2004 CHEVROLET SILVERADO open hood

Engine Coolant Heater
In very cold weather,
0°F (−18°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.
At temperatures above 32°F (0°C), use of the coolant
heater is not required.
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord. The
cord is located on the driver’s side of the engine
compartment, near the power steering uid
reservoir. If you have a diesel engine, refer to
diesel supplement for location.
3. Plug it into a normal, grounded 110-volt AC outlet.
{CAUTION:
Plugging the cord into an ungrounded outlet
could cause an electrical shock. Also, the
wrong kind of extension cord could overheat
and cause a re. You could be seriously
injured. Plug the cord into a properly grounded
three-prong 110-volt AC outlet. If the cord will
not reach, use a heavy-duty three-prong
extension cord rated for at least 15 amps.
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Outlet Adjustment
Use the air outlets located
in the center and on the
side of your instrument
panel to direct the airow.
Your vehicle has air outlets that allow you to adjust the
direction and amount of airow inside the vehicle.
Move the louvers up or down. Use the thumbwheel next
to or underneath the outlet to close the louvers. For
the most efficient airow and temperature control, keep
the outlet in the fully opened position.
Rear seat outlets can be used to adjust airow toward
either seating area, the oor or upward. Move the center
louvers up or down to direct the airow.
Operation Tips

Keep the hood and front air inlets free of ice, snow,
or any other obstruction (such as leaves). The
heater and defroster will work far better, reducing
the chance of fogging the inside of your windows.
Keep the air path under the front seats clear
of objects. This helps air to circulate throughout
your vehicle.
Adding outside equipment to the front of your
vehicle, such as hood-air deectors, etc., may affect
the performance of the heating and air conditioning
system. Check with your dealer before adding
equipment to the outside of your vehicle.
3-32

Checking Things Under
the Hood
{CAUTION:
Things that burn can get on hot engine parts
and start a re. These include liquids like fuel,
oil, coolant, brake uid, windshield washer and
other uids, 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.
Hood Release
To open the hood do the following:
1. Pull the handle inside
the vehicle located
under and to the left of
the steering wheel.
5-12

If Steam Is Coming From Your Engine
{CAUTION:
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
CAUTION: (Continued)
CAUTION: (Continued)
from the vehicle until it cools down. Wait until
there is no sign of steam or coolant before you
open the hood.
If you keep driving when your engine is
overheated, the liquids in it can catch re.
You or others could be badly burned. Stop
your engine if it overheats, and get out of the
vehicle until the engine is cool.
See “Overheated Engine Protection Operating
Mode” underEngine Overheating on page 5-38
for information on driving to a safe place in
an emergency.
Notice:If your engine catches re because you keep
driving with no coolant, your vehicle can be badly
damaged. The costly repairs would not be covered by
your warranty. See “Overheated Engine Protection
Operating Mode” underEngine Overheating on
page 5-38for information on driving to a safe place in
an emergency.
5-39

