2004 BMW 325I maint

119
Overview
Controls and features
Operation, maintenance
Owner service procedures
Technical data
Index
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General driving notes
Brakes: do not rest your foot on
the brake pedal while driving.
Even light but consistent pedal pres-
sure can lead to high temperatures,
brake wear and possibly even brake
failure.
Hydroplaning: when driving on wet or
slushy roads, reduce road speed. If you
do not, a wedge of water can form
between tires and road surface. This
phenomenon can lead to partial or
complete loss of contact between the
tires and road surface, as well as loss of
vehicle control and braking ability.
Driving through water: do not drive
through water on the road if it is deeper
than 1 ft/30 cm, and then only at walk-
ing speed. Otherwise, the vehicle's
engine, the electrical systems and the
transmission may be damaged.
Rear parcel tray: never use it to store
heavy or hard objects; otherwise, occu-
pants could be injured if the vehicle is
braked hard.
Clothes hooks: when hanging clothing
from the hooks, be sure that they will
not obstruct the driver's vision. Do not
hang heavy objects on the hooks. If you
do so, they could cause personal injury
during braking or evasive maneuvers.<
Antilock Brake System (ABS)The conceptABS keeps the wheels from locking
during braking, thereby enhancing
active driving safety.Braking with ABSIf you are in a situation that requires full
braking, you will exploit the full benefits
of the ABS system if you apply maxi-
mum pedal pressure – panic stop.
Since the vehicle maintains steering
responsiveness, you can avoid possible
obstacles with a minimum of steering
effort, despite the full brake application.
Pulsation at the brake pedal combined
with sounds from the hydraulic circuits
indicates to the driver that ABS is in its
active mode.Dynamic Brake Control (DBC)DBC is included in the DSC, refer to
page 87.
The system responds to sudden, high-
intensity applications of force to the
brake pedal by automatically braking
the vehicle with maximum boost to
achieve the shortest possible braking
distances during panic stops. This sys-
tem exploits all the benefits of ABS.Do not reduce the pressure exerted
against the brake pedal until the brak-
ing maneuver has been completed.
DBC is deactivated when you release
the brake pedal.
Cornering Brake Control (CBC)CBC is an advanced engineering
design of the ABS. When braking while
cornering at high speed or braking dur-
ing high lateral acceleration, or when
braking during a lane change, vehicle
stability is improved and steering
response is enhanced.
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123
Portable phone in the vehicleBMW recommends using mobile com-
munications devices, e.g. portable
phones, inside the vehicle with a suit-
able outside antenna. Otherwise, it can-
not be ruled out that the vehicle elec-
tronics and portable phone may
interfere with each other.Brake system
OverviewControlsMaintenanceRepairsDataIndex

124Wheels and tires
Tire inflation pressureInformation for your safetyThe factory-approved tires are matched
to your vehicle and have been selected
to provide optimum safety and driving
comfort when used properly.
It is not merely the tire's service life, but
also driving comfort and – above all else
– driving safety that depend on the con-
dition of the tires and the maintenance
of the specified tire inflation pressure.
Incorrect tire inflation pressure is a fre-
quent cause of tire damage. Tire pres-
sure also has a major effect on your
BMW's handling response.
Be sure to check the tire inflation
pressure, including the space-
saver spare tire or the spare tire, on a
regular basis, at least twice a month
and before every extended journey,
refer to page 25. If this is not done,
incorrect tire pressures can cause driv-
ing instability and tire damage, ulti-
mately resulting in accidents.<
Tire conditionTire tread – tire damageInspect your tires frequently for tread
wear, signs of damage and for foreign
objects lodged in the tread. Check the
tread depth.
Tread depth should not be allowed to
go below 1/8 in / 3 mm, even though
the legally specified minimum tread
depth is 1/16 in / 1.6 mm.
Below 1/8 in / 3 mm tread depth, there
is a great risk of hydroplaning, even at
relatively moderate speeds and with
only small amounts of water on the
road. Tread wear indicators in the
tread-groove base – see arrow – are
distributed around the wheel circumfer-
ence and are labeled on the tire side-
wall with TWI – Tread Wear Indicator. At
a tread depth of 1/16 in / 1.6 mm, the
indicators signal that the legally permis-
sible wear limit has been reached.

