Fig
.
11
.
BMW
special
tool
no
.
11
2300
installed
through
bellhousin
and
finto
flywheel
(arrow)
tolockcrankshaft
at
TDC
.
Fig
.
12
.
BMW
special
tool
no
.
11
3
240
installed
on
rear
of
camshafts
tohold
them
at
TDC
.
(M44
engine
shown
.
Other
engínes
are
similar
.)
CAUTION-
The
camshafts
must
be
locked
in
the
TDC
position
using
the
special
service
tool,
or
equivalent,
be-
fore
removing
the
timing
chaín
.
The
tool
holds
the
camshafts
parallel
to
each
other
and
perpendicu-
larto
the
valve
covergasket
surface
.
CYLINDER
HEAD
REMOVAL
AND
INSTALLATION
113-5
6011966
28
.
Remove
hydraulic
chain
tensiones
from
right
side
ofcyl-
inder
head
.
See
Fig
.
13
.
Fig
.
13
.
Hydraulic
chain
tensioner
(arrow)
.
NOTE-
It
is
not
necessary
to
remove
the
cam
sprockets
from
the
chainuntessthese
parts
are
being
reptaced
.
tire
tie
each
sprocket
to
the
chain
to
keep
the
sprockets
timed
to
each
other
.
Keeping
the
sprockets
timed
will
símplífy
instaftation
.
uu
11999
Fig
.
14
.
Chainguide
and
guide
adjusting
sleeve
(arrow)
.
Allen-head
retaining
screwhasbeen
removed
.
Use
slotted
screwdriver
to
loosen
adjusting
sleeve
.
29
.
Remove
mounting
bolts
from
left
and
right
camshaft
sprockets
.
Then
remove
camshaft
sprockets
from
cam-
_
Cylinder
head
assembly,
removing
shafts
.
On
M44
engines,
note
orientation
of
sensor
31
.
Remove
crankshaft
locking
tool
(BMW
special
tool
no
.
wheel
.
11
2
300)
.
Usingthe
crankshaft
vibration
damper
bolt,
30
.
Remove
upper
bolt
from
left
chainguide
.
Loosen
chain
turn
engine
opposite
its
normal
direction
of
rotation
guide
adjusting
sleeve
approximately
two
turns
.
See
(counterclockwise
asviewed
from
the
front)
approxi
Fig
.
14
.
mately
45°
.
This
prevents
accidental
contact
between
valves
and
pistons
during
installation
.
CYLINDER
HEAD,
4-CYLINDER
113-14
CYLINDER
HEAD
REMOVAL
AND
INSTALLATION
29
.
Remove
mounting
nuts
from
front
of
exhaustcamshaft
sprocket
.
Remove
secondary
sprockets
together
with
timing
chain
from
front
of
camshafts
.
CAUTION-
The
crankshaft
must
not
be
allowed
to
rotate
once
the
camshaft
timing
chain
is
removed
.
The
pistons
can
contact
thevalves
.
NOTE-
Do
not
remove
the
sprockets
from
the
chain
unless
these
parts
are
being
replaced
.
Wire
tie
each
sprocket
to
the
chain
to
keep
the
sprockets
timed
to
each
other
.
30
.
Unbolt
secondary
timing
chain
tensioner
from
top
of
cylinder
head
.
31
.
Remove
primary
timing
chaintensioner
from
side
of
cylinder
head
.
See
Fig
.
37
.
Fig
.
37
.
Primary
timing
chain
tensioner
(arrow)
.
WARNING
-
Remove
tensioner
slowly-¡t
ís
under
spring
pres-
sure
.
32
.
Remove
timing
chainguíde
(Tono
E8
socket)
.
See
Fig
.
38
.
33
.
Lift
primary
chain
sprocket
off
exhaust
camshaft
.
Re-
move
sprocket
from
chain
.
Suspend
chainusing
stiff
wire
.
Cylinder
head
assembly,
removing
34
.
Remove
two
mounting
bolts
holding
cylinder
head
to
lower
timing
chaincover
(Torx
E8
socket)
.
See
Fig
.
39
.
CYLINDER
HEAD,
6-CYLINDER
Fig
.
