2003 BMW Z4 2.5I engine

Maintenance
82
Maintenance
The BMW Maintenance
System
The BMW Maintenance System has been
designed as a reliable means of providing
maximum driving and operating safety –
and as cost-effectively for you as possible.
Please keep in mind that regular mainte-
nance is not only necessary for the safety
of your vehicle, but also plays a significant
role in maintaining the resale value of your
vehicle.
Service interval display
While conventional systems rely on dis-
tance traveled alone to determine when a
service is due, the BMW Maintenance Sys-
tem has taken the actual conditions under
which the vehicle is operated into consid-
eration for years, because miles can be
traveled in many different ways:
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 speeds in long-distance highway
travel.
The BMW Maintenance System includes
the Engine Oil Service and Inspections I
and II.
Determining the maintenance intervals
based on the actual loads on the vehicle
covers every kind of operating situation.
Minimal use drivers, who drive fewer than
6,200 miles / 10,000 km per year, should
nevertheless have the oil changed at least every 2 years since engine oil deteriorates
over time, regardless of use.
Service and Warranty Information
Booklet for US models/Warranty and
Service Guide Booklet for Canadian
models
For detailed information on required main-
tenance items and the work involved,
please refer to the Service and Warranty
Information Booklet for US models or to the
Warranty and Service Guide Booklet for
Canadian models.
Depending on operating conditions, it may
be advisable to have the body checked for
damage from rocks or gravel as a precau-
tion against corrosion.
BMW recommends that you have your
BMW center perform the mainte-
nance and repair.
Check that the maintenance work is
recorded in the Service Manual. These
entries will serve as proof that the vehicle
has received regular maintenance.<
Care
Interesting facts about the care of your
vehicle are found in the Caring for your
vehicle brochure.

At a glance
Controls
Driving tips
Mobility
Reference
83
Laws and regulations
California Proposition 65
warning
California laws require us to state the fol-
lowing warning:
Engine exhaust, some of its constitu-
ents, and certain vehicle components
contain or emit chemicals known to the
State of California to cause cancer and
birth defects and reproductive harm. In
addition, certain fluids contained in vehi-
cles and certain products of component
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 acces-
sories contain lead and lead compounds.
Wash your hands after handling. Used
engine oil contains chemicals that have
caused cancer in laboratory animals.
Always protect your skin by washing thor-
oughly with soap and water.<
OBD interface socket
The Onboard Diagnostic OBD interface
socket is located on the left of the driver's
side behind a specially marked cover
located beneath the instrument panel. The
cover has the letters OBD on it.
This interface makes it possible to access
data on emissions – related components
using special equipment.If the Service Engine Soon indicator
lamp comes on either continuously
or intermittently, this indicates a
fault in the emissions-related electronic
systems. Although the vehicle remains
operational, you should have the systems
checked by your BMW center at the earli-
est possible opportunity.
The illuminated indicator informs you of the
need for service, not that you need to stop
the vehicle. However, the systems should
be checked by your BMW center at the
next opportunity.
If the indicator blinks or flashes, this indi-
cates a high level of engine misfire. Reduce
speed and contact the nearest BMW center
immediately. Severe engine misfiring over
even a short period of time can seriously
damage emission control system compo-
nents, especially the catalytic converter.
Service Engine Soon
warning lamp for Canadian
models.
If the fuel filler cap is not on tight
enough, the OBD system can detect
leaking vapor and the indicator will light up.
If the fuel filler cap is then tightened, the
indicator will usually go out after a short
period of time.<

