check engine BUICK ENCLAVE 2008 Owner's Guide

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

Filling a Portable Fuel Container
{CAUTION:
Never ll a portable fuel container while it is in the
vehicle. Static electricity discharge from the
container can ignite the fuel vapor. You can be
badly burned and the vehicle damaged if this
occurs. To help avoid injury to you and others:
Dispense fuel only into approved containers.
Do not ll a container while it is inside a
vehicle, in a vehicle’s trunk, pickup bed,
or on any surface other than the ground.
Bring the ll nozzle in contact with the inside
of the ll opening before operating the nozzle.
Contact should be maintained until the lling
is complete.
Do not smoke while pumping fuel.
Do not use a cellular phone while pumping fuel.
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.
5-12

A.Underhood Fuse Block on page 5-101.
B. Remote Positive (+) Battery Terminal. SeeJump
Starting on page 5-46.
C. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-39.
D. Engine Coolant Recovery Tank. SeeCooling System
on page 5-26.
E. Radiator Pressure Cap. SeeCooling System on
page 5-26.
F. Power Steering Fluid Reservoir (Out of View).
SeePower Steering Fluid on page 5-38.G. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-17.
H. Engine Oil Dipstick (Out of View). See “Checking
Engine Oil” underEngine Oil on page 5-17.
I. Automatic Transmission Fluid Dipstick. See
“Checking the Fluid Level” underAutomatic
Transmission Fluid on page 5-23.
J. Brake Fluid Reservoir. See “Brake Fluid” under
Brakes on page 5-40.
K.Engine Air Cleaner/Filter on page 5-22.
5-15

A.Underhood Fuse Block on page 5-101.
B. Remote Positive (+) Terminal. SeeJump Starting on
page 5-46.
C. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-39.
D. Engine Coolant Surge Tank and Pressure Cap.
SeeCooling System on page 5-26.
E. Remote Negative (−) Terminal. SeeJump Starting
on page 5-46.
F. Power Steering Fluid. SeePower Steering Fluid on
page 5-38.
G. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-17.
H. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 5-17.
I. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-40.
J. Automatic Transmission Fluid Cap and Dipstick
(Out of View). SeeAutomatic Transmission Fluid on
page 5-23.
K.Engine Air Cleaner/Filter on page 5-22.Engine Oil
Checking Engine Oil
It is a good idea to check the engine oil every time you
get fuel. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.
The engine oil dipstick handle is a yellow loop.
SeeEngine Compartment Overview on page 5-14
for the location of the engine oil dipstick.
1. Turn off the engine and give the oil several minutes
to drain back into the oil pan. If you do not do this,
the oil dipstick might not show the actual level.
2. Pull out the dipstick and clean it with a paper towel
or cloth, then push it back in all the way. Remove it
again, keeping the tip down, and check the level.
5-17

Engine Oil Additives / Engine Oil
Flushes
Do not add anything to the oil. The recommended oils
with the starburst symbol that meet GM Standard
GM6094M are all that is needed for good performance
and engine protection.
Engine oil system ushes are not recommended and
could cause engine damage not covered by the vehicle
warranty.
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system that indicates when
to change the engine oil and lter. This is based on
engine revolutions and engine temperature, and not on
mileage. Based on driving conditions, the mileage at
which an oil change is indicated can vary considerably.
For the oil life system to work properly, the system
must be reset every time the oil is changed.When the system has calculated that oil life has been
diminished, it indicates that an oil change is necessary.
A CHANGE ENGINE OIL SOON message comes on.
SeeDIC Warnings and Messages on page 3-56. Change
the oil as soon as possible within the next 600 miles
(1 000 km). It is possible that, if driving under the best
conditions, the oil life system might not indicate that an oil
change is necessary for over a year. However, the engine
oil and lter must be changed at least once a year and at
this time the system must be reset. Your dealer/retailer
has trained service people who will perform this work
using genuine parts and reset the system. It is also
important to check the oil regularly and keep it at the
proper level.
If the system is ever reset accidentally, the oil must be
changed at 3,000 miles (5 000 km) since the last oil
change. Remember to reset the oil life system whenever
the oil is changed.
5-20

