2008 BUICK ENCLAVE octane

An emission system malfunction might be corrected by
doing the following:
Make sure the fuel cap is fully installed. SeeFilling
the Tank on page 5-10. The diagnostic system
can determine if the fuel cap has been left off or
improperly installed. A loose or missing fuel cap
allows fuel to evaporate into the atmosphere.
A few driving trips with the cap properly installed
should turn the light off.
If the vehicle has been driven through a deep puddle
of water, the vehicle’s electrical system might be wet.
The condition is usually corrected when the electrical
system dries out. A few driving trips should turn the
light off.
Make sure to fuel the vehicle with quality fuel.
Poor fuel quality causes the engine not to run as
efficiently as designed and can cause: stalling after
start-up, stalling when the vehicle is changed into
gear, misring, hesitation on acceleration, or
stumbling on acceleration. These conditions
might go away once the engine is warmed up.
If one or more of these conditions occurs, change
the fuel brand used. It will require at least one full
tank of the proper fuel to turn the light off.
SeeGasoline Octane on page 5-6.
If none of the above have made the light turn off, your
dealer/retailer can check the vehicle. The dealer/retailer
has the proper test equipment and diagnostic tools to x
any mechanical or electrical problems that might have
developed.
Emissions Inspection and Maintenance
Programs
Some state/provincial and local governments have or
might begin programs to inspect the emission control
equipment on the vehicle. Failure to pass this inspection
could prevent getting a vehicle registration.
Here are some things to know to help the vehicle pass
an inspection:
The vehicle will not pass this inspection if the check
engine light is on with the engine running, or if the
key is in ON/RUN and the light is not on.
The vehicle will not pass this inspection if the
OBD II (on-board diagnostic) system determines
that critical emission control systems have not been
completely diagnosed by the system. The vehicle
would be considered not ready for inspection. This
can happen if the battery has recently been replaced
or if the battery has run down. The diagnostic system
is designed to evaluate critical emission control
systems during normal driving. This can take several
days of routine driving. If this has been done and the
vehicle still does not pass the inspection for lack of
OBD II system readiness, your dealer/retailer can
prepare the vehicle for inspection.
3-45

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................5-4
California Perchlorate Materials Requirements.....5-4
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of
the Vehicle.................................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-6
Gasoline Specications....................................5-6
California Fuel...............................................5-6
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...................................................5-17
Engine Oil Life System..................................5-20
Engine Air Cleaner/Filter................................5-22
Automatic Transmission Fluid.........................5-23
Cooling System............................................5-26
Engine Coolant (4.6L Engine).........................5-28
Engine Coolant (3.9L Engine).........................5-32Radiator Pressure Cap..................................5-35
Coolant Surge Tank Pressure Cap..................5-35
Engine Overheating.......................................5-35
Overheated Engine Protection
Operating Mode.........................................5-37
Power Steering Fluid.....................................5-38
Windshield Washer Fluid................................5-39
Brakes........................................................5-40
Battery........................................................5-44
Jump Starting...............................................5-46
Headlamp Aiming...........................................5-51
Bulb Replacement..........................................5-54
Halogen Bulbs..............................................5-54
Taillamps, Turn Signal, Stoplamps and
Sidemarker Lamps.....................................5-54
Taillamps and Back-Up Lamps.......................5-56
License Plate Lamp......................................5-57
Replacement Bulbs.......................................5-57
Windshield Wiper Blade Replacement..............5-57
Tires..............................................................5-59
Tire Sidewall Labeling...................................5-60
Tire Terminology and Denitions.....................5-63
Ination - Tire Pressure.................................5-66
Tire Pressure Monitor System.........................5-67
Tire Pressure Monitor Operation.....................5-69
Section 5 Service and Appearance Care
5-1

This vehicle has an airbag system. Before attempting
to do your own service work, seeServicing Your
Airbag-Equipped Vehicle on page 1-72.
Keep a record with all parts receipts and list the
mileage and the date of any service work performed.
SeeMaintenance Record on page 6-15.
Adding Equipment to the Outside of
the Vehicle
Things added to the outside of the vehicle can affect the
airow around it. This can cause wind noise and can
affect fuel economy and windshield washer performance.
Check with your dealer/retailer before adding equipment
to the outside of the vehicle.
Fuel
Use of the recommended fuel is an important part of the
proper maintenance of this vehicle. To help keep the
engine clean and maintain optimum vehicle performance,
we recommend the use of gasoline advertised as TOP
TIER Detergent Gasoline.
The 8th digit of the Vehicle Identication Number (VIN)
shows the code letter or number that identies the
vehicle’s engine. The VIN is at the top left of the
instrument panel. SeeVehicle Identification Number
(VIN) on page 5-100.
If the vehicle has the 3.9L V6 engine (VIN Code M),
you can use either unleaded gasoline or ethanol fuel
containing up to 85% ethanol (E85). SeeFuel E85
(85% Ethanol) on page 5-8. In all other engines, use only
the unleaded gasoline described underGasoline Octane
on page 5-6.
5-5

