2008 CHEVROLET SILVERADO coolant

This message displays and a chime sounds if the
engine cooling system reaches unsafe temperatures for
operation. Stop and turn off the vehicle as soon as it
is safe to do so to avoid severe damage. This message
clears when the engine has cooled to a safe operating
temperature.
ENGINE POWER IS REDUCED
This message displays and a chime sounds when the
cooling system temperature gets too hot and the engine
further enters the engine coolant protection mode.
SeeEngine Overheating on page 5-32for further
information.
This message also displays when the vehicle’s engine
power is reduced. Reduced engine power can affect the
vehicle’s ability to accelerate. If this message is on,
but there is no reduction in performance, proceed
to your destination. The performance may be reduced
the next time the vehicle is driven. The vehicle may
be driven at a reduced speed while this message is on,
but acceleration and speed may be reduced. Anytime
this message stays on, the vehicle should be taken
to your dealer/retailer for service as soon as possible.
FAST IDLE ON
If your vehicle has this feature, this message displays
when the fast idle feature is on. SeeFast Idle System
on page 2-25for more information.
FUEL LEVEL LOW
This message displays and a chime sounds if the fuel
level is low. Refuel as soon as possible. SeeFuel Gage
on page 3-55andFuel on page 5-6for more information.
HOOD OPEN
This message displays and a chime sounds if the hood is
not fully closed. Stop and turn off the vehicle, check the
hood for obstructions, and close the hood again. Check to
see if the message still appears on the DIC.
LEFT REAR DOOR OPEN (Crew Cab)
This message displays and a chime sounds if the driver
side rear door is not fully closed and the vehicle is in
a drive gear. Stop and turn off the vehicle, check
the door for obstructions, and close the door again.
Check to see if the message still appears on the DIC.
3-69

Turn Signals When Towing a Trailer
The arrows on your instrument panel will ash whenever
you signal a turn or lane change. Properly hooked up,
the trailer lamps will also ash, telling other drivers
you’re about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will ash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It’s
important to check occasionally to be sure the trailer
bulbs are still working.
Driving On Grades
Reduce speed and shift to a lower gearbeforeyou start
down a long or steep downgrade. If you don’t shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.You can tow in DRIVE (D). You may want to shift the
transmission to lower gear selection if the transmission
shifts too often (e.g., under heavy loads and/or hilly
conditions).
You may also want to activate the tow/haul mode if the
transmission shifts too often. See “Tow/Haul Mode”
later in this section.
When towing at high elevation on steep uphill grades,
consider the following: Engine coolant at higher
elevations will boil at a lower temperature than at or
near sea level. If you turn your engine off immediately
after towing at high elevation on steep uphill grades,
your vehicle may show signs similar to engine
overheating. To avoid this, let the engine run while
parked, preferably on level ground, with the transmission
in PARK (P) at least ve minutes before turning the
engine off. If you do get the overheat warning, see
Engine Overheating on page 5-32.
4-88

Service............................................................5-4
Accessories and Modications..........................5-4
California Proposition 65 Warning.....................5-4
California Perchlorate Materials Requirements.....5-5
Doing Your Own Service Work.........................5-5
Adding Equipment to the Outside of
Your Vehicle..............................................5-5
Fuel................................................................5-6
Gasoline Octane............................................5-6
Gasoline Specications....................................5-6
California Fuel...............................................5-7
Additives.......................................................5-7
Fuel E85 (85% Ethanol)..................................5-8
Fuels in Foreign Countries...............................5-9
Filling the Tank............................................5-10
Filling a Portable Fuel Container.....................5-12
Checking Things Under the Hood....................5-12
Hood Release..............................................5-13
Engine Compartment Overview.......................5-14
Engine Oil (Gasoline Engine)..........................5-15
Engine Oil Life System..................................5-18
Engine Air Cleaner/Filter (Gasoline Engines).....5-20
Automatic Transmission Fluid
(6-Speed Transmission)..............................5-22Automatic Transmission Fluid
(4-Speed Transmission)..............................5-26
Engine Coolant.............................................5-29
Coolant Surge Tank Pressure Cap..................5-32
Engine Overheating.......................................5-32
Overheated Engine Protection
Operating Mode (V8 Engines Only)..............5-34
Cooling System............................................5-35
Engine Fan Noise.........................................5-40
Power Steering Fluid.....................................5-41
Windshield Washer Fluid................................5-42
Brakes........................................................5-43
Battery........................................................5-46
Jump Starting...............................................5-47
Rear Axle.......................................................5-52
Four-Wheel Drive............................................5-54
Front Axle......................................................5-56
Noise Control System.....................................5-57
Tampering with Noise Control System
Prohibited.................................................5-57
Headlamp Aiming...........................................5-58
Section 5 Service and Appearance Care
5-1

