engine GMC SAVANA 2007 Service Manual

{CAUTION:
Snow can trap exhaust gases under
your vehicle. This can cause deadly CO
(carbon monoxide) gas to get inside.
CO could overcome you and kill you.
You cannot see it or smell it, so you might
not know it is in your vehicle. Clear away
snow from around the base of your
vehicle, especially any that is blocking
the exhaust pipe and/or the fuel operated
heater exhaust system, if equipped. And
check around again from time to time to be
sure snow does not collect there. If your
vehicle has a diesel engine and a fuel
operated heater, see “Fuel Operated Heater
(FOH)” in the diesel engine supplement.
Open a window just a little on the side of
the vehicle that is away from the wind.
This will help keep CO out.Run your engine only as long as you must.
This saves fuel. When you run the engine, make it
go a little faster than just idle. That is, push the
accelerator slightly. This uses less fuel for the heat
that you get and it keeps the battery (or batteries)
charged. You will need a well-charged battery
(or batteries) to restart the vehicle, and possibly for
signaling later on with your headlamps. Let the
heater run for a while.
Then, shut the engine off and close the window
almost all the way to preserve the heat. Start
the engine again and repeat this only when you
feel really uncomfortable from the cold. But do it as
little as possible. Preserve the fuel as long as
you can. To help keep warm, you can get out of
the vehicle and do some fairly vigorous exercises
every half hour or so until help comes.
257

If Your Vehicle is Stuck in Sand,
Mud, Ice, or Snow
In order to free your vehicle when it is stuck,
you will need to spin the wheels, but you do not
want to spin your wheels too fast. The method
known as rocking can help you get out when you
are stuck, but you must use caution.
{CAUTION:
If you let your vehicle’s tires spin at high
speed, they can explode, and you or others
could be injured. And, the transmission or
other parts of the vehicle can overheat.
That could cause an engine compartment
re or other damage. When you are stuck,
spin the wheels as little as possible. Do not
spin the wheels above 35 mph (55 km/h) as
shown on the speedometer.Notice:Spinning the wheels can destroy
parts of your vehicle as well as the tires. If
you spin the wheels too fast while shifting the
transmission back and forth, you can destroy
the transmission.
For information about using tire chains on your
vehicle, seeTire Chains on page 359.
Rocking Your Vehicle to Get It Out
First, turn the steering wheel left and right.
That will clear the area around the front wheels.
Then shift back and forth between REVERSE (R)
and a forward gear, spinning the wheels as
little as possible. Release the accelerator pedal
while you shift, and press lightly on the accelerator
pedal when the transmission is in gear. By
slowly spinning the wheels in the forward and
reverse directions, you will cause a rocking motion
that may free your vehicle. If that does not get
your vehicle out after a few tries, it may need to be
towed out. If your vehicle does need to be
towed out, seeTowing Your Vehicle on page 264.
258

To identify the trailering capacity of your vehicle,
you should read the information in “Weight of
the Trailer” that appears later in this section.
Trailering is different than just driving your vehicle
by itself. Trailering means changes in acceleration,
braking, handling, durability and fuel economy.
Successful, safe trailering takes correct equipment,
and it has to be used properly.
That’s the reason for this part. In it are many
time-tested, important trailering tips and safety
rules. Many of these are important for your safety
and that of your passengers. So please read
this section carefully before you pull a trailer.
If You Do Decide To Pull A Trailer
If you do, here are some important points:
•There are many different laws, including speed
limit restrictions, having to do with trailering.
Make sure your rig will be legal, not only where
you live but also where you’ll be driving. A
good source for this information can be state
or provincial police.
•Consider using a sway control. See “Hitches”
later in this section.
•Don’t tow a trailer at all during the first
500 miles (800 km) your new vehicle is driven.
Your engine, axle or other parts could be
damaged.
•Then, during the first 500 miles (800 km) that
you tow a trailer, don’t drive over 50 mph
(80 km/h) and don’t make starts at full throttle.
This helps your engine and other parts of
your vehicle wear in at the heavier loads.
•See also “Driving on Grades” later in this
section.
Three important considerations have to do
with weight:
•the weight of the trailer
•the weight of the trailer tongue
•and the weight on your vehicle’s tires
267

