1992 BMW 318i Intake

116-12



CYLINDER
HEADAND
VALVETRAIN

Valve
Seats



Valve
Springs

The
valve
seats
should
be
resurfaced
whenever
new
valves



The
valvesprings
should
be
checked
for
fatigue
.
To
quickly
or
valve
guides
are
installed
.
Cutters
are
required
to
resurface



check
the
springs,
line
them
up
in
a
row
.
Place
a
straight
edge
the
seats
.
Always
check
thevalves
for
leaks
after
recondition-



across
thetop
of
the
springs
.
Any
spring
that
is
significantly

ing
a
valve
seat
as
described
above
.
Table
e
lists
valve
seat



shorter
than
theothers
is
worn
and
should
be
replaced
.

dimensions
.

NOTE-
NOTE-



Valve
spring
specifications
and
wear
límits
arenot
Standard
size
replacement
valve
seats
are
not
avail-



available
from
BMW
.
ablefrom
BMW
.
Replacement
valve
seats
are
only
available
from
BMW
in
0
.4
mm
oversize
(oversized
in
both
height
and
diameter)
.
The
manufacturer
does
not
provide
specífications
for
valve
seat
replacement
for
the
enginescovered
by
this
manual
.

Table
e
.
Valve
Seat
Dimensions

"Y

Valve
seat
outside
dia
.
(B)

CYLINDER
HEAD
AND
VALVETRAIN,
RECONDITIONING

60
°
yl
1
B11110c

Specification



M42
engine



M42
engine



M44
engine



M50
engine



M501M52
engines



S50USIS52US
(1992)



(
(1993-1995)



I
(1996-1998)



(1992)



I
(1993-1998)



I
engines
(1995-
1998)

Valve
seat



45°



451



145°



145°



(
45°



145°
angle

Correction



1
15°



15°



115°



(
15°



15°



15
angle,
outside

Correction
60°



60°



I60°



60°



I60°



I60°
angle,
inside

Va
lve
seat
width
(A)
intake



1
1
.65
±0
.25
mm



1
1.65
±0
.25
mm



1
1
.65
t
0
.25
mm



1
1
.4
-1
.9
mm



1
1
.65
±0
.25
mm



1
1
.65
±
0
.25
mm
(0
.065
+0
.014
in)



I
(0.065
t
0
.014
in)



(0
.065
:E
0
.014
in)



(0
.055-0.075
in)



(0
.065
t
0
.014
in)



l(0
.065t0
.014
in)
____
___
exhaust



12
.0
±0
.25
mm



12
.0
t
0
.25
mm



1
1
.65
t
0
.25
mm



1
1
.4
-
1
.9
mm



11
.65
±
0
.25
mm



1
1
.65
:t
0
.25
mm
(0.079
±
0
.014
in)



1
(0
.079
t0
.014
in)



1
(0
.065
±
0
.014
in)



1
(0
.055-0.075
in)



1
(0
.065
t
0
.014
in)



1
(0.065
t0
.014
in)

intake



32
.4
mm
(1
.276
in)



32
.4
mm
(1
.276m)



32
.4
mm
(1
.276
in)



32
.4
mm
(1
.276
in)



32
.4
mm
(1
.276
in)



29
.4
mm
(1
.157
in)

exhaust



30
.1
mm
(1
.185
in)



30
.1
mm
(1
.185
in)



30
.1
mm
(1
.185
in)



30
.1
mm
(1
.185
in)



29
.4
mm
(1
.157
in)



26
.4
mm
(1
.039
in)

GENERAL
......
.
.
.
.
.
.
.
.
.
...
.
.
.
.
.
.
.
.
.
.
117-1



Camshaft
timing
chains,
removing

(6-cylinder
engines)
....
.
....
..
....
..
...
.117-7
CAMSHAFT
TIMING
CHAIN,



Camshaft
timing
chains,
installing
4-CYLINDER
....
.
.
.
.
.
.
.
.
.
.
.
.......
.
...
117-2



6-clinderen
nes



117-11
Camshaft
timingchain,
removing



(



y



gi

(4-cylinder
engines)
...
..
....
..
...
...
....
117-2



VANOS
(VARIABLE
VALVE
TIMING)
.
..
117-14

Camshaft
timingchain,
installing



VANOS
system
operation,
testing
.....
.
....
117-14

(4-cylinder
engines)



...
..
...
....
..
.
.....
117-4



VANOS
control
unit,
removing
.
..
..........
117-16

CAMSHAFT
TIMINGCHAINS,



VANOS
control
unit,
installing
..
..
..........
117-17

6-CYLINDER
.
.........................
117-6

GENERAL

117
Camshaft
Timing
Chain

This
repair
group
covers
timing
chain
repair
information
for

the
4-
and
6-cylinder
engines
.

