1995 BMW M3 cylinder head

Fig
.
22
.
Vibration
damper
with
drive
belt
pulley
being
removed
.
Notehub
locating
dowel
(arrow)
.

Fig
.
23
.
BMW
special
tool
no
.
11
2
300
installed
through
bellhousing
and
into
flywheel
.

20
.
Remove
primary
chain
tensioner
plug
and
primary

chain
tensioner
.
See
Fig
.
25
.

CAMSHAFT
TIMING
CHAIN



117-
9

Fig
.
24
.
BMW
special
tool
no
.
113
240
installed
on
rear
of
camshafts
to
position
camshafts
at
TDC
.
(M44
camshafts
shown
.
Other
engines
are
similar
.)

Fig
.
25
.
Primary
chain
tensioner
plug
(arrow)
.

CAUTION-

"
Check
thattool
is
squarely
seated
on
cytinder
head
gasket
surface
.
If
necessary,
rotate
cam-
shafts
slightly
using
a
24
mm
wrench

"
On
pre-VANOS
engines
(engines
built
up
to
8-
92),
the
camshaft
locking
tool
may
not
fit
correct-
ly
when
the
crankshaft
is
set
to
TDC
.
Do
notas-
sume
the
valve
train
is
out
oftime
.
On
some
engines,
valve
overlap
may
havebeen
reduced

as
a
dealer
service
campaign
to
correct
for
an

uneven
idle
.
Check
thetiming
by
placing
a
3mm
drill
bit
under
the
left
and
right
outside
edges
while
pressíng
down
on
thecenter
of
the
tool
(tool
center
bolts
loosened)
.
If
the
tool
now
fits,

the
campaign
has
beendone
on
the
engine
.

CAMSHAFT
TIMING
CHAINS,
6-CYLINDER

117-
1
0



CAMSHAFT
TIMING
CHAIN

21
.
On
1993
and
lates
engines
:
Remove
access
plugs
from



24
.
On
1993
and
later
engines
:

VANOS
control
unit
in
front
of
exhaust
camshaft



"
Remove
VANOS
control
unit
as
described
laterinthis
sprocket
.
Remove
4
bolts
from
exhaust
camshaft



repair
group
.
sprocket
(useTono
El0
socket)
.
See
Fig
.
26
.



"
Remove
intake
camshaft
sprocket
mounting
nuts
.

"
Remove
intake
and
exhaust
sprockets
together
with

secondary
chain
.
Note
location
of
thrust
washers
and

spring
plate
(where
applicable)
on
intake
sprocket
.

Fig
.
26
.
Exhaust
camshaftmounting
bolts
(arrows)
.

CAMSHAFT
TIMING
CHAINS,
6-CYLINDER

0013056

22
.
Depress
secondary
timing
chain
tensiones
and
lock

down
by
inserting
stiff
wire
into
the
openings
in
rear
of
tensioner
.
See
Fig
.
27
.

Fig
.
27
.
Secondary
timing
chaintensioner
being
locked
down
on
M50
engine
.
Press
tensioner
downand
insert
locking
wire
through
holes(arrows)
.
Tensioner
on
M52/S52
US
engines
vary
slight-

23
.
Remove
secondary
chain
tensioner
and
lift
out
primary
chain
guide
.

NOTE-

Hold
the
camshaft
stationary
(at
hex
on
camshaft)
when
loosening
ortightening
sprocket
mounting
boits
.

CAUTION-

The
crankshaft
must
not
be
allowed
to
rotate
once
the
timing
chain
is
removed
.
The
pistons
can
con-
tact
the
valves
.

25
.
On
1992
engines
:

"
Remove
from
intake
and
exhaust
sprocket
mounting

bolts
.
"
Remove
sprockets
together
with
secondary
chain
.

26
.
Remove
bolts
holding
lower
timing
chain
cover
to
cylin-

der
head
(use
Torx
E8
socket)
.
See
Fig
.
28
.

MR111:
R

Fig
.
28
.
Cylinderhead-to-timingchain
covermounting
bolts
(arrows)
.

27
.
Using
a
drift,
drive
two
locatiog
dowels
in
left
and
right

sides
of
lower
timing
chaincover
toward
rear
of
car
.
Re-
move
covermounting
boits
and
carefully
lift
cover
off
.
See
Fig
.
29
.

CA
UTION-

Use
care
when
removing
the
cover
from
the
cylin-
der
head
gasket
.
If
the
cover
is
stuck,
useasharp
knife
to
separate
it
from
the
head
gasket
.

