117-2
CAMSHAFT
TIMING
CHAIN
CAMSHAFT
TIMING
CHAIN,
4-CYLINDER
Special
BMW
service
tools
are
needed
for
timing
chain
re-
moval
and
installation
procedures
.
The
special
tools
assure
proper
timing
of
the
valvetrain
.
Precíse
marks
to
setthe
timing
on
the
camshafts
are
not
provided
for
reassembly
.
Read
the
procedures
through
before
beginning
the
job
.
CAUTION-
lf
the
camshaftsare
not
properly
timed,
the
pis-
tons
can
contact
thevalves
.
Camshaft
timing
chain,
removing
(4-cylinder
engines)
U0119-
Fig
.
3
.
Upper
timing
chain
covermounting
bolts(arrows)
.
Thermo-
1
.
Disconnect
negative
(-)cablefrom
battery
.
stat
housing
shown
removed
.
Cylinder
ídentification
sensor
(A)
also
shown
.
CAUTION-
Prior
to
disconnecting
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
viii
.
2
.
Drain
engine
coolant
.
Drain
engine
block
byremoving
block
drain
.
Remove
radiator
cooling
fan
shroud
and
cooling
fan
.
See
170
Radiator
and
Cooling
System
..
WARNING
-
Allow
the
engine
to
cool
before
openingor
draining
the
cooling
system
.
CA
UTION-
On
cars
with
viscous-type
fan
clutch,
fan
has
left
hand
threads
.
NOTE-
The
block
drain
plug
is
located
on
the
exhaust
sideof
the
engine,
below
cylinder
no
.
4
.
3
.
Remove
cylinder
head
cover
.
See
113
Cylinder
HeadRemoval
and
Installation
.
NOTE-
Make
note
of
the
arrangement
of
the
rubber
insulators
when
removing
the
cylinder
head
cover
mounting
belts
.
4
.
Loosen
sparkplugs
.
See
120
Ignition
System
.
5
.
Disconnect
coolant
hoses
from
thermostat
housingon
front
of
cylinder
head
.
Unbolt
thermostat
housing
from
cylinder
head
.
6
.
Remove
cylinder
identification
sensor
from
upper
tim-
ing
chain
cover
.
Remove
upper
timing
chain
cover
.
See
Fig
.
3
.
CAMSHAFT
TIMING
CHAIN,
4-CYLINDER
7
.
Set
engine
to
approximate
TDC
by
rotating
in
normal
operating
direction
until
camshaft
lobes
at
cylinder
no
.
1
are
facing
up
and
toward
each
other
.
See
Fig
.
4
.
0011998
Fig
.
4
.
Engine
set
to
approximate
TDC
.
Cylinder
no
.
1
camshaft
lobes
face
in
and
sprocket
arrows
point
up
(arrows)
.
8
.
Remove
air
conditioning
drive
belt
.
Loosenand
push
aside
air
conditioning
compressor
.
Remove
air
condi-
tioning
compressor
mounting
bracket
.
See
640
Heat-
ing
and
Air
Conditioning
.
9
.
Remove
engine
drive
belts
and
coolant
pump
pulley
.
See
020
Maintenance
Program
.
10
.
Secure
crankshaft
vibration
damper
to
prevent
crank-
shaft
from
turning
.
Using
a
socket,
loosen
vibration
damper
hub
center
bolt
.
117-
4
CAMSHAFT
TIMING
CHAIN
15
.
Remove
mounting
bolts
from
left
and
right
camshaft
4
.
Insta¡¡
and
hand-tighten
sprocket
mounting
bolts
.
sprockets
.
16
.
On
M42
engines,
remove
upper
bolt
on
right
side
chainguide
and
unbolt
lower
timing
chainguide
below
crank-
shaft
.
17
.
Remove
camshaft
sprockets
from
camshafts
together
with
chain
and
crankshaft
sprocket
.
NoteWoodruffkey
when
removing
crankshaftsprocket
.
CA
UTION-
The
crankshaft
must
not
be
allowed
to
rotate
when
the
timing
chaín
is
removed
.
