1997 BMW 323i battery replacement

Please
read
these
warnings
and
cautions

before
proceeding
with
maintenance
and
repair
work
.

CAUTION-

"
See
also
Warnings
onpage
vi¡



"
Beforedoing
any
electrical
welding
on
cars
equipped
with
ABS,
disconnect
the
battery
negative
(-)
terminal
(ground
strap)
and
the
"
If
you
lack
the
skills,
tools
and
equipment,
ora
suitable
work-



ABS
control
unit
connector
.
shop
for
any
procedure
described
in
this
manual,
we
suggest
you
leave
such
repairs
to
an
authorized
BMW
dealer
or
other
qualified



"
On
cars
equipped
with
anti-theft
radios,
make
sureyou
know
the
shop
.



correct
radio
activation
code
before
disconnecting
the
battery
or
removing
the
radio
.
lf
the
wrong
code
is
entered
into
the
radio
"
BMW
is
constantly
improving
its
cars
and
sometimes
these



when
power
is
restored,
that
radio
may
lock
up
and
be
renderedchanges,
both
in
parts
and
specifications,
are
made
applicable
to



inoperable,
even
if
the
correct
code
is
thenentered
.
earlier
models
.
Therefore,
part
numbers
listed
in
this
manual
are
for
reference
only
.
Always
check
with
your
authorized
BMW
dealer



"
Always
make
sure
ignition
is
off
before
disconnecting
battery
.
parts
department
for
the
latest
information
.
"
Label
battery
cablesbefore
disconnecting
.
Onsome
models,
"
Before
starting
a
job,
make
certain
that
you
have
all
the
neces-



battery
cablesarenot
color
coded
.
sary
tools
and
parts
on
hand
.
Read
al¡
the
instructions
thoroughly,
do
not
attempt
shortcuts
.
Use
tools
appropriate
to
the
work
and



"
Disconnecting
the
battery
may
erase
fault
code(s)
stored
in
con-

use
only
replacement
parts
meeting
BMW
specifications
.
Make-



trol
module
memory
Using
special
BMW
diagnostíc
equipment,
shift
tools,
parts
and
procedures
will
not
make
good
repairs
.



check
forfault
codes
prior
to
disconnecting
the
battery
cables
.If
the
Check
Engine
light
is
illuminated,
see100
Engine-General
for
"
Use
pneumatic
and
electric
tools
only
to
loosenthreaded
parts



On-Board
Diagnostics
(OBD)
fault
code
information
.
lf
any
other
and
fasteners
.
Never
use
these
tools
to
tighten
fasteners,
espe-



system
faults
have
been
detected
(indicated
by
an
ílluminated
cially
on
light
alloy
parts
.
Always
use
a
torque
wrench
to
tighten



warning
light),
see
an
authorized
BMW
dealer
.
fasteners
to
the
tightening
torque
specification
listed
.
"
If
a
normal
or
rapid
charger
is
used
to
charge
battery,
the
battery
"Be
mindful
of
the
environment
and
ecology
.
Before
you
drain
the



mustbe
disconnected
and
removed
fromthe
vehicle
in
order
to
crankcase,
find
outthe
proper
way
to
dispose
of
the
oil
.
Do
not



avoid
damaging
paint
and
upholstery
pour
oil
onto
the
ground,
down
a
drain,
or
into
a
stream,
pond
orlake
.
Dispose
of
in
accordance
withFederal,
State
and
Local
laws
.



"Do
not
quick-chargethe
battery
(for
boost
starting)
for
longer
than
one
minute
.
Wait
at
least
one
minute
before
boosting
the
bat-
e
If
battery
power
is
lost
or
the
battery
has
been
disconnected,
the



tery
a
second
time
.
powerwindows
must
be
re-initialized
.
Both
one
touch
up/down
and
pinch-protection
will
be
inactive
until
windows
are
re-initial-



"
Connect
and
disconnect
a
battery
charger
only
with
the
battery
ized
.
See
512
Door
Windows
.



charger
switched
off
.

"
The
control
module
for
the
anti-lock
brake
system
(ABS)
cannot
withstand
temperatures
from
a
paint-drying
booth
or
aheat
lamp
in
excess
of
203°F
(95°C)
and
should
not
be
subjected
to
temper-
atures
in
excess
of
185°F
(85°C)
for
more
than
twohours
.

"
Sealed
or
"maintenance
free"
batteries
shouldbeslow-charged
only,
at
anamperage
ratethat
is
approximately
10%
of
the
bat-
tery's
ampere-hour
(Ah)
rating
.

"
Do
not
allow
battery
chargingvoltage
to
exceed
16
.5
volts
.
If
the
battery
begins
producing
gas
or
boiling
violently,
reduce
the
charg-
ing
rate
.
Boosting
a
sulfated
battery
at
a
high
charging
rate
can
cause
an
explosion
.

