engine coolant HUMMER H3 2010 User Guide

10-18 Vehicle Care
Cooling System
The cooling system allows the
engine to maintain the correct
working temperature.
3.7L L5 Engine
A. Coolant Recovery Tank
B. Engine Cooling Fan
C. Radiator Pressure Cap
5.3L V8 Engine
A. Coolant Recovery Tank
B. Radiator Pressure Cap
C. Engine Cooling Fan
{WARNING
An electric engine cooling fan
under the hood can start up even
when the engine is not running
and can cause injury. Keep
hands, clothing, and tools away
from any underhood electric fan.
{WARNING
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 fire, and you
could be burned. Get any leak
fixed before you drive the vehicle.
Notice: Using coolant other
than DEX-COOL
®can cause
premature engine, heater core,
or radiator corrosion. In addition,
the engine coolant could require
changing sooner, at 50 000 km
(30,000 miles) or 24 months,
whichever occurs first. Any
repairs would not be covered by
the vehicle warranty. Always use
DEX-COOL
®(silicate-free) coolant
in the vehicle.

Vehicle Care 10-19
Engine Coolant
The cooling system in the vehicle
is filled with DEX-COOL®engine
coolant. This coolant is designed to
remain in the vehicle for five years
or 240 000 km (150,000 miles),
whichever occurs first.
The following explains the cooling
system and how to check and add
coolant when it is low. If there is a
problem with engine overheating,
see Engine Overheating
on
page 10‑22.
What to Use
{WARNING
Adding only plain water to
the cooling system can be
dangerous. Plain water, or some
other liquid such as alcohol,
can boil before the proper
coolant mixture will. The vehicle's
coolant warning system is set
for the proper coolant mixture.
(Continued)
WARNING (Continued)
With plain water or the wrong
mixture, the engine could get too
hot but you would not get the
overheat warning. The engine
could catch fire and you or
others could be burned. Use a
50/50 mixture of clean, drinkable
water and DEX-COOL
®coolant.
Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. If using this mixture,
nothing else needs to be added.
This mixture:
.Gives freezing protection down
to −37°C (−34°F), outside
temperature.
.Gives boiling protection up
to 129°C (265°F), engine
temperature.
.Protects against rust and
corrosion.
.Will not damage aluminum parts.
.Helps keep the proper engine
temperature.
Notice: If an improper coolant
mixture is used, the engine could
overheat and be badly damaged.
The repair cost would not be
covered by the vehicle warranty.
Too much water in the mixture
can freeze and crack the engine,
radiator, heater core, and other
parts.
Notice: If extra inhibitors
and/or additives are used in the
vehicle's cooling system, the
vehicle could be damaged. Use
only the proper mixture of the
engine coolant listed in this
manual for the cooling system.
See Recommended Fluids and
Lubricants
on page 11‑8for more
information.

10-20 Vehicle Care
Checking Coolant
The vehicle must be on a level
surface when checking the coolant
level.
The coolant recovery tank cap has
this symbol on it.
It is located toward the rear of
the engine compartment on the
passenger side of the vehicle. See
Engine Compartment Overview
on
page 10‑6for more information on
location.
Check to see if coolant is visible in
the coolant recovery tank. If the
coolant inside the coolant recovery
tank is boiling, do not do anything
else until it cools down. 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 recovery tank, but be sure
the cooling system is cool before
this is done.
The vehicle must be on a level
surface. When the engine is cold,
the coolant level should be at FULL
COLD, or a little higher. When the
engine is warm, the level could be
above the FULL COLD level.
When the engine is cold, the coolant
level should be at least up to the
FULL COLD mark. If it is not, there
could be a leak in the cooling
system.
How to Add Coolant to the
Recovery Tank
{WARNING
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.
Notice:
This vehicle has a
specific coolant fill procedure.
Failure to follow this procedure
could cause the engine to
overheat and be severely
damaged.
When the coolant in the coolant
recovery tank is at the FULL COLD
mark, start the vehicle.
If coolant is needed, add the proper
DEX-COOL coolant mixture at the
coolant recovery tank.
How to Add Coolant to the
Radiator
{WARNING
An electric engine cooling fan
under the hood can start up even
when the engine is not running
and can cause injury. Keep
hands, clothing, and tools away
from any underhood electric fan.