At a glance
Controls
Driving tips
Mobility
Reference
85
1.Open the caps with a suitable object –
coin or screwdriver
2.Flip open the headlamp cover.
Removing the protective cover
1.Pull the wire clamp out straight, see
arrow 1
2.Fold the wire clamp down past the
catches; see arrows
3.Flip the protective cover open and
remove.
Reinstalling the protective cover
Reinstall the protective cover care-
fully. If the protective cover is not on
tight, the headlamp installation could be
damaged.<
1.Insert the protective cover into the
guides
2.Check that the protective cover is posi-
tioned correctly
3.Press the wire clamp past both
catches; see arrow.
Low beams and high beams
Left side of engine compartment:
1Low beams
2High beams
H7 bulb, 55 watts
The H7 bulb is pressurized. There-
fore, wear safety glasses and protec-
tive gloves. Failure to comply with these
precautions could result in physical injury if
the bulb is damaged.<
1.Turn the bulb holder to the left and pull
out
2.Remove and replace the bulb
3.Install in the reverse order.
When cleaning the headlamps,
please observe 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 continue driving with great cau-

Replacement procedures
88 Please consult your BMW center
whenever you have any questions
concerning the battery. Since the battery is
absolutely maintenance-free, the following
statements are for your information only.<
Do not disconnect the battery cables
when the engine is running. Discon-
necting the battery cables when the engine
is running will cause a voltage surge which
will damage the vehicle's onboard elec-
tronics.<
Indicator lamp
The indicator lamp for the battery
charge current lights up:
The battery is no longer being
charged. The alternator drive belt is defec-
tive or there is a malfunction in the charging
circuit of the alternator. Please contact the
nearest BMW center.
If the drive belt is defective, pull over
and switch off the engine immediately
to prevent overheating and serious engine
damage.
If the onboard supply voltage drops to a
very low level, increased steering effort
may also be necessary.<
Charging the battery
Charge the battery in the vehicle only when
the engine is not running. Use the terminals
provided in the engine compartment. For
information on connections, refer to Jump-
Starting on page 89.
Battery disposal
Return used batteries to a recycling
point or to your BMW center. Maintain
the battery in an upright position for trans-
port and storage. Secure the battery
against tilting when transporting.<
Fuses
You will find the fuses and information on
their respective allocation behind the glove
compartment.
1.Press the lock on the left; see arrow 1
2.Press the lock on the right; see arrow 2
3.Swing the glove compartment down.
Spare fuses and plastic tweezers for grasp-
ing the fuses are found in the onboard tool
kit; refer to page 84.
Do not attempt to repair a burned fuse
or replace it with a fuse having a dif-
ferent color or amperage rating. To do this
could cause a fire in the vehicle as a result
of circuit overload.<

At a glance
Controls
Driving tips
Mobility
Reference
89
Giving and receiving assistance
Warning triangle*
The warning triangle is stored in the rear
luggage compartment panel.
Pull the ends of the rubber bands upward
and out of the fasteners; see arrow.
Always observe all legal regulations
requiring a warning triangle to be car-
ried in the vehicle.<
First-aid kit*
The first-aid kit is located beneath the pas-
senger seat.
To open
Pull the handle and fold the cover down-
ward.
To close
Fold the cover up and press into the catch.
Some of the articles in the first-aid kit
have a limited period of use before
expiration. For this reason, check the expi-ration dates of each of the items regularly,
and replace any whose expiration dates
have passed. You can acquire replace-
ments in any drugstore or pharmacy.
Always observe all legal regulations requir-
ing a first-aid kit to be carried in the vehi-
cle.<
Jump-starting
When your battery is discharged you can
use two jumper cables to start your vehicle
with power from the battery in a second
vehicle. You can also use the same method
to help start another vehicle. Always use
jumper cables with fully insulated handles
on the terminal clamps.
Do not touch components carrying
current on a running engine. Contact
with these components can cause fatal
injury. Carefully observe the following
instructions to avoid personal injury and/or
damage to one or both vehicles.<
Never use spray starter fluids to start
the engine.<
Preparations for jump-starting the
vehicle
1.Check that the battery on the other
vehicle is also rated at 12 volts, and that
the capacities – in Ah – of the two bat-
teries are roughly comparable. This
information is provided on the top of the
battery casing
2.Turn off the engine of the support vehi-
cle
3.Switch off all electrical accessories in
both vehicles
>Do not disconnect the battery from
your vehicle's electrical system
>Make absolutely certain that there is
no contact between the bodywork of
the two vehicles – short circuit hazard.