FUNDAMENTALS
FOR
THEDO-ITYOURSELF
OWNER



010-
5

WARNING
-

Avoid
getting
tools
or
clothing
near
the
battery
.
Bat-tery
electrolyte
is
a
corrosive
acid
.
Be
careful
with

brake
fluid,
as
it
can
damage
the
cars
paint
Finally,
keep
rubber
parts
such
as
hoses
and
bolts
free
from
oil
orgasoline,
as
they
will
cause
the
material
to
soften
and
fail
prematurely
.

Non-reusable
Fasteners

Many
fasteners
usedon
the
cars
coveredby
this
manual

mustbe
replaced
with
new
osesonce
they
are
removed
.
These



Fig
.
4
.
General
sequence
for
alternately
tightening
multiple
fasten-

include
butarenot
limited
to
:
bolts,
nuts
(self-locking,
nylock,



ers
.

etc
.),
cotterpins,
studs,
brake
fittings,
rol¡
pins,clips
and
wash-

ers
.
Genuine
BMW
parts
should
be
the
only
replacement
parts



NOTE-

used
for
this
purpose
.



"
Metric
bolt
classes
or
grades
are
markedon
the
bolt'

head
.

Some
bolts
are
designed
to
stretch
during
assembly
and
are

permanently
altered
rendering
them
unreliable
once
removed
.

These
are
known
as
torque-to-yield
fasteners
.
Always
replace
fasteners
where
instructed
to
doso
.
Failure
to
replace
these

fasteners
could
cause
vehicle
damage
and
personal
injury
.

See
an
authorized
BMW
dealer
for
applications
and
ordering

information
.

Tightening
Fasteners

When
tighteningthe
bolts
ornuts
that
attach
acomponent,
it

is
always
good
practice
to
tighten
the
bolts
gradually
and
evenly

to
avoid
misalignment
or
over
stressing
anyone
portion
of
the

component
.
For
components
sealed
with
gaskets,
this
method

helps
to
ensure
that
thegasket
will
seal
properly
and
complete-

ly
.

Where
there
are
severa¡
fasteners,
tighten
them
in
a
se-

quence
alternating
between
opposite
sides
of
the
component
.

Fig
.
4
shows
such
a
sequence
for
tightening
six
bolts
attaching

a
typical
component
.
Repeat
the
sequence
until
al¡
the
bolts
are
evenly
tightened
to
theproper
specification
.

"
Do
not
confuse
wrench
sizewithbolt
diameter
size
.
Fora
listing
of
the
common
wrenches
used
on
vari-
ous
bolt
diameters,
see
Basic
Tool
Requirements
.

Table
a
.
General
Bolt
Tightening
Torques
in
Nm

(max
.
permissible)

Bolt
Class
(according
to
DIN
267)
Bolt
diameter
5
.6
5
.8
6
.8
8
.8
10
.9
12
.9

M5
2
.5
3
.5
4
.5
6810

M6



4
.5



6



7
.5



10



14
`
17

M8



11



15
-



18



24



34



40

M10
233036476679

M12
3952
62
82115140

M14
6282
98
130
180220

M16
9426150
200280340

M18
130174210280
390
470

For
some
repairs
a
specific
tightening
sequence
is
neces-

sary,
or
a
particular
order
of
assembly
is
required
.
Such
special



Gaskets
and
Seals

conditions
are
noted
in
the
text,
and
the
necessary
sequence
is

described
or
illustrated
.
Where
no
specific
torque
is
listed,
Ta-



The
smoothest
metal
mating
surfaces
still
have
imperfec

blea
can
be
used
as
a
general
guide
for
tightening
fasteners
.



tions
that
can
allow
leakage
.
To
prevent
leakage
atcritica¡

joints,
gaskets
of
soft,
form-fitting
material
are
used
to
fill
in
the

WARNING
-



imperfections
.
Table
ais
a
general
reference
only
.
The
values
list-

ed
in
the
table
are
not
intended
to
be
used
asa
sub-



To
be
most
effective,
gaskets
are
designed
to
crush
and
be-
stitutefor
torques
specifically
called
out
in
the
text



come
thinner
as
the
mating
parts
are
bolted
together
.
Once
a
throughout
this
manual
.



gasket
has
been
used,
it
is
no
longer
capable
of
makingas

good
a
sea¡
as
when
new,
and
is
muchmore
likely
toleak
.
For

this
reason,
gaskets
should
not
be
reused
.
Always
plan
to
use

new
gaskets
for
any
reassembly
.
Some
gaskets-such
as
head
gaskets-are
directional
.
Make
sure
that
these
are
in-

stalled
correctly
.
This
same
logic
applies
to
any
part
used
for

sealing,
including
rubber
O-rings
and
copper
sealing
washers
.