Vehicle Care 10-21
{WARNING
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 surge tank pressure
cap—even a little —they can
come out at high speed. Never
turn the cap when the cooling
system, including the surge tank
pressure cap, is hot. Wait for the
cooling system and surge tank
pressure cap to cool if you ever
have to turn the pressure cap.
If coolant is needed, add the proper
mixture directly to the radiator, but
be sure the cooling system is cool
before this is done.
1. Remove the radiator pressure cap when the cooling system,
including the 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.
2. Keep turning the cap to remove it. 3. Fill the radiator with the proper
DEX‐COOL coolant mixture,
up to the base of the filler
neck. See Engine Coolant
on
page 10‑19for more information
about the proper coolant
mixture.
4. Fill the coolant recovery tank to
the FULL COLD mark.
5. Reinstall the cap on the coolant recovery tank, but leave the
radiator pressure cap off.

10-22 Vehicle Care
6. Start the engine and let it rununtil you can feel the upper
radiator hose getting hot. Watch
out for the engine cooling fan.
7. By this time, the coolant level inside the radiator filler neck
might be lower. If the level is
lower, add more of the proper
DEX‐COOL coolant mixture
through the filler neck until the
level reaches the base of the
filler neck.
8. Then replace the pressure cap. At any time during this procedure
if coolant begins to flow out of
the filler neck, reinstall the
pressure cap.
Notice:
If the pressure cap is not
tightly installed, coolant loss and
possible engine damage may
occur. Be sure the cap is properly
and tightly secured.
Engine Overheating
The vehicle has an indicator to warn
of engine overheating.
A coolant temperature gauge is
displayed on the instrument panel.
See Engine Coolant Temperature
Gauge on page 5‑9.
You may decide not to lift the
hood when this warning appears,
but instead get service help right
away. See Roadside Service
on
page 13‑5.
If you do decide to lift the hood,
make sure the vehicle is parked on
a level surface. Then check to see if the engine
cooling fans are running. If the
engine is overheating, both fans
should be running. If they are not,
do not continue to run the engine
and have the vehicle serviced.
The air conditioning might stop
working if the engine is too hot. This
is normal and helps cool the engine.
Notice:
Engine damage from
running the engine without
coolant is not covered by the
warranty.
Notice: If the engine catches
fire because of being driven
with no coolant, your vehicle can
be badly damaged. The costly
repairs would not be covered by
the vehicle warranty.

Vehicle Care 10-23
If Steam Is Coming From The
Engine Compartment
{WARNING
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 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 fire. You or others
could be badly burned. Stop your
engine if it overheats, and get out
of the vehicle until the engine
is cool.
If No Steam Is Coming From
The Engine Compartment
If an engine overheat warning is
displayed but no steam can be seen
or heard, the problem may not be
too serious. Sometimes the engine
can get a little too hot when the
vehicle:
.Climbs a long hill on a hot day.
.Stops after high-speed driving.
.Idles for long periods in traffic.
.Tows a trailer. See“Driving on
Grades” underTrailer Towingon
page 9‑74.
If the overheat warning is displayed
with no sign of steam:
1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest
fan speed. Open the windows as
necessary. 3. In heavy traffic, let the engine
idle in N (Neutral) while stopped.
If it is safe to do so, pull off
the road, shift to P (Park) or
N (Neutral) and let the
engine idle.
If the temperature overheat gauge
is no longer in the overheat zone
or an overheat warning no longer
displays, the vehicle can be driven.
Continue to drive the vehicle slow
for about 10 minutes. Keep a safe
vehicle distance from the car in front
of you. If the warning does not come
back on, continue to drive normally.
If the warning continues, pull
over, stop, and park the vehicle
right away.
If there is no sign of steam, idle
the engine for three minutes while
parked. If the warning is still
displayed, turn off the engine until
it cools down.

Vehicle Care 10-25
What to Use
To determine what kind of fluid to
use, seeRecommended Fluids and
Lubricants
on page 11‑8. Always
use the proper fluid.
Notice: Use of the incorrect fluid
may damage the vehicle and the
damages may not be covered by
the vehicle's warranty. Always
use the correct fluid listed in
Recommended Fluids and
Lubricants on page 11‑8.
Washer Fluid
What to Use
When windshield washer fluid
is needed, be sure to read the
manufacturer's instructions before
use. If operating the vehicle in an
area where the temperature may fall
below freezing, use a fluid that has
sufficient protection against
freezing.
Adding Washer Fluid
Open the cap with the washer
symbol on it. Add washer fluid
until the tank is full. See Engine
Compartment Overview
on
page 10‑6for reservoir location.
Notice:
.When using concentrated
washer fluid, follow the
manufacturer's instructions
for adding water.
.Do not mix water with
ready-to-use washer fluid.
Water can cause the solution
to freeze and damage the
washer fluid tank and other
parts of the washer system.
Also, water does not clean as
well as washer fluid.
.Fill the washer fluid tank
only three-quarters full
when it is very cold. This
allows for fluid expansion if
freezing occurs, which could
damage the tank if it is
completely full.
.Do not use engine coolant
(antifreeze) in the windshield
washer. It can damage the
vehicle's windshield washer
system and paint.