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

Fig
.
34
.
Primary
timíng
chain
tensioner
being
instafed
.
Pistoncutout
mustbe
in
position
shown
to
engage
chain
rail
.

12
.
On
1993
and
later
engines
:
Install
VANOS
control
unit

as
described
later
in
this
repair
group
.

13
.
Unlock
and
release
secondary
chaintensioner
.



NOTE-

On
pre-VANOS
engines,
be
sure
toinstall
the
3mm
drill
bits
on
left
and
right
sides
of
tool
.
14
.
On
1992
engines
:
Tighten
intake
and
exhaust
timing
chain
sprocket
bolts
alternately
in
two
stages,
working
at
intake
side
first
.

Tightening
Torques

"
Secondary
timing
chaira
sprockets
to
camshafts

(M7
Torx
bolts)

Stage
1
....
.
.
.
...
...............
5
Nm
(44
in-lb)
Stage
2
..
.
.
.
.
.
.
................
22
Nm
(17
ft-Ib)

15
.
On
1992
engines
:
Install
upper
timing
chaincover
to
cylinder
head
using
a
new
gasket
.
Apply
a
small

amount
ofliquid
gasket
sealer
(3-Bond
1209
®
orequiv-

alent)
around
coveralignment
dowels
.

16
.
On
1993
and
later
engines
:
Preloadprimary
chain
by
tightening
BMW
special
tool
no
.
11
3
390
(dummy



21
.
Install
cylinder
head
cover
mounting
studs
.
Insta¡¡
oil
chain
tensioner)
to
1
.3
Nm
(11
in-lb)
.
Then
tighten
ex-



baffle
cover
.
Install
cylinder
head
cover
.
haust
camshaft
sprocket
bolts
alternately
in
twostages
.

Tightening
Torques
(1993
and
later
engines)

"
Exhaust
camshaft
sprockets
to
camshafts

(M7
Torx
bolts)

Stage
1
..
...
..
..
................
5
Nm
(44
in-lb)

Stage
2
.....
.
.
...
..............
22
Nm
(17
ft-Ib)

17
.
Remove
flywheel
locking
tool
from
transmission
bell-

housing
.
Remove
camshaft
locking
tool
from
rear
of

cylinder
head
.

CAMSHAFT'TIMING
CHAIN



117-
1
3

18
.
Insta¡¡
crankshaft
hubandwasher
while
aligning
woo-
druff
key
.
Hold
hub
stationary
and
tighten
mounting
bolt
.
Install
vibration
damper
and
pulley,
making
sure
that
lo-
cating
pin
in
hub
engages
hole
in
vibration
damper
.

NOTE-

When
installing
crankshaft
hub
mounting
bolt,
the
stepped
(shouldered)
sideof
the
washer
should
fase
the
hub
.

Tightening
Torques

Crankshaft
hub
to
crankshaft
(stretch
bolt-
always
replace)
........
410
±
20
Nm
(300
±
15
ft-1b)

"
Vibration
damper
and
pulley

to
crankshaft
hub
(M8)
...
..
.
..
....
22
Nm
(17
ft-Ib)

19
.
Turn
engine
over
by
hand
in
direction
of
rotation
atleast
two
full
rotations
.
Reinstall
camshaft
and
crankshaft
locking
tools
to
check
engine
timing
.
Remove
locking
tools
if
no
faults
are
found
.

20
.
On
1993
and
later
engines
:
Remove
BMW
special
tool11
3
390
(dummy
tensioner)
.
Install
primary
chain
ten-sioner
so
that
cutout
in
tensioner
piston
engages
the
chain
rail
.
See
Fig
.
34
.
Install
and
tighten
access
plugs

in
VANOS
control
unit
.

Tightening
Torques

"
Access
plugs

to
VANOS
control
unit
..........
.
..
50
Nm
(37
ft-Ib)

"
Primary
timing
chain
tensioner
to
tensioner
sleeve

M50/S50US
engine
.......
.
..
..
.
.
50
Nm
(37
ft-Ib)

M52/S52US
engine
..........
..
.
.
40
Nm
(30
ft-Ib)

Tightening
Torque

"
Cylinder
head
cover

to
cylinder
head
............
...
.
.10
Nm
(89
in-lb)

CAMSHAFT
TIMINGCHAINS,
6-CYLINDER

117-
1
4



CAMSHAFT
TIMING
CHAIN

22
.
Installation
of
remaining
parts
is
reverse
of
removal,



When
theengine
is
running,
the
piston
housing
is
supplied

noting
the
following
:



with
pressurized
engine
oil
.
At
idie,
the
solenoid
isin
the
off

"
When
installing
thermostat,
make
sure
arrow
or
vent



position
(de-energized)
and
valve
timing
is
maintained
in
the

hole
faces
up,
if
applicable
.



normal
position
:
When
the
solenoid
is
energized,
the
gear
cup

"
Refill
cooling
systemas
described
in
170
Radiator



piston
moves
forward
to
advance
the
camshaftby
a
maximum

and
Coming
System
.



of
12
.5
.