ADVICE
FOR
THE
BEGINNER

010-
6



FUNDAMENTALS
FOR
THE
DO-ITYOURSELF
OWNER

In
places
where
a
shaft
mustpass
through
a
housing,
flexible
lip
seals
areused
to
keep
the
lubricating
oil
or
grease
from
leak-

ingout
past
the
rotating
shaft
.
Seals
should
never
be
reused

once
they
have
been
removed
.
When
removing
a
seal,
be
care-
ful
not
lo
scratch
or
otherwise
damage
the
metal
surfaces
.
Even
minor
damage
to
sealing
surfaces
can
cause
sea¡
damage
and
leakage
.

The
key
to
sea¡
installation
is
to
get
the
sea¡
in
straight
without

damaging
¡t
.
Use
a
sea¡
driver
that
is
the
same
diameter
as
the
seal
housing
to
gently
and
evenly
insta¡I
into
place
.
If
a
proper
size
seal
driver
is
not
available,
a
socket
of
the
right
size
will
do
.

When
installing
a
seal,
¡t
a
good
idea
to
coat
the
sea¡
with
o¡I

to
aid
installation
.
Some
seals
are
directional
and
special
instal-
lation
instructions
apply
.
Make
sure
¡t
is
installed
with
the
lip
fac-
ing
the
correct
way
.
Normally
the
lip
faces
the
inside
.
Note
the
installation
direction
of
the
old
sea¡before
removing
¡t
.

Electrical
Testing

Many
electrical
problems
canbe
understood
and
solved
with
only
a
little
fundamental
knowledge
of
how
electrical
circuits



Insulate
the
finished
connection
.
Electronics
stores
can
sup-
function
.



ply
heat-shrinkable
insulating
tubing
that
can
be
placed
onto
the
wire
before
connectiog,
slid
over
the
finished
joint,
and
Electric
current
only
flows
in
a
complete
circuit
.
To
operate,



shrunk
to
a
tight
fit
with
a
heat
gun
orhair
dryer
.
The
nextbest
every
electrical
device
in
thecar
requires
a
complete
circuit
in-



alternative
is
electrical
tape
.
Make
sure
the
wire
is
clean
and
cluding
a
voltage
source
and
a
pathto
ground
.
The
positive
(+)



free
ofsolder
flux
or
other
contamination
.
Wrap
the
joint
tightly
side
of
the
battery
is
the
original
voltagesource,
and
ground
is
to
sea¡
out
moisture
.
See
600
Electrical-General
for
more
in-
any
retum
path
to
the
negative
()
-
side
ofth
e
battery°
whether
li



formation
.
through
the
wiring
harness
or
thecar
body
.
Except
for
portions
of
the
charging
system,
al¡
electrical
current
in
the
car
is
direct
current
(DC)
and
flows
from
positive
(+)
to
negative
(-)
.



BVYING
PART$

Switches
are
used
to
turn
components
on
or
off
by
complet-
ing
or
interrupting
#he
circuit
.
A
switch
is
"open"
when
the
circuit



Many
of
the
maíntenance
and
repair
tasks
in
this
manual
cal¡
is
ínterrupted,
and
"closed"
when
the
circuit
is
completed
.
Fig
.
5



for
the
installation
of
new
parte,
or
the
use
of
new
gaskets
and

shows
a
basic
circuit
schematic
.
See600
Electrical
System-



other
materials
when
reinstalling
parts
.
Most
often,
the
parts

General
for
electrical
troubleshooting
.



that
will
be
needed
should
be
on
hand
beforebeginningthe
job
.
Read
the
introductory
text
and
the
complete
procedure
to
de-
termine
which
parts
will
be
needed
.

B029ELG

Fig
.
5
.



Schematic
representation
of
simple
circuit
for
light
bulb
.
Igni-
tion
switch
is
shown
closed,
making
circuit
complete
.

BVYING
PARTS

Wire
Repairs

Repairs
to
a
wiring
harness
requirespecial
care
to
make
the

repair
permanent
.
The
wire
endsmust
be
clean
.
lf
frayedor
oth-

erwise
damaged,
cut
off
the
end
.
If
the
wire
is
too
short,
splice
in

a
new
piece
of
wire
of
the
same
size
and
make
two
connec-
tions
.

Use
connectors
that
are
designed
for
the
purpose
.
Crimped-

on
or
soldered-onconnectors
are
best
.
Crimp
connectors
and

special
crimping
pliers
are
widely
available
.
If
soldering,
use

needlenose
pliers
tohold
the
wire
near
the
solder
joint
and
cre-
ate
a
"heat
dam"
.
This
keeps
the
heat
and
the
solder
from
trav-
eling
up
the
wire
.
Always
use
a
solder
made
specifically
for
electrical
work
(rosin
core)
.