If No Steam Is Coming From
Your Engine
An overheat warning, along with a low coolant condition,
can indicate a serious problem. For more information,
seeDriver Information Center (DIC) on page 3-53.
If you get an engine overheat warning and don’t have a
low coolant condition, but see or hear no steam, the
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. See “Driving on Grades” under
Towing a Trailer on page 4-70.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. If you have an air conditioner and it’s on, turn it off.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.3. If you’re in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving – AUTOMATIC OVERDRIVE
Xor
DRIVE (D) for automatic transmissions.
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning doesn’t come back on, you can
drive normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there’s still no sign of steam, push down the
accelerator until the engine speed is about twice as fast
as normal idle speed for at least three minutes while
you’re parked. If you still have the warning,turn off the
engine and get everyone out of the vehicleuntil it
cools down. Also, see “Overheated Engine Protection
Operating Mode” listed previously in this section.
You may decide not to lift the hood but to get service
help right away.
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Notice:If the other vehicle’s system is not a 12-volt
system with a negative ground, both vehicles can
be damaged. Only use vehicles with 12-volt systems
with negative grounds to jump start your vehicle.
2. If you have a vehicle with a diesel engine with two
batteries (or more), you should know before you
begin that, especially in cold weather, you may not
be able to get enough power from a single
battery in another vehicle to start your diesel engine.
If your vehicle has more than one battery, use
the battery that’s closer to the starter – this
will reduce electrical resistance.
3. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren’t touching
each other. If they are, it could cause a ground
connection you don’t want. You wouldn’t be able to
start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brake rmly on both vehicles involved in
the jump start procedure. Put an automatic
transmission in PARK (P) or a manual transmission
in NEUTRAL before setting the parking brake. If
you have a four-wheel-drive vehicle, be sure
the transfer case is in a drive gear not in NEUTRAL.Notice:If you leave your radio or other accessories
on during the jump starting procedure, they could
be damaged. The repairs would not be covered
by your warranty. Always turn off your radio and
other accessories when jump starting your vehicle.
4. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or accessory power outlets. Turn off the
radio and all lamps that aren’t needed. This
will avoid sparks and help save both batteries. And
it could save your radio!
5. Open the hoods and locate the positive (+) and
negative (−) terminal locations of the other vehicle.
Your vehicle has a remote positive (+) jump
starting terminal and a remote negative (−) jump
starting terminal. You should always use these
remote terminals instead of the terminals on
the battery.
The remote positive (+) terminal is located behind a
red plastic cover, if equipped, near the engine
accessory drive bracket. To uncover the remote
positive (+) terminal, open the red plastic cover,
if equipped.
The remote negative (−) terminal is located on the
engine drive bracket on all V8 and diesel engines,
and on the thermostat housing on the 8.1L engine.
On V8 engines it is marked “GND.”
5-54

Maintenance Footnotes
†The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to
the completion of the vehicle’s useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the
maintenance be recorded.
#Lubricate the front suspension, ball joints, steering
linkage, transmission shift linkage and parking
brake cable guides. Ball joints should not be lubricated
unless their temperature is 10°F (-12°C) or higher,
or they could be damaged. Vehicles used under severe
commercial operating conditions require lubrication
on a regular basis every 3,000 miles (5 000 km).
(a)Visually inspect brake lines and hoses for proper
hook-up, binding, leaks, cracks, chang, etc. Inspect
disc brake pads for wear and rotors for surface
condition. Inspect other brake parts, including calipers,
parking brake, etc.
(b)Visually inspect front and rear suspension and
steering system for damaged, loose or missing parts,
signs of wear or lack of lubrication. Inspect power
steering lines and hoses for proper hook-up, binding,
leaks, cracks, chang, etc. Visually check constant
velocity joints, rubber boots and axle seals for leaks.(c)Visually inspect hoses and have them replaced if
they are cracked, swollen or deteriorated. Inspect all
pipes, ttings and clamps; replace with genuine GM parts
as needed. To help ensure proper operation, a pressure
test of the cooling system and pressure cap and cleaning
the outside of the radiator and air conditioning condenser
is recommended at least once a year.
(d)Visually inspect wiper blades for wear or cracking.
Replace blade inserts that appear worn or damaged
or that streak or miss areas of the windshield.
(e)Make sure the safety belt reminder light and all your
belts, buckles, latch plates, retractors and anchorages
are working properly. Look for any other loose or
damaged safety belt system parts. If you see anything
that might keep a safety belt system from doing its
job, have it repaired. Have any torn or frayed safety belts
replaced. Also look for any opened or broken air bag
coverings, and have them repaired or replaced. (The air
bag system does not need regular maintenance.)
(f)Lubricate all key lock cylinders, body door hinges,
hood latch assembly, secondary latch, pivots, spring
anchor, release pawl, tailgate hinges, tailgatelinkage,
tailgate handle pivot points, latch bolt, fuel door
hinge, locks and folding seat hardware. More frequent
lubrication may be required when exposed to a corrosive
environment. Applying silicone grease on weatherstrips
with a clean cloth will make them last longer, seal
better and not stick or squeak.
6-8