"
Install
oil
pan
as
described
in
119
Lubrication
Sys-

tem
.
"
Fill
engine
with
oil
and
install
a
new
oil
filter
as
de-

scribed
in
020
Maintenance
Program
.

"
Insta¡¡
ground
wires
at
cylinder
head
cover
mounting

studs
and
at
front
of
cylinder
head
and
thermostat

housing,
where
applicable
.



VANOS
system
operation,
testing

Tightening
Torques



There
are3
special
tools
required
to
check
VANOS
opera-

"
Coolant
drain
plugto
cylinder
block
.
.
25
Nm
(18
ft-Ib)



tion
;
an
electricaltest
lead
(BMW
special
tool
no
.
12
6
410),
an

"
Radiator
cooling
fan
to
coolant
pump
.
40
Nm
(30
ft-Ib)



air
line
fitting
(BMW
special
tool
no
.
11
3
450),
and
a
crank-

"
Radiator
drain
screw
to
radiator
...
.
2
.5
Nm
(22
in-Ib)



shaft
TDC
locking
tool
(BMW
special
tool
no
.
112
300)
.

"
Upper
timing
chaincover
to
cylinder
head



The
test
leal
is
used
to
power
the
solenoid,
simulating
the
M6
nut
...
.....
.............
..
.
10
Nm
(89
in-lb)



ground
signal
from
the
DME
control
unit
.
The
air
line
fitting
M8
bolt
.....
....
.
.
.............
22
Nm
(17
ft-Ib)



takes
the
place
of
the
oil
supply
line
fitting
to
simulate
oil
Ares-
"
VANOS
control
unit
to
cylinder
head



sure
.
The
locking
tool
positions
and
locks
the
crankshaft
at

M6
nut
.........
..
..
.
..........
10
Nm
(89
in-lb)



TDC,
cylinder
no
.
l.
M8
bolt
........
...
.............
22
Nm
(17
ft-Ib)

"
VANOS
oil
supply
pipe
to
VANOS
control
unit



1
.
Remove
alternator
cooling
air
duct
.

banjo
bolt
.......
..
..
.
..........
32
Nm
(24
ft-Ib)

VANOS
(VARIABLE
VALVE
TIMING)



3
.
Remove
top
plastic
enginecovers
.
Disconnect
ignition

coil
harness
connectors
fromcofs
.
Remove
ignition

1993
and
later
6-cylinder
engines
are
equipped
with
a
vari-



coils
.

able
valve
timing
system
called
VANOS
.
This
system
is
con-

trolled
by
the
engine
management
system
and
dynamically



4
.
Remove
cylinder
head
cover
mounting
bolts
and
re-

adjusts
intake
camshaft
timing
based
on
engine
load,
engine



move
cylinder
head
cover
.
Unclip
andremove
oil
baffle

speed
and
engine
temperature
.



cover
from
above
intake
camshaft
.
See
113
Cylinder

Head
Removal
and
installation
.

The
main
components
of
the
VANOS
system
are
the
control

unit
with
piston
housing
and
integral
spool
valve,
and
the
mod-

ified
intake
camshaft
.
See
Fig
.
35
.

VANOS
(VARIABLE
VA
LVE
TIMING)

Fig
.
35
.
VANOS
control
unit
with
modified
intake
camshaft
.

B11001

WARNING
-

Special
BMW
service
tools
are
required
to
check
and
repair
the
VANOS
System
.
Read
theproce-

dures
through
before
beginning
the
job
.

2
.
Disconnect
crankcase
ventilation
hose
fitting
from
cyl-

inder
head
cover
.

NOTE-

Note
the
arrangement
of
the
cylinder
head
cover
bolt
insulators
and
gaskets
during
removal
.

5
.
Set
engine
to
approximate
TDC
by
rotating
in
normal

operating
direction
until
camshaft
lobes
at
cylinder
no
.

1
are
facing
each
other
.
See
Fig
.
20
.

6
.
Set
engine
to
TDC
by
aligning
"0/T"
mark
(0°TDC)on

front
vibration
damper
withcast
boss
on
lower
timing
chain
cover
.
See
Fig
.
21
.