Gasoline Octane
If the vehicle has the 3.9L V6 engine (VIN Code 1) or the
3.9L V6 engine (VIN Code M), use regular unleaded
gasoline with a posted octane rating of 87 or higher. If the
octane rating is less than 87, you might 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, the engine needs service.
If the vehicle has the 4.6L V8 engine (VIN Code 9), use
premium unleaded gasoline with a posted octane rating
of 91 or higher. You can also use regular unleaded
gasoline rated at 87 octane or higher, but the vehicle’s
acceleration could be slightly reduced, and you might
notice a slight audible knocking noise, commonly referred
to as spark knock. If the octane is less than 87, you might
notice a heavy knocking noise when you drive. If this
occurs, use a gasoline rated at 87 octane or higher as
soon as possible. Otherwise, you could damage the
engine. If you are using gasoline rated at 87 octane or
higher and you hear heavy knocking, the engine needs
service.
Gasoline Specications
At a minimum, gasoline should meet ASTM specication
D 4814 in the United States or CAN/CGSB-3.5 or 3.511 in
Canada. Some gasolines contain an octane-enhancing
additive called methylcyclopentadienyl manganese
tricarbonyl (MMT). We recommend against the use of
gasolines containing MMT. SeeAdditives on page 5-7
for additional information.
California Fuel
If the 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, the vehicle will operate
satisfactorily on fuels meeting federal specications, but
emission control system performance might be affected.
The malfunction indicator lamp could turn on and the
vehicle might fail a smog-check test. SeeMalfunction
Indicator Lamp on page 3-43. If this occurs, return to your
authorized dealer/retailer for diagnosis. If it is determined
that the condition is caused by the type of fuel used,
repairs might not be covered by the vehicle warranty.
5-6

Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that help prevent
engine and fuel system deposits from forming, allowing
the emission control system to work properly. In most
cases, you should not have to add anything to the fuel.
However, some gasolines contain only the minimum
amount of additive required to meet U.S. Environmental
Protection Agency regulations. To help keep fuel injectors
and intake valves clean, or if the vehicle experiences
problems due to dirty injectors or valves, look for gasoline
that is advertised as TOP TIER Detergent Gasoline. Also,
your dealer/retailer has additives that will help correct and
prevent most deposit-related problems.
Gasolines containing oxygenates, such as ethers and
ethanol, and reformulated gasolines might be available in
your area. We recommend that you use these gasolines,
if they comply with the specications described earlier.
However, E85 (85% ethanol) and other fuels containing
more than 10% ethanol must not be used in vehicles that
were not designed for those fuels.Notice:This vehicle was not designed for fuel
that contains methanol. Do not use fuel containing
methanol. It can corrode metal parts in the fuel
system and also damage plastic and rubber parts.
That damage would not be covered under the
vehicle warranty.
Some gasolines that are not reformulated for low
emissions can contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. We recommend against
the use of such gasolines. Fuels containing MMT can
reduce the life of spark plugs and the performance of
the emission control system could be affected. The
malfunction indicator lamp might turn on. If this occurs,
return to your dealer/retailer for service.
5-7

Fuel E85 (85% Ethanol)
The 8th digit of the Vehicle Identication Number (VIN)
shows the code letter or number that identies the
vehicle’s engine. The VIN is at the top left of the
instrument panel. SeeVehicle Identification Number
(VIN) on page 5-100.
If the vehicle has the 3.9L V6 engine (VIN Code M),
you can use either unleaded gasoline or ethanol
fuel containing up to 85% ethanol (E85). SeeFuel on
page 5-5. In all other engines, use only the unleaded
gasoline described underGasoline Octane on page 5-6.
Only vehicles that have the 3.9L V6 engine
(VIN Code M) can use 85% ethanol fuel (E85).
We encourage the use of E85 in vehicles that are
designed to use it. The ethanol in E85 is a “renewable”
fuel, meaning it is made from renewable sources such
as corn and other crops.Many service stations will not have an 85% ethanol fuel
(E85) pump available. The U. S. Department of Energy
has an alternative fuels website (www.eere.energy.gov/
afdc/infrastructure/locator.html) that can help you nd
E85 fuel. Those stations that do have E85 should have a
label indicating ethanol content. Do not use the fuel if the
ethanol content is greater than 85%.
At a minimum, E85 should meet ASTM Specication
D 5798. By denition, this means that fuel labeled E85
will have an ethanol content between 70% and 85%.
Filling the fuel tank with fuel mixtures that do not meet
ASTM specications can affect driveability and could
cause the malfunction indicator lamp to come on.
5-8