38
.
Timing
chain
guide
mounting
bolts
(arrows)
.
M50
engine
shown
.
Fig
.
39
.
Cylinder
head-to-timing
chain
covermounting
boits(arrows)
.
(Bolt
A
also
retains
secondary
chain
tensioner
.)
35
.
Using
BMMI
special
tool
no
.
11
2
250
or
an
equivalent
tool,
loosen
cylinder
head
bolts
in
several
stages
.
See
Fig
.
40
.
Discard
head
boits
.
CAUTION-
Torx-type
cylinder
head
bolts
should
not
be
re-
used
.
Theyare
stretch-type
bolts
and
must
atwaysbe
replaced
whenever
loosened
.
NOTE-
Cylinder
head,
installing
(6-cylinder
engine)
CAUTION-
If
the
camshafts
were
removed
and
installed
while
the
cylinder
head
was
off,
a
minimum
waiting
time
is
required
after
ínstalling
the
camshafts
.
When
the
camshaftsareremoved,
the
hydraullc
lifters
can
expand
.
This
expansion
can
cause
increased
valve
lift
when
the
camshafts
are
bolted
down,
re-
sulting
in
open
valves
.
Cylinder
head
installation
waiting
times
"
68°F
(20°C)
and
higher
.
.
.
..
..........
10
minutes
"
50-68°F
(10-20°C)
........
..
.........
30
minutes
"
32-50°F
(0-10
°C)
.........
...
........
75
minutes
CYLINDER
HEAD
REMOVAL
AND
INSTALLATION
113-
1
5
1
.
Clean
cylinder
head
and
gasket
surfaces
of
cylinder
block
and
al¡
timing
chain
covers
.
"
Remove
all
foreign
matter
and
any
¡¡quid
from
bolt
holes,
then
clean
with
a
thread
chaser
.
CA
UTION-
Do
not
use
ametal
scraper
or
wire
brush
to
clean
the
aluminum
cylinder
head
or
pistons
.
If
neces-
sary,
use
a
hard
wooden
or
plastic
scraper
.
Also
available
are
abrasive
discs
to
be
used
in
conjunc-
tion
with
an
electric
drill
.
Be
sure
to
use
the
correct
disc
for
the
typeof
metal
being
cleaned
.
2
.
Check
gasket
surface
of
cylinder
head
and
cylinder
block
for
warpage
using
a
straight
edge
.
NOTE-
Fig
.
40
.
Cylinder
head
bolt
loosening
sequence
.
If
the
cylinder
head
has
been
machined,a
special
0
.3
mm
thickergasketshould
be
installed
.
The
thickergas-
ket
is
available
from
an
authorized
BMW
dealer
.
BMW
special
tool
no
.
112250
is
a
thin-walled
Torx
E12
socket
wíth
anextended
reach
.
The
cylinder
head
bolts
3
.
Place
new
cylinder
head
gasket
on
cylinder
block
.
are
recessed
finto
the
head
below
the
camshaft
towers
Check
that
two
locating
dowels
are
correctly
positioned
wíth
liffle
working
space
.
in
block
and
arenot
damaged
.
36
.
Remove
crankshaft
locking
tool
(BMW
special
tool
no
.
NOTE-
11
2
300)
.
Using
the
crankshaft
vibration
damper
bolt,
The
word
"OBEN",
printed
on
the
gasket,
should
face
turn
engine
opposite
its
normal
direction
of
rotation
up
.Thecylinderheadgasketwillfitcorrectlyinonlyone
(counterclockwise
asviewed
from
the
front)
approxi-
orientation
.
mately
45°
.
This
prevents
accidental
contact
between
valves
and
pistons
during
installation
.
4
.
With
camshafts
locked
in
TDC
positionwith
BMW
spe-
cial
tools
as
described
earlier,
set
cylinder
head
in
po
NOTE-
sition,
guiding
primary
chain
through
cylinder
head
Guide
cam
chain
to
keep
it
from
jamming
when
turning
opening
.
the
crankshaft
.
