2003 GMC SIERRA Engine Compartment Overview

5. Then replace the
pressure cap. Be sure
the pressure cap is
hand-tight and
fully seated.
Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the fan is spinning slower and the clutch is
not fully engaged. This improves fuel economy and
reduces fan noise. Under heavy vehicle loading, trailer
towing and/or high outside temperatures, the fan
speed increases as the clutch more fully engages.
So you may hear an increase in fan noise. This
is normal and should not be mistaken as the
transmission slipping or making extra shifts. It is merely
the cooling system functioning properly. The fan will
slow down when additional cooling is not required and
the clutch disengages.You may also hear this fan noise when you start the
engine. It will go away as the fan clutch partially
disengages.
Power Steering Fluid
When to Check Power Steering Fluid
It is not necessary to regularly check power steeringfluid
unless you suspect there is a leak in the system or
you hear an unusual noise. Afluid loss in this system
could indicate a problem. Have the system inspected
and repaired. SeeEngine Compartment Overview
on page 5-12for reservoir location.
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How to Check Power Steering Fluid
Turn the key off, let the engine compartment cool down,
wipe the cap and the top of the reservoir clean, then
unscrew the cap and wipe the dipstick with a clean rag.
Replace the cap and completely tighten it. Then remove
the cap again and look at thefluid level on the dipstick.
The level should be at the FULL COLD mark. If
necessary, add only enoughfluid to bring the level up to
the mark.
What to Use
To determine what kind offluid to use, seePart D:
Recommended Fluids and Lubricants on page 6-15.
Always use the properfluid. Failure to use the proper
fluid can cause leaks and damage hoses and seals.
Windshield Washer Fluid
What to Use
When you need windshield washerfluid, be sure to read
the manufacturer’s instructions before use. If you will
be operating your vehicle in an area where the
temperature may fall below freezing, use afluid that has
sufficient protection against freezing. SeeEngine
Compartment Overview on page 5-12for reservoir
location.
Adding Washer Fluid
Open the cap with the
washer symbol on it. Add
washerfluid until the
tank is full.
Notice:
•When using concentrated washerfluid, follow the
manufacturer’s instructions for adding water.
•Don’t mix water with ready-to-use washerfluid.
Water can cause the solution to freeze and
damage your washerfluid tank and other parts of
the washer system. Also, water doesn’t clean as
well as washerfluid.
•Fill your washerfluid tank only three-quarters full
when it’s very cold. This allows for expansion if
freezing occurs, which could damage the tank if
it is completely full.
•Don’t use engine coolant (antifreeze) in your
windshield washer. It can damage your washer
system and paint.
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Brakes
Brake Fluid
Your brake master cylinder reservoir isfilled with DOT-3
brakefluid. SeeEngine Compartment Overview on
page 5-12for the location of the reservoir.
There are only two reasons why the brakefluid level in
the reservoir might go down. Thefirst is that the
brakefluid goes down to an acceptable level during
normal brake lining wear. When new linings are put in,
thefluid level goes back up. The other reason is
thatfluid is leaking out of the brake system. If it is, you
should have your brake systemfixed, since a leak
means that sooner or later your brakes won’t work well,
or won’t work at all.
So, it isn’t a good idea to“top off”your brakefluid.
Adding brakefluid won’t correct a leak. If you addfluid
when your linings are worn, then you’ll have too
muchfluid when you get new brake linings. You should
add (or remove) brakefluid, as necessary, only when
work is done on the brake hydraulic system.
{CAUTION:
If you have too much brakefluid, it can spill on
the engine. Thefluid will burn if the engine is
hot enough. You or others could be burned,
and your vehicle could be damaged. Add brake
fluid only when work is done on the brake
hydraulic system. See“Checking Brake Fluid”
in this section.
Refer to the Maintenance Schedule to determine when
to check your brakefluid. SeePart C: Periodic
Maintenance Inspections on page 6-14.
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Replacing Brake System Parts
The braking system on a vehicle is complex. Its many
parts have to be of top quality and work well together if
the vehicle is to have really good braking. Your
vehicle was designed and tested with top-quality GM
brake parts. When you replace parts of your braking
system–for example, when your brake linings
wear down and you need new ones put in–be sure
you get new approved GM replacement parts.
If you don’t, your brakes may no longer work properly.
For example, if someone puts in brake linings that
are wrong for your vehicle, the balance between your
front and rear brakes can change—for the worse.
The braking performance you’ve come to expect can
change in many other ways if someone puts in the
wrong replacement brake parts.
