartment Overviewº
in the Index for more
information on location.
Be sure to fill it enough to put the level somewhere in
the proper operating range. Push the dipstick all the way
back in when you're through.
What Kind of Engine Oil to Use
Oils recommended for your vehicle can be identified by
looking for the starburst symbol.
This symbol indicates that the oil has been certified by
the American Petroleum Institute (API). Do not use any
oil which does not carry this starburst symbol.
If you change your own oil,
be sure you use oil that
has the starburst symbol
on the front of the oil
container. If you have your
oil changed for you, be sure
the oil put into your engine
is American Petroleum
Institute certified for
gasoline engines.
You should also use the proper viscosity oil for your
vehicle, as shown in the following chart:

6-13
As in the chart shown previously, SAE 5W-30 is best for
your vehicle. However, you can use SAE 10W
-30 if it's
going to be 0F (
-18C) or above. These numbers on
an oil container show its viscosity, or thickness. Do not
use other viscosity oils, such as SAE 20W
-50.
NOTICE:
Use only engine oil with the American
Petroleum Institute Certified For Gasoline
Engines starburst symbol. Failure to use the
recommended oil can result in engine damage
not covered by your warranty.
GM Goodwrench
oil meets all the requirements for
your vehicle.
If you are in an area where the temperature falls below
-20F (-29C), consider using either an SAE 5W-30
synthetic oil or an SAE 0W
-30 oil. Both will provide
easier cold starting and better protection for your engine
at extremely low temperatures.

6-14 Engine Oil Additives
Don't add anything to your oil. The recommended oils
with the starburst symbol are all you will need for good
performance and engine protection.
When to Change Engine Oil
If any one of these is true for you, use the short trip/city
maintenance schedule:

Most trips are less than 5 miles (8 km). This is
particularly important when outside temperatures are
below freezing.

Most trips include extensive idling (such as frequent
driving in stop
-and-go traffic).

You frequently tow a trailer.

The vehicle is used for delivery service, police, taxi
or other commercial application.
Driving under these conditions causes engine oil to
break down sooner. If any one of these is true for your
vehicle, then you need to change your oil and filter
every 3,000 miles (5 000 km) or 3 months
-- whichever
occurs first.If none of them is true, use the long trip/highway
maintenance schedule. Change the oil and filter every
7,500 miles (12 500 km) or 12 months
-- whichever
occurs first. Driving a vehicle with a fully warmed
engine under highway conditions will cause engine oil
to break down slower.
What to Do with Used Oil
Used engine oil contains certain elements that may be
unhealthy for your skin and could even cause cancer.
Don't let used oil stay on your skin for very long.
Clean your skin and nails with soap and water, or a good
hand cleaner. Wash or properly throw away clothing or
rags containing used engine oil. See the manufacturer's
warnings about the use and disposal of oil products.
Used oil can be a threat to the environment. If you
change your own oil, be sure to drain all the oil from
the filter before disposal. Never dispose of oil by putting
it in the trash, pouring it on the ground, into sewers, or
into streams or bodies of water. Instead, recycle it by
taking it to a place that collects used oil. If you have a
problem properly disposing of your used oil, ask your
dealer, a service station or a local recycling center
for help.

6-15
Engine Air Cleaner/Filter
(Gasoline Engines)
Your engine air cleaner/filter is located between the
battery and coolant recovery tank. See ªEngine
Compartment Overviewº in the Index for more
information on location.
The engine air cleaner/filter
assembly has an indicator
that lets you know when
the engine air cleaner/filter
is dirty and needs to
be serviced.
The indicator is located in the air intake tube between
the engine air cleaner/filter and the engine. See ªEngine
Compartment Overviewº in the Index for more
information on location.
See ªOwner Checks and Servicesº in the Index to
determine when to check the indicator.
If the area inside the clear section of the indicator is
green, no engine air cleaner/filter service is required.
When the area inside the indicator is orange and
CHANGE AIR FILTER appears, the filter should
be replaced.

6-16
To remove the engine air cleaner/filter do the following:
1. Unhook the two retaining clips and remove the
housing cover.
2. Lift the filter and the connected duct out of the air
cleaner/filter housing. Hold the duct and remove the
filter by both pulling and twisting the filter away
from the duct. Care should be taken to dislodge as
little dirt as possible.
3. Clean the filter sealing surface of the duct and the
filter housing.4. Install the new filter by pushing it all the way to the
stop on the duct.
5. Install the duct and the filter into the engine air
cleaner/filter housing. Make sure that the duct fits
properly into the housing.
6. Install the cover and fasten the two retaining clips.
7. After the engine air cleaner/filter is properly
serviced, the indicator should be reset. Push the
button on top of the indicator to reset it to the
green (clean) filter zone.

6-17
Refer to the Maintenance Schedule to determine when to
replace the engine air cleaner/filter. See ªOwner Checks
and Servicesº in the Index.
CAUTION:
Operating the engine with the air cleaner/filter
off can cause you or others to be burned. The air
cleaner not only cleans the air, it stops flame if
the engine backfires. If it isn't there, and the
engine backfires, you could be burned. Don't
drive with it off, and be careful working on the
engine with the air cleaner/filter off.
NOTICE:
If the air cleaner/filter is off, a backfire can
cause a damaging engine fire. And, dirt can
easily get into your engine, which will damage it.
Always have the air cleaner/filter in place when
you're driving.
Automatic Transmission Fluid
If your vehicle has a diesel engine, see ªAutomatic
Transmission Fluidº in the Diesel Supplement.
When to Check and Change
A good time to check your automatic transmission
fluid level is when the engine oil is changed.
Change both the fluid and filter every
50,000 miles (83 000 km).
See ªScheduled Maintenance Servicesº in the Index.
How to Check
Because this operation can be a little difficult,
you may choose to have this done at the dealership
service department.
If you do it yourself, be sure to follow all the
instructions here, or you could get a false reading
on the dipstick.