2004 BMW 325I SEDAN service engine

122
Brake systemBrake fluid levelLow brake fluid level in the reservoir
combined with longer than usual pedal
travel may indicate a defect in one of
the brake system's hydraulic circuits.
Proceed to the nearest BMW cen-
ter. It may be necessary to apply
higher levels of pressure to the pedal
when stopping and braking distances
may also be longer. Please remember
to adapt your driving style accord-
ingly. sionally, during extended periods when
the vehicle is not used at all, and in
operating conditions where brake appli-
cations are less frequent, there is an
increased tendency for corrosion of the
rotors and accumulation of contamina-
tion on the brake pads. This occurs
because the minimal pressure that must
be exerted by the pads to clean the
rotors by brake applications is not
reached.
Corrosion on brake rotors is signaled by
a running or pulsation during braking;
even extended subsequent braking will
not cure this phenomenon.
It is a good idea to periodically dry the
brakes with a gentle application when
driving in rain and on wet roads. Watch
traffic conditions to ensure that this
maneuver does not endanger other
road users. The heat generated in this
process helps dry the pads and rotors
to ensure that your brake system will
respond with undiminished efficiency
when you need it.
When descending steep hills and
extended grades, downshift to a gear
that will allow you to continue safely
with only a minimal amount of braking.
This helps avoid placing excessive
loads on the brake system. Use care to
avoid exceeding the approved engine-
speed range, refer to page 80.Do not coast with the clutch
depressed or with the transmis-
sion or selector lever in Neutral. Do not
coast with the engine shut off. The
engine provides no braking effect when
the clutch is depressed and there is no
power-assist for braking or steering
when the engine is not running.
325xi, 330xi: always refer all brake
inspection and service work to your
BMW center, as failure to observe the
special procedures could result in dam-
age to components of the all-wheel
drive.
Never allow floor mats, carpets or any
other objects to protrude into the area
around the accelerator, clutch and
brake pedals and obstruct their move-
ment.<
Brake pads
For your own safety: use only
brake pads which BMW has
approved for your specific vehicle
model. BMW cannot evaluate non-
approved brake pads to determine if
they are suitable for use, and therefore
cannot ensure the operating safety of
the vehicle if they are installed.<

129 In the engine compartment
HoodTo releasePull the lever located under the left-
hand side of the instrument panel.
Do not attempt to service your
vehicle if you do not have the
required technical background. Failure
to work in an informed, professional
manner when servicing components
and materials constitutes a safety haz-
ard for vehicle occupants and other
road users. If you are not familiar with
the guidelines, BMW recommends that
you have the operations performed by
your BMW center.<
To openPull the release handle and open the
hood.
To closeAllow the hood to fall from a height of
about 1 ft/30 cm so that it audibly
engages.
To avoid injuries, be sure that the
travel path of the hood is clear
when it is closed, following the same
safety precautions used in all closing
procedures.
If you notice while driving that the hood
is not completely closed, stop immedi-
ately and close it securely.<
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133
Adding engine oilOnly add engine oil when the oil level
has dropped to just above the lower
mark on the dipstick.
BMW engines are designed to
operate without oil additives; the
use of additives could lead to damage
in some cases. This also applies to the
manual transmission, the automatic
transmission, the differential, and the
power steering system.<
Recommendation: have the oil changed
at your BMW center.
Continuous exposure to used oil
has caused cancer in laboratory
testing. For this reason, any skin areas
that come into contact with oil should
be thoroughly washed with soap and
water.
Store oils, grease and similar materials
so that they are inaccessible to chil-
dren. Comply with warning labels and
information on containers.<
Comply with the applicable envi-
ronmental laws regulating the dis-
posal of used oil.<
Specified engine oilsThe quality of the engine oil is
extremely important for the operation
and service life of an engine. Based on
extensive testing, BMW has approved
only certain grades of engine oil.
Use only approved BMW High Perfor-
mance Synthetic Oil.
If an approved BMW High Performance
Synthetic Oil should be unavailable, you
may use small volumes of other syn-
thetic oils for topping up between oil
changes. Use only oils with the specifi-
cation API SH or higher.
Ask your BMW center for details
concerning the specific BMW
High Performance Synthetic Oil or syn-
thetic oils that have been approved.<
You can also call BMW of North
America toll-free at 1-800-831-1117 or
visit this website: www.bmwusa.com to
obtain this information.
Viscosity ratingsViscosity is the oilflow rating as estab-
lished in SAE classes.
The selection of the correct SAE class
depends on the climatic conditions in
the area where you drive your BMW.
Approved oils are in SAE classes
5W-40 and 5W-30.<
These kinds of oil may be used for driv-
ing in all ambient temperatures.
Engine oil
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135
Brake fluid is hygroscopic, that is,
it absorbs moisture from the air
over time.
In order to ensure the brake system's
safety and reliability, have the brake
fluid changed every two years by a
BMW center. Refer to the Service and
Warranty Information Booklet for US
models or the Warranty and Service
Guide Booklet for Canadian models.
Brake fluid is toxic and damages the
vehicle's paint. You should always store
it in its closed original container and in
a location which is out of reach of chil-
dren.
Do not spill the brake fluid and do not
fill the brake fluid reservoir beyond the
MAX mark. The brake fluid could ignite
upon contact with hot engine parts and
cause serious burns.<
Comply with the applicable envi-
ronmental laws regulating
the disposal of brake fluid.<
Brake fluid
OverviewControlsMaintenanceRepairsDataIndex