NOTE-

Twisting
wirestogether
to
make
a
repair
is
not
recom-
mended
.
Corrosion
and
vibration
will
eventually
spoil
the
connection
and
may
lead
to
irreparable
damage
to
sensitive
electronic
componente
.

NOTE-

For
some
bigger
jobs,
partial
disassembly
and
inspec-
tion
are
required
to
determine
acomplete
parts
list
.
Read
the
procedure
carefully
and,
if
necessary,
make
other
arrangements
to
get
the
necessary
parts
while
your
car
is
disassembled
.

Genuine
BMW
Parts

Genuine
BMW
replacement
parts
from
an
authorized
BMW
dealer
are
designed
and
manufactured
lo
the
same
high
stan-
dards
as
the
original
parts
.
They
will
be
the
correct
material,
manufactured
to
the
same
specifications,
and
guaranteed
lo
fit
and
work
as
intended
by
the
engineers
who
designed
thecar
.
Some
genuine
BMW
parts
have
a
limited
warranty
.

010-12



FUNDAMENTALSFOR
THE
DO-IT
YOURSELF
OWNER

Jump
Starting
Car

Cars
with
discharged
or
dead
batteries
can
be
jump-started
using
the
good
battery
from
another
car
.
When
jump-starting

the
engine,
always
note
the
following
warnings
.

WARNING
-

"
Battery
acid
(electrolyte)
can
cause
severe
burns,
and
will
damage
the
car
and
clothing
.
lf
electrolyte
is
spilled,
wash
the
surface
with
large
quantities
of
water
.
lfit
gets
finto
eyes,
flush
them
with
water
for
severa¡
minutes
and
cal¡
a
doctor
.

"
Batteries
produce
explosive
and
noxious
gas-
ses
.
Keep
sparks
and
flames
away
.
Do
not
smoke
near
batteries
.

"
Do
not
jump-start
the
engine
if
you
suspect
that
the
battery
is
frozen
.
Trapped
gas
may
explode
.
Allow
the
battery
to
thaw
first
.

"
Do
not
quick-charge
the
battery
(for
boost
start-
ing)for
longer
than
one
minute,
and
donot
ex-
ceed
15
volts
at
the
battery
with
the
boosting
cables
attached
.
Wait
at
least
one
minutebefore
boosting
the
battery
a
second
time
.

"
Some
electrical
system
'comfort"
features
may
not
function
correctly
once
battery
power
is
restored
.
For
example,
the
front
window
one-touch-up
func-
tion
may
be
disabled
.
Some
electrical
systems
will
need
to
be
reinitialized
Consult
the
appropriate
re-
pairgroup
formore
specific
information
.

1
.
Place
cars
close
together,
but
do
not
allow
them
to'touch
each
other
.
Turn
off
the
engine
of
thecar
with
the
good
battery
.

2
.
Connect
oneend
of
the
positive
(+)
cable
to
the
positive
(+)
post
of
the
good
battery
.
Remove
the
coverfromthe

positive
(B+)
junction
post
in
the
engine
compartment
of
the
dead
car
and
connect
the
other
end
of
the
posi-
tive
(+)
cable
to
the
junction
post
.
See
Fig
.
17
.

EMERGENCIES

3
.
Connect
one
end
of
the
negative
(-)
cable
to
the
nega-

tive
(-)
battery
post
of
the
good
battery
.
Connect
oppo-

site
end
of
the
negative
cable
(-)
to
the
engine
block
of

thecar
with
the
dead
battery
.

4
.
Start
thecar
with
the
good
battery
and
runthe
engine

at
about2,000
rpm,
then
start
the
car
with
the
dead
bat-
tery
.

5
.
With
the
engine
at
¡dle,
switch
on
the
headlights,
blower

motor
and
rear
window
defogger
to
avoid
damaging
the

cars
electrical
system
.
Carefully
disconnect
the
jumper

cables,
starting
with
the
negative
cable
on
the
engine

block
.
Turn
all
electrical
consumers
off
.

NOTE-

The
engineshould
be
run
for
at
least
an
hour
to
re-
charge
the
battery
.

Overheating

lf
the
temperature
gauge
needle
goes
into
the
red
band
on
the
gauge
face,
the
coolant
temperature
is
too
high
.
Find
a
safe
place
to
stop
and
turn
the
engine
off
.
Open
the
hood
and
allow

the
engine
to
cool
until
the
temperature
gauge
needle
is
at
the

lower
thirdof
the
scale
.
Continuing
to
drive
an
overheated
car

can
cause
extensive
engine
damage
.

WARNING
-

Do
not
remove
the
coolant
reservoir
or
radíator
cap
with
the
engine
hot
.
Undoing
either
couldspray
hot
coolant
and
cause
burns
or
damage
the
engine
.