7
.
Lock
crankshaft
in
position
by
inserting
BMW
special

tool
no
.
11
2
300
through
transmission
bellhousing
and

into
hole
in
flywheelor
driveplate
.
See
Fig
.
36
.

NOTE-

Confirm
that
the
locking
tool
has
been
correctly
in-
stalled
by
trying
to
rotatethe
crankshaft
.

117-
1
6



CAMSHAFT
TIMING
CHAIN

15
.
Remove
crankshaft
locking
tool
.
Remove
special
test

equipment
.
Insta¡¡
oil
supply
line
using
new
seals
and

reconnect
solenoid
connector
.
Remainder
of
installa-

tion
is
reverse
of
removal
.

Tightening
Torque

"
Cylinder
head
cover
to
cylinder
head
.
10
Nm
(89
in-lb)

"
VANOS
oil
supply
line
to
VANOS

control
unit
(banjo
bolt)



..
.........
32
Nm
(24
ft-Ib)

"
VANOS
solenoidlo
VANOS

control
unit
........
.
.
.
..
........
30
Nm
(22
ft-Ib)

VANOS
control
unit,
removing

Special
BMW
service
tools
are
required
lo
remove
and
in-

stall
the
VANOS
control
unit
.
Read
the
procedure
through
be-

forestarting
the
job
.

1
.
Remove
radiator
cooling
fan
shroud
and
cooling
fan
.

See
170
Radiator
and
Cooling
System
.

CAUTION-

Radiator
fan
has
left
hand
threads
.

2
.
Remove
top
plastic
engine
covers
.
Disconnect
ignition

coil
harness
connectors
from
coils
.
Remove
ignition

coils
.
Remove
cylinder
head
cover
.
Unclip
andremove

oil
baffle
cover
from
above
intake
camshaft
.See
113

Cylinder
Head
Removal
and
Installation
.

NOTE-

Make
note
of
the
mounting
bolt
insulator
arrangement
during
removal
of
the
cylinder
head
cover
.

3
.
Set
engine
lo
TDC
by
rotating
engine
in
normal
operat-

ing
direction
until
camshaft
lobes
at
cylinder
no
.
1
are

facing
each
other
and
"0/T"
mark
(0°TDC)
on
vibration

damper
lines
up
with
cast
boss
on
lower
timing
chain
cover
.
See
Fig
.
38
.

4
.
Lock
crankshaft
at
TDC
by
inserting
BMW
special
tool

no
.
11
2
300
through
transmission
bellhousing
and
finto

flywheel
or
drive
plate
.
Refer
to
Fig
.
36
given
earlier
.

NOTE-

Confirm
that
the
locking
tool
has
been
correctly
in-
stalled
by
trying
to
rotatethe
crankshaft
.

5
.
Remove
three
cylinder
head
cover
mounting
studs
from
rear
of
head
.
Lockcamshafts
at
TDC
bymounting

BMW
special
tool
no
.
11
3
240
at
ends
of
camshafts
.

Check
that
tool
is
squarely
seated
on
cylinder
head
gasket
surface
.
If
necessary,
rotate
camshafts
slightly
using
a24
mm
wrench
.
Refer
to
Fig
.
24
given
earlier
.

VANOS
(VARIABLE
VALVE
TIMING)

Fig
.
38
.
Camshafts
positioned
at
TDC-Cyl
.
No
.
1
cam
lobes
face
in
Note
0/T
mark
(0°TDC)
on
vibration
damper
alígned
with
boss
on
front
cover
.

CA
UTION-

Thecamshafts
mustbe
locked
in
the
TDC
position
using
the
specialservice
tool
or
an
equivalent
be-
fore
removing
the
timing
chain
.
Thearrows
on
the
sprockets
should
not
be
used
to
accurately
set
the
engine
to
TDC
The
special
tool
holds
the
cam-
shafts
parallel
to
each
other
and
perpendicular
to
the
valve
cover
gasket
surface
.

6
.
Disconnect
harness
connector
and
oil
line
fitting
from
bottom
of
VANOS
control
unit
.

NOTE-

Wrap
the
VANOS
oilfine
fitting
with
a
shop
rag
to
ab-
sorb
leaking
oil
.

7
.
Remove
two
access
plugs
from
VANOS
control
unit
in
frontof
exhaustcamshaft
sprocket
.
Loosen
4exhaustcamshaft
sprocket
mounting
bolts
but
do
not
remove

(Torx
El
0
socket)
.

NOTE-

Removal
of
the
access
plugs
allows
the
lower
exhaust
camshaft
sprocket
mounting
bolts
to
be
accessed
.