CA
UTION-
"
The
camshafts
must
be
locked
in
the
MC
posi-
tion
at
the
rear
of
the
cylinder
head
with
BMW
special
tool
no
.
113240
before
installing
the
cyl-
inder
head
.
"
Make
sure
the
crankshaft,
which
had
been
rotat-
ed
approximately
45°
opposite
thedirection
of
engine
rotation,is
still
in
that
position
before
low-
ering
the
cylinder
head
into
position
.
5
.
Lightly
lubricate
new
cylinder
head
bolts
.
Loosely
instan
bolts
and
their
washers,
then
thread
them
in
until
they
are
finger
tight
.
Install
cylinder
head-to-lower
timing
chaincover
boitsfinger
tight
.
CAUTION-
Tonc-type
cylinder
head
bolts
should
not
be
re-
used
.
They
are
stretch-typebolts
and
must
always
be
replaced
whenever
loosened
.
CYLINDER
HEAD,
6-CYLINDER
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
117-
6
CAMSHAFT
TIMING
CHAIN
15
.
Insta¡¡
upper
timing
chaincover
:
17
.
Remove
crankshaft
locking
tool
from
transmission
bell-
"
Thoroughly
clean
profile
gasketgroove
and
all
sealing
housing
and
camshaft
locking
tool
from
rear
of
cylinder
surfaces
.
head
.
"
Applya
small
bead
ofsilicon
sealer
(3-Bond
1209®
or
equivalent)
to
upper
and
lower
joint
comers
where
18
.
Turn
engine
over
by
hand
in
direction
of
rotation
at
least
chaincover
meets
cylinder
head
.
two
full
rotations
.
Reinstall
camshaft
and
crankshaft
"
Insta¡¡
new
profile
gasket
to
groove
in
lowerchain
cover
.
locking
tools
to
check
engine
timing
.
Repeat
cam
timing
"
Protect
top
of
profile
gasket
using
thin
sheetmetal
procedure
if
tools
do
not
fit
easily
into
position
.
Remove
(BMW
special
tool
no
.
11
2
330
or
equivalent)
.
See
locking
tools
.
Fig
.
15
.
"
Attach
new
gaskets
to
cover
with
light
dabs
of
gasket
19
.
Install
cylinder
head
cover
as
described
in
113
Cylin-
sealant,
hold
gaskets
in
placeusing
cover
mounting
der
HeadRemoval
and
Installation
.
screws
.
"
Place
upper
timing
cover
into
position
.
Snug
down
al¡
NOTE-
screws,
without
tightening
.
Carefully
slide
out
sheet
OnM44
engines,
note
oil
supply
O-ring
and
replace
ff
metal
.
necessary
.
"
Temporarily
install
cylinder
head
cover
without
gasket
.
Insta¡¡
and
tighten
at
least
two
cylinder
head
cover
mounting
bolts
to
seat
upper
timing
chaincover
.
"
Tighten
all
upper
timing
cover
screws
.
Tightening
Torque
"
Remove
valve
cover
.
"
Cylinder
head
cover
to
cylinder
head
(M6
screws)
...
..
.
.
10
Nm
(89
ín-Ib)
-
CAMSHAFT
TIMING
CHAINS,
Fig
.
15
.
When
installing
upper
timing
chain
cover,
use
thin
sheetmetal
6-CYLINDER
(arrow)
to
protect
profile
gasket
when
installing
uppercover
.
Tightening
Torque
"
Upper
timing
chaincover
to
engine
block
or
cylinder
head
(M6
screws)
....
.
..
10
Nm
(89
in-lb)
16
.
Install
vibration
damper
while
aligning
woodruff
key
.
Hold
crankshaft
stationary
and
tighten
mounting
bolt
.
Tightening
Torques
I
CAUTION-
"
Pulley
to
vibration
damper
..
.
.
.
....
22
Nm
(17
ft-Ib)
lf
the
camshaftsare
not
properly
timed,
the
1
pis-
tons
can
contact
thevalves
.
"
Vibration
damper
tocrankshaft
M16
stretch
bolt
(always
replace)
.
330
Nm
(244
ft-Ib)
CAMSHAFT
TIMINGCHAINS,
6-CYLINDER
20
.
