1995 BMW M3 air cleaner

Please
read
these
warnings
and
cautions

before
proceeding
with
maintenance
and
repair
work
.

WARNING-



"
Friction
materials
(such
as
brake
pads
or
shorts
or
clutchdiscs)
contain
asbestos
fibers
or
other
friction
materials
.
Do
notcreate
"
See
also
Cautionson
page
viü



dustby
grinding,
sanding,
orby
cleaning
with
compressed
air
.

"
Some
repairs
may
be
beyond
your
capability
.
If
you
lack
the



Avoid
breathing
dust
.
Breathing
any
friction
material
dust
can
lead

skills,
tools
and
equipment,
or
a
suitable
workplace
for
any
proce-



to
serious
diseases
and
may
result
in
death
.

duredescribed
in
this
manual,
we
suggestyou
leave
such
repairs



"
Batteries
give
off
explosive
hydrogen
gas
during
charging
.
to
an
authorized
BMW
dealer
service
department
or
other
quali-



Keep
sparks,
lighted
matches
and
open
flame
away
from
the
top
fied
shop
.



of
the
battery
If
hydrogen
gas
escaping
from
the
cap
vents
is

"Do
not
re-use
any
fasteners
that
are
worn
or
deformed
in
normal



ignited,
it
will
ignite
gas
trapped
in
the
cells
and
cause
the
battery

use
.
Many
fasteners
are
designed
to
be
used
only
once
and



to
explode
.

become
unreliable
and
may
fail
when
used
a
second
time
.
This



"
Connect
and
disconnect
battery
cables,
jumper
cablesora
bat-
includes,
but
is
not
limited
to,
nuts,
bolts,
washers,
self-locking
nuts
or
bolts,
circlips
and
cotterpins
.
Always
replace
these
fasteners

with
new
parts
.
"Do
not
quick-charge
the
battery
(for
boost
starting)
for
longer
"
Never
work
under
a
lifted
car
unless
it
is
solidly
supportedon



than
one
minute
.
Wait
at
least
one
minute
before
boosting
the
bat-
stands
designed
for
the
purpose
.
Do
not
support
a
car
on
cinder



tery
a
second
time
.
blocks,
hollow
tiles
or
other
props
that
may
crumble
under
contin-

uous
load
.
Never
work
under
acar
that
is
supported
solely
by
a



"Do
not
allow
battery
charging
voltage
to
exceed
16
.5
volts
.
If
the

jack
.
Never
work
under
thecar
while
the
engine
is
running
.



battery
beginsproducing
gas
or
boiling
violently,
reduce
the
charg-
ing
rate
.
Boosting
a
sulfated
battery
at
a
high
charging
rate
can
"
If
you
are
going
to
work
under
acar
on
the
ground,
make
sure



cause
an
explosion
.
that
the
ground
is
level
.
Block
the
wheels
to
keep
the
carfrom
roll-

ing
.
Disconnect
the
battery
negative
(-)
terminal
(ground
strap)to



"
The
air-conditioning
system
is
filled
with
chemical
refrigerant,

prevent
others
from
starting
thecar
while
youare
under
it
.



which
is
hazardous
.
TheA/C
system
should
be
servicedonly
by

trained
technicians
using
approved
refrigerant
recovery/recycling
"
Never
run
the
engine
unless
the
work
area
is
well
ventilated
.



equipment,
trained
in
related
safetyprecautions,
and
familiar
with
Carbon
monoxide
kills
.



regulations
governing
the
discharging
and
disposal
of
automotive

"
Finger
rings,
bracelets
and
other
jewelry
shouldbe
removed
so



chemical
refrigerants
.

tery
charger
only
with
the
ignition
switched
off,
to
prevent
sparks
.