Tow/Haul Mode
Tow/haul is designed to assist while your vehicle
is pulling a large or heavy load or trailer.
Tow/haul is most useful while pulling such a load
in rolling terrain, in stop-and-go traffic, or when
you need improved low-speed control, such
as when parking. The purpose of the tow/haul
mode is to:
•Reduce the frequency and improve the
predictability of transmission shifts,
•provide the same solid shift feel when pulling
a heavy load as when the vehicle is unloaded,
•improve control of vehicle speed while
requiring less throttle pedal activity.
Press this button
located to the right of
the steering wheel
on the instrument panel
to turn tow/haul
mode on and off.While activated, the
indicator light on the
instrument panel
will be on.
Tow/haul mode will turn off automatically when the
ignition is turned off. SeeTow/Haul Mode Light
on page 185.
Tow/haul is most effective when the vehicle and
trailer combined weight is at least 75 percent of the
vehicle’s Gross Combined Weight Rating
(GCWR). See “Weight of the Trailer” later in this
section.
Driving with tow/haul activated without a heavy
load will cause reduced fuel economy and
unpleasant engine and transmission driving
characteristics, but will not cause damage.
268

If you’ll be pulling a trailer that, when loaded, will
weigh more than 5,000 lbs (2 270 kg), be sure to
use a properly mounted weight-distributing hitch
and sway control of the proper size. This equipment
is very important for proper vehicle loading and
good handling when you’re driving. You should
always use a sway control if your trailer will weigh
more than these limits. You can ask a hitch dealer
about sway controls.
Will you have to make any holes in the body of
your vehicle when you install a trailer hitch?
If you’re using the wiring provided with the
factory-installed trailering package, you should not
need to make any holes in the body of your vehicle.
However, if you have an aftermarket hitch installed,
you may need to make holes in the body.
If you do, then be sure to seal the holes later
when you remove the hitch. If you don’t seal them,
deadly carbon monoxide (CO) from your exhaust
can get into your vehicle as well as dirt and water.
See “Carbon Monoxide” underEngine Exhaust
on page 132.Safety Chains
You should always attach chains between your
vehicle and your trailer. Cross the safety chains
under the tongue of the trailer to help prevent the
tongue from contacting the road if it becomes
separated from the hitch. Instructions about safety
chains may be provided by the hitch manufacturer
or by the trailer manufacturer. Follow the
manufacturer’s recommendation for attaching
safety chains and do not attach them to the
bumper. Always leave just enough slack so you can
turn with your rig. Never allow safety chains to drag
on the ground.
Trailer Brakes
If your trailer weighs more than 1,000 lbs (450 kg)
loaded, then it needs its own brakes – and they
must be adequate. Be sure to read and follow the
instructions for the trailer brakes so you’ll be
able to install, adjust and maintain them properly.
Since your vehicle is equipped with StabiliTrak
®,
your trailer brake system cannot tap into the
vehicle’s hydraulic brake system.
277

Driving with a Trailer
{CAUTION:
If you have a rear-most window open and
you pull a trailer with your vehicle, carbon
monoxide (CO) could come into your
vehicle. You can not see or smell CO. It can
cause unconsciousness or death. See
Engine Exhaust on page 132. To maximize
your safety when towing a trailer:
Have your exhaust system inspected
for leaks, and make necessary repairs
before starting on your trip.
Keep the rear-most windows closed.
If exhaust does come into your vehicle
through a window in the rear or another
opening, drive with your front, main
heating or cooling system on and with
the fan on any speed. This will bring
fresh, outside air into your vehicle.
CAUTION: (Continued)
CAUTION: (Continued)
Do not use the climate control setting for
maximum air because it only recirculates
the air inside your vehicle. See Climate
Control System in the Index.
Towing a trailer requires a certain amount of
experience. Before setting out for the open road,
you’ll want to get to know your rig. Acquaint yourself
with the feel of handling and braking with the added
weight of the trailer. And always keep in mind that
the vehicle you are driving is now a good deal
longer and not nearly as responsive as your vehicle
is by itself.
Before you start, check all trailer hitch parts and
attachments, safety chains, electrical connector,
lamps, tires and mirror adjustment. If the trailer has
electric brakes, start your vehicle and trailer moving
and then apply the trailer brake controller by hand
to be sure the brakes are working. This lets you
check your electrical connection at the same time.
278