8
.
Depress
secondary
timing
chain
tensioner
and
lock
it
in
down
position
by
inserting
a
stiff
wire
into
rear
of
ten-
sioner
.
See
Fig
.
27
.

9
.
Remove
VANOS
control
unít
mounting
nuts
and
boltat

front
of
cylinder
head
.

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)

117-
1
8



CAMSHAFT
TIMING
CHAIN

CAUTION-

It
is
crítical
that
the
exhaustcamshaft
sprocket
be

turned
only
the
mínimum
amount
necessary
to

engage
the
gear
cup
.
If
this
procedure
is
done
ín-
correctly,
the
VANOS
system
may
not
function

throughout
íts
full
range
.

NOTE-

As
the
control
unit
isinstalled,
the
secondary
sprockets
will
rotate
in
the
counterclockwise
direction
.
It
may
be

necessary
to
guide
sprockets
counterclockwise
as
the

control
unit
is
installed
.

8
.
On
cars
built
from3/95
:
Use
a
spanner
tool
(See
Fig
.

39
.),
turn
exhaust
sprocket
counterclockwise
(as

víewed
from
front
of
engine)
only
enough
to
mesh

gear
cup
splines
with
camshaftgear
.
Slowly
push

VANOS
control
unit
towards
camshaft
until
it
is
fully

seated,guiding
chains
in
counterclockwise
direction
.

CA
UTION-

Ensure
that
the
first
available
tooth
engages
.

9
.
Install
and
tightencontrol
unit
nuts
and
bolt
.

10
.
Connect
harness
connector
to
VANOS
solenoid
.
Using

new
seals,
insta¡¡
oil
line
fitting
.

Tightening
Torques

"
VANOS
control
unitto
cylinder
head

M6
nut
.....
..
..
.
.
.............
10
Nm
(89
in-lb)

M8
bolt
.....
.
.
.
.
..
.............
22
Nm
(17
ft-Ib)

"
VANOS
oil
supply
line
to
control
unit
.
32
Nm
(24
ft-Ib)

11
.
Slowlyunlock
and
release
secondary
chain
tensioner
.

12
.
Preloadprimary
chain
by
tightening
BMW
special
tool

no
.
112
240
(dummy
chain
tensioner)
to
1
.3
Nm
(11
in-
lb)
.
Then
tighten
exhaust
camshaft
sprocket
mounting

bolts
alternately
in
two
stages
.

Tightening
Torque

"
Secondarytiming
chain
sprockets
to
camshafts

(Tora
boits)

Stage
1
..
...............
...
.
.
...
5
Nm
(44
in-lb)

Stage
2
..
...............
...
.
.
..
22
Nm
(17
ft-Ib)

VANOS
(VARIABLE
VALVE
TIMING)

13
.
Remove
flywheel
locking
tool
from
transmission
bell-

housing
.
Remove
camshaft
locking
tool
from
rear
of

cylinder
head
.

14
.
Turn
engine
over
by
hand
at
least
two
fui¡
crankshaft
ro-

tations
.
Reinstall
camshaft
locking
tool
and
flywheel

locking
toolto
make
sure
all
adjustments
are
correct
.
If

settings
are
correct,
remove
locking
tools
.

15
.
Remove
BMW
special
tool
112
420
(dummy
chain
ten-
sioner)
from
side
of
cylinder
head
.
Install
primary
chain

tensioner
so
that
cutout
in
tensioner
piston
engages

chain
rail
.
See
Fig
.
34
.
Using
new
seals,
install
and

tighten
access
plugs
in
VANOS
control
unit
.

Tightening
Torque

"
Access
plugs
to

VANOS
control
unit
.
..
.
.....
.
..
...
50
Nm
(37
ft-lb)

"
Primary
timing
chain
tensioner
plug
to
tensioner
sleeve

M50/S50USengine
.
.
..
.
.
...
.
...
..
50
Nm
(37
ft-Ib)

M52/S52US
engine
...
..
...
...
...
40
Nm
(30
ft-Ib)

16
.
Install
oil
baffle
cover
above
intake
camshaft
.
Install

three
cylinder
head
covermounting
studs
to
rear
of

head
.
Instali
cylinder
head
cover
.

Tightening
Torque

"
Cylinder
head
cover

to
cylinder
head
(M6
screws)
......



10
Nm
(89
in-Ib)

17
.
Installationof
remaining
parts
is
reverse
of
removal
.

NOTE-

Be
sure
to
install
the
ground
wíres
at
the
cylinder
head
cover
mounting
studs
and
at
the
front
of
the
cylinder
head,
if
applicable
.