The
pistons
can
contact
the
valves
.
Camshaft
timing
chain,
installing
(4-cylinder
engines)
Inspectal¡
sprockets
for
wear
or
damage
.
Inspect
the
chain
guide
and
tensioner
rails
for
grooves
caused
by
chain
contact
.
Replace
any
partthat
is
worn
.
If
any
of
the
sprockets
are
worn,
the
chain
and
sprocketsare
replaced
asan
assembly
.
The
procedure
outlined
below
assumes
that
the
camshafts
and
the
crankshaft
arelocked
in
the
TDC
installation
positionwithspecial
tools
(shown
earlier
in
Fig
.
5
and
Fig
.
6)
.
1
.
Install
timing
chain
to
crankshaft
sprocket,
then
slide
sprocket
on
crankshaft
whílealigníng
woodruff
key
.
2
.
Place
camshaft
sprockets
on
chain,
then
place
sprock-
ets
oncamshafts
so
that
arrows
on
sprockets
point
up
and
elongatedholes
in
sprockets
are
centered
lo
tapped
holes
in
camshafts
.
See
Fig
.
9
.
.
I
Pa
-
s
~_
a
Ge
..
.
0012509
5
.
On
M42
engine
:
Install
lowerchainguide
.
6
.
On
M44
engine
:
Remove
allen-head
retaining
screw
at
left
chain-guide
.
Turn
slotted-head
of
adjusting
sleeve
so
that
sleeve
contacts
cylinder
head
.
Then
install
and
tighten'allen-head
screw
fully
.
See
Fig
.
10
.
Fig
.
10
.
Left
upper
chain
guide
adjusting
sleeve
(arrow)
.
Note
cam-
shaft
position
CAUTION-
Different
hydraulic
chaintensioners
were
used
duringmanufacture,
depending
onengíne
type
.
See
Fig
.
11
.
Note
that
the
late
style
tensioner
canbe
retrofitted
to
the
earlier
engíne,
so
be
sure
to
identify
the
versíon
of
tensioner
ínstalled
as
ínstal-
lation
instructions
vary
between
the
two
.
7
.
On
M42
engine
:
Disassemble
chain
tensioner
by
strik-
ing
outer
sleeve
against
a
solid
object
.
This
will
release
snap
ring
and
tensioner
will
separate
.
See
Fig
.
12
.
8
.
On
M42
engine
:
Clamp
chain
tensioner
piston
in
vice
(soft
jaws)
.
Slowly
compress
piston,
making
sure
de-
tent
ring
fits
into
taper
of
outer
sleeve
.
If
necessary,
press
ends
of
detent
ring
together
.
Slowly
continueFig
.
9
.
Camshaft
sprockets
correctly
installed
with
arrows
pointing
pressing
tensioner
together
until
snap
ring
audibly
upand
bores
centered
to
tapped
holes
(M44
engine)
.
clicks
into
outer
sleeve
.
Measure
overall
length
of
ten-
sionerto
confirm
correct
assembly
:
68
.5
mm
(2
.7
in
.)
.
3
.
On
M44
engine
:
Place
cylinder
position
sensor
plate
on
intake
camshaft
sprocket
so
that
arrowonsensor
plate
NOTE-
points
up
.
The
¡ate-style
tensioner
on
the
M44
engine
can
be
ret-rofittedto
the
M42
engíne
.
CAMSHAFT
TIMING
CHAIN,
4-CYLINDER
GENERAL
.
........
.
...........
.
.
.
.
.
.
.
120-1
Camshaft
Position
(CMP)
Sensor
....
.
.
.
...
120-6
Disabling
Ignition
System
.
.
.
.
.....
.
.
.
.
.
.
.
120-2
Camshaft
position
(CMP)
sensor,
replacing
Warnings
and
Cautions
.
.
.
.
.
.
.....
.
.
.
.
.
.
.
120-2
(4-cylinder
engine)
..
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
...
120-6
Camshaft
position
(CMP)
sensor,
replacing
IGNITION
SYSTEM
DIAGNOSTICS
.