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Do not drive on a flat tire unless
your vehicle is equipped with Run
Flat tires. A flat tire greatly impairs
steering and braking response, and can
lead to complete loss of control over
the vehicle. Avoid overloading the vehi-
cle so that the permitted load on the
tires is not exceeded. Overloading can
lead to overheating and internal tire
damage.
The ultimate result can assume the
form of a sudden air loss.
Unusual vibrations encountered during
normal vehicle operation can indicate a
flat tire or some other vehicle malfunc-
tion. This type of problem can be
caused by contact with curbs, etc. This
is also true for abnormalities in the vehi-
cle's handling characteristics, such as a
pronounced tendency to pull to the left
or right. Should this occur, respond by
immediately reducing your speed. Pro-
ceed carefully to the nearest BMW cen-
ter or professional tire center, or have
the vehicle towed in to have it, its
wheels or its tires inspected.
Tire damage up to and including sud-
den and complete air loss can endan-
ger the lives of both the vehicle occu-
pants and other road users.<
Tire replacementTo maintain good handling and vehicle
response, use only tires of a single
tread configuration from a single manu-
facturer.
Comply with the specified tire inflation
pressures — and be sure to have the
wheel and tire assembly balanced
every time you change a tire or wheel.DOT quality gradesTread wear
Traction AA A B C
Temperature A B C
All passenger car tires must con-
form to Federal Safety Require-
ments in addition to these grades. rating based on the wear rate of the tire
when tested under controlled condi-
tions on a specified government test
course.
For example, a tire graded 150 would
wear one and one-half – 1
1/2 – times as
well on the government course as a tire
graded 100. The relative performance
of tires depends upon the actual condi-
tions of their use, however, and may
depart significantly from the norm due
to variations in driving habits, service
practices and differences in road char-
acteristics and climate.TractionThe traction grades, from highest to
lowest, are AA, A, B, and C.
Those grades represent the tire's ability
to stop on wet pavement as measured
under controlled conditions on speci-
fied government test surfaces of
asphalt and concrete. A tire marked C
may have poor traction.
The traction grade assigned to
this tire is based on straight-
ahead braking traction tests, and does
not include acceleration, cornering,
hydroplaning, or peak traction charac-
teristics. highest – B, and C, representing the
tire's resistance to the generation of
heat and its ability to dissipate heat
when tested under controlled condi-
tions on a specified indoor laboratory
test wheel.
Tire condition
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127
Wheel and tire combinationsThe right choice
BMW recommends using only
wheels and tires that have been
approved by BMW for use on your par-
ticular model. Although other wheels
and tires may theoretically have the
same dimensions, variations in factors
such as manufacturing tolerances can
result in contact between tire and body-
work, ultimately leading to serious acci-
dents. BMW cannot evaluate all tires
and wheels on the market, and is thus
unable to guarantee that the vehicle will
continue to perform safely if unap-
proved tires and/or wheels are
mounted.<
For each tire size, BMW has assessed
the safe performance of specific tire
brands and approved them for use.
Consult any BMW center for details.
Comply with any local/national regula-
tions, for example by recording the tire
type in the vehicle documents.
The correct wheel and tire combi-
nation affects various systems
that would otherwise be impaired, for
example ABS, DSC and ADB-X/DBC.
For this reason, use only tires of the
same manufacture and tread configura-
tion. In the event of a flat tire, for exam-
ple, remount the approved wheel and
tire combination as soon as possible.<
StorageAlways store tires in a cool, dry place.
Store them away from light whenever
possible. Protect the tires against con-
tact with oil, grease and fuel.
Do not exceed the maximum tire infla-
tion pressures specified on the tire
sidewall.
Winter tiresChoosing the right tireBMW recommends the use of winter
tires for operation under winter road
conditions. While all-season tires – with
M+S designation – provide better winter
traction than the corresponding sum-
mer tires, they generally do not achieve
the performance of winter tires.
In the interest of safe tracking and
steering response, install winter tires
made by the same manufacturer and
having the same tread configuration on
all four wheels.
Never exceed the maximum
speed for which the winter tires
are rated.
Unprofessional attempts by laymen to
service tires can lead to damage and
accidents.
Have this work performed by trained
professionals only. Any BMW center
has the required technical knowledge
and the proper equipment and will be
happy to assist you. your BMW is eqipped with Run Flat
tires. These are indicated by a circular
symbol containing the letters RSC on
OverviewControlsMaintenanceRepairsDataIndex

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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1Brake fluid reservoir134
2Engine oil dipstick132
3Coolant expansion tank134
4Reservoir for the headlamp and
windshield washer system132
5Engine oil filler neck133
6Auxiliary terminal for jump-
starting153Engine compartment essentials
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