CAUTION-

Do
not
add
cold
water
or
coolant
to
a
hot
engine
.
Engine
damage
could
result
from
the
sudden
tem-
perature
change
.

NOTE-

If
the
enginecannot
be
safely
tumed
off,
make
sure
the
air
condifioner
isoff
and
turn
the
heater
to
high
.
This
will
helo
cool
the
engine
until
a
salestopping
place
canbe
reached
.

Overheating
may
be
caused
bylow
coolant
leve¡
or
a
dam-aged
engine
drive
belt
.
Visually
check
the
coolant
leve¡
and
en-
gine
belts
as
described
in
020
Maintenance
Program
.
lf
the
coolant
leve¡
is
low,
check
the
filler
cap,hoses,
clamps
and
ra-
diator
for
signs
of
leakage
.
Check
for
leaks
at
the
water
pump
on
the
frontof
theengine
.

lf
no
leaks
are
found,
add
coolant
after
the
engine
has
cooled
.
The
carcan
be
driven,
but
have
the
cooling
system
thoroughly
checked
assoonas
possible
.
lf
replacement
cool
0013245



-



ant
is
not
available,
then
plain
water
canbe
used,
butthe
cool-
antshould
later
be
drained
and
refilled
with
theproper
mixture
Fig
.
17
.
Battery
jump
starting
posts
(arrows)
behind
right
frontstrut



of
anti-freeze
and
water
.
tower
.
Lift
cover
to
access
positive
post
.

020-
1
2



MAINTENANCE
PROGRAM

6-cylinder
engines
use
a
coil-on-plug
configuration,
and
re-



Battery
cablesshould
be
tight
.
The
terminals,
the
cable
moval
of
thetop
engine
cover
(between
the
camshafts)
and
ig-



clamps,
and
the
battery
case
should
be
freeof
the
white
deposits
nition
cofs
are
necessary
.
See
Fig
.
12
.
Blow
away
any
dust
or



that
indicate
corrosion
and
acid
salts
.
Even
a
thin
¡ayer
of
dust
dirt
around
the
ignition
coils,
and
then
remove
the
coils
.
Blow



containing
conductive
acid
salts
can
cause
battery
discharge
.
away
any
dustor
dirt
around
the
sparkplugs
.
Remove
the
spark

plugs
.



To
remove
battery
corrosion,
begin
by
disconnecting
theca-

bles
.
Disconnect
the
negative
(-)
cable
first
.
Clean
the
terminal

posts
and
the
cable
clamps
with
a
wire
brush
.
Clean
the
main
chassis
ground
terminal
next
to
the
battery
.
Corrosion
can
be
washedaway
with
a
baking
soda
and
water
solution
that
will
neutralize
the
acid
.
Apply
the
solution
carefully,
though,since
ít
will
also
neutralize
the
acid
inside
the
battery
.
Reconnect
the
ca-
ble
clamps,
positive
(+)
cable
first
.
Lightly
coat
the
outside
of
the

terminals,
hold
down
screws,
and
clamps
with
petroleum
jelly,
grease,
or
a
commercial
battery
terminal
corrosion
inhibitor
.

Fig
.
12
.
Ignition
coil
being
removed
from
spark
plug
on
M52
engine
.

NOTE-

If
necessary,
see
120
Ignition
System
for
more
details
on
coil
removal
.

B11004

Lightlylubricate
the
new
spark
plug
threads
with
a
small
amount
of
anti-seize
compound
.
Thread
the
plugs
into
the
cyl-
inder
head
byhand
to
prevent
cross-threading
.

Tightening
Torque

"
Spark
plug
to
cylinder
head
.......
25
Nm
(18
ft-ib)

Idie
Speed

Engine
¡dle
speed
canchange
due
to
a
number
of
factors,
in-
cluding
normal
wear
.
The
idle
speed
is
electronically
adaptive
and
non-adjustable
.
See
130
Fuel
Injection
for
more
information
.

Battery,
checking
and
cleaning

The
battery
is
located
in
the
right
side
of
the
luggage
com-
partment
.
Simple
maintenance
of
the
battery
and
its
terminal
connections
will
ensure
maximum
starting
performance,
espe-
cially
in
winter
when
colder
temperaturesreduce
battery
power
.

ENGINE
COMPARTMENT
MAINTENANCE

WARNING
-

"
Prior
to
disconnecting
the
battery,
read
the
bat-
tery
disconnection
cautions
given
at
the
front
of
this
manualonpage
viii
.

"
Battery
acid
is
extremely
dangerous
.
Take
care
to
keep
it
from
contacting
eyes,
skin,
or
clothing
.
Wear
eye
protection
.
Extinguish
all
smoking
ma-
terials
and
do
not
worknear
any
oyen
flames
.