.
.
.
.
.
120-3
(6-cylinder
engine)
..
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
120-7
Basic
Troubleshooting
Principles
...
.
.
.
.
.
.
.
120-3
Knock
sensors,
replacing
.
.
...
.
.
.
.
.
.
.
.
.
.
.
.
120-7
Ignition
Firing
Order
.....
.
...
.
.
.
.....
.
.
.
.120-7
IGNITION
SYSTEM
SERVICE
.
.........
.
120-3
Checking
for
Spark
..
.
.
.
.
.
.
.
.
.
.......
.
.
.
120-3
Ignition
coil,
testing
and
replacing
(4-cylinder
engine)
.
.
.
.
.
.
.
.
.
.
.........
.
120-3
Ignition
coil,
testing
and
replacing
(6-cylinder
engine)
.........
.
..........
120-4
Crankshaft
Positionlrpm
Sensor
.......
.
...
120-5
Crankshaft
position/rpm
sensor,
testing
and
replacing
(front
mounted)
.........
.
.
.
.
.
.
120-6
Crankshaft
position/rpm
sensor,replacing
(rear
mounted)
.....
.
.....
.
.....
.
.
.
.
.
.
120-6
GENERAL
Troubleshooting
and
testing
of
the
engine
management
system
should
be
carried
out
using
the
BMW
specialized
ser
This
repair
group
covers
repair
andcomponent
replace-
vice
tester
(scan
tool)
.
ment
information
for
the
ignition
system
.
All
engines
use
a
distributorless
ignition
system
with
indívid-
ual
ignitioncoils
for
each
cylinder
.
There
is
no
distributor
cap
NOTE-
or
ignition
rotor
.
Each
coil
can
be
selectively
controlled
by
the
"
Spark
plug
replacement
is
covered
in
020
Mainte-
engine
control
module
on
a
cylinder-by-cylinder
basis
.
On
later
nance
Program
.
systems,
knock
sensors
are
used
to
monitor
and
control
igni-
"
For
fuel
related
troubleshooting
and
testing,
see
130
tion
knock
(ping)
and
adjusttiming
accordingly
.
Fuel
lnjection
.
Ignition
timing
is
electronically
controlled
and
not
adjust-
All
engines
covered
by
this
manual
use
an
advanced
en-
able
.
The
engine
control
module
(ECM)
usesengine
load,
en-
gine
management
system
.
The
engine
management
system
gine
speed,
coolant
temperature,
and
intake
air
temperature
incorporates
on-board
diagnostics,
fuel
injection,
ignition
and
as
the
basic
inputs
for
timing
control
.
Knock
detection
is
also
other
advanced
engine
control
functions
.
an
input
to
the
control
module,
where
applicable
.
Table
a
.
Engine
Management
System
Variants
Engine
code
1
System
4-cylinder
M42
(1.8
I)
Bosch
DME
Ml
.7
M44
(1
.9
I)
Bosch
DME
M5
.2
(OBD
II)
6-cylinder
M50
1992
(2.5
I)
Bosch
DME
M8
.1
1993-1995
(2
.5
I)
Bosch
DME
M33
.1
M52
1996-1998
(2.8
I)
Siemens
MS
41
.1
(OBD
II)
1998
(2
.5
I)
Siemens
MS
41
.1
(013D
11)
S50US
(3.0
I)
Bosch
DME
M3
.3.1
S52US
(3.2
I)
Siemens
MS
41
.1
(OBD
II)
120
Ignition
System
IGNITION
SYSTEM
120-1
IGNITION
SYSTEM
SCHEMATICS
...
.
.
.
.120-7
TABLES
a
.
Engine
Management
System
Variants
......
120-1
b
.
Ignition
Coil
Resistance
(M42
engine)
......
120-4
c
.
Ignition
Coil
Resistance
(M44
engine)
......
120-4
d
.
Ignition
Coil
Resistance
(6-cylinder
engine)
..
.
.
.
.
.
.
.
.
.
.
.