Installation
of
remaining
parts
is
reverse
of
removal
.
When
installing
thermostat,
make
sure
arrow
or
vent
hole
faces
up
.
Refill
cooling
system
as
described
in
170
Radiator
and
Cooling
System
.
Tighteníng
Torques
"
Coolant
drain
plug
to
cylinder
block
.
..
.
.
.
...
.
..
.....
25
Nm
(18
ft-Ib)
"
Radiator
cooling
fan
to
coolant
pump
.
..
.
...
...
..
.....
40
Nm
(30
ft-Ib)
"
Radiator
drain
screw
to
radiator
....
2
.5
Nm
(22
in-lb)
Camshaft
timing
chainremovalon
6-cylinder
engines
re-
quires
that
you
Rmove
the
engine
oil
pan
by
raising
the
en-
gine
and/or
lowering
the
front
suspension
crossmember
.
Special
BMW
service
tools
are
needed
for
timing
chain
re-
moval
and
installation
procedures
.
The
special
tools
assure
proper
timing
of
the
valvetrain
.
Precise
marks
to
setthe
timing
on
the
camshafts
arenot
provided
for
reassembly
.
Read
the
procedures
through
before
beginning
thejob
.
9)
B11126
Fig
.
29
.
Lower
timing
chain
cover
mounting
bolts
(arrows)
anddowel
locations
(A)
.
Coolant
hose
fitting
B
is
replaced
by
coolant
pipe
pressure
fitting
in
later
models
.
28
.
Remove
remaining
Torx
bolt
from
timing
chain
guide
.
See
Fig
.
30
.
Fig
.
30
.
Timing
chainguide
mounting
bolt(A)
.
CAMSHAFT
TIMING
CHAIN
117-
11
29
.
Lift
primary
chain
sprocket
off
exhaust
camshaft
and
remove
chain
.
NOTE-
"
If
any
of
the
sprockets
are
being
replaced
due
to
wear,
the
chain
should
also
be
replaced
.
"
If
the
crankshaft
sprocket
requires
replacement,
the
oil
pump
drive
sprocket
and
chain
must
be
removed
as
described
under
119
Lubrication
System
.
Camshaft
timing
chains,
installing
(6-cylinder
engines)
Inspecttiming
chainsprockets
.
Sprockets
that
haveworn
or
missing
teeth
should
be
replaced
.
Inspect
guide
rail
and
ten-
sioner
rail
for
deep
grooves
caused
by
chain
contact
.
Replace
any
parí
that
is
worn
.
The
procedure
outlined
below
assumes
that
the
camshafts
and
the
crankshaft
are
locked
in
the
TDC
installation
position
with
special
tools
(shown
earlier
in
Fig
.
23
and
Fig
.
24)
.
NOTE-
NOTE-
On
pre-VANOS
engines
(engines
built
up
to
8-92),
the
"
The
timing
chain
cover
can
be
removed
with
the
cool-
camshaft
locking
tool
(Fig
.
24)should
be
raised
upon
ant
pump
installed
.
eitherside
by
3mm
(use
feeler
gauge
or
dril¡
bits)
.
Be
sure
the
clamping
bolts
on
tool
are
loose
and
thecenter
"
Use
care
when
removing
the
chain
cover
from
the
of
the
tool
is
contacting
the
cylinder
head
surface
.
This
coolant
pipe
or
hose
at
the
rearof
the
cover
.
service
campaign
helps
improve
idle
characteristics
by
reducing
valve
overlap
.
1
.
Install
primary
timing
chain
to
crankshaft
sprocket
and
tie
it
up
through
cylinder
head
opening
.
2
.
Using
new
gaskets
and
coolant
pipe
O-ring
;
insta¡¡
low-
ertiming
chain
cover
:
"
Drive
timing
cover
doweis
inuntil
they
just
protrude
slightly
from
sealing
surface
.
"
Apply
a
small
bead
of
silicon
sealer
(3-Bond
1209
©
or
equivalent)
to
corners
of
cylinder
head
where
timing
cover
meets
cylinder
head
and
engine
block
.
"
Tap
cover
into
position
to
engage
doweis
.