Battery
electrolyte
should
be
maintained
at
the
correct
level
just
above
the
battery
plates
and
their
separators
.
The
correct
leve¡
is
approximately
5
mm
(
1
/4
in
.)
above
thetop
of
battery
plates
orto
thetop
of
the
indicator
marks
(if
applicable)
.
The
battery
plates
and
the
indicator
marks
can
beseen
once
the
fill-
er
caps
are
removed
.
If
the
electrolyte
level
is
low,
replenish
it
by
adding
distilled
water
only
.

Battery,
repiacing

Batteries
are
rated
by
ampere
hours
(Ah),
the
number
of
hoursa
specific
current
draín
can
be
sustained
before
complete
discharge,
or
by
cold
cranking
amps
(CCA),
the
number
of
amps
available
to
crank
the
engine
in
cold
weather
conditions
.
In
general,
replacement
batteries
should
alwaysbe
rated
equal
or
higherthan
the
original
battery
.

CAUTION-

Prior
to
disconnecting
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
thls
manual
on
page
viii
.

The
battery
is
held
in
place
bya
single
hand
screw
and
píate
.
A
secure
battery
hold-down
is
important
in
order
to
prevent
vi-
brations
and
road
shock
from
damaging
the
battery
.

NOTE-
NOTE-
"
Always
disconnect
the
negative
()
cable
first,
and
Design
characteristics
of
the
convertible
body
cause
vi-



connect
ft
last
While
changing
batteries,
clean
away
brations
in
the
trunk
area
.
Therefore,
E36
convertibles



any
corrosion
in
or
around
the
battery
tray
.
require
a
specialbattery
designed
for
constant
vibra-
tion
.
When
repiacing
the
battery,
be
sure
the
replace-



"
Design
characteristics
of
the
convertible
body
cause
ment
is
designed
specffically
for
the
convertible
.



vibrations
to
oscillate
in
the
trunk
area
.
Therefore,
the
convertible
model
uses
a
specialbattery
designed
for
this
constant
vibration
.

100-
1
2
ENGINE-GENERAL

NOTE-

The
oxygen
sensor
signal
is
ignored
until
the
engine
reachesa
specified
minimum
temperature
.
Therefore,



The
primary
input
usedby
the
fuel
injection
system
to
deter-

when
troubleshooting
cold
engine
driveability
prob-



mine
how
much
fuel
should
be
delivered
is
the
signal
from
the

lems,
the
oxygensensor
canbe
ruled
out
asa
possible



mass
air
flow
sensor
in
the
intake
air
ductwork
.

cause
.

As
the
oxygen
sensor
ages,
its
ability
to
react
quickly
to

changing
conditions
deteriorates,
and
it
may
eventually
cease

to
produce
any
signal
at
all
.
To
check
the
operation
of
the
oxy-

gen
sensor,
see
130
Fuel
Injection
:

NOTE-

On
1996
and
latercars,
OBD
11
enhanced
emission
standards
require
the
engine
control
module
(ECM)
to
monitor
the
oxygen
content
in
the
exhaust
both
before
and
after
the
catalytic
converter
.
Thisallows
for
tighter
control
of
the
tail
pipe
emissions
and
also
allowsthe
ECM
to
diagnose
converter
problems
.
If
the
DME
de-
tects
that
catalytic
converter
or
oxygensensor
efficien-
cyhas
degraded
pasta
certain
pre-programmed
limit,
it
will
turn
on
the
Check
Engine
light,
and
store
a
diag-
nostic
trouble
code
(DTC)
in
the
ECM
.

DRIVEABILITY
TROUBLESHOOTING

Catalytic

B9506

Air
Flow
Measurement
and
Vacuum
Leaks

Because
proper
fuel
metering
depends
on
accurate
mea-

surement
of
the
incoming
air,
any
unmeasured
air
that
enters

the
engine
downstream
of
the
mass
air
flow
sensor
will
cause

a
lean
air-fuel
mixture
and
possibly
affectdriveability
.

NOTE-

Fig
.
10
.
Regulating
oxygen
sensor
measures
oxygen
content
of
ex-



gattery
Voltage
hausY
gas
as
indicator
of
.¡_fi
.1
ratio
and
"-k,
.

E-
effi-
ciency
.
Monitoríng
oxygen
sensor
(not
shown)
monitors

If
a
large
air
leak
is
causing
driveability
problems,
the
Check
Engine
light
will
usually
be
illuminated
and
a
fault
will
be
stored
in
the
fault
code
memory
.
See
On
Board
Diagnostics
(OBD)
.

