Page 98 of 759
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
.
Page 104 of 759
117-
8
CAMSHAFT
TIMING
CHAIN
Fig
.
18
.
Oil
baffle'
cover
being
removed
.
Fig
.
19
.
Upper
timing
chaincover
mounting
nuts
(arrows)
on
pre-
VANOS
engines
.
16
.
Secure
crankshaft
hub
to
prevent
crankshaft
from
turn-
ing
.
Using
a
socket,
loosen
but
do
not
remove
crank-
shaft
hub
center
bolt
.
CAMSHAFT
TIMINGCHAINS,
6-CYLINDER
Fig
.
20
.
Engine
set
to
approximate
TDC
.
Camshaft
lobes
face
in
and
arrows
on
sprockets
point
up
(arrows)
.
B1
1123a
Fig
.
21
.
O/
T
(0°TDC)
mark
on
vibration
damper
aligned
with
boss
on
timing
chain
cover
(arrow)
.
17
.
Lock
crankshaft
in
TDC
position
by
inserting
BMW
spe-
cial
tool
no
.
11
2
300
through
transmissionbellhousing
and
into
hole
in
flywheelor
drive
plate
.
See
Fig
.
23
.
NOTE-
Confirm
that
the
locking
tool
has
been
correctly
in-
stalled
by
trying
to
rotate
the
crankshaft
.
NOTE-
The
crankshaft
hub
center
bolt
is
tightened
to
a
torque
18
.
Remove
crankshaft
hub
bolt
and
washer
.
Remove
hub
of
410
Nm
(300
ft-ib)
.
A
heavy
duty
holding
device,
from
crankshaft
.
suchas
BMW
special
tool
no
.
112150,
should
be
used
to
hold
the
crankshaft
hub
stationary
while
the
bolt
is
19
.
Remove
cylinder
head
cover
mounting
studs
at
rear
of
loosened
.
Use
a
heavy
duty
314-inch
drive
socket
and
head
.
Lock
camshafts
at
TDC
using
BMW
special
tool
breaker
bar
to
break
the
bolt
free
.
no
.
11
3
240
at
ends
of
camshafts
.
See
Fig
.
24
.
.
Page 130 of 759
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
.