121-
6
BATTERY
STARTER,
ALTERNATOR
Alternator,
removing
and
installing
(6-cylinder
engine)
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
disconnectiog
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
onpage
viii
.
2
.
Remove
alternator
cooling
duct
and
air
filter
housing
assembly
from
car
.
Disconnect
wiring
from
rear
of
alter-
nator
.
3
.
Remove
radiator
cooling
fan
and
fan
shroud
.
See
170
Radiator
and
Cooling
System
.
4
.
Remove
alternator
drive
belt
from
alternator
pulley
.
On
engines
with
hydraulic
belt
tensioner,
remove
tensioner
idler
pulley
(upper
roller)
from
alternator
bracket
.
See
Fig
.
5
.
ALTERNATOR
SERVICE
Fig
.
5
.
Pry
off
cover
from
tensioner
and
then
lever
tensioner
clock-
wise
to
release
belt
tension
.
Remove
upper
roller
(A)
once
belt
ís
removed
.
NOTE-
If
reusing
drive
belt,
mark
direction
of
rotation
on
belt
before
removing
.
5
.
Remove
upper
and
lower
mounting
bolts
and
lift
out
al-
ternator
.
6
.
Installation
is
reverse
of
removal
.
Note
locating
notches
on
tensioner
idler
pulley
(upper
roller)
alternator
brack-
et
when
installing
pulley
.
Tightening
Torques
"
D+
wire
to
alternator
(M6
nut)
.......
7
Nm
(53
in-lb)
"
B+
wireto
alternator
(M8
nut)
.......
13
Nm
(10
ft-Ib)
"
Pulley
to
alternator
(M16
nut)
.......
60
Nm
(44
ft-Ib)
Voltage
regulator,
removing
and
installing
1
.
Disconnect
negative
(-)
cable
from
battery
.
NOTE-
2
.
Remove
alternator
as
described
earlier
.
The
radiator
cooling
fan
nut
(32
mm
wrench)has
left-
hand
threads
.
3
.
Remove
cooling
duct
from
rear
of
alternator
.
See
Fig
.
6
.
Alternator
.
.g-
p~
J
-..
.
Fig
.
6
.
Alternator
assemblyand
related
parts
.
Cooling
duct
0012524
4
.
Remove
voltage
regulator
mounting
screws
and
re-
move
regulator
from
alternator
.
5
.
Installation
is
reverse
of
removal
.
Clean
brush
contact
surfaces
in
alternator
and
check
brush
length
asde-
scribed
later
.
121-
8
BATTERY,
STARTER,
ALTERNATOR
1f
the
solenoid
audibly
cliicks
but
the
motor
does
not
turn,
Starter,
removing
and
installing
switch
on
the
lights
andtum
the
key
to
the
start
position
.
lf
the
(6-cylinder
engine
with
lights
go
out
while
attempting
to
start,
the
battery
cable
may
be
manual
transmission)
loose
or
the
starter
may
have
a
short
circuit
.
If
the
lights
stay
on,the
solenoid
is
most
likely
atfault
.
The
starter
on
a
6-cylinder
car
with
manual
transmission
is
Starter,
removing
and
installing
(4-cylinder
engine)
1
.
Disconnect
negative
(-)
battery
cable
.
1
.
Disconnect
negative
(-)
cable
from
battery
.
CAUTION-
Prior
to
disconnecting
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
viii
.
2
.
Remove
guide
tube
for
oil
dipstick
.
3
.
Raise
vehicle
.
WARNING
-
Make
sure
the
car
ís
stable
and
wefl
supported
at
all
times
.
Use
a
professional
automotive
lift
or
jack
stands
designed
forthe
purpose
.
A
floor
jack
is
not
adequate
support
.
4
.
Disconnect
wiring
from
starter
.
5
.
Remove
top
and
bottom
starter
bolts
.
Bottom
bolt
must
be
removed
from
below
car
.
Remove
starter
support
bracket,
if
applicable
.
removed
from
below
.
2
.
Raise
vehicle
.
3
.
Remove
reinforcing
cross
bracefromunder
transmís-
sion,
if
applicable
.
4
.