Using the Maintenance Schedule
We want to help keep this vehicle in good working
condition. But we do not know exactly how you will drive
it. You might drive very short distances only a few times
a week. Or you might drive long distances all the time in
very hot, dusty weather. You might use the vehicle in
making deliveries. Or you might drive it to work, to do
errands, or in many other ways.
Because of all the different ways people use their
vehicles, maintenance needs vary. You might need
more frequent checks and replacements. So please
read the following and note how you drive. If you have
any questions on how to keep the vehicle in good
condition, see your dealer/retailer.
This schedule is for vehicles that:
carry passengers and cargo within recommended
limits on the Tire and Loading Information label.
SeeLoading the Vehicle on page 4-18.
are driven on reasonable road surfaces within legal
driving limits.
use the recommended fuel. SeeGasoline Octane
on page 5-6.
The services inScheduled Maintenance on page 6-4
should be performed when indicated. SeeAdditional
Required Services on page 6-6andMaintenance
Footnotes on page 6-7for further information.
{CAUTION:
Performing maintenance work on a vehicle can be
dangerous. In trying to do some jobs, you can be
seriously injured. Do your own maintenance work
only if you have the required know-how and the
proper tools and equipment for the job. If you
have any doubt, see your dealer/retailer to have
a qualied technician do the work. SeeDoing
Your Own Service Work on page 5-4.
Some maintenance services can be complex. So, unless
you are technically qualied and have the necessary
equipment, have your dealer/retailer do these jobs.
When you go to your dealer/retailer for service, trained
and supported service technicians will perform the
work using genuine parts.
To purchase service information, seeService
Publications Ordering Information on page 7-16.
Owner Checks and Services on page 6-8tells what
should be checked, when to check it, and what can easily
be done to help keep the vehicle in good condition.
6-3

Electronic Immobilizer Operation
PASS-Key®III+...........................................2-19
Engine
Air Cleaner/Filter.........................................5-22
Check and Service Engine Soon Lamp...........3-43
Coolant..............................................5-28, 5-32
Coolant Heater............................................2-24
Coolant Temperature Gage...........................3-42
Coolant Temperature Warning Light................3-42
Drive Belt Routing.......................................6-14
Engine Compartment Overview......................5-14
Exhaust.....................................................2-32
Oil .............................................................5-17
Oil Life System...........................................5-20
Overheated Protection Operating Mode...........5-37
Overheating................................................5-35
Starting......................................................2-22
Entry Lighting.................................................3-18
Event Data Recorders.....................................7-17
Extender, Safety Belt.......................................1-34
Exterior Lamps...............................................3-15
Exterior Lighting Battery Saver..........................3-17
F
Filter
Engine Air Cleaner......................................5-22
Finish Damage...............................................5-99
Flashers, Hazard Warning.................................. 3-6Flash-to-Pass................................................... 3-9
Flat Tire........................................................5-81
Flat Tire, Changing.........................................5-82
Flat Tire, Storing.............................................5-89
Fluid
Automatic Transmission................................5-23
Power Steering...........................................5-38
Windshield Washer......................................5-39
Fog Lamp
Fog ...........................................................3-17
Fog Lamp Light..............................................3-47
Front Reading Lamps......................................3-18
Front Storage Area.........................................2-57
Fuel............................................................... 5-5
Additives...................................................... 5-7
California Fuel.............................................. 5-6
Driving for Better Economy............................. 4-2
E85 (85% Ethanol)........................................ 5-8
Filling a Portable Fuel Container....................5-12
Filling the Tank...........................................5-10
Fuels in Foreign Countries.............................. 5-9
Gage .........................................................3-48
Gasoline Octane........................................... 5-6
Gasoline Specications.................................. 5-6
Fuses
Fuses and Circuit Breakers.........................5-101
Rear Underseat Fuse Block.........................5-104
Underhood Fuse Block...............................5-101
5