4-cylinder
enginesuse
one
double-row
chain
to
drive
the

dual
overhead
camshafts
.
See
Fig
.
1
.

Fig
.
1
.



M44
engine
valvetrain
chain
drive
.
M42
engine
is
similar
.

CAMSHAFT
TIMING
CHAIN



117-1

6-cylinder
enginesusetwo
chains
to
drive
the
camshafts
.
A

primary
chain
is
driven
off
the
crankshaft
and
drives
the
prima-

ry
sprocket
on
the
exhaustcamshaft
.
The
secondary
chain

drives
the
intake
camshaft
.
Each
chain
is
tensioned
by
a
hy-

draulic
tensioner
.
See
Fig
.
2
.

The
timing
chainsare
lubricated
by
engine
oil
and
do
not
re-`

quire
maintenance
.
A
worn
timing
chain
and
sprockets
can

lead
to
noisy
operation
and
erratic
valve
timing
.
A
faulty
ten-

sioner
can
also
cause
timing
chaín
noises
.

Primarychain

NOTE-

See
100
Engine-General
for
engine
code
and
applica-

tion
information
.

Secondary
chain
tensioner

Secondary
chain
B11115

Fig
.
2
.



Cutaway
view
of
camshaft
timing
chains
on1963
and
later
6-

cylinder
engine
with
VANOS
.

GENERAL

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

Camshaft
timing
chains,
removing

(6-cylinder
engines)

1
.
Disconnect
negative
(-)
cable
from
battery
.

CA
UTION-

Disconnecting
the
battery
may
erase
fault
codes)
stored
in
control
module
memory
.
Check
for
fault
codes
using
special
BMW
diagnostic
equipment
.

2
.
Drain
engine
coolant
.
Drain
engine
block
by
removing

block
drain
.
Remove
radiator
cooling
fan
shroud
and

cooling
fan
.
See170
Radiator
and
Cooling
System
.
.

WARNING
-

Allow
the
engine
to
cool
before
openingor
draining
the
system
.

CAUTION-

Radiator
fan
has
left
hand
threads
.

NOTE-

The
block
drain
plug
is
located
on
the
exhaust
side
of
the
engine,
below
cylinder
no
.
4
.

3
.
Drain
engine
oíl
andremove
oil
pan
.
See
119
Lubrica-

tion
System
.

4
.
Remove
alternator
cooling
duct
.

5
.
Remove
two
large
coolant
hoses
from
thermostat

housing
.
Remove
engine
lifting
bracket
and
thermostat

housing
from
front
of
cylinder
head
.

6
.
Loosen
bolts
for
coolant
pump
pulley
.
Then
remove

drive
belts
for
alternator
andA/C
compressor
.
See
020

Maintenance
Program
.
Remove
coolant
pump
pulley
.

Fig
.
16
.

NOTE-

OnM50
engines
with
a
two-roller
drive
belt
tensioner,

remove
the
upper
rollerto
access
thetensioner
mount-
ing
bolts
.

NOTE-

Make
note
of
the
arrangement
of
the
rubber
insulators

when
removing
the
cylinder
head
cover
mounting
bolts
.

CAMSHAFT
TIMING
CHAIN



117-
7

Fig
.
16
.
Drive
belt
tensioner
mounting
bolts
(arrows)
.

B11055

7
.
Remove
drive
belt
tensioner
from
front
of
engine
.
See



Fig
.
17
.
1992-1995
M50
engine
speed
sensor
on
timing
cover
(ar-
row)
.

10
.
Unclip
andremove
baffle
cover
from
above
intake
cam-

shaft
.
See
Fig
.
18
.