Battery
Your new vehicle comes with a maintenance free
ACDelco®battery. When it’s time for a new battery, get
one that has the replacement number shown on the
original battery’s label. We recommend an ACDelco
®
battery. SeeEngine Compartment Overview on
page 5-12for battery location.
Warning:Battery posts, terminals and related
accessories contain lead and lead compounds,
chemicals known to the State of California to cause
cancer and reproductive harm. Wash hands after
handling.
Vehicle Storage
If you’re not going to drive your vehicle for 25 days or
more, remove the black, negative (−) cable from
the battery. This will help keep your battery from
running down.
{CAUTION:
Batteries have acid that can burn you and gas
that can explode. You can be badly hurt if you
aren’t careful. See“Jump Starting”next for
tips on working around a battery without
getting hurt.
Contact your dealer to learn how to prepare your
vehicle for longer storage periods.
Also, for your audio system, seeTheft-Deterrent
Feature on page 3-75.
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Notice:If you leave your radio on, it could be badly
damaged. The repairs wouldn’t be covered by
your warranty.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or in the accessory power outlets. Turn off
the radio and all the lamps that aren’t needed. This
will avoid sparks and help save both batteries.
And it could save your radio!
4. 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 near the engine accessory drive
bracket. To uncover the remote positive (+) terminal,
open the red plastic cover.
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.″
SeeEngine Compartment Overview on page 5-12
for more information on location.
{CAUTION:
Using a match near a battery can cause battery
gas to explode. People have been hurt doing
this, and some have been blinded. Use a
flashlight if you need more light.
Be sure the battery has enough water. You
don’t need to add water to the ACDelco
®
battery installed in your new vehicle. But if a
battery hasfiller caps, be sure the right
amount offluid is there. If it is low, add water
to take care of thatfirst. If you don’t, explosive
gas could be present.
Batteryfluid contains acid that can burn you.
Don’t get it on you. If you accidentally get it in
your eyes or on your skin,flush the place with
water and get medical help immediately.
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Underhood Fuse BlockThe underhood fuse block in the engine compartment
on the driver’s side of the vehicle near the battery.
Lift the cover for access to the fuse/relay block.
To remove fuses hold the end of the fuse between your
thumb and indexfinger and pull straight out.
SeeEngine Compartment Overview on page 5-12for
more information on its location.
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Driving (cont.)
Drunken....................................................... 4-2
Freeway.....................................................4-36
Hill and Mountain Roads..............................4-38
In Rain and on Wet Roads...........................4-32
Winter........................................................4-40
Driving Across an Incline..................................4-27
Driving Downhill..............................................4-25
Driving in Mud, Sand, Snow or Ice....................4-28
Driving in Water..............................................4-29
Driving On Grades..........................................4-59
Driving on Off-Road Hills.................................4-23
Driving on Snow or Ice....................................4-40
Driving Through Deep Standing Water...............4-34
Driving Through Flowing Water.........................4-34
Driving Uphill..................................................4-24
Driving with a Trailer.......................................4-58
Dual Automatic Climate Control System.............3-18
E
Easy Exit Seat...............................................2-42
Electrical System
Add-On Equipment......................................5-91
Fuses and Circuit Breakers...........................5-91
Power Windows and Other Power Options......5-91
Windshield Wiper Fuses...............................5-91
Electrochromic Mirror Operation........................2-28
Emissions Inspection and Maintenance
Programs...................................................3-39Engine
Air Cleaner/Filter
.........................................5-18
Battery
.......................................................5-39
Check and Service Engine Soon Light
............3-37
Compartment Overview
................................5-12
Coolant
......................................................5-23
Coolant Heater
............................................2-18
Coolant Temperature Gage
...........................3-36
Cooling System Inspection
............................6-14
Exhaust
.....................................................2-26
Fan Noise
..................................................5-34
Oil
.............................................................5-13
Overheating
................................................5-26
Starting
......................................................2-17
ENGINE COOLANT HOT
.................................3-52
Engine Coolant Level Check
.............................6-10
Engine Hour Meter Display
...............................3-26
Engine Oil Additives
........................................5-16
Engine Oil Level Check
...................................6-10
ENGINE OVERHEATED
..................................3-52
Entry Lighting
.................................................3-15
Environmental Concerns
..................................4-20
Erasing HomeLink
®Buttons
..............................2-38
Exit Lighting
...................................................3-15
Express-Down Windows
...................................2-12
Extender, Safety Belt
.......................................1-28
Exterior Lamps
...............................................3-11
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2003 - Sierra Denali