Remove
cover
from
fuel
filter
and
fuel
lines
on
left
side
underneath
car,
if
applicable
.
Detach
fuel
lines
and
har-
ness
connectors
from
retainingbrackets,
as
necessary
5
.
Disconnect
wiring
from
starter
.
6
.
Loosen
andremove
bolts
and
nuts
fastening
starter
to
transmission
bell
housing
and/or
engine
block
.
Remove
starter
supportbracket
.
7
.
Remove
starter
from
below
.
8
.
Check
starter
pinion
gear
and
flywheel
teeth
for
dam-
age
.
9
.
Installation
is
reverse
of
removal
.
6
.
Pull
starter
downward
and
turn
until
solenoid
is
at
top,
Tightening
Torques
then
remove
from
car
.
"
Re¡
nforcing
cross
brace
to
chassis
(M10)
..
...............
42
Nm
(31
ft-Ib)
7
.
>Check
starter
pinion
gear
and
flywheel
teeth
for
dam-
"
Starter
to
engine
block
(M10
bolt)
...
50
Nm
(37
ft-Ib)
age
.
"
Support
bracket
to
starter
(M5
nut)
...
5
Nm
(44
in-lb)
"
Support
bracket
8
.
Installation
is
reverse
of
removal
.
to
engine
block
(M10
bolt)
.........
47
Nm
(35
ft-Ib)
"
Wire
to
terminal
50
(M6
nut)
.........
6
Nm
(53
ín-Ib)
"
Wire
to
terminal
30
(M8
nut)
.........
12
Nm
(9
ft-lb)
Tightening
Torques
"
Starter
to
engine
block
(M10
bolt)
...
50
Nm
(37
ft-lb)
Wire
to
terminal
50
(M6
nut)
........
6
Nm
(53
in-lb)
"
Wire
toterminal
30
(M8
nut)
...
,
..:.
12
Nm
(9
ft-Ib)
STARTER
SERVICE
Starter,
removing
and
installing
(6-cylinder
engine
with
automatic
transmission)
The
starter
on
a
6-cylinder
car
with
automatic
transmission
ís
removed
from
above
.
It
is
necessary
to
remove
the
íntake
manifold
and
disconnect
a
number
of
electrical
harness
con-
nectors
.
1
.
Disconnect
negative
(-)
battery
cable
.
2
.
Remove
air
plenum
from
rear
of
engine
compartment
.
See640
Heating
and
Air
Conditioning
.
3
.
Remove
top
enginecovers
.
See
Fig
.
9
.
Fig
.
9
.
Remove
top
engine
cover
by
prying
out
plugs
and
removing
nuts
(A)
.
Make
sure
rubber
insulators
(B)
on
either
sideof
large
cover
do
not
fall
off
during
cover
removal
.
4
.
Remove
ignition
coil
harness
connectors
.
Remove
ground
connection
at
front
of
cylinder
head
.
5
.
Remove
two
retaining
bolts
and
lift
off
fuel
injector
har-
ness
connector
strip
.
Carefully
fold
away
all
harnesses
toward
right
side
of
engine
compartment
and
place
at
base
of
windshield
.
See
Fig
.
10
.
6
.
Remove
intake
manifold
.
See
113
Cylinder
Head
Re-
moval
and
Installation
.
7
.
Disconnect
wiring
from
starter
.
BATTERY,
STARTER,
ALTERNATOR
121-
9
Fig
.
10
.
Fuel
injection
harness
(A)
and
ignition
coíl
harness
connectors
(B)
being
lifted
off
engine
to
be
placed
at
base
ofwindshield
.
M50
engine
shown
.
Other
6-cylinder
engines
are
similar
.
8
.
Loosen
and
remove
bolts
and
nuts
fastening
starter
to
transmission
bell
housing
and/or
engine
block
.
Remove
starter
support
bracket
.
Fig
.
11
.
Starter
wiring
terminals
and
support
bracket(arrow)
.
Intake
manifold
has
been
removed
.
STARTER
SERVICE
121-1
O
BATTERY,
STARTER,
ALTERNATOR
9
.
Remove
starter
from
above
.
10
.
Check
starter
pinion
gear
and
flywheel
teeth
for
dam-
age
.