There
are
many
places
for
unmeasured
air
to
enter
theen-

gine
.
First,
inspect
all
hoses,
fittings,
ducts,
seals,
and
gaskets

in
the
intake
air
tract
for
cracks
or
looseness
.
It
may
be
neces-

sary
to
remove
parts
that
cannot
be
fully
checked
in
their
in-

stalled
positions
.
Also
make
sure
all
of
the
intake
manifold
and

throttle
body
mounting
nuts
are
tight
.

In
addition
to
air
leaks,
air
restrictions
can
also
cause
drive-

ability
problems
.
Remove
the
air
filter
and
hold
it
up
to
a
strong

light
source
.
If
the
filter
does
not
pass
light,
it
is
restricted
and

should
be
replaced
.
Also,
remove
the
intake
air
ductwork
and

check
for
oily
deposits
at
the
throttle
plate
.
Buildup
in
this
area

can
cause
an
erratic
idle
.
Clean
away
any
deposits
using
a

cloth
wetted
withcarburetor
cleaner
and
reinstall
the
ductwork
.

CAUTION-

Do
not
spray
carburetor
cleaner
directly
in
the
throt-
tle
anea
.
Spraying
cleaner
may
force
it
into
the
throt-
tle
position
switch
or
sensor
and
cause
damage
.

catalytic
converter
operation
.



All
of
the
electrical
components
in
the
fuelinjection
and
igni-
tion
systems
require
a
minimum
voltage
to
operate
properly
.

When
troubleshooting
engine
driveability
problems,
one
of
Replacement
of
oxygensensors
at
the
specified
intenrals
en-



the
first
checks
should
be
to
make
sure
the
battery
is
fully
sures
that
the
engine
and
emission
control
system
wili
continue



charged
and
capable
of
delivering
allits
power
to
the
electricalto
operate
as
designed
.
As
the
oxygen
sensor
ages,
its
ability
to



system
.
react
quickly
to
changing
conditions
deteriorates,
and
it
may
eventually
cease
to
produceany
signal
at
all
.



To
make
a
quick
check
of
battery
charge,
measure
the
volt-
age
across
the
battery
terminals
with
all
cables
attached
and
As
the
oxygen
sensor
ages,
its
ability
to
react
quickly
to



the
ignition
off
.
A
fully
charged
battery
will
measure
12
.6
volts
changing
conditions
deteriorates,
and
it
may
eventually
cease



or
slightly
more,
compared
to
12
.15
volts
for
a
battery
with
a
to
produce
any
signal
at
all
.
To
check
theoperation
of
the
oxy-



25%
charge
.
gen
sensor,
see130
Fuel
Injection
.

Even
a
fully
charged
battery
cannot
deliver
power
unless
it

is
properly
connected
to
the
electrical
system
.
Check
the
bat-
tery
terminals
for
corrosion
and
loosecableconnections
.
If
the
battery
does
not
maintain
the
proper
voltage,
the
charging
system
may
be
atfault
.
See
121
Battery,
Starter,
Alternator
.

Fig
.
36
.
BMW
special
tool
no
.
11
2
300
installed
through
bellhousing
and
finto
flywheel
.

8
.
Remove
oil
line
fitting
from
VANOS
control
unit
.

NOTE-

Wrap
the
VANOS
oil
line
fitting
with
a
shop
to
absorb
leaking
oil
.

9
.
Using
hollow
bolt
and
seals
from
oil
supply
line,
instan

BMW
special
tool
no
.
11
3
450
(air
line
fitting)
and
con-
nect
a
supply
of
compressed
air
(30-115
psi)
to
VANOS

oil
fitting
.

10
.
Measure
and
record
distance
between
trigger
plate

edge
and
side
of
secondary
timing
chain
tensioner
.

See
Fig
.
37
.

Fig
.
37
.
VANOS
reference
measurement
(dimension
A)
between
trig-
ger
píate
(sender
gear)
and
side
of
secondary
chain
tensioner
.

CAMSHAFT
TIMING
CHAIN



117-
1
5

11
.
Disconnectharness
connector
from
VANOS
solenoid
.
Connect
BMW
special
tool
no
.
12
6
410
(electrical
test
lead)
to
VANOS
solenoid
connector
.

"
Connect
positive
(+)
test
lead
to
positive
(+)
terminal
ofbattery
Connect
negative
(-)
test
leadto
chassis
ground
.
solenoid
should
audibly
click
and
intake
cam-
shaft
should
advance
.

CA
UTION-

"
Be
sure
to
connect
the
test
hamess
polaritycor-
rectly
.
lf
the
polarity
is
reversed,
the
intemal
diode
in
the
VANOS
solenoid
will
be
destroyed
.
Although
the
solenoid
will
still
functionwith
a
faultydiode,
a
fault
code
may
be
set
in
the
ECM
memory
.