Do
not
disconnect
the
battery
while
the
engine
is
running
.

that
theycannot
cause
electrical
shorts,
get
caught
in
running



"
Do
not
expose
any
partof
the
A/Csystem
to
high
temperatures
machinery,
or
be
crushed
by
heavy
parts
.



suchas
open
flame
.
Excessiveheat
will
increase
system
pressure

"
Tie
long
hair
behind
your
head
.
Do
not
wear
a
necktie,
a
scarf,



and
may
cause
the
system
to
burst
.

loose
clothing,
or
a
necklace
when
you
work
near
machine
tools
or



"
Some
aerosol
tire
inflators
are
highly
flammable
.
Be
extremely
running
engines
.
If
your
hair,
clothing,
or
jewelry
were
to
get
caught



cautious
when
repairing
a
tire
that
may
havebeen
inflated
using
in
the
machinery,
severe
injury
could
result
.



an
aerosol
tire
inflator
.
Keep
sparks,
open
flame
or
other
sources

"
Do
not
attempt
to
work
onyourcar
if
you
do
not
feel
well
.
You



of
ignition
away
from
the
tire
repair
area
.
Inflate
and
deflate
the
tire

increase
the
danger
of
injury
toyourself
and
others
if
you
are
tired,



at
least
four
times
before
breaking
the
bead
from
therim
.
Com-

upset
or
have
takenmedication
or
any
other
substance
that
may



Pletely
remove
the
tire
from
the
rim
beforeattempting
any
repair
.

keep
you
from
being
fully
alert
.

"
Illuminate
your
work
areaadequately
but
safety
.
Use
a
portable

safety
light
for
working
inside
or
under
thecar
.
Make
surethe
bulb

is
enclosedbya
wire
cage
.
The
hot
filament
of
an
accidentally
bro-

ken
bulb
can
ignite
spilled
fuel
or
oil
.

"
Catch
draining
fuel,
oil,
orbrake
fluid
in
suitable
containers
.
Do

not
use
food
or
beverage
containers
that
mightmislead
someone

into
drínking
from
them
.
Store
flammable
fluids
away
from
fire
haz-

ards
.
Wipe
up
spills
at
once,
but
do
not
store
the
oily
rags,
which

can
ignite
and
burn
spontaneously
.

"
Always
observe
good
workshop
practices
.
Wear
goggles
when

youoperate
machine
tools
or
work
with
battery
acid
.
Gloves
or

other
protectioeclothing
should
be
worn
whenever
thejob
requires

working
with
harmful
substances
.

"
Greases,
lubricants
and
other
automotive
chemicals
contain

toxic
substances,
many
of
which
are
absorbed
directly
through
the

skin
.
Read
the
manufacturer's
instructions
and
warnings
carefully
.

Use
hand
andeye
protection
.
Avoid
direct
skin
contact

"
Cars
covered
by
this
manual
are
equipped
with
a
supplemental

restraint
system
(SRS),
that
automatically
deploys
an
airbag(s)
in

theevent
of
a
frontal
ímpact
.
The
airbag(s)
is
inflated
byan
explo-

sive
device
.
Handled
improperly
or
without
adequate
safeguards,

can
be
accidently
activated
and
cause
serious
injury
.

"
The
ignition
system
produces
high
voltages
that
can
be
fatal
.

Avoid
contact
with
exposed
terminals
and
use
extreme
care
when

working
ona
car
with
the
engine
running
or
the
ígnition
switched
on
.

"
Place
jack
stands
only
at
locations
specified
bymanufacturer
.

The
vehicle
lifting
jacksupplied
with
the
vehicle
is
intended
for
tire

changes
only
.
A
heavy
duty
floor
jack
shouldbe
used
to
lift
vehicle

before
installing
jack
stands
.
See
010
Fundamentals
for
theDo-
.

it-Yourself
Owner
.

"
Battery
acid
(electrolyte)
can
cause
severeburns
.
Flush
contact

area
with
water,
seek
medical
attention
.

"
Aerosolcleaners
and
solvents
may
contain
hazardous
ordeadly
vapors
and
are
highly
flammable
.
Use
only
in
a
wellventilated

area
.
Do
not
use
on
hot
surfaces
(engines,
brakes,
etc
.)
.