11
.
Installation
is
reverse
of
removal
.
Tightening
Torques
"
tntakemanifold
to
cylinder
head
M7
nut
...
.
................
...
.
15
Nm
(11
ft-Ib)
M8
nut/bolt
.............
.
.
..
...
22
Nm
(16
ft-Ib)
"
Starter
to
engine
block
(M10
bolt)
...
50
Nm
(37
ft-Ib)
"
Support
bracket
to
starter
(M5
nut)
...
5
Nm
(44
in-lb)
"
Support
bracket
to
engine
block
(M10
bolt)
.
.
..
..
...
47
Nm
(35
ft-Ib)
"
Wire
toterminal
50
(M6
nut)
.
..
.....
6
Nm
(53
in-lb)
"
Wire
toterminal
30
(M8
nut)
...
.....
12
Nm
(9
ft-Ib)
Solenoid
switch,
removing
and
installing
1
.
Remove
starter
as
described
above
.
Tightening
Torque
2
.
Remove
cover
from
solenoid
switch
.
"
Field
winding
strap
to
starter
(M8)
...
.
12
Nm
(9
ft-Ib)
3
.
Disconnect
fieid
winding
strap
between
starter
motor
and
solenoid
switch
.
NOTE-
The
condition
of
the
field
winding
strap
is
critical
.
If
it
is
damaged,
bumed
or
partially
melted
through,
a
new
or
rebuilt
starter
motor
is
needed
.
4
.
Remove
solenoidswitch
mounting
screws,
and
sepa-
,
rate
solenoid
from
starter
.
See
Fig
.
12
.
CAUTION-
When
installing
fieid
winding
strap
to
starter,
posi-
tion
it
so
that
it
does
not
contact
the
starter
body
.
STARTER
SERVICE
131~184
Fig
.
12
.
Starter
solenoid
mounting
screws
(arrows)
are
tight
.
Use
en
impact
screwdriver
to
loosen
the
screws
.
5
.
Installation
is
reverse
of
removal
.
Lubricate
solenoid
pistos
with
light
grease
.
Oxygen
Sensor
FUEL
DELIVERY
TESTS
FUEL
INJECTION
130-
9
"
Voltage
at
¡dle
..
.
..
..
....
0
.2
to
0
.8
VDC,
fluctuating
Checking
fuel
delivery
is
afundamental
part
of
trouble-
shooting
and
diagnosing
the
engine
management
system
.
Fuel
pressure
directly
influences
fuel
delivery
.
An
accurate
NOTE-
fuel
pressure
gauge
will
be
needed
to
make
the
tests
.
To
check
sensorresponse
to
lean
and
rich
mixtures,
createenairleak,
orpull
vacuumhoseofffue¡
pressure
There
are
three
significant
fuel
delivery
values
to
be
mea-
regulator
to
increase
fuel
pressure
.
sured
:
3
.
Separate
sensorharness
connector
from
sensor
.
Check
for
battery
voltage
between
terminals
3
and
4
(green
wire
and
brown
wire)
in
main
wiring
harness
side
of
con-
nector
with
engine
running
.
If
voltage
is
not
present,
check
oxygen
sensor
heater
relay
.
See610
Electrical
Component
Locations
.
4
.
Check
heater
element
resistance
between
terminals
3
and
4
in
sensor
side
of
connector
.
If
element
is
electri-
cally
open
(no
continuity),
replace
sensor
.
NOTE-
The
oxygen
sensor
heater
relay
is
mounted
in
the
main
power
distributfon
box
in
the
left
rear
of
the
engine
com-
partment
.
Refer
to
Fig
.
6
.
The
heater
relay
is
energized
wíth
positive
(+)
battery
voltage
from
the
main
relayanda
switched
ground
from
the
ECM
.
See
Electrical
Wir-
ing
Diagrams
.
"
Oxygen
sensor
to
exhaust
pipe
...
..
55
Nm
(41
ft-Ib)
"
System
pressure-created
by
the
fuel
pump
and
main-
tained
by
the
pressure
regulator
.
"
Fuel
delivery
volume-created
by
the
fuel
pump
and
af-
fected
by
restrictions,
suchasclogged
fuel
filter
.
