2007 GMC SIERRA CLASSIC engine

A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan
{CAUTION:
An electric fan under the hood can start up
and injure you even when the engine is not
running. Keep hands, clothing, and tools
away from any underhood electric fan.
If the coolant inside the coolant surge tank is
boiling, do not do anything else until it cools down.
The vehicle should be parked on a level surface.
Check the coolant level after the system cools
down. Some amount of coolant may be lost due to
overheating.
All Other Engines
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The coolant level should
be at or above the FULL
COLD mark. If it is not,
you may have a leak at
the pressure cap or in
the radiator hoses,
heater hoses, radiator,
water pump, or
somewhere else in the
cooling system.
{CAUTION:
Heater and radiator hoses, and other
engine parts, can be very hot. Do not
touch them. If you do, you can be burned.
Do not run the engine if there is a leak.
If you run the engine, it could lose all
coolant. That could cause an engine re,
and you could be burned. Get any leak
xed before you drive the vehicle.If your vehicle has an electric engine cooling
fan, check the coolant temperature gage.
If the coolant temperature is approximately
232°F (111°C), the electric cooling fan should be
running. If it is not, your vehicle needs service.
Turn off the engine.
If your vehicle has an engine-driven cooling fan,
start the engine again and see if the fan speed
increases when idle speed is doubled by pushing
the accelerator pedal down. If it does not, your
vehicle needs service. Turn off the engine.
Notice:Engine damage from running your
engine without coolant is not covered by your
warranty. SeeOverheated Engine Protection
Operating Mode (V8 Engines Only) on page 508
for information on driving to a safe place in
an emergency.
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
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.
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How to Add Coolant to the Coolant
Surge Tank for Gasoline Engines
If your vehicle has a diesel engine, see “Cooling
System” in the DURAMAX®Diesel Supplement for
the proper coolant ll procedure.
If you have not found a problem yet, check to see
if coolant is visible in the surge tank. If coolant
is visible but the coolant level is not at or above
the FULL COLD mark, add a 50/50 mixture
of clean, drinkable water and DEX-COOL
®coolant
at the coolant surge tank, but be sure the
cooling system, including the coolant surge tank
pressure cap, is cool before you do it. SeeEngine
Coolant on page 502for more information.If no coolant is visible in the surge tank, add
coolant as follows:
{CAUTION:
Steam and scalding liquids from a hot
cooling system can blow out and burn
you badly. They are under pressure, and if
you turn the coolant surge tank pressure
cap — even a little — they can come out at
high speed. Never turn the cap when the
cooling system, including the coolant
surge tank pressure cap, is hot. Wait for
the cooling system and coolant surge
tank pressure cap to cool if you ever have
to turn the pressure cap.
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{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 a proper coolant.
Notice:In cold weather, water can freeze and
crack the engine, radiator, heater core and
other parts. Use the recommended coolant and
the proper coolant mixture.
{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.
1. You can remove the
coolant surge tank
pressure cap when
the cooling system,
including the coolant
surge tank pressure
cap and upper
radiator hose, is no
longer hot.
Turn the pressure cap slowly counterclockwise
about one full turn. If you hear a hiss, wait
for that to stop. A hiss means there is
still some pressure left.
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2. Then keep turning the pressure cap slowly,
and remove it.
3. Fill the coolant surge tank with the proper
mixture, to the FULL COLD mark.4. With the coolant surge tank pressure cap off,
start the engine and let it run until you can
feel the upper radiator hose getting hot. Watch
out for the engine cooling fan.
By this time, the coolant level inside the
coolant surge tank may be lower. If the level is
lower, add more of the proper mixture to the
coolant surge tank until the level reaches
the FULL COLD mark.
5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
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Engine Fan Noise
If 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.If your vehicle has electric cooling fans, you may
hear the fans spinning at low speed during
most everyday driving. The fans may turn off if no
cooling is required. Under heavy vehicle loading,
trailer towing, and/or high outside temperatures, or
if you are operating your air conditioning system,
the fans may change to high speed and you
may hear an increase in fan noise. This is
normal and indicates that the cooling system is
functioning properly. The fans will change to
low speed when additional cooling is no longer
required.
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Power Steering Fluid
SeeEngine
Compartment Overview
on page 480for
reservoir location.
When to Check Power Steering Fluid
It is not necessary to regularly check power
steering uid unless you suspect there is a leak in
the system or you hear an unusual noise. A
uid loss in this system could indicate a problem.
Have the system inspected and repaired.
How to Check Power Steering Fluid
To check the power steering uid, do the following:
1. Turn the key off and let the engine
compartment cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a
clean rag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the
uid level on the dipstick.
The level should be at the FULL COLD mark. If
necessary, add only enough uid to bring the level
up to the mark.
What to Use
To determine what kind of uid to use, see
Recommended Fluids and Lubricants on page 629.
Always use the proper uid. Failure to use the
proper uid can cause leaks and damage hoses
and seals.
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Windshield Washer Fluid
What to Use
When you need windshield washer uid, 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 a uid that has sufficient protection against
freezing.
Adding Washer Fluid
Your vehicle has a low washer uid message that
comes on when the washer uid is low. The
message is displayed for 15 seconds at the start
of each ignition cycle. When the CHECK WASHER
FLUID message is displayed, you will need to
add washer uid to the windshield washer
uid reservoir.
Open the cap with the
washer symbol on it.
Add washer uid
until the tank is full. See
Engine Compartment
Overview on page 480
for reservoir location.Notice:
When using concentrated washer uid,
follow the manufacturer’s instructions
for adding water.
Do not mix water with ready-to-use washer
uid. Water can cause the solution to
freeze and damage your washer uid tank
and other parts of the washer system.
Also, water does not clean as well
as washer uid.
Fill your washer uid tank only
three-quarters full when it is very cold.
This allows for expansion if freezing
occurs, which could damage the tank if it
is completely full.
Do not use engine coolant (antifreeze) in
your windshield washer. It can damage
your washer system and paint.
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