engine BMW CONVERTIBLE 1998 Owner's Manual

79
At a glanceControls Car careRepairsTechnicalDataIndex
Estimated cruising rangeDisplays the estimated travel range
based on the remaining fuel. The value
takes into account the way in which
way the car has been driven.
Data request: press RANGE key.
A plus symbol (+) in front of the value
indicates that the cruising range is still
being corrected (measuring tolerance).
If three segments flash in the display,
the cruising range is less than 9 miles
(15 km) and the car should be refueled
as soon as possible.
When you refuel, the onboard computer
registers the action only
dif the fuel amount is over 1.2 gallons
(approx. 4 liters).
dthe engine is switched off.
Average fuel consumptionThe computer can calculate average
fuel consumption rates simultaneously
for two distances, e.g., for an entire
journey and for a single section of it.
To start calculations for distance 1:
Key sequence as in illustration.
To start calculations for distance 2:
Repeat key sequence as in illustration.
Data request: press CONSUM key.
Press the key repeatedly to switch
between the average consumption of
the 1st and 2nd section of the journey.
At the same time, the display also indi-
cates which consumption (1 or 2) is cur-
rently indicated.
Distance remaining to destinationDisplays the distance to the destination.
Available only if the total distance was
entered before the start of the journey.
Enter the distance:
Key sequence as in illustration.
Data request: press DIST key.
At the same time, the estimated time of
arrival is displayed, which is continuously
calculated in accordance with the driving
style.
Any additional mileage extending
beyond the total defined in the initial
entry is indicated by a minus sign.
To change scale:
Press the km/mls key once
dto change the distance
or twice to also
dchange the arrival time.
360us116
360us117
360us118
Onboard computer*

82
Switch on directlyAvailable only with ignition key at posi-
tion 1.
Key sequence as in illustration.Switch off directlyIn ignition key position 1: key sequence
as in the illustration.
In ignition key position 0: press only the
key SET/RES.
Enter codeIn addition to electronic vehicle immo-
bilization (refer to page 30), you can
attain further engine immobilization or
protection against tampering by enter-
ing a code into the onboard computer.
A code number is used to arm the sys-
tem. The code is then required for sub-
sequent starting attempts. Always
remember the code number.To set (ignition key in position 1):
Press the keys in the sequence illus-
trated and then turn the ignition key into
position 0 or remove the key.
Code numbers from "0000" to "9999"
can be entered. (You will have to re-
enter the code each time you activate
the system).
The LED lights up for up to 36 hours
with the ignition key in position 0 or with
the key removed. If the LED flashes for
10 seconds the engine hood has not
been closed or the radio has been
removed.
To cancel with ignition key in position 1
or 2:
A gong and the display "---- Code"
request you to enter a code.
dUse entry keys to enter the code
number
dPress the SET/RES key
dStart the engine.
The system responds to attempts to
start the vehicle using an incorrect code
or no code at all by preventing the
engine from starting.
2
1TIMER
km/mls
MEMOSET/RES 1000 100
10 1
SPEED CONSUM TEMP DIST CHECK CLOCK
DATE
LIMIT RANGE CODE
360us313
360us122
Onboard computer*

84
Automatic Stability Control plus
Traction (ASC+T)This system is designed to enhance
operating stability, especially while
accelerating and during cornering.
ASC+T automatically assumes opera-
tion each time you start the engine.
The indicator lamp in the instrument
cluster goes out shortly after you switch
on the ignition.
To deactivate the systemPress the button; the indicator lamp
comes on.To reactivate the systemPress the button again; the indicator
lamp goes out.Indicator lamp flashesThe system is actively regulating drive
torque in response to monitored vehicle
operating conditions.Indicator lamp fails to go out after
the engine is started, or comes on
in the course of normal vehicle
operationThe system has a defect. The vehicle
normally remains operational even with-
out ASC+T. Consult your authorized
BMW Retailer for repair.When ASC+T is switched off, you drive
with a conventional drive system. We
recommend that you deactivate the
system for increased traction
dwhen rocking the vehicle or starting
off in deep snow or on loose surfaces
(refer to "Starting off", page 10 5)
dor when driving with snow chains.
b
But even with ASC+T the laws of
physics can not be suspended. Any
consequences arising from traction loss
due to excessive vehicle speed remain
the responsibility of the driver. We
therefore urge you to avoid using the
additional safety margin of the system
as an excuse for taking risks.c
For more details, please refer to section
"Advanced Technology" on page 156.
ASC
360de064ASC+T