"
Residual
pressure-the
pressure
maintained
in
the
closed
system
after
the
engine
and
fuel
pump
are
shut
off
.
Procedures
for
measuring
the
first
two
quantities
arede-
scribed
in
160
Fuel
Tank
and
Fuel
Pump
.
Residual
fuel
pres-
sure
is
checked
using
the
procedure
detailed
later
in
this
group
.
Operating
fuel
pump
fortests
To
operate
the
fuel
pump
for
testing
purposes
without
hav-
íng
to
runthe
engine,
the
fuel
pump
relay
can
be
bypassed
to
power
the
pump
directly
.
Fuel
pump
relay
location
is
shown
in
Fig
.
6
.
5
.
¡f
oxygen
sensor
doesn't
produce
a
fluctuating
voltage
To
runthe
fuel
pump,
remove
the
fuel
pump
relay
and
con-
and
preheater
circuit
is
OK,
replace
sensor
.
nect
the
socket
for
relayterminal
30
to
the
socket
for
relay
ter-
mina¡
87
with
a
fused
jumper
wire
.
After
completing
the
tests,
NOTE-
remove
the
jumper
wire
.
If
not
already
applied,
coat
the
oxygen
sensor
threads
with
an
anti-seize
compound
before
installation
.
Do
not
CAUTION-
getthe
compound
on
the
sensor
tip
.
"
Relay
locations
may
vary
.
Use
care
when
identi-
fying
relays
and
making
electrical
checks
at
the
fuselrelay
panel
.
See
610
Electrical
Compo
Tightening
Torque
nent
Locations
for
additional
relay
information
.
"
The
fuel
pump
relay
has
a
1
.5
mm2
red
wire
at
ter-
minal
30
in
the
relay
socket
.
Terminal
87
has
a
1
.5
mm
2
greenlviolet
wire
.
See
Electrical
Wiring
Di-
agrams
for
additional
wiring
information
.
NOTE-
Thejumper
wire
should
be
1.5
mm2
(14
ga
.)
and
in-
clude
an
in-line
tuse
holder
with
a15
amp
tuse
.
To
avoid
fuselrelay
panel
damage
from
repeated
connect-
ing
and
disconnecting,
also
include
a
toggle
switch
.
A
heavy-duty
jumper,
BMW
tool
no
.
61
3
050,
is
also
available
from
an
authorized
BMW
dealer
.
FUEL
DELIVERYTESTS
130-
1
2
FUEL
INJECTION
Fig
.
14
.
Voitmeter
connected
across
fuel
injector
connector
with
en-
gine
running
.
M50
engine
shown
.
2
.
If
no
signal
is
present,
check
for
b+
power
to
injectors
.
There
should
be
battery
voltage
(+)
at
red/whitewire
of
each
injector
connector
with
the
ignition
key
on
.
If
volt-
age
is
not
present,
check
main
relay
output
.
Injector
b+
power
comes
from
main
relay
(terminal
87)
.
NOTE-
If
there
is
positive
(+)
batteryvoltage
at
injectors
but
there
was
no
pulsedresponse
at
voltmeter,
check
the
wire(s)
from
the
ECM
to
the
injectors
.
If
no
wiring
faults
can
be
found,
the
pulsed
ground
signal
from
the
control
module
may
be
missing
.
Check
the
outputs
from
the
ECM
.
Fuel
rail
and
injectors,
replacing
1
.
Disconnect
negative
(-)
battery
cable
.
CAUTION-
Prior
to
disconnectiog
the
battery,
read
the
battery
disconnection
cautions
given
at
the
tront
of
this
manual
on
page
viii
.
2
.
M42
and
M50/S50US
engines
:
Working
at
end
offuel
rail,
disconnect
small
vacuum
hose
from
fuel
pressure
regulator
.
3
.
M50/S50US
engines
:
Remove
two
nuts
from
injector
duct
.
Carefully
pry
injector
wiring
duct
off
ínjectors
.
See
Fig
.
15
.
4
.
On
4-cylinder
cars,
remove
upper
intake
manifold
to
ac-
cess
the
fuel-rail
and
injectors
.