.....
.
..
120-5
NOTE-
All
engines
coveredby
this
manual,
with
theexception
of
the
1992
M50,
incorporate
knocksensors
as
part
of
the
engine
management
system
.
The
initial
ignition
point
is
determined
by
the
crankshaft
po-
sition/rpm
sensor
during
cranking
.
Once
the
engine
is
run-
ning,
timing
is
continually
adjusted
based
on
operating
conditions
.
A
characteristic
ignition
map
is
shown
in
Fig
.
1
.
A
map
similar
to
the
one
shown
is
digitally
stored
in
the
engine
control
module
.
GENERAL
CAUTION
-
The
wiring
to
termina¡
15
(+)
of
the
coil(vía
the
ig-
nition
switch)
is
not
fuse
protected
.
Use
care
when
testíng
thiscircuit
.
4
.
Turn
ignition
off
.
5
.
Use
a
multimeter
to
test
coil
primary
resistanceat
coil
terminals
.
See
Table
d
.
Table
d
.
Ignition
Coil
Resistance
(6-cylinder
Engine)
Terminals
Resistance
(referto
Fig
.
4
.)
Coil
primary
1
1
(-)
and
15
(+)
X
0
.4-0
.8
ohms
Coil
secondary
l
N
.A
.
N
.A
.
6
.
Remove
coil
and
inspect
coil
housing
for
hairline
cracks
or
leaking
casting
material
.
See
Fig
.
7
.
A
leaky
ignition
coil
may
indícate
a
faulty
engine
control
module
(ECM)
.
Check
ECM
before
installing
a
new
coil
.
811004
Fig
.
7
.
Ignition
coil
being
removed
on
6-cylinder
engine
(M52
engine
shown)
.
CA
UTION-
"
Note
location
of
coil
ground
straps
before
coilre-
moval
;
reinstallin
the
same
location
.
"
When
replacing
ignition
coils,
ensure
that
the
re-
placement
coil(s)
are
from
the
same
manufactur-
er
containing
the
same
partlcode
numbers
.
If
individual
coils
with
the
correct
specifications
are
not
available,
all
coils
should
be
replaced
.
IGNITION
SYSTEM
120-
5
Crankshaft
Position/rpm
Sensor
If
the
engine
control
module
(ECM)
does
not
receive
a
crankshaft
position
signal
during
cranking,
the
engine
will
not
start
.
On
1992-1995(pre-OBD
II)
cars,
the
crankshaft
posi-
tion/rpm
sensor
is
mounted
on
the
front
engine
cover
and
reads
the
toothed
vibration
dampener
wheel
.
See
Fig
.
8
.
Fig
.
8
.
Crankshaft
position/rpm
sensor
mounted
at
front
of
engine
on
1992-1995
cars
.
(arrow)
.
On
1996
and
latee
cars
(OBD
II
compliant),
the
crankshaft
position/rpm
sensor
is
mounted
in
the
left
rear
side
of
the
cyl-
inderblock
.
The
sensor
reads
a
toothed
wheel
mounted
to
the
end
of
the
crankshaft
.
See
Fig
.
9
.
Fig
.
9
.
Crankshaft
position/rpm
sensor
toothed
wheel
mounted
to
rear
of
crankshaft
OBD
II
compliant
cars
.
The
sensor
is
mounted
in
the
left
rear
side
of
the
cylinder
block
.
IGNITION
SYSTEM
SERVICE
120-
6
IGNITION
SYSTEM
Crankshaft
position/rpm
sensor,
testing
and
replacing
(front
mounted)
1
.
Disconnect
sensor
harness
connector
.
2
.
Using
a
digital
multimeter,
check
resistance
between
terminals
1
and
2
in
connector
.
See
Fig
.
10
.
n1
n2n3
Fig
.
10
.
Crankshaft
position/rpm
sensorconnector
.
Crankshaft
positionlrpm
sensor
specifications
"
Coil
resistance
(approx
.)
terminais
1
and
2
....
.
..
...
....
