1998 BMW M3 warning

7
.
Lightly
lubricate
new
cylinder
head
bolts
.
Loosely
instan
bolts
and
their
washers,
then
thread
them
in
until
they
are
finger
tight
.

NOTE-

Check
that
all
washers
for
the
cylinder
head
bolts
are
in
place
before
installing
the
bolts
.

8
.
Tighten
cylinder
head
bolts
in
correct
sequence
.
See
Fig
.
17
.

UU125U2

Fig
.
17
.
Cylinder
head
bolt
tightening
sequence
for
4-cylinder
en-
gines
.
Note
oil
supply
tube
seal
(arrow)
on
M44
engine
.

WARNING
-

The
bolts
should
be
tightennd
in
three
stages
as
líst-
ed
below
.
The
final
stages
require
the
use
of
a
spe-

cial
tool
(BMW
tool
No
.
11
2
110)
ora
suitable

protractor
to
tighten
the
bolts
to
a
specified
torqueangle
.
See
Fig
.
18
.

Tightening
Torques

"
Cylinder
head
to
engine
block
(Torx
El2
M10
bolts)

Stage
1



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

Stage
2



.
...
...
.
.
...................
..
.
+90°

Stage
3
.....
...
.
..
...................
..
+90°

9
.
Carefully
rotate
crankshaft
in
direction
of
engine
rota-
tion
and
lock
it
at
TDC
by
inserting
BMW
special
tool

no
.
11
2
300
through
transmission
bellhousing
.
See

Fig
.
19
.

CYLINDER
HEAD
REMOVAL
AND
INSTALLATION



113-
7

Fig
.
18
.
Protractor
and
pointer
being
used
to
tighten
bolts
to
specified
torqueangle
(6-cylinder
engine
shown)
.

Fig
.
19
.
BMW
special
tool
11
2
300
inserted
through
bellhousing
hole
and
finto
flywheel
(arrow)
to
lockcrankshaft
at
TDC
.

10
.
Turn
left
chainguide
adjusting
sleeve
in
until
it
just
con-

tacts
the
cylinder
head
(See
Fig
.
14
.)
.
Insert
chain
guide
retaining
screw
and
tighten
.

CAUTION-



11
.
Placechain
sprockets
with
chains
oncamshaftsso
that
Be
sure
timing
chain
does
not
bind
oncrank
gear

when
turning
crankshaft
.



arrowson
sprockets
point
up
and
elongated
holes
in

sprocketsare
centered
to
tapped
holes
in
camshafts
.

See
Fig
.
20
.

CYLINDER
HEAD,
4-CYLINDER

113