"
Disconnect
the
battery
negative
(-)
terminal
(Ground
strap)



"
Do
not
remove
coolant
reservoir
or
radiator
cap
with
theengine

whenever
you
work
on
the
fuel
system
orthe
electrical
system
.
Do



hot
.
Danger
of
bums
and
engine
damage
.

not
smoke
or
work
near
heaters
or
other
fire
hazards
.
Keep
an

approved
fire
extinguisher
handy
.



continued
on
next
page
vii

010-
4



FUNDAMENTALS
FOR
THE
DO-ITYOURSELF
OWNER

Fig
.
3
.



BMW
supplied
jack
correctly
positioned
in
front
jacking
point
.



Most
of
the
repairs
and
maintenance
tasks
described
in
this

manual
can
be
successfully
completedby
anyone
with
basic

tools
and
abilities
.
To
prevent
getting
in
too
deep,
know
what

WARNING-



the
wholejob
requires
before
starting
.
Read
the
procedure
thor-

"
Do
not
rely
on
thetransmission
or
the
emergen-



oughly,
from
beginning
to
end,
in
order
to
know
just
what
to
ex
cybrake
to
keep
thecar
from
rolling
.
They
are



pect
and
what
parts
will
have
to
be
replaced
.

nota
substitute
for
positively
blocking
the
oppo-
site
wheel
.

"
Never
work
undera
car
that
is
supported
only
by
ajack
Use
jack
stands
that
are
properly
de-
signed
to
support
the
car
.
See
Tools
.

Working
under
car
safely

1
.
Disconnect
negative
(-)
cable
from
battery
so
that
no

one
else
can
start
thecar
.
Let
others
know
what
you
will

be
doing
.

CAUTION-

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

2
.
Raisecar
slowly
as
described
above
.

3
.
Use
at
least
two
jack
stands
to
support
thecar
.
A
jack
is
atemporary
lifting
device
and
should
not
be
used
alone
to
support
the
car
while
you
are
under
it
.
Use
jack
stands
designed
for
the
purpose
of
supporting
a
car
.
For
more
information
on
jack
stands,
see
Toolsbelow
.

WARNING
-

Do
notusewood,
concrete
blocks,
orbricks
to
sup-
port
acar
.
Woodmay
split
.
Blocks
or
bricks,
while
strong,
are
not
designed
for
that
kind
of
load,
and
may
brakkor
collapse
.

ADVICE
FOR
THE
BEGINNER

4
.
Place
jack
stands
on
firm,
solid
surface
.
If
necessary,

use
a
flat
board
or
similar
solid
object
to
provide
a
firm

footing
.

5
.
Lower
car
slowly
until
its
weight
is
fully
supportedby

jack
stands
.
Watch
to
make
sure
that
the
jack
stands
do

not
tip
orlean
as
thecar
settles
on
them
.

6
.
Observe
all
jacking
precautions
again
when
raising
car

to
remove
jack
stands
.

ADVICE
FORTHE
BEGINNER

The
tips
in
the
paragraphs
that
follow
are
general
advice
to

help
any
do-it-yourself
BMW
owner
perform
repairs
and
main-

tenance
tasks
more
easily
and
more
professionally
.

Planning
Ahead

Cleanliness

Keeping
things
organized,
neat,
and
clean
is
essential
to
do-

ing
a
good
job
.
When
working
under
the
hood,
fender
covers

will
protect
the
finish
from
scratches
and
other
damage
.
Make
sure
the
car
is
relatively
clean
so
thatdi
rt
under
the
cover
does

not
scratch
the
finish
.

Any
repair
job
will
be
less
troublesome
if
the
parts
are
clean
.

For
cleaning
old
parts,
there
are
many
solvents
and
parts

cleaners
commercially
available
.

For
cleaning
parts
priorto
assembly,
commercially
available
aerosol
cans
of
parts
cleaner
or
brake
cleaner
are
handy
to
use,
and
the
cleaner
will
evaporate
completely
.