136Maintenance
The BMW Maintenance SystemThe BMW Maintenance System has
been designed as a reliable means of
providing maximum driving and operat-
ing safety – and as cost-effectively as
possible for you.
Please keep in mind that regular main-
tenance is not only necessary for the
safety of your vehicle, but also plays a
significant role in maintaining the resale
value of the vehicle.
Service interval displayWhile conventional systems rely on
milage alone to determine when service
is due, the BMW Maintenance System
reflects the actual conditions under
which the vehicle is operated: some
miles are more strenuous than others.
From a maintenance point of view,
62,000 miles/100,000 km accumulated
in short-distance urban driving are not
the equivalent of the same distance
covered at moderate cruising speeds in
long-distance highway travel.
The BMW Maintenance System
includes the Engine Oil Service and
Inspections I and II.
This service strategy accurately reflects
your own vehicle's specific needs by
defining maintenance intervals accord-
ing to individual operating conditions.
Minimal use drivers – those who drive
significantly fewer than
6,200 miles/10,000 km annually –
should have the engine oil changed at
least every 2 years since oil deterio-
rates over time, regardless of use.Service and Warranty Information
Booklet for US models/
Warranty and Service Guide
Booklet for Canadian modelsFor additional information on required
maintenance intervals and procedures,
please refer to the Service and War-
ranty Information Booklet for US mod-
els, or the Warranty and Service Guide
Booklet for Canadian models.
As a precaution against corrosion, if
your vehicle is exposed to potential
damage from unimproved road sur-
faces we suggest that you have the
body checked for damage from stone
chips and gravel at the same time.

138Laws and regulations
California Proposition 65 warningCalifornia laws require us to state the
following warning:
Engine exhaust and a wide variety
of automobile components and
parts, including components found in
the interior furnishings in a vehicle, con-
tain or emit chemicals known to the
State of California to cause cancer and
birth defects and reproductive harm. In
addition, certain fluids contained in
vehicles and certain products of com-
ponent wear contain or emit chemicals
known to the State of California to
cause cancer and birth defects or other
reproductive harm.
Battery posts, terminals and related
accessories contain lead and lead com-
pounds. Wash your hands after hand-
ling.
Used engine oil contains chemicals that
have caused cancer in laboratory ani-
mals. Always protect your skin by
washing thoroughly with soap and
water.<
OBD interface socketThe interface socket for onboard diag-
nostics is located on the left-hand side
of the driver's side, behind a specially
marked cover located beneath the
instrument panel. The cover has the let-
ters OBD on it.
This interface makes it possible to
access data on emissions-related com-
ponents using special equipment.
An illuminated indicator informs
you of the need for service, not
that you need to stop the vehi-
cle. However, the systems should be
checked by your BMW center at the
earliest possible opportunity.
If the indicator blinks or flashes, this
indicates a high level of engine misfire.
Reduce speed and contact the nearest
BMW center immediately. Severe

139
engine misfiring for even a short period
of time can seriously damage emission
control system components, especially
the catalytic converter.
SERVICE ENGINE SOON warn-
ing lamp for Canadian models.
If the gas cap is not on tight
enough, the OBD system can
detect leaking vapor and the indicator
will light up. If the gas cap is then tight-
ened, the indicator will usually go out
after a short period of time. OverviewControlsMaintenanceRepairsDataIndex

143
Lamps and bulbsThe lamps and bulbs make essential
contributions to the safety of your vehi-
cle. Therefore, proceed carefully when
handling bulbs. BMW recommends that
you have such work performed by your
BMW center if you are not familiar with
the procedures.
Do not touch the glass portion of
a new bulb with your bare hands
since even small amounts of impurities
burn in to the surface and reduce the
service life of the bulb. Use a clean
cloth, paper napkin, or a similar mate-
rial, or hold the bulb by its metallic
base.<
A replacement bulb set is available from
your BMW center.
Before working on the electrical
system, switch off the electrical
accessory you are working on or dis-
connect the cable from the negative
terminal of the battery. Failure to
observe this precaution could result in
short circuits.
To prevent injuries and damage, com-
ply with any instructions provided by
the bulb manufacturer.<
Low beams and high beamsEngine compartment, left side:
1Low beams
2High beams
H7 bulb, 55 watts
The H7 bulb is pressurized. There-
fore, wear safety glasses and pro-
tective gloves. Failure to comply with
this precaution could lead to injury if the
bulb is damaged.<
1. Turn the two release catches at the
front to the left – see arrow – to
remove the bulb holder
2. Remove and replace the bulb.
Insert the new bulb as shown in
the inset.
When attaching the bulb holder, ensure
that the lock snaps in place properly.<
When cleaning the headlamps,
please follow the instructions in
the Caring for your vehicle brochure.<
Xenon lamps*The service life of these bulbs is very
long and the probability of a failure is
very low, provided that they are not
switched on and off an unusual number
of times. If one of these bulbs should
nevertheless fail, it is possible to con-
tinue driving with great caution using
the fog lamps, provided local traffic
laws do not prohibit this.
Because of the extremely high
voltages involved, any work on the
xenon lighting system, including bulb-
changing, should be carried out by
technically-qualified personnel only.
Otherwise, there is a risk of fatal
injury.<
OverviewControlsMaintenanceRepairsDataIndex