Giving and receiving assistance
90 4.Start the engine on the support vehicle
and allow it to run
5.Open the cover of the BMW jump-start
support terminal by pulling on the tab;
see arrow.
Connect jumper cable
Always adhere to this sequence when
connecting jumper cables, even when
jump-starting other vehicles. Failure to
observe this procedure can lead to sparks
and pose a danger of personal injury.<
1.With the + jumper cable, connect the
positive terminal of the drained battery
and the positive terminal of the support
battery
2.With the – jumper cable, connect the
negative terminals of both vehicles.
Your BMW is equipped with a special
nut for this purpose, refer to Engine
compartment on page 78.
To do so:
>Attach one cable clamp to the nega-
tive battery terminal or to a suitable
ground on the engine or body work of
the support vehicle
>Attach the second cable clamp to
the negative battery terminal or to a
suitable ground on the engine or body
work of the vehicle to be jump-started.
Jump-starting the vehicle
1.Let the engine of the support vehicle
run for several minutes at a slightly ele-
vated engine idle speed
2.Start the engine of the other vehicle as
usual
>If the first start attempt is not suc-
cessful, wait a few minutes before
another attempt in order to allow the
discharged battery to recharge.
3.Let the engines run for several minutes
4.Then disconnect the jumper cables in
reverse sequence.
Depending on the cause of the fault,
have the battery checked and
recharged at a BMW center.<
Towing and tow-starting the
vehicle
Towing eyelet
The screw-in towing eyelet is stored in the
onboard tool kit; be sure that it remains in
the vehicle at all times. This eyelet is
designed for installation in the tow sockets
located at the front and rear of the vehicle,
and is intended for towing on paved road
surfaces only.
Access to towing socket
Front:
Press out the cover panel with a screw-
driver inserted in the recess at the top.

At a glance
Controls
Driving tips
Mobility
Reference
91
Rear:
Press out the cover panel with a screw-
driver inserted in the recess at the top.
Make sure the towing eyelet is firmly
screwed all the way in, otherwise the
thread could be damaged.
Do not tow the vehicle by any components
of the chassis or suspension, or lash them
down in any way. If you do, the compo-
nents could be damaged, possibly leading
to accidents.
If the engine is off, increased effort will be
required to steer the vehicle since power
support will not be available.<
Towing with a commercial tow truck
>Do not tow with sling-type equipment
>Use wheel lift or flatbed equipment
>Please comply with applicable state
towing laws.
Never allow passengers to ride in a
towed vehicle for any reason.
Never attach tie-down hooks, chains,
straps or tow hooks to tie rods, control
arms or any other part of the vehicle sus-
pension, as severe damage to these com-
ponents will occur, leading to possible
accidents.<

Technical data
94
Technical data
Engine data
Weights

Z4 roadster 2.5iZ4 roadster 3.0i
Displacement
Number of cylinderscu in/cmµ152.1/2,494
6181.7/2,979
6
Maximum power output
at engine speedhp/kW
rpm184/141
6,000225/170
5,900
Maximum torque
at engine speedlb ft/Nm
rpm181/245
3,500222/300
3,500
Compression ratio
ε10.5 10.2
Stroke
Borein/mm
in/mm2.95/75
3.31/843.53/89.6
3.31/84
Fuel-injection system Digital electronic engine-management system DME
Z4 roadster 2.5iZ4 roadster 3.0i
Curb weight
with manual transmission
with automatic transmissionlbs/kg
lbs/kg2,932/1,330
2,998/1,3602,998/1,360
3,042/1,380
Approved gross vehicle weight
with manual transmission
with automatic transmissionlbs/kg
lbs/kg3,483/1,580
3,549/1,6103,549/1,610
3,593/1,630
Approved front axle load lbs/kg 1,720/780 1,742/790
Approved rear axle load lbs/kg 1,841/835 1,863/845
Luggage compartment capacity
with the convertible top compartment raisedcu ft/l
cu ft/l8.5/240
9.2/2608.5/240
9.3/260
Never exceed either the approved axle loads or the approved gross vehicle weight.