1998 BMW 740I Owners Manual

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Overview
Controls and features
Operation, care
and maintenance
Owner service procedures
Technical data
Index Advanced technology
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RepairsIndexOverview Controls Car care Technology Data
Special operating instructions:
Break-in procedure122
Driving notes123
Catalytic converter124
Antilock Brake System
(ABS)125
Disc brakes126
Brake system128
Winter operation128
Power steering130
Level control system130
Cellular phone131
Radio reception131
Wheels and tires:
Tire inflation pressure132
Tire condition132
Tire replacement133
Tire rotation133
Wheel and tire
combinations134
Winter tires135
Snow chains135
Approved wheel and tire
specifications136Under the hood:
Hood137
Engine compartment138
Washer fluids142
Washer nozzles142
Engine oil143
Coolant146
Brake fluid147
Oil for power steering/
Level control system148
Vehicle Identification
Number148
Care and maintenance:
The BMW Maintenance
System149
Caring for your car150
Airbags156
Vehicle storage156
Laws and regulations:
Technical modifications to the
vehicle157
OBD connector158

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To ensure that your vehicle provides
maximum economy throughout a long
service life, we request that you comply
with the following:
Engine and differentialUp to 1,200 miles (2,000 km):
Drive at varying engine speeds and
road speeds, but do not exceed
4500 rpm and/or 105 mph (170 km/h)
during this initial period. Comply with
the legal speed limit at all times.
Refrain from using full throttle and avoid
pressing the accelerator beyond the
kickdown point.
Once 1,200 miles (2,000 km) have
elapsed, engine speeds and road
speeds can gradually be increased.
You should also comply with these
break-in procedures if the engine or dif-
ferential is replaced later in the course
of the vehicle service life.TiresDue to technical factors associated with
their manufacture, tires do not achieve
their full traction potential until an initial
break-in period has elapsed.
Thus drive with extra care during the
initial 200 miles (300 km).When the vehicle is operated on
wet or slushy roads, a wedge of
water may form between the tire and
the road surface. This phenomenon is
referred to as aquaplaning, or hydro-
planing, and can lead to partial or com-
plete loss of traction, vehicle control
and braking effectiveness. Reduce your
speed on wet roads.<
Brake systemApproximately 300 miles (500 km) must
elapse before the brake pads and rotors
achieve the optimal pad-surface and
wear patterns required for trouble-free
operation and long service life later on.
To break-in the separate parking brake
drums, apply the parking brake lightly
when coasting to a standstill (at a traffic
signal, for instance), provided that traf-
fic conditions allow you to do so.
To avoid corrosion, repeat this proce-
dure from time to time.
The brake lamps do not come on
when the parking brake is applied.
Vacuum for the brake system servo unit
on your BMW is available only when the
engine is running. When you move the
car with the engine shut off – when tow-
ing, for instance – substantially higher
levels of pedal force will be required to
brake the vehicle.<
Break-in procedure

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RepairsIndexOverview Controls Car care Technology Data
Driving notes
Brakes:
Do not drive with your foot resting
on the brake pedal. Even light but con-
sistent pedal pressure can lead to high
temperatures, brake wear and possibly
even brake failure.
Aquaplaning:
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 is
referred to as aquaplaning or hydro-
planing. It is characterized by a partial
or complete loss of contact between
the tires and the road surface. The ulti-
mate results are loss of steering and
braking control.
Driving through water:
Do not drive through water more than
1 foot (30 cm) deep. In water of this
depth, drive only at walking speed, oth-
erwise damage to the engine, the elec-
trical system and the transmission can
occur.
Rear parcel tray:
Do not use the rear parcel tray to store
heavy or bulky objects. They could
pose a danger to the occupants during
braking maneuvers.
Clothes hooks:
Hang items of clothing from the hooks
so that they will not obstruct the driver's
vision. In order to avoid personal inju-
ries during braking maneuvers, do not
hang heavy objects on the hooks.<