"
Install
mounting
bolts
hand
tight,
including
two
outer
Torx
bolts
from
above
.
"
Drive
doweis
in
flush
to
front
of
cover
.
"
Tighten
cover
mounting
bolts
alternately
and
in
stages
.
Tightening
Torque
"
Lower
timing
cover
to
cylinder
block
M7
................
...
..
.
.....
15
Nm
(11
ft-Ib)
M8
.............
.
.
...
.........
20
Nm
(15
ft-Ib)
3
.
Insta¡¡
oil
pan
using
a
new
gasket
.
See
119
Lubrication
Systern
.
CAMSHAFT
TIMINGCHAINS,
6-CYLINDER
10
.
On
cars
built
up
to
3/95
:
Slide
control
unit
off
front
of
cylinder
head,
hand
turning
the
exhaust
sprocket
clock-
wise
(as
viewedfrom
front)
as
the
unit
is
removed
.
11
.
On
cars
built
3/95
and
latee
:
Use
a
spanner
toolto
ro-
tate
exhaust
sprocket
until
stop
on'
intake
sprocket
is
contacted
.
See
Fig
.
39
.
Then
slide
control
unit
off
front
of
cylinder
head
.
EMAÑ
0012514
Fig
.
39
.
On
VANOS
control
unit
withspringplate
(cars
built
3/95
and
later),
rotate
exhaust
camshaft
sprocket
clockwise
until
intake
NOTE-
camshaft
contacts
stop
.
BMW
special
tool11
5490shown
.
BMW
special
tool
no
.
113
'390
is
a
dummy
chain
ten-
sioner
and
simulates
the
function
of
thetensioner
.
VANOS
control
unit,
installing
CAUTION
-
Incorrect
installation
of
the
VANOS
control
may
result
in
damage
to
the
engine
valvetráin
.
1
.
Lock
camshafts
and
crankshaft
in
TDC
positionwith
BMW
special
tools
as
described
above
in
removal
pro-
cedure
.
CA
UTION-
The
camshafts
and
crankshaft
mustbe
locked
in
the
TDC
position
using
BMW
special
tools
no
.
11
2
300and
113
240
.
If
the
camshafts
and
crank-
shaft
are
not
at
TDC,
the
valves
can
contact
the
pistons
when
the
engine
is
turned
over
.
NOTE-
Be
sure
the
secondary
timing
chain
tensioner
is
locked
down
and
the
exhaustcamshaft
mounting
bolts
are
loosebefore
proceeding
.
2
.
Remove
primary
timing
chain
tensioner
from
side
of
cylinder
head
.
See
Fig
.
40
.
CAMSHAFT
TIMING
CHAIN
117-
1
7
Fig
.
40
.
Primary
timing
chain
tensioner
(arrow)
.
Remove
tensioner
slowlyto
relieve
spring
tension
beneath
end
plug
.
3
.
Install
BMW
special
tool
no
.
11
3
390
into
primary
tim-
ing
chain
tensionersleeve
.
Thread
tool
in
finger
tight
to
remove
chain
slack
.
4
.
Hand
turn
secondary
sprocketsclockwise
(as
viewed
from
front
of
engine)
until
sprockets
contact
stops
.
5
.
Apply
a
small
amount
of
¡¡quid
gasketsealer
(3-Bond
1209
®
or
equivalent)
to
VANOS
housing
alignment
doweis
on
front
of
cylinder
head
.
lnstall
a
new
gasket
.
6
.
Push
VANOS
piston
gear
cup
finto
VANOS
housing
until
it
bottoms
out
in
housing
.
Position
VANOS
control
unitinto
place,
but
do
not
engage
splines
on
gear
cup
.
7
.
On
cars
built
up
to
3/95
:
"
Hand
turn
exhaust
sprocketcounterclockwise
(as
viewedfrom
front
of
engine)
only
enough
to
mesh
gear
cup
splines
with
camshaft
gear
:
"
Slowly
push
VANOS
control
unit
in
untilfully
seated,
guiding
chains
in
counterclockwise
direction
.
VANOS
(VARIABLE
VALVE
TIMING)