"
To
confirm
voltage
polarity,
turn
the
ignition
on
and
check
for
positive
(+)
batteryvoltage
at
the
terminal
corresponding
to
the
redlwhite
wire
in
the
main
harness
connector
.
Check
that
the
pos-
itive
terminal
(+)
in
the
main
connector
corre-
sponds
to
the
same
terminal
in
the
solenoid
connector
that
is
being
connected
to
the
battery
.

12
.
With
solenoid
actuated,
measure
and
record
new
dis-

tance
between
trigger
plate
edge
and
side'of
second-
ary
timing
chain
tensioner,
as
shown
in
Fig
.
37
.

13
.
Difference
between
first
measurement
(step
10)
andsecond
measurement
(step12)
should
be
at
least
8
.5
mm
(0
.3346
in
.)
.
lf
any
faults
arefound,
solenoid
may

be
faulty,
or
hydraulic
control
unit
may
be
faulty
or
incor-
rectly
installed
.

14
.
Check
VANOS
solenoid
byremoving
it
from
control
unit
.
Check
that
solenoid
plunger
and
control
unit

plunger
move
freely
.
Install
solenoid
using
tighteníng

torque
given
below
.

NOTE-

"
The
solenoid
is
available
asareplacement
part
.
lf
the
control
unit
plunger
is
sticking,
the
complete
control
unit
will
have
to
be
replaced
.

"lf
the
VANOS
system
does
not
advance
correctly
and
no
other
faults
can
be
found,
itis
possible
that
the
VANOS
control
unit
may
Nave
been
fnstalled
incor-
rectly-especially
if
the
camshaft
sprockets
have
pre-
víously
been
removed
for
other
repairs
.
Check
the
installation
by
removing
and
reinstalling
the
control
unit
as
described
later
.

VANOS
(VARIABLE
VALVE
TIMING)

2
.
Remove
cooling
duct
or
terminal
cover
from
rear
of
al-



2
.
Remove
air
cleaner
upper
section
with
mass
air
flow
ternator
.



sensor
.

3
.
Check
for
battery
voltage
between
ground
and
terminal



3
.
Remove
terminal
cover
from
rear
of
alternator
.
Discon
B+
at
back
of
alternator
.
Then
turn
ignition
on
and



nect
wiring
.
check
for
battery
voltage
between
terminal
D+
and
ground
.
See
Fig
.
3
.
lf
voltage
is
not
present
at
either



4
.
Remove
drive
belt
from
alternator
pulley
.
See
020
point,
check
wiring
for
faults
.



Maintenance
program
.

001
¡987
Fig
.
3
.



Terminal
B+
is
supplied
battery
voltage
directly
from
the
bat-
tery
.
Terminal
D+
is
supplied
battery
voltage
via
the
charge
warning
bulb
when
thekey
is
on
or
the
engine
is
running
.

4
.
lf
no
faults
are
foundup
to
thispoint,test
alternator
out-

put
using
a
load
tester
.

5
.
If
a
load
tester
is
not
available,
a
crude
output
test
can
be
done
by
running
engine
at
about
2000
rpmand
turn-
ing
on
electrical
loads
(fans,
lights
and
rear
window
de-
froster,
wipers)
.
With
al¡
accessories
on,
battery
voltage
should
be
above
12
.0
VDC
.

A
replacement
alternator
should
have
the
same
rating
as
the
original
.
Alternator
manufacturer
and
ampere
rating
are
normally
marked
on
the
alternator
housing
.
1
.
Disconnect
negative
(-)
battery
cable
.

CAUTION-

Prior
to
disconnecting
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
vi¡¡
.

BATTERY,
STARTER,
ALTERNATOR



121-
5

6
.
Remove
upper
and
lower
mounting
bolts
and
lift
out
al-
ternator
.
See
Fig
.
4
.

NOTE
-

If
reusing
drive
belt,
mark
direction
of
rotation
on
belt
before
removing
.

5
.
On
M44
engine
with
hydraulic
belt
tensioner
:
Remove
tensioner
idler
pulley
(upper
roller)
from
alternator

bracket
.

Fig
.
4
.



Alternator
mounting
bolts
(arrows)
.

O



u
J
S
v~~

U

I



1
i
n
-12
.22

Alternator,
removing
and
installing



7
.
Installation
is
reverse
of
removal
.
Install
drive
belt
as

(4-cylinder
engine)



described
in
020
Maintenance
Program
.

Tightening
Torques

"
D+
vire
to
alternator
(M6
nut)
.
...
.
.
.
7
Nm
(53
in-lb)

"
B+
wire
to
alternator
(M8
nut)
..
.
.
.
.
.
13
Nm
(10
ft-Ib)

"
Pulley
to
alternator
(M16
nut)
...
..
..
60
Nm
(44
ft-Ib)

ALTERNATOR
SERVICE