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Catalytic converterThe catalytic converter reduces harmful
exhaust emissions, and is designed for
use with unleaded fuel only.
Even minute quantities of lead would be
enough to permanently damage both
the catalytic converter and the system's
oxygen sensor.
To ensure efficient, trouble-free engine
operation and avoid potential damage:
>Be sure to comply with the scheduled
maintenance requirements
>Fill the fuel tank well before it is
empty
>If you have problems starting the en-
gine, use jumper cables (you cannot
tow-start the vehicle with an auto-
matic transmission)>Avoid other situations in which the
fuel is not burned, or burns incom-
pletely, such as engaging the starter
frequently or for extended periods, or
repeated start attempts in which the
engine does not start (stopping and
restarting an engine which is running
properly does not present a problem).
Never let the engine run with any of
the spark plug cables disconnected.Be sure to comply with the in-
structions above to prevent un-
burned fuel from reaching the catalytic
converter. Otherwise there is danger of
overheating and damage to the cata-
lytic converter.
Extreme temperatures occur at the
catalytic converter on this and every
catalyst-equipped vehicle. Heat shields
are installed adjacent to some sections
of the exhaust system. Never remove
these shields; do not apply undercoat-
ing to their surfaces. When driving,
standing at idle, and parking the vehi-
cle, take care to avoid contact between
the exhaust system and flammable ma-
terials (grass, hay, leaves, etc.). Such
contact could lead to a fire, resulting in
personal injury and property damage.<

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RepairsIndexOverview Controls Car care Technology Data
Antilock Brake System (ABS)The conceptABS enhances active safety by helping
to prevent the wheels from locking dur-
ing brake applications. The reason:
Locked wheels are dangerous. When
the front wheels slide, the driver loses
steering control over the vehicle. Trac-
tion loss at the rear wheels can cause
the rear end to break into an uncon-
trolled skid.
The system can achieve the shortest
braking distances possible under most
conditions (on straights and in curves,
on asphalt, ice, wet road surfaces, etc.).
ABS is designed to meet two essential
requirements during every brake appli-
cation:
>To help provide vehicle stability
>To help maintain steering control and
maneuverability – on all types of road
surfaces (asphalt, concrete, mud, wet
pavement, snow, ice).
Braking with ABSThe system becomes operative once
the vehicle exceeds a speed of approx.
6 mph (10 km/h). The ABS is deactivated
whenever the vehicle's speed drops
back below approx. 4 mph (6 km/h). This
means that the wheels can lock in the fi-
nal phase of a panic stop – a factor of no
significance in actual use.
If you are in a situation which requires
full braking, you will exploit the full bene-
fits of the ABS system if you apply maxi-
mum brake pressure ("panic stop").
Since the vehicle maintains steering re-
sponsiveness, you can avoid possible
obstacles with a minimum of steering ef-
fort, despite the full brake application.
The ABS system closed-loop control cir-
cuit cycles in fractions of a second.
A pulsation at the brake pedal indicates
to the driver that ABS is active, that is,
that the vehicle is within its maximum
braking range. In addition, a pulsation – a
result of the control function cycles – in-
dicates to the driver that vehicle speed
should be reduced to adapt to road sur-
face conditions when there is reduced
traction and grip between tires and road
surface (slippery road surface).
Always depress the brake pedal with
constant pressure. Keep the brake pedal
down. Do not pump the brakes.In driving conditions where there is a
loose upper surface together with a
subsurface which provides better trac-
tion (on gravel or snow, for instance), or
with snow chains, the braking distance
may also be longer than when the
wheels are locked. However, ABS con-
tinues to provide enhanced vehicle sta-
bility and steering response under
these conditions.
Information for your safetyNot even ABS can suspend the laws of
physics. ABS alone cannot prevent ac-
cidents when the brakes are applied
without an adequate safety interval be-
tween vehicles, if the car is driven at an
excessive rate of speed in curves, or if
aquaplaning occurs. Responsibility for
these types of situations remains in the
hands (and at the feet) of the driver. You
should never allow the added safety of
ABS to lull you into a false sense of se-
curity, or mislead you into taking in-
creased risks that could affect your own
safety and that of others.
Do not make any modifications to
the ABS system.
Service procedures on ABS are to be
performed by authorized technicians
only.<