1280
±
10%
ohms
"
Air
gap
(sensor
distance
from
toothed
wheel)
..
.
.
........
.1
.0
±
0
.3
mm
(0
.04
±
0
.01
in
.)
3
.
If
the
resistance
is
not
correct,
the
sensor
is
faulty
and
should
be
replaced
.
NOTE
-
When
installing
the
new
sensor,
be
sure
thewiring
Is
rerouted
in
the
same
orientation
.
Secure
the
sensor
us-
ing
new
wire
ties
.
Tightening
Torque
"
Crankshaft
position/rpm
sensor
to
mounting
bracket
.........
.
.
5
t
1
Nm
(62
t
9
in-lb)
Crankshaft
position/rpm
sensor,
4
.
Installation
is
reverse
of
removal
.
Use
a
new
O-ring
replacing
(rear
mounted)
when
installing
sensor
.
Be
sure
wiring
is
rerouted
in
same
orientation
.
1
.
Disconnect
sensor
harness
connector
.
6502AGN56
2
.
Locatesensor
on
rear
left
sideof
cylinder
block
.
Re-
move
sensormounting
bolt
and
remove
sensorfrom
cylinder
block
.
IGNITION
SYSTEM
SERVICE
3
.
Installation
is
reverse
of
removal
.
Use
a
new
O-ring
when
installing
sensor
.
Be
sure
wiring
is
rerouted
in
same
orientation
.
Secure
sensor
using
new
wire
ties
.
NOTE-
It
may
be
easier
to
remove
the
sensor
working
from
the
underside
of
the
vehicle
.
Camshaft
Position
(CMP)
Sensor
The
camshaft
position
(CMP)
sensor
is
usedby
the
engine
management
system
for
sequential
fuel
injection
and
knock
control
.
Camshaft
position
(CMP)
sensor,
replacing
(4-cylinder
engine)
1
.
Remove
CMP
sensorfromtop
timing
cover,
just
above
coolantthermostat
housing
.
See
Fig
.
11
.
Fig
.
11
.
Camshaft
position
sensor
mounting
bolt
(arrow)
.
M42
engine
shown
.
2
.
On
M42
engines
to
9/93
:
Disconnect
CMP
harness
plug
just
above
oil
filter
housing
.
3
.
On
M42
from9/93
and
all
M44
engines
:
Remove
upper
intake
manifold
as
described
in
113
Cylinder
Head
Re-
moval
and
Installation
.
Then
unplug
CMP
sensor
har-
ness
connector
below
manifold
.
120-8
IGNITION
SYSTEM
1
1
.0
GN
1
.0
Gl
.0
GN
I
Ign
coil
1
.0
GN
.
Tti
%ti
r,
_%ti
_
_
ice_
I
25
52
5524
51
54
56
I
Power
input
power
input
t
U
Engine
Control
Module
(Bosch
DME
Ml
.7)
II
Powerinput
Mainrelaycontrol
I
15
42
43
16442868
67
34
6
26
27
1
-----
__
V
_
--
_
~
8K
.35
BK
.35
13,1
1
.35
YE
1
.35
BK35
VE
.35
3
cyl
.1
1
11
E
S
2
1
.0
BR
2
.5
BR
Ign
.
coil
cyl
.
3
II
Ign
.
coil
Ign
.
coil
3
cyI
.
2
1
Y
_
Y
2
k
3
cyl
.
4
IGNITION
SYSTEM
SCHEMATICS
Battery
voltage
in
run
or
start
(
vía
ignition
switchterminal
15)
WIRING
COLOR
CODE
4
.0
GN
1
.0
BR'V
.
Camshaft
Knock
Sensor
Knock
Sensor
Position
(cyl
.1-2)
(cyl
.3-4)
Sensor
Fig
.
13
.
Bosch
DME
M1
.7
ignition
system
circuit
for
M42
engine
.