11
.
On
1992
engines
:
Remove
upper
timing
chain
cover

from
front
of
cylinder
head
.
See
Fig
.
19
.

8
.
Remove
engine
speed
sensor
from
lower
timing
chain



12
.
Loosen
spark
plugs
.
See
120
Ignition
System
.

cover,
if
applicable
.
See
Fig
.
17
.

13
.
Set
engine
to
approximate
TDC
by
rotating
in
normal

9
.
Remove
cylinder
head
cover
.
See
113
Cylinder
Head



operating
direction
until
camshaft
lobes
at
cylinder
no
.

Removal
and
Installatíon
.



1
are
facing
each
other
.
See
Fig
.
20
.

14
.
Set
engine
to
TDC
by
aligning
"0/T'
mark
(0°TDC)on

front
vibration
damper
with
cast
bosson
lower
timing

chain
cover
.
See
Fig
.
21
.

15
.
Remove
vibration
damper
mounting
bolts
and
remove

vibration
damper
and
pulley
.
See
Fig
.
22
.

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
.

117-
1
2



CAMSHAFT
TIMING
CHAIN

4
.
Mount
primary
timing
chain
sprocket
to
primary
chain

so
that
arrowon
sprocket
faces
up
.
Mount
sprocket
to

camshaftso
that
tapped
holes
in
camshaftare
on
left

side
of
elongated
holes
in
sprocket
.
See
Fig
.
31
.

NOTE-

On
engines
built
beginning
from
March
1995,
the
VANOS
intake
cam
sprocket
assembly
was
updated
to
ínclude
a
spring
plate
and
two
thrust
washers
.
See
Fig
.

Fig
.
31
.
Primary
timing
chain
sprocket
correctly
alignedto
exhaust



33
.
camshaft
.
Elongated
sprocket
holes
should
be
aligned
to
left
side
of
threaded
camshaft
holes
.

5
.
On
1993
and
later
engines
:Install
BMW
special
tool
no
.
11-3
390
into
primary
timíng
chain
tensionersleeve
.
Thread
toolin
finger
tight
until
slack
is
removed
from

chain
.

"
Check
that
elongatedholes
in
primary
sprocket
are

centered
to
bolt
holes
in
camshaft
and
chain
is
free
of
slack
.

NOTE-

BMW
special
tool
no
.
11
3
390
ís
a
dummy
primary
chaín
tensioner
and
simulatesthe
function
of
the
hy-
draulic
tensíoner
.

7
.
Install
cylinder
identification
trigger
píate
to
front
of
in-

take
camshaft
.
On
1993
and
later
engines,
instanthrust
washer
tofrontof
intake
camshaft
.

CAMSHAFT
TIMING
CHAINS,
6-CYLINDER

B11136

Fig
.
32
.
Secondary
chain
sprockets
being
installed
.
Attach
sprockets
with
arrows
pointing
up
and
elongated
holes
centered
to
threaded
holes
in
shaft
flange
.

6
.
Install
primary
timing
chainguide
and
secondary
chain
tensioner
.
Tighten
mounting
bolts
.
(Tensioner
remains



Fig
.
33
.
VANOS
spring
plate
and
thrust
washers
on
engines
built
3/95locked
down
for
now
.)



and
later
.

10
.
On
1993
and
later
cars,
tighten
nuts
at
intake
camshaft
sprocket
.

8
.
Insta¡¡
secondary
chainsprockets
and
chain
asan
as-
sembly
so
that
arrows
on
sprockets
are
pointing
up
.



Tightening
Torque
(1996
and
later)

Centermounting
holes
in
sprockets
tobolt
holes
in



"
Intake
camshaft
sprocket
nut
camshafts
.
See
Fig
.
32
.



to
stud
(M6)
.............
.10t
1
Nm
(89
±9
in-lb)

9
.
On
1993
and
later
engines
:
Insta¡¡
thrust
washers
and
spring
plate
(where
applicable)
to
intake
cam
sprocket
.



11
.
On
1992
engines
:
Insta¡¡
primary
chain
tensioner
so
that
cutout
in
tensioner
piston
engages
chain
rail
.
See
Fig
.
34
.
Check
that
chain
is
free
of
slack
.

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
.