91
At a glanceControls Car careRepairsTechnicalDataIndex
To defrost windshield and door
windows
Air conditioner Circulated air mode/Automatic
recirculated air control (AUC)
*
Press the button repeatedly to run
through the following control sequence:
dIndicator lamps off: outside air flow
operational.
dLeft-hand indicator lamp on Ð AUC
mode: the system detects pollutants
in the outside air and responds by
deactivating the outside air flow as
required. The system then recircu-
lates the air currently within the vehi-
cle.
dRight-hand indicator lamp on: the
flow of outside air into the vehicle is
permanently blocked. The system
then recirculates the air currently
within the vehicle.a
If the windshields fog over in circu-
lated air mode, switch off the circulated
air mode/Automatic recirculated air
control and increase the air supply. if
necessary.c
Rear window defrosterBMW Convertible: Heated rear-window
blower.
The rear-window blower is always
switched off with the convertible top
down.
When the hardtop
* is in place, press
the rear-window heating button.
Temperature
This program is designed for
rapid removal of ice and con-
densation from the windshield and side
windows.
The air conditioner cools and
dehumidifies incoming air
before reheating it to the selected tem-
perature.
Depending on the weather, the wind-
shield may fog over briefly when the
engine is started.
Switching off the air conditioner at out-
side temperatures below approx. 41 5F
(56) will prevent the windows from
fogging up.
Frequently switching the air condi-
tioner on and off may also promote the
formation of condensation on the win-
dow surfaces.
b
Condensation forms in the air
conditioner system during operation,
which then exits under the vehicle. It is
not unusual for a small puddle to form
there.c
You can respond to unpleas-
ant odors in the outside air
by temporarily excluding the outside air.
The system then recirculates the air
currently within the vehicle.
A
The indicator lamp comes
on to confirm that the rear
defroster is operating.
The defroster switches off automatically
after approx. 15 minutes.
On both the driver's and the
passenger's side you can
adjust the specific temperature. The fig-
ures in the display provide a general
indication of interior temperature. We
recommend 70 5F (226) as a standard
setting for comfortable travel, both with
and without the air conditioner. When
you start the vehicle, the system
ensures that the selected temperature
is achieved as quickly as possible and
maintained at a constant level by the
control.
Automatic climate control

At a glance
Controls and featuresCare and maintenanceAdvanced technology
Technical data
Owner service procedure
At a glanceControlsCar careRepairsTechnicalDataIndex
Index
99
Special operating instructions:
Break-in procedures100
Driving notes100
Catalytic converter102
Antilock Brake System (ABS)103
Disc brakes104
Brake system105
Winter driving105
Roof-mounted luggage rack107
Radio reception108
Cellular phones108
Hardtop Ð Convertible109
Technical modifications to
the vehicle110
Wheels and tires:
Tire inflation pressures111
Tire tread111
Tire replacement112
Interaxle tire changes112
The right choice113
Winter tires114
Approved wheels and tires115Under the hood:
Hood118
Engine compartment 120
Washer fluids124
Engine oil124
Coolant127
Brake fluid128
Power steering fluid128
Vehicle Identification Number118
Care and maintenance:
The BMW Maintenance
System130
Caring for your car131
Cleaning and care of the
convertible top136
Vehicle storage137