See
113
Cylinder
Head
Removal
and
Installation
.
FUELDELIVERYTESTS
Fig
.
15
.
Injector
wiring
harness
duct
being
removed
from
M50
engine
.
NOTE
-
Late-model
M42
and
all
M44
fuel
injectors
are
afr-
shrouded
.
See
Fig
.
16
.
When
removing
the
fuel
rail
it
is
necessary
to
remove
the
air
shroud
feeder
hose
from
the
intake
manifold
ducting
.
Fig
.
16
.
Cutaway
view
of
fuelinjector
usedon
M42
or
M44
engine
.
5
.
Disconnect
fuel
supply
line
and
fuel
retum
line
from
fuel
rail
ends
.
WARNING
-
"
Clamp
off
the
fuel
lines
and
then
wrapa
clean
shop
towei
around
the
lines
before
removing
them
.
Residual
fuel
pressure
is
present
in
the
lines
.
"
Fuel
will
be
discharged
.
Do
not
disconnect
any
wires
that
could
cause
electrical
sparks
.
Do
not
smoke
or
worknear
heaters
or
other
fire
hazards
.
Keepan
approved
fire
extinguisher
handy
.
6
.
Remove
fuel
rail
mounting
bolts
.
See
Fig
.
17
.
0012504
Fig
.
17
.
Location
of
fuel
rail
mounting
bolts
(A)
and
fuel
inlet
and
return
lines
(B)
on
M44
engine
.
Upper
manifold
has
been
removed
.
7
.
Pull
upon
fuel
rail
and
remove
injector
rail
with
injec-tors
.
Remove
individualinjectors
by
removing
injector
retaining
clip
and
pullinginjector
from
rail
.
See
Fig
.
18
.
Fig
.
18
.
Pry
retaining
clip
from
injector
(1),
then
pull
injector
from
rail
(2)
.
8
.
Installation
is
reverse
of
removal
.
Tightening
Torque
"
Fuel
rail
to
cylinder
head
..
.
..
..
...
10
Nm
(89
in-lb)
FUEL
INJECTION
130-
1
3
Fuel
Pressure
Regulator
The
fuel
pressure
regulator
location
on
E36
models
is
mounted
in
one
of
two
locations
:
Fuel
Pressure
Regulator
Location
"
4-cylinder
engines
1992-
January
1997
............
...
..
on
fuel
rail
January
1997-
on
...............
..
...
under
car
"
6-cylinderengines
1992-1995
.
.
...
...
.
...........
...
..
on
fuel
rail
1996-on
..
.
..
................
...
...
undercar
Fuel
pressure
regulator,
replacing
(fuel
rail
mount)
WARNING
-
Fuel
will
be
discharged
.
Do
not
disconnect
any
wires
that
could
cause
electrícal
sparks
.
Do
not
smoke
or
work
near
heaters
or
other
fire
hazards
.
Keepan
approved
fire
extinguisher
handy
.
9
.
On
6-cylinder
engines,
remove
top
engine
covers
.
Re-
move
fuel
rail
mounting
bolts
and
lift
up
fuel
rail
.
1
.
Disconnect
vacuum
hose
from
fuel
pressure
regulator
.
See
Fig
.
19
.
"
Fit
new
O-rings
when
installing
injectors
.
For
ease
of
installation,
lightly
lubricate
O-rings
with
SAE
90
or
0012732
equivalent
lubricant
.
Fig
.
19
.
Fuel
pressure
regulator
(arrow)
on
M42
engine
.
Vacuum
hose
"
Check
that
injector
electrical
connections
are
correctly
shown
at
A
.
fitted
and
that
injectors
are
fully
seated
prior
to
install-
ing
fuel
rail
mounting
bolts
.
2
.
Remove
bolt
from
regulator
clamp
.
Remove
clamp
.
Note
"
Replace
wire
ties
.
installed
direction
of
regulator
to
fuel
rail
.
3
.
Wrap
a
shop
rag
around
regulator,
then
remove
regula-
tor
from
fuel
rail
by
pulling
straight
out
.
FUELDELIVERYTESTS
130-
1
4
FUEL
INJECTION
NOTE-
Be
sure
to
retrieve
thrust
washer
behind
fuel
pressure
regulator
on
6-cylinder
engine
.