Filling a Portable Fuel Container
{CAUTION:
Never ll a portable fuel container while it is
in your vehicle. Static electricity discharge
from the container can ignite the fuel vapor.
You can be badly burned and your vehicle
damaged if this occurs. To help avoid injury to
you and others:
Dispense fuel only into approved
containers.
Do not ll 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 ll nozzle in contact with the
inside of the ll opening before operating
the nozzle. Contact should be maintained
until the lling is complete.
Do not smoke while pumping fuel.
Do not use a cellular phone while
pumping fuel.
Checking Things Under
the Hood
{CAUTION:
An electric engine cooling fan can start even
when the engine is not running. To avoid
injury, always keep hands, clothing, and tools
away from any engine cooling fan.
{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.
5-12

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter (Gasoline Engines) on page 5-20.
B. Air Filter Restriction Indicator (If Equipped).
SeeEngine Air Cleaner/Filter (Gasoline Engines)
on page 5-20.
C. Coolant Surge Tank and Pressure Cap. SeeCooling
System on page 5-35andCoolant Surge Tank
Pressure Cap on page 5-32.
D. Positive (+) Terminal. SeeJump Starting on
page 5-47.
E. Battery. SeeBattery on page 5-46.
F. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil (Gasoline Engine) on page 5-15.
G. Automatic Transmission Dipstick. See “Checking the
Fluid Level” underAutomatic Transmission Fluid
(6-Speed Transmission) on page 5-22orAutomatic
Transmission Fluid (4-Speed Transmission) on
page 5-26.
H. Remote Negative (−) Terminal (Out of View).
SeeJump Starting on page 5-47.
I. Engine Oil Dipstick (Out of View). See “Checking
Engine Oil” underEngine Oil (Gasoline Engine)
on page 5-15.
J. Engine Cooling Fan. SeeCooling System on
page 5-35.
K. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-41.L. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-43.
M. Underhood Fuse Block. SeeUnderhood Fuse Block
on page 5-129.
N. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-42.
Engine Oil (Gasoline Engine)
If your vehicle has a diesel engine, see “Engine Oil” in
the DURAMAX®Diesel manual.
Checking Engine Oil
It is a good idea to check the 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 handle is a yellow loop.
SeeEngine Compartment Overview on page 5-14for
the location of the engine oil dipstick.
1. Turn off the engine and give the oil several minutes
to drain back into the oil pan. If you do not do this,
the oil dipstick might not show the actual level.
2. 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.
5-15

Engine Coolant
If your vehicle has the DURAMAX®Diesel engine, see
the DURAMAX®Diesel manual for more information.
The cooling system in your vehicle is lled with
DEX-COOL
®engine coolant. This coolant is designed
to remain in your vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst, if you add only
DEX-COOL
®extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, seeEngine Overheating on
page 5-32.A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at the rst maintenance
service after each 30,000 miles (50 000 km) or
24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
5-29

What to Use
Use a mixture of one-half clean, drinkable water and
one-half DEX-COOL®coolant which will not damage
aluminum parts. If you use this coolant mixture, you do
not need to add anything else.
{CAUTION:
Adding only plain water to your cooling system
can be dangerous. Plain water, or some other
liquid such as alcohol, can boil before the
proper coolant mixture will. Your vehicle’s
coolant warning system is set for the proper
coolant mixture. With plain water or the wrong
mixture, your engine could get too hot but you
would not get the overheat warning. Your
engine could catch re and you or others could
be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.Notice:If you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost would not be covered by your
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core, and
other parts.
If you have to add coolant more than four times a year,
have your dealer/retailer check your cooling system.
Notice:If you use extra inhibitors and/or additives
in your vehicle’s cooling system, you could
damage your vehicle. Use only the proper mixture
of the engine coolant listed in this manual for
the cooling system. SeeRecommended Fluids and
Lubricants on page 6-14for more information.
5-30

Checking Coolant
The coolant surge tank is located in the engine
compartment on the passenger’s side of the vehicle.
SeeEngine Compartment Overview on page 5-14
for more information on location.
{CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. Never turn the surge tank pressure
cap — even a little — when the engine and
radiator are hot.
The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at the
FULL COLD mark on the coolant surge tank.
If your vehicle has a low coolant sensor and the
LOW COOLANT LEVEL message comes on and
stays on, it means you are low on engine coolant.
See “LOW COOLANT LEVEL” underDIC Warnings
and Messages on page 3-66.
Adding Coolant
If you need more coolant, add the proper DEX-COOL®
coolant mixture at the surge tank, but only when the
engine is cool. SeeCooling System on page 5-35
for more information.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand-tight and fully seated.
5-31