10 0
To ensure that your vehicle provides
maximum economy throughout a long
service life, we request that you
observe the following.
Engine and differentialUp to 1,250 miles (2,000 km):
Drive at different engine speeds and
vehicle speeds, but be careful not to
exceed the following engine speed:
4,500 rpm
Refrain from using full throttle and avoid
pressing the accelerator beyond the
kickdown point.
After 1,250 miles (2,000 km) you can
gradually increase the number of revo-
lutions or the speed.
You should also observe these break-in
procedures if the engine or differential
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. This
means that you should drive with addi-
tional caution for the first 200 miles
(300 km).Brake systemBrake pads and disks attain their opti-
mal wear patterns only after approx.
300 miles (500 km).
EngineDo not allow the engine to warm to its
normal operating temperature by leav-
ing it idling with the vehicle parked.
However, when starting in extremely
cold weather it is a good idea to allow
the engine to run at fast idle for about
30 seconds before getting underway;
this precaution ensures adequate lubri-
cation.
Avoid high engine speeds while the
engine is still cold; this helps avoid pre-
mature wear and reduced service life.
When driving under high engine loads
(acceleration, steep hills), try to keep
the engine running above 1,500 rpm.
We recommend downshifting into a
more suitable range, especially when
driving up extended inclines.
It is a good idea to follow extended
periods of low-speed operation (dense
urban traffic, stop-and-go driving) by
maintaining an engine speed consis-
tently above 3,000 rpm for several
miles. This procedure helps prevent
deposits from accumulating in the
engine.
Break-in procedures Driving notes

101
At a glanceControlsCar careRepairsTechnicalDataIndex
ClutchDepress the clutch throughout its com-
plete travel range to shift gears. Do not
"ride" the clutch by driving with your
foot resting against the pedal.a
Brakes:
Do not drive with your foot resting on the
brake pedal. Even light but consistent
pedal pressure can lead to high temper-
atures, brake wear and possibly even
brake failure.
Aquaplaning:
A wedge of water can form between
tires and road surface when you oper-
ate the vehicle on wet or slushy roads.
This phenomenon is referred to as
aquaplaning, or hydroplaning, and it is
characterized by a partial or complete
loss of contact between the tires and
the road surface. The ultimate results
are loss of steering and braking control.Water on the roads:
When driving through water (maximum
depth one foot = 30 cm) always drive at
walking speed, otherwise damage to
the engine, the electrical system and
the transmission can occur.
Rear window shelf:
Never use the rear window shelf to
store heavy or bulky objects. They
could pose a danger to the occupants
when the car is braked heavily.
Clothes hooks:
When suspending clothing from the
hooks, ensure that they will not obstruct
the driver's vision. Refrain from hanging
heavy objects from the hooks, as these
could cause personal injury when the
car is braked heavily.c
Driving notes

10 2
The catalytic converter reduces harmful
exhaust emissions.
It 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:
dAlways have your car serviced in
accordance with maintenance
instructions.
dNever continue driving until the fuel
tank is empty.
dRespond to engine miss by switching
off the engine at once.
dNever tow-start the car unless the
engine is cold, or else unburned fuel
may reach the catalytic converter.
Better yet: use jumper cables!
dAvoid other situations in which the
fuel would not be (completely)
burned, for instance:
Frequent, extended, or repeated
starting attempts during which the
engine fails to start. (Switching off
and restarting a healthy engine
causes no damage).
Never let the engine run with any of
the spark-plug cables disconnected.
a
Always observe the above points
to prevent unburned mixture from
entering the catalytic converter. This
could result in overheating, leading to
serious damage.
High temperatures occur on all vehicles
equipped with a catalytic converter.
Heat shields are installed adjacent to
some sections of the exhaust system.
Never remove these shields; do not
apply undercoating to their surfaces.
When driving, standing at idle or park-
ing the vehicle, take care to avoid con-
tact between the exhaust system and
flammable materials (e.g., grass, hay,
leaves, etc.). Such contact could lead to
a fire, resulting in personal injury and
property damage.c
Traveling abroadAlways make sure that unleaded fuel
meeting your engineÕs octane require-
ments will be available when planning
trips outside the country. The use of
fuel failing to meet the official octane
requirements could result in engine
damage.
If you are considering traveling to a
country in which unleaded fuel is not
readily available, please remember that
leaded fuel will destroy the lambda oxy-
gen sensor and the catalytic converter
on your BMW. After operation on
leaded fuel, your vehicle will no longer
meet American and Canadian exhaust
emission standards, and there will also
be a loss of fuel economy. Upon your
return to the US or Canada, you will be
expected to comply with legal ordi-
nances requiring that you replace both
the oxygen sensor and the catalytic
converter, and to have the fuel system
flushed to remove any traces of leaded
fuel.
Catalytic converter

