2007 HUMMER H3 open hood

Engine Coolant Heater
Your vehicle may have this feature.
In very cold weather, 0°F (–18°C) or colder, the
engine coolant heater can help. You will 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. Your
vehicle may also have an internal thermostat in the
plug end of the cord. This will prevent operation of
the engine coolant heater when the temperature is
at or above 0F (−18C) as noted on the cord.
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord.
The cord is located in the engine compartment
behind the underhood fuse block on the
driver’s side of the vehicle.
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.
4. Before starting the engine, be sure to unplug
and store the cord as it was before to keep it
away from moving engine parts. If you do not, it
could be damaged.
How long should you keep the coolant heater
plugged in? The answer depends on the outside
temperature, the kind of oil you have, and some
other things. Instead of trying to list everything here,
we ask that you contact your dealer in the area
where you will be parking your vehicle. The dealer
can give you the best advice for that particular area.
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Adding Equipment to the Outside
of Your Vehicle
Things you might add to the outside of your
vehicle can affect the airow around it. This may
cause wind noise and affect windshield washer
performance. Check with your dealer before
adding equipment to the outside of your vehicle.
Fuel
Use of the recommended fuel is an important part
of the proper maintenance of your vehicle. To
help keep your engine clean and maintain optimum
vehicle performance, GM recommends the use
of gasoline advertised as TOP TIER Detergent
Gasoline.
Gasoline Octane
Use regular unleaded gasoline with a posted
octane rating of 87 or higher. If the octane rating is
less than 87, you may notice an audible knocking
noise when you drive, commonly referred to as
spark knock. If this occurs, use a gasoline rated at
87 octane or higher as soon as possible.If you are using gasoline rated at 87 octane or
higher and you hear heavy knocking, your engine
needs service.
Gasoline Specications
At a minimum, gasoline should meet ASTM
specication D 4814 in the United States or
CAN/CGSB-3.5 in Canada. Some gasolines may
contain an octane-enhancing additive called
methylcyclopentadienyl manganese tricarbonyl
(MMT). General Motors recommends against the
use of gasolines containing MMT. SeeAdditives
on page 317for additional information.
California Fuel
If your vehicle is certied to meet California
Emissions Standards, it is designed to operate on
fuels that meet California specications. See the
underhood emission control label. If this fuel is not
available in states adopting California emissions
standards, your vehicle will operate satisfactorily on
fuels meeting federal specications, but emission
control system performance may be affected.
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Checking Things Under
the Hood
{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.
{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
with this symbol
on it. It is located
inside the vehicle
on the lower
left side of the
instrument panel.
2. Release the secondary latch on the hood.
It is located below the front center of
the hood.
3. Lift the hood.
Before closing the hood, be sure all the ller caps
are on properly. Then pull the hood down and
close it rmly.
321

Engine Compartment Overview
When you open the hood on the engine, this is what you will see:
322

Add coolant mixture at the recovery tank, but be
careful not to spill it.
{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.
Occasionally check the coolant level in the
radiator. For information on how to add coolant to
the radiator, seeCooling System on page 340.
Radiator 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.
SeeEngine Compartment Overview on page 322
for more information on location.
Engine Overheating
A coolant temperature gage is on the instrument
panel. SeeEngine Coolant Temperature Gage
on page 185.
The air conditioning might stop working if the
engine is too hot. This is normal and helps cool
the engine.
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 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.
CAUTION: (Continued)
338

CAUTION: (Continued)
You or others could be badly burned.
Stop your engine if it overheats, and get
out of the vehicle until the engine is cool.
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.
If No Steam Is Coming From Your
Engine
If you get an engine overheat warning 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 297.If you get the overheat warning with no sign of
steam, try this for a minute or so:
1. In heavy traffic, let the engine idle in
NEUTRAL while stopped. If it is safe to do so,
pull off the road, shift to PARK (P) or
NEUTRAL and let the engine idle.
2. Turn off the air conditioning.
3. Turn on your heater to full hot at the highest fan
speed and open the windows as necessary.
If you no longer have the overheat warning, you
can drive. Just to be safe, drive slower for
about 10 minutes. If the warning does not come
back on, you can drive normally.
If the warning continues, pull over, stop, and park
your vehicle right away.
If there is still no sign of steam, idle the engine for
three minutes while you are parked. Push down
the accelerator until the engine speed is about
twice as fast as normal idle speed for at least three
minutes while you are parked. If you still have
the warning, turn off the engine and get everyone
out of the vehicle until it cools down.
You may decide not to lift the hood but to get
service help right away.
339

4. Open the hoods and locate the batteries on
both vehicles. You will use the positive (+)
battery terminal and the remote negative (−)
jump starting terminal to jump start your
vehicle. To access the positive (+) battery
terminal, open the terminal cover. SeeEngine
Compartment Overview on page 322for
more information on the terminal locations.
{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 ashlight if you need
more light.
CAUTION: (Continued)
CAUTION: (Continued)
Be sure the batteries have enough water.
You do not need to add water to the
ACDelco
®battery (or batteries) installed in
your new vehicle. But if a battery has ller
caps, be sure the right amount of uid is
there. If it is low, add water to take care of
that rst. If you do not, explosive gas
could be present.
Battery uid contains acid that can burn
you. Do not get it on you. If you
accidentally get it in your eyes or on your
skin, ush the place with water and get
medical help immediately.
354

The vehicle should be properly prepared as follows:
The vehicle should be placed so the headlamps
are 25 ft. (7.6 m) from a light colored wall or
other at surface.
The vehicle must have all four tires on a level
surface which is level all the way to the wall or
other at surface.
The vehicle should be placed so it is
perpendicular to the wall or other at surface.
The vehicle should not have any snow, ice, or
mud on it.
The vehicle should be fully assembled and all
other work stopped while headlamp aiming is
being performed.
The vehicle should be normally loaded with a
full tank of fuel and one person or 160 lbs
(75 kg) sitting on the driver’s seat.
Tires should be properly inated.
The spare tire is in its original location in
the vehicle.To adjust the vertical aim, do the following:
1. Open the hood. SeeHood Release on
page 321for more information.
2. Find the aim dot on the lens of the headlamp.
3. Measure the distance from the ground to
the aim dot on the headlamp. Record the
distance.
359