Service and Maintenance 11-3
life system whenever the oil is
changed. SeeEngine Oil Life
System on page 10‑11.
When the “Change Oil” message
displays, certain services, checks,
and inspections are required.
The services described for
Maintenance Ishould be performed
at every engine oil change. The
services described for Maintenance
II should be performed when:
.Maintenance Iwas performed
the last time the engine oil was
changed.
.It has been 10 months or more
since the “Change Oil” message
has displayed or since the last
service.
Maintenance I
.Change engine oil and filter.
SeeEngine Oilon page 10‑9.
An Emission Control Service.
.Engine coolant level check. See
Engine Coolant on page 10‑19.
.Windshield washer fluid level
check. See Washer Fluidon
page 10‑25.
.Tire inflation check. See Tire
Pressure on page 10‑51.
.Tire wear inspection. See Tire
Inspection on page 10‑57.
.Rotate tires. See Tire Rotationon page 10‑57.
.Fluids visual leak check
(or every 12 months, whichever
occurs first). A leak in any
system must be repaired and
the fluid level checked.
.Engine air cleaner filter
inspection (vehicles driven in
dusty conditions only). See
Engine Air Cleaner/Filter
on
page 10‑17.
.Brake system inspection
(or every 12 months, whichever
occurs first).
Maintenance II
.Perform all services described in
MaintenanceI.
.Steering and suspension
inspection. Visual inspection for
damaged, loose, or missing
parts or signs of wear.
.Lubricate the front suspension,
steering linkage, and parking
brake cable guides. Control arm
ball joints require lubrication but
should not be lubricated unless
their temperature is −12°C
(10°F) or higher, or they could
be damaged.
.Engine cooling system
inspection. Visual inspection
of hoses, pipes, fittings, and
clamps and replacement,
if needed.

11-4 Service and Maintenance
.Windshield wiper blade
inspection for wear, cracking,
or contamination and windshield
and wiper blade cleaning,
if contaminated. SeeExterior
Care
on page 10‑92. Worn
or damaged wiper blade
replacement. See Wiper Blade
Replacement on page 10‑32.
.Body hinges and latches, key
lock cylinders, folding seat
hardware, and rear compartment
hinges, linkage, and handle
pivot points lubrication. See
Recommended Fluids and
Lubricants
on page 11‑8.
More frequent lubrication may
be required when vehicle
is exposed to a corrosive
environment. Applying silicone
grease on weatherstrips with a
clean cloth makes them last
longer, seal better, and not stick
or squeak.
.Restraint system component
check. See Safety System
Check on page 3‑26.
.Automatic transmission fluid
level check and adding fluid,
if needed. See Automatic
Transmission Fluid
on
page 10‑12.
.Four‐wheel drive vehicles:
Transfer case fluid level check
and adding fluid, if needed.
.Engine air cleaner filter
inspection. See Engine Air
Cleaner/Filter on page 10‑17.
Additional Required Services
At Each Fuel Stop
.Engine oil level check. See
Engine Oil on page 10‑9.
.Engine coolant level check. See
Engine Coolant on page 10‑19.
.Windshield washer fluid level
check. See Washer Fluidon
page 10‑25. Once a Month
.Tire inflation check. See
Tire
Pressure on page 10‑51.
.Tire wear inspection. See Tire
Inspection on page 10‑57.
Once a Year
.See Starter Switch Checkon
page 10‑30.
.See Automatic Transmission
Shift Lock Control System
Check on page 10‑30.
.See Ignition Transmission Lock
Check on page 10‑31.
.See Park Brake and P (Park)
Mechanism Checkon
page 10‑31.
.Engine cooling system and
pressure cap pressure check.
Radiator and air conditioning
condenser outside cleaning. See
Cooling System on page 10‑18.

11-6 Service and Maintenance
ServiceMaintenanceIMaintenance
II
Change engine oil and filter. Reset oil life system. ••
Engine coolant level check. ••
Windshield washer fluid level check. ••
Tire inflation pressures check. ••
Tire wear inspection. ••
Rotate tires. ••
Fluids visual leak check. ••
Engine air cleaner filter inspection (vehicles driven in dusty conditions only). ••
Brake system inspection. ••
Body components lubrication. •
Steering and suspension inspection. •