10 3
At a glanceControlsCar careRepairsTechnicalDataIndex
ABS enhances active safety by helping
to prevent the wheels from locking under
braking. When the front wheels slide, the
driver loses steering control over the
vehicle. Traction loss at the rear wheels
can cause the rear end to break into
uncontrolled oversteer.
ABS is designed to meet two essential
requirements during every application:
dto help provide vehicle stability on all
types of road surface (asphalt,
cement, dirt, moisture, snow and ice).
dto help to retain steering and maneu-
vering capability under the same con-
ditions.
However, certain important consider-
ations must be borne in mind in connec-
tion with these requirements:
Not even ABS can suspend the normal
laws of physics. ABS alone can not pre-
vent accidents when the brakes are
applied without an adequate safety
interval between vehicles, when the car
reaches excessive rates of lateral accel-
eration in curves, or if aquaplaning
occurs. Responsibility for these types of
situations remains in the hands (and feet)
of the driver. You should never allow the
added safety of ABS to lull you into a
false sense of security, or mislead you
into taking increased risks that could
affect your own safety and that of others.
Driving with ABSThe yellow ABS warning in the instru-
ment panel goes out as soon as the
engine is started.
The system becomes operative once the
vehicle exceeds a speed of 5 mph
(8 km/h). The ABS is deactivated when-
ever the vehicle's speed drops below
approx. 2 mph (3 km/h). This means that
the wheels can lock in the Þnal phase of
a braking action - a factor of no signiÞ-
cance in actual practice.
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 car is within its maximum braking
range. In addition, the audible pulsation
that accompanies the control operation
calls your attention to the reduced trac-
tion between tires and road surface
(marginal adhesion), and reminds you
that the vehicle's speed should be
reduced to adapt to road conditions.On road surfaces featuring a loose top
layer on a Þrmer substratum, e.g., on
gravel or snow, the braking distances
with ABS may be longer than with the
wheels locked. However, ABS continues
to provide enhanced vehicle and steer-
ing control under these conditions.
a
To ensure that the system remains
completely operational, never modify the
ABS. Service procedures on ABS are to
be performed by authorized technicians
only.c
ABS may fail to function with maximum
efÞciency when tires of different sizes
are mounted (e.g., winter tires/spare tire;
remount the correct tires at all wheels as
soon as possible).
In the event of a fault, the ABS warning
lamp in the instrument cluster lights up,
refer to page 18. The braking system
then reverts to conventional operation as
on a vehicle without ABS. However,
have the brake system checked by your
BMW Retailer as soon as possible. To
prevent undetected defects and cumu-
lative faults from adversely affecting the
brake system, refer any problems to
your authorized BMW Retailer at the
earliest opportunity.
Antilock Brake System (ABS)

10 4
Disc brakes furnish optimum decelera-
tion and braking control as well as
greater fade resistance under heavy
use.
Limited vehicle use, extended periods
with the car parked or in storage and
light loading will increase the tendency
for corrosion to form on the rotors, and
dirt to accumulate on the pads. This
happens because the minimum pres-
sure between the pad and the disc
required for the self-cleaning function
of the disc brakes is not achieved.
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.
a
Use only original BMW-approved
brake pads, as otherwise vehicle autho-
rization is no longer valid.c
Driving notes While 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
endanger other road users. The heat
generated 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
described above (refer to page 106).
Extended or steep mountain descents
do not necessarily have to lead to
reduced braking efficiency; downshift
to a gear in which only minimal periodic
brake applications are required (you
can move the selector lever to the
appropriate lower range if your car is
equipped with an automatic transmis-
sion).
You can further increase the engine's
braking effect by selecting a lower gear,
downshifting as far as first gear or plac-
ing the selector lever in position 1 (2).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 at 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.
a
Do not allow the vehicle to coast by
pressing down the clutch pedal or shift-
ing into neutral while underway. Never
drive with the engine switched
off (!). The engine provides no braking
effect when the clutch is disengaged or
the transmission is in neutral, and there
is no power-assist for brakes and steer-
ing when the engine is not running.
Never allow floor mats, carpets or other
objects to protrude into the area around
the accelerator, clutch and brake pedals
and obstruct their movement.c
Disc brakes