Turn Signals When Towing a Trailer
When you tow a trailer, your vehicle has to have
extra wiring and a heavy-duty turn signal
flasher (included in the optional trailering package).
The arrows on your instrument panel will flash
whenever you signal a turn or lane change.
Properly hooked up, the trailer lamps will also flash,
telling other drivers you’re about to turn, change
lanes or stop.
When towing a trailer, the arrows on your
instrument panel will flash 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 gearbefore
you 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 THIRD (3) or a lower gear
under heavy loads and/or hilly conditions.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a
lower temperature than at normal altitudes. If you
turn your engine off immediately after towing at high
altitude 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 automatic transmission in
PARK (P) for a few minutes before turning the
engine off. If you do get the overheat warning, see
Engine Overheating on page 309.
280

Parking on Hills
{CAUTION:
You really should not park your vehicle,
with a trailer attached, on a hill.
If something goes wrong, your rig could
start to move. People can be injured, and
both your vehicle and the trailer can be
damaged.
But if you ever have to park your rig on a hill,
here’s how to do it:
1. Apply your regular brakes, but don’t shift into
PARK (P) yet. Then turn your wheels into the
curb if facing downhill or into traffic if facing
uphill.
2. Have someone place chocks under the trailer
wheels.3. When the wheel chocks are in place, release
the regular brakes until the chocks absorb
the load.
4. Reapply the regular brakes. Then apply your
parking brake and then shift to PARK (P).
5. Release the regular brakes.
When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal
down while you:
•start your engine,
•shift into a gear, and
•release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the
chocks.
4. Stop and have someone pick up and store
the chocks.
281

Maintenance When Trailer Towing
Your vehicle will need service more often when
you’re pulling a trailer. See the Maintenance
Schedule for more on this. Things that are
especially important in trailer operation are
automatic transmission fluid (don’t overfill), engine
oil, axle lubricant, belt, cooling system and brake
system. Each of these is covered in this manual,
and the Index will help you find them quickly.
If you’re trailering, it’s a good idea to review these
sections before you start your trip.
Check periodically to see that all hitch nuts and
bolts are tight.
Trailer Wiring Harness
The optional heavy-duty trailer wiring package
includes a seven-wire harness assembly at
the rear of the vehicle and a four-wire
harness assembly under the left hand side
of the instrument panel. The seven-wire
harness assembly is taped together and
located in a frame pocket at the driver side
rear left corner of the frame.The seven-wire harness includes a 30-amp feed
wire. Both harnesses come without connectors and
should be wired by a qualified electrical technician.
The technician can use the following color code
chart when connecting the wiring harness to
your trailer and trailer brake controller.
Seven-Wire Harness
•Light Green: Back-up lamps
•Brown: Parking lamps
•Yellow: Left stoplamp and turn signal
•Dark Green: Right stoplamp and turn signal
•Dark Blue: Use for electric trailer brakes
•Red/Black Stripe: Trailer accessory
•White (heavy gage): Ground wire
Four-Wire Harness (Trailer Brake Controller)
•Black: Ground
•Red/White Stripe: Fused Battery
•Dark Blue: Trailer Brake Feed
•Light Blue: Fused Stoplamp/CHMSL
282

Service........................................................ 286
Accessories and Modifications................... 286
California Proposition 65 Warning.............. 286
Doing Your Own Service Work.................. 287
Adding Equipment to the Outside
of Your Vehicle...................................... 287
Fuel............................................................. 288
Gasoline Octane........................................ 288
Gasoline Specifications.............................. 288
California Fuel........................................... 289
Additives................................................... 289
Fuel E85 (85% Ethanol)............................ 290
Fuels in Foreign Countries........................ 291
Filling the Tank......................................... 292
Filling a Portable Fuel Container............... 294
Checking Things Under the Hood.............. 294
Hood Release........................................... 295
Engine Compartment Overview.................. 296
Engine Oil (Gasoline Engine).................... 297Engine Oil Life System
(Gasoline Engine).................................. 300
Engine Air Cleaner/Filter............................ 302
Automatic Transmission Fluid.................... 303
Engine Coolant.......................................... 306
Radiator Pressure Cap.............................. 309
Engine Overheating................................... 309
Cooling System......................................... 311
Engine Fan Noise..................................... 317
Power Steering Fluid ................................. 317
Windshield Washer Fluid........................... 318
Brakes...................................................... 319
Battery...................................................... 323
Jump Starting............................................ 324
All-Wheel Drive........................................... 330
Rear Axle.................................................... 331
Front Axle................................................... 331
Section 5 Service and Appearance Care
283