Ground
(RH
rearof
engine
compartment,
rear
of
shock
tower)
N[INS
Crankshaftlrpm
Position
Sensor
Battery
voltage
in
run
or
start
(vía
main
relay
terminal
87)
Ground
(RH
rearof
engine
compartment,
rearof
shock
tower)
5GN
BK
-
BLACK
BR
"
BROWN
RD
-
RED
YL-
YELLOW
GN
-
GREEN
BL
-
BLUE
VI
-
VIOLET
GY
-
GREY
WT
-
WHITE
PK
-
PINK
Warning
:
Lethal
voltagepresent
Battery
voltage
at
all
times
to
Main
relay
(terminal
85)
'Y
Y
---------------------
0013087
^1
.5WT
^1
.5RD
^1
.5YL
^1
.5BL
r
--__
____-
__-_
___-_
-___-_____--__--
-____-___
____-
i
26
g
5022
23
54
5
I
Power
input
power
input
I
Engine
Control
Module
(Bosch
DME
M5
.2)
I
I
grounds
I
P
owerinput
Main
relay
control
I
70
40
71
21
2078
34
55
626
27
----------------------
-
---------
-
--
-
------------
-
-----------
.,
v
1
1
.1
v
`
1
35BK
35BK
2
(
1Y
¡3
194
Knock
Sensor
Knock
Sensor
(cyl
.1-2)
(cyl
.3-4)
Frommain
relay
terminal
87
(battery
voltage
in
run
or
start
Battery
voltage
in
run
or
start
(
via
ignition
switch
Warnin
terminal
15)
Lethal
óltage
WIRING
present
COLOR
CODE
2
.5
GN
'
1
.0
YL
/
1
.0
BL
/
1
.0
RDNJT
.35
BK
/
/
.35
BK
Camshaft
Position
Sensor
-_
Fig
.
14
.
Bosch
DME
M5
.2
ignition
system
circuit
for
M44
engine
.
Ground
(RH
rear
of
engine
compartment,
rearof
shock
tower)
Crankshaftirpm
Position
Sensor
IGNITION
SYSTEM
120-9
Batteryvoltage
Battery
voltage
in
run
or
start
in
run
or
start
(via
main
relay
(
via
ignition
switch
terminal
87)
terminal
15)
BK
-
BLACX
BR
-
BROWN
RD
-
RED
YL
-
YELLOW
GN
-
GREEN
BL
-
BLUE
VI
-
VIOLET
GY
-
GREY
WT
-
WHITE
PK
-
PINK
Battery
voltage
at
all
times
to
Main
relay
(terminal
85)
Ground
(RH
rear
of
engine
compartment,
rearof
shock
tower)
0012721
lGNITION
SYSTEM
SCHEMATlCS
120-10
IGNITION
SYSTEM
Ground
(rear
of
engine
compartment,
rear
of
passenger
side
shock
tower)
.!
BK
Camshaft
Position
Sensor
IGNITION
SYSTEM
SCHEMATICS
Batteryvoltage
in
run
or
start
(
via
ignition
switch
terminal
15)
---------------------------------------------------------
55
S5154
i
power
input
Power
input
1
DME
Control
Module(Bosch
DME
M3
.1)
Ground
-
(RHrear
of
enginecompartment,
rearof
passenger
side
shock
tower)
Fig
.
15
.
Bosch
DME
M3
.1
usedon1992
M50
engines(without
VANOS)
.
.EBK
Crankshaftlrpm
Position
Sensor
5GN
1.0
RD
Ground
(RH
rearof
enginecompartment,
rear
of
passenger
side
shock
tower)
WIRING
COLOR
CODE
BK
-
BLACK
BR
-
BROWN
RD
-
RED
YL
-
YELLOWGN
-
GREEN
BL
-
BLUE
VI-
VIOLET
GY
"
GREY
WT
"
WHITE
PK
-
PINK
Batteryvoltage
in
run
or
start
(
via
main
relay
Battery
voltage
terminal
87)
in
run
or
start
(via
ignition
switch
terminal
15)
11508
1
grounds
Main
rela
control
P
ower
Input
Y
I
-
34
---"--
6
26
27
1
Battery
voltage
at
all
times
to
Main
relay
(terminal
85)