WARNING
-

Virtually
all
solvents
used
for
cleaning
parts
are
highly
flammable,
especially
in
aerosol
form
.
Use
wíth
extreme
care
.
Do
not
smoke
.
Do
not
use
these
products
near
any
source
of
heat,
sparksor
flame
.

Let
any
solvent
orcleaning
product
dry
completely
.
Low-
pressure,
dry
compressed
air
is
helpful
if
available
.
Also,
use
only
lint-free
rags
for
cleaning
and
drying
.

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
.

110
Engine
Removal
and
Installation

GENERAL
.
.
.
.
.......
.
.
.
..........
.
...
110-1



Engine,
removing
and
installing
(4-cylinder
engines)
.
..
.....
..
...........
110-1

ENGINE
REMOVAL
AND
INSTALLATION
110-1



Engine,
removing
and
installing
(6-cylinder
engines)
..
...
...
..
.....
..
....
110-4

GENERAL

Some
special
tools
are
required
for
removal
and
installation
of
the
engine
.
Be
sure
to
have
the
necessary
equipment
on
hand
before
starting
thejob
.

CAUTION-

"
Engine
removal
requires
disconnecting
the
bat-
tery
.
This
may
erase
any
system
fault
code(s)
that
havebeen
stored
in
control
unit
memories
.
Check
forfault
codes
prior
to
disconnecting
the
battery
cables
.

"
If
the
Check
Engine
lightis
illuminated
with
the
engine
running,
see
100
Engine-General
for
On-Board
Diagnostics
(08D)
fault
code
infor-
mation
.
"
If
any
other
system
faults
have
been
detected,
as
indicated
by
an
illuminated
ANTI
LOCK,
SRS
or
AST
warning
light,
see
the
appropriate
repair
group
inthis
manual
or
an
authorized
BMW
dealer
for
more
information
on
fault
codes
.

ENGINE
REMOVALAND
INSTALLATION

Engine,
removing
and
installing

(4-cylinder
engines)

Cover
al¡
painted
surfaces
before
beginning
theremoval

procedure
.
Asan
aid
to
installation,
label
al¡
components,

wires,
and
hoses
before
removing
them
.
Do
not
reuse
gas-

kets,
O-rings
or
seals
during
reassembly
.

WARNING
-

Due
to
risk
of
personal
injury,
be
sure
the
engine
is

cold
before
beginning
the
removalprocedure
.

1.
Disconnect
negative
(-)
cable
from
battery
in
luggage

compartment
.



0011969

CAUTION-

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

ENGINE
REMOVAL
AND
INSTALLATION



110-1

2
.
Remove
transmission
from
car
.
See230
Manual
Transmission
or
240
Automatic
Transmission
.

3
.
Remove
enginehood
or
place
hood
in
service
positíon
.
See
410
Fenders,
Engine
Hood
.

NOTE-

tt
is
notnecessary
to
remove
the
engine
hood,
but
it
is
helpful
and
will
make
engine
removal
and
installation
easier
.

4
.
Remove
splash
guard
under
engine,
if
applicable
.

5
.
Unbolt
ignition
coil
assembly
from
bracket
on
strut
tow-er
.
Disconnect
wiring
to
ignition
cofs,
then
place
coil
assembly
on
engine
.

6
.
Disconnect
al¡
cables
and
harness
connectors
at
throt-
tle
housing
.

7
.
Unbolt
andremove
complete
air
cleaner
housing
with

mass
air
flow
sensor,
disconnecting
and
labeling
con-

nectors,
ducting
and
hoses
asnecessary
.
See
Fig
.
1
.

Fig
.
1
.



Intake
air
duct
hose
clamp
(A),
mass
air
flow
sensor
connec-
tor
(B),
and
air
cleanerto
air
flow
sensor
clips
(C)
on
M44
en-
gine
.

ENGINE
REMOVAL
AND
INSTALLATION

110-
4



ENGINE
REMOVAL
AND
INSTALLATION

Engine,
removing
and
installing

(6-cylinder
engines)

Engineremoval
procedures
for
the
various
6-cylinder
en-

gines
arecovered
in
this
section
.
Most
steps
in
theproce-

dures
are
similar
or
the
same
for
al¡
engines
.
Specific

differences
that
apply
are
noted
at
the
beginning
of
each
step
.

Be
sure
to
cover
all
painted
surfaces
before
beginning
the

removal
procedure
.
As
an
aid
to
installation,
label
all
compo-

nents,wires,
and
hoses
before
removing
them
.
Do
not
reuse

gaskets,
O-rings
or
seals
during
reassembly
.

WARNING
-

Due
to
risk
of
personal
injury,
be
sure
the
engine
is
cold
before
beginning
the
removalprocedure
.

1
.
Disconnect
negative
(-)
battery
cable
in
luggage
com-

partment
.

CAUTION-

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

2
.
Remove
engine
hood
or
place
hood
in
service
position
.

See410
Fenders,
Engine
Hood
.

NOTE-

1t
is
not
necessary
to
remove
the
engine
hood,
but
it
is
helpful
and
will
make
engine
removal
and
installation
easier
.

3
.
Remove
splash
guardunder
engine,
if
applicable
.

4
.
Remove
transmission
from
car
.
See
230
Manual

Transmission
or
240Automatic
Transmission
.

5
.
Remove
vacuum
hosefrom
brake
booster
on
bulkhead
.

Cover
hole
in
booster
and
plug
hose
end
.

6
.
Remove
intake
air
plenum
panel
in
rear
of
engine
com-
partment
.
See
640
Heating
and
AirConditioning
.

7
.
Remove
ground
strap
from
timing
case
cover,
if
appli-

cable
.

8
.
Remove
top
enginecovers
and
disconnect
ignition
coil
harness
connectors
.
Working
at
fuel
injectors,
pry
open
small
wire
clipsat
each
injector
.
Remove
main
harness

hold-down
nuts
and
lift
completeharness
away
.
See
Fig
.
7
.

ENGINE
REMOVAL
AND
INSTALLATION

Fig
.
7
.



Remove
mainharnessfrom
top
engine
and
place
at
base
of

windshield
.

0012703

Fig
.
8
.



Mass
air
flow
sensor
connector
air
duct
hose
clamp,
and
air
cleaner
housing
mounting
bolts
(arrows)
.

9
.
Unbolt
andremove
complete
air
cleaner
housing
with



10
.
On
cars
with
automatic
transmission,
remove
front
and
mass
air
flow
sensor,
disconnecting
and
labeling
con-



rearbrackets
holding
transmission
cooler
linesto
side
nectors,
ducting
and
hoses
asnecessary
.
See
Fig
.
8
.



of
engine
.

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

130-2



FUEL
INJECTION

GENERAL

This
repair
group
covers
fuel
injection
system
component

testing
and
repair
.
Special
equipment
is
necessary
for
some

of
the
procedures
given
in
this
repair
group
.
If
you
do
not
have

the
equipment
required
to
do
the
job,
it
is
recommended
that

these
repairs
be
left
to
an
authorized
BMW
dealer
.
The
BMW

dealer
is
equipped
with
sophisticated
diagnostic
test
equip-

ment
that
is
capable
of
quicklypinpointing
hard-to-find
fuel
in-

jection
problems
.

NOTE-

"
Wiring
diagrams
for
the
engine
management
system,

can
be
found
at
the
rear
of
the
manual
under
Electri-
cal
Wiring
Diagrams
.

"
For
ignition
system
repairinformation,
see120
Igni-

tion
System
.

"
For
fuel
supply
system
testing
and
repair,
see160



The
engine
control
module
(ECM)
uses
electrical
signals

Fuel
Tank
and
Fuel
Pump
.



from
the
mass
air
flow
sensor,
the
air
and
coolant
temperature

sensors,
the
crankshaft
position/rpm
sensor,
the
knock
sen

Principies
Of
Operation



sors
and
the
oxygen
sensorsas
the
primary
inputs
to
electron-

ically
control
fuel
delivery
and
ignition
timing
.

There
are
five
versions
of
engine
management
systems

usedon
the
E36
cars
.
Each
has
the
same
basic
components

and
operating
principles
.
The
most
notable
difference
is
that

1996
and
later
cars
use
a
sophisticated
OBD
II-compliant
sys-

tem
.
See
Table
a
.

Table
a
.
Engine
Management
System
Variants

Engine
code/year



1
System

4-cy1inder
M42
(1
.8
I)
1992-1995



Bosch
DME
Ml
.7
M44
(1
.91)
1996-1998



~
Bosch
DME
M5
.2
(OBD
II)

6-cylinder
M50
1992
(2.5
I)



Bosch
DME
M3
.1
1993-1995
(2.5
I)



Bosch
DME
M3
.3.1
(VANOS)
M52
1996-1998
(3281-
2
.8
I)



Siemens
MS
41
.1
(OBD
II)
1998
(3231
-
2
.5
I)



Siemens
MS
41
.1
(OBD
II)
M-Power
S50US
(M3
-
3
.01)
1995



Bosch
DME
M3
.3
.1
S52US
(M3
-
3
.21)
1997-1998



Siemens
MS
41
.1
(0131)
11)

NOTE-

-
Descriptions
and
procedures
in
the
first
partof
this
re-

pairgroup
refer
to
all
the
various
engine
management
systems
.

"
Particulars
of
each
fuel
injection
system
are
treated
in
separate
sections
in
the
second
part
of
this
repair
group
.

GENERAL

Fig
.1
.



OBD
II
diagnostic
connector
locatíon
.

The
fuel
injection
system
is
completely
electronic
in
opera-

tion
.
Air
flow
is
measured
electronically
via
a
mass
air
flow

sensor
and
additional
sensors
supply
information
about
en-

gine
operating
conditions
.
The
ECM
calculates
the
amount
of
fuel
needed
for
the
correct
air-fuel
ratio
and
actuates
the
fuel

injectors
accordingly
.
The
amount
offuel
metered
to
theen-

gine
is
determined
by
how
long
the
injectors
are
open
.

Airintake
.
Air
entering
the
engine
passes
through
a
pleat-

ed
paper
air
filter
in
the
air
cleaner
.
Intake
air
volume
or
mass

is
then
measured
bya
mass
air
flow
(MAF)
sensor
.
In
al¡
ex-

cept
the
vane
type
sensor
(DME
M1
.7),
a
reference
current
is

used
to
heat
a
thin
wireor
film
in
the
sensor
when
the
engine

is
running
.
The
current
used
to
heat
the
wire/film
is
electroni-

cally
converted
into
a
voltage
measurement
corresponding
to

the
mass
of
the
intake
air
.

Table
b
.
Mass
Air
Flow
Sensor
Variants

System



Al
r
flow
sensor
type

Bosch
DME
M1
.7



Vane
(volume
sensor)

Bosch
DME
M3
.1



Hot
wire
(mass
sensor)

Bosch
DME
M3
.3
.1



Hot
film
(mass
sensor)

Bosch
DME
M5
.2



Hot
film
(mass
sensor)

Siemens
MS
41
.1



Hot
film
(mass
sensor)

"
The
16-pin
OBD
11
diagnostic
connector
is
located
on



NOTE-

the
lower
left
dashpanel
.
See
Fig
.
1
.



On
cars
equipped
wíth
tractioncontrol,
an
additional
throttle
valve
is
controlled
by
an
electronic
throttle
actu-
ator
(motor)
.
This
valve
is
used
for
engine
speed
inter
vention
.
Repair
information
forthis
system
is
notcovered
here
due
to
the
special
electrical
testing
equip-
ment
required
to
service
it
.

130-
6



FUEL
INJECTION

Warnings
and
Cautions

For
personal
safety,
as
well
as
the
protection
of
sensitive

electronic
components,
the
following
warnings
and
cautions

should
be
adhered
to
when
working
on
the
engine
manage-

ment
system
.

GENERAL
WARNING
-

"
The
ignition
system
produces
high
voltages
that

can
be
fatal
.
Avoid
contact
with
exposed
termi-

nals
.
Use
extreme
caution
when
working
onacar
with
the
ignition
switched
on
or
the
engine
run-
ning
.

"
Do
not
touch
or
disconnect
any
high
voltage
ca-

bles
from
the
coils
or
spark
plugs
while
the
engine

is
running
or
beingcranked
by
the
starter
.

"
Connect
and
disconnect
the
DME
system
wiring
and
test
equipment
leads
only
when
the
ignition
is
switched
off
.

"
Gasoline
is
highly
flammable
and
fts
vaporsare

explosive
.
Do
not
smoke
or
work
on
a
car
near
heaters
or
other
fire
hazards
when
diagnosing
and
repalring
fuel
system
problems
.
Have
a
tire
extinguisher
avaílable
in
case
of
an
emergency
.

"
When
working
onan
open
fuel
system,
wear
suit-
able
hand
protection,
asprolonged
contact
wfth
fuel
can
cause
illnesses
and
skin
disorders
.

"
Renew
fuel
system
hoses,
clamps
and
O-rings
any
timethey
are
removed
.

"
Before
makingany
electrical
tests
that
require
the
engine
to
be
cranked
using
the
starter,
disable
the
ignition
system
as
described
in
120
Ignition
System
.

CAUTION-

"
Prior
to
disconnecting
the
battery,
read
the
bat-
tery
disconnectinn
cautions
given
at
the
front
of
this
manual
onpage
vifi
.

"
Do
not
connect
any
test
equipment
that
delivers

a
12-volt
power
supply
to
terminal
15
(+)
of
the
ig-

nitioncoil
.
The
current
flow
may
damage
the

ECM
.
In
general,
connect
test
equipment
only
as

speclfied
by
BMW,
this
manual,
or
the
equipment

maker
.

"
Only
use
a
digital
multlmeter
for
electrical
test
.

"
Only
use
an
LED
test
light
for
quick
tests
.

"
Disconnecting
the
battery
may
erase
fault

code(s)
stored
in
memory
.
Check
for
fault
codes

prior
to
disconnecting
the
battery
cables
.
ff
the

Check
Engine
light
ís
illuminated,
see100En-
gine-General
for
DME
fault
code
information
.
ff
any
other
system
faults
have
been
detected
(indi-
catedbyan
illuminated
warning
light),
see
an
au-
thorized
BMW
dealer
.
Additional
systems
with
self-diagnostic
capabilities
include,
ABS
(Anti-
lock
brakes),
SRS
(Airbags),
EML
and
ASC+T
and
AST
(Traction
Control)
.

"
Do
not
run
the
engine
wfth
any
of
the
spark
plug
wires
dlsconnected
.
Catalytic
converter
damage
may
result
.

"
Always
waitat
least
40
seconds
afterturning
off
the
ignition
before
removing
the
engine
control
module
(ECM)
connector
.
ff
the
connector
isre-
moved
before
this
time,
residual
power
in
the
sys-
tem
relay
may
damage
the
control
module
.

"
Cleanliness
is
essential
when
working
onan
open
fuel
system
.
Thoroughly
clean
fuel
line
con-
nections
and
surroundlng
areas
before
loosen-
ing
.
Avoid
moving
the
car
.
Only
fnstall
cleanparts
.

"
Fuel
system
cleaners
and
other
chemical
addi-
tives
other
than
those
specifically
recommended
by
BMW
may
damage
the
catalytic
converter,
the
oxygensensor
or
other
fuel
supply
components
.