4
.
Installation
is
reverse
of
removal
.
Replace
O-rings
.
Fuel
pressure
regulator,
replacing
(under
car
mount)
WARNING
-
Fuel
will
be
discharged
.
Do
not
disconnect
any
wires
that
could
cause
electrical
sparks
.
Do
not
smoke
or
work
near
heaters
or
other
fire
hazards
.
Keep
an
approved
tire
extinguisher
handy
.
On
late
4-
and
6-cylinder
cars,
the
fuel
pressure
regulator
is
mounted
beneath
the
left
sideof
the
car,
under
a
protective
cover
.
See
Fig
.
20
.
0012726
Fig
.
20
.
Fuel
pressure
regulatorlocation
underneath
car
(arrow)
.
Vac-
uum
hose
to
regulator
is
shown
at
A
.
(Protective
cover
has
been
removed
.)
5
.
Installation
is
reverse
of
removal
.
Replace
O-rings
.
BOSCH
DME
Ml
.
7
COMPONENT
TESTS
AND
REPAIRS
BOSCH
DME
Ml
.7
COMPONENT
TESTS
AND
REPAIRS
CA
UTION-
Use
only
a
digital
multimeter
when
testing
compo-
nents
and
wiring
.
Use
of
an
analog
VOM
may
damage
the
engine
control
module
.
4-cylinder
cars
with
M42
engines(1992
to
1995)use
the
Bosch
DME
M1
.7
fuel
injection
system
.
Electrical
tests
of
the
main
and
fuel
pump
relays
and
the
DME
engine
control
module
(ECM)
are
covered
earlier
in
this
section
.
Fuel
pump
tests
arecovered
in
160
Fuel
Tank
and
Fuel
Pump
.
Air
flow
sensor,
testing
and
replacing
DME
M1
.7
fuel
injection
uses
a
volume
air
flow
type
sensor
with
integrated
intake
air
temperature
(IAT)
sensor
.
The
sen-
sor
provides
a
varyingvoltage
signal
to
the
ECM
based
on
the
position
of
the
air
vane
.
As
the
vane
doorswings
open
thepo-
tentiometer
increases
the
voltage
signal
to
the
ECM
.
The
IATsensor
adapts
theoutput
signal
to
the
ECM
based
on
intake
air
temperature
.
1
.
Check
ECM
reference
voltage
to
sensor
:
"
Peel
back
rubber
boot
from
air
flow
sensor
harness
connector
.
"
Turn
ignition
keyon
.
"
Check
for
5
volts
between
terminal
1
of
harness
con-
nector
and
ground
.
See
Fig
.
21
.
"
Turn
ignition
key
off
.
"
If
voltage
is
not
present
or
incorrect,
check
wring
from
ECM
and
check
air
flow
sensor
reference
voltage
out-
put
at
ECM
.
See
Table
h
.
1
.
Working
under
car
below
driver's
seat,
remove
protec-
tive
cover
from
below
fuel
pressure
regulator
.
"
Remove
intake
air
bootfrom
sensor
.
2
.
Remove
vacuum
hosefrom
fuel
pressure
regulator
.
"
Connect
a
digital
multimeter
(ohms)
across
terminais
1
and
2
.
Swing
air
flow
sensor
vane
through
its
travel
3
.
Remove
locking
clip
retaining
fuel
pressure
regulator
.
range
.
Resistance
should
change
steadily
without
in-
terruption
.
4
.
Wrap
a
shop
rag
around
regulator,
then
remove
regula-
"
If
any
faults
are
found,
the
air
flow
sensor
is
faulty
and
tor
from
213
way
valve
by
pullingstraight
out
.
should
be
replaced
.
2
.
Check
air
flow
sensor
potentiometer
:
3
.
Check
IAT
sensor
resistance
:
"
With
harness
connector
disconnected
at
air
flow
sen-
sor,
check
resistance
across
sensor
terminais
4
and
5
of
air
flow
sensor
.
Compare
tests
results
to
values
in
Table
d
given
later
.
If
any
faults
are
found,
the
air
flow
sensor
should
be
replaced
.