To reinstall the cover:
1. Align the two hinges located on the inboard side of
the cover.
2. Push the cover slightly down and towards the
engine to engage the tabs in the hinges and
align the two screws.
3. Tighten the two screws on the top of the engine air
cleaner/lter cover.
{CAUTION:
Operating the engine with the air cleaner/lter off
can cause you or others to be burned. The air
cleaner not only cleans the air; it helps to stop
ames if the engine backres. If it is not there and
the engine backres, you could be burned. Do not
drive with it off, and be careful working on the
engine with the air cleaner/lter off.Notice:If the air cleaner/lter is off, a backre
can cause a damaging engine re. And, dirt
can easily get into the engine, which will damage it.
Always have the air cleaner/lter in place when
you are driving.
Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
A good time to check your automatic transmission uid
level is when the engine oil is changed.
Change the uid and lter at the intervals listed in
Scheduled Maintenance on page 6-4, and be sure to
use the transmission uid listed inRecommended Fluids
and Lubricants on page 6-12.
5-23

How to Check Automatic Transmission
Fluid (3.9L Engine)
Because this operation can be a little difficult, you may
choose to have this done at the dealer/retailer service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
Notice:Too much or too little uid can damage
your transmission. Too much can mean that some
of the uid could come out and fall on hot engine
parts or exhaust system parts, starting a re.
Too little uid could cause the transmission to
overheat. Be sure to get an accurate reading if
you check your transmission uid.
Wait at least 30 minutes before checking the
transmission uid level if you have been driving:
When outside temperatures are above 90°F (32°C).
At high speed for quite a while.
In heavy traffic — especially in hot weather.
While pulling a trailer.To get the right reading, the uid should be at normal
operating temperature, which is 180°F to 200°F
(82°C to 93°C).
Get the vehicle warmed up by driving about
15 miles (24 km) when outside temperatures are
above 50°F (10°C). If it is colder than 50°F (10°C),
you may have to drive longer.
Checking the Fluid Level
Prepare your vehicle as follows:
1. Park your vehicle on a level place. Keep the engine
running.
2. With the parking brake applied, place the shift lever
in P (Park).
3. With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position
the shift lever in P (Park).
4. Let the engine run at idle for three to ve minutes.
5-24

Then, without shutting off the engine, follow these steps:
For the 3.9L V6 engine the
transmission uid dipstick
top is a round loop
with this symbol.
SeeEngine Compartment Overview on page 5-14for
more information on location.
1. Pull out the dipstick and wipe it with a clean rag or
paper towel.
2. Push it back in all the way, wait three seconds and
then pull it back out again.3. Check both sides of the dipstick, and read the
lower level. The uid level must be in the
cross-hatched area.
4. If the uid level is in the acceptable range, push the
dipstick back in all the way.
How to Add Automatic Transmission
Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission uid to use. SeeRecommended
Fluids and Lubricants on page 6-12.
3.9L V6 Engine
5-25

If the uid level is low, add only enough of the proper
uid to bring the level into the cross-hatched area on the
dipstick.
1. Pull out the dipstick.
2. Using a long-neck funnel, add enough uid at the
dipstick hole to bring it to the proper level.
It does not take much uid, generally less than
one pint (0.5 L). Do not overll.
Notice:Use of the incorrect automatic transmission
uid may damage the vehicle, and the damages may
not be covered by the vehicle’s warranty. Always
use the automatic transmission uid listed in
Recommended Fluids and Lubricants on page 6-12.
3. After adding uid, recheck the uid level as
described under “How to Check Automatic
Transmission Fluid,” earlier in this section.
4. When the correct uid level is obtained, push the
dipstick back in all the way.
How to Check Automatic Transmission
Fluid (4.6L Engine)
For the 4.6L V8 engine, it is not necessary to check the
transmission uid level. A transmission uid leak is the
only reason for uid loss. If a leak occurs, take your
vehicle to the dealer/retailer service department and
have it repaired as soon as possible.
Cooling System
The Cooling System allows the engine to maintain the
correct working temperature.
A. Coolant Recovery Tank
B. Radiator Pressure Cap
C. Electric Engine Cooling Fans3.9L Engine
5-26

Engine Coolant (4.6L Engine)
The cooling system in the vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in the vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst.
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, seeEngine
Overheating on page 5-35.
What to Use
{CAUTION:
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
CAUTION: (Continued)
CAUTION: (Continued)
is set for the proper coolant mixture. 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 re 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−34°F (−37°C),
outside temperature.
Gives boiling protection up to 265°F (129°C), engine
temperature.
Protects against rust and corrosion.
Will not damage aluminum parts.
Helps keep the proper engine temperature.
5-28