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Antilock Brake System (ABS) Disc brakesIn the event of a fault
If the ABS warning lamp in the
instrument cluster comes on, re-
fer to page 21. The brake sys-
tem then reverts to conventional
operation as on vehicles without
ABS. However, have the brake
system checked by your BMW center
as soon as possible. To prevent unde-
tected defects and cumulative faults
from adversely affecting the brake sys-
tem, refer any problems to your autho-
rized BMW center at the earliest oppor-
tunity.
Disc brakes furnish optimum decelera-
tion and braking control and greater
fade resistance under heavy use.
When the vehicle is driven only occa-
sionally, during extended periods when
the vehicle is not used at all, and in op-
erating conditions where brake applica-
tions are less frequent, there is an in-
creased tendency for corrosion of the
rotors and accumulation of contamina-
tion on the brake pads. This occurs be-
cause the minimal pressure which must
be exerted by the pads to clean the ro-
tors by brake applications is not
reached.
If the brake rotors are corroded, they
will tend to respond to braking with a
pulsating effect which even extended
application will fail to cure.
We recommend the use of original
BMW brake pads and compo-
nents, otherwise driving safety can be
impaired.<

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RepairsIndexOverview Controls Car care Technology Data
Disc brakesDriving notesWhile driving in wet conditions and in
heavy rain, it is a good idea to apply
light pressure to the brake pedal every
few miles. Watch traffic conditions to
ensure that this maneuver does not en-
danger other road users. The heat gen-
erated in this braking process helps dry
the brake pads and rotors.
Maximum braking force is obtained
while the wheels continue to rotate,
peaking when the wheels remain on the
verge of locking without actually doing
so. ABS maintains this state automati-
cally. If the ABS fails, you should revert
to the staggered braking technique de-
scribed below (refer to page 129).
Extended or steep mountain descents
do not necessarily have to lead to re-
duced braking efficiency; downshift to a
gear in which only minimal periodic
brake applications are required - move
the selector lever to the appropriate
lower range.
You can continue to increase the brak-
ing effect of the engine by selecting a
lower gear - you can select transmis-
sion ranges as low as position 2 for ex-
treme conditions.Should engine braking prove inade-
quate, you should still avoid extended,
continuous braking. Instead of main-
taining low to moderate pressure over
an extended period of time, you should
decelerate the vehicle by applying more
substantial force on the pedal (watch
for following traffic!) and then pausing
before repeating the application. This
staggered braking technique allows the
brakes to cool in the intervals between
active braking phases, preventing over-
heating and ensuring that full braking
capacity remains available at all times.
Do not coast with the transmission
selector lever in neutral. Do not
drive with the engine shut off. The en-
gine provides no braking effect when
the transmission is in neutral, and there
is no power-assist for braking or steer-
ing when the engine is shut off.
Never allow floor mats, carpets or any
other objects to protrude into the area
around the accelerator and brake ped-
als and obstruct their movement.<
Dynamic Brake Control (DBC)
*
If you apply the brakes rapidly, this sys-
tem automatically produces the maxi-
mum braking force boost and thus
helps to achieve the shortest possible
braking distance during "panic stops."
All of the benefits of the ABS system
are exploited under these circum-
stances.
Do not reduce the pressure on the
brake pedal for the duration of the
brake application. When the brake
pedal is released, the DBC is deacti-
vated.
In the event of a malfunction, the
warning lamp comes on with a
yellow light. Conventional brak-
ing efficiency is available with-
out limitations.
Have the system checked and
repaired at your BMW center as soon
as possible.
For "Information for your safety"
covering the ABS system, refer to
page 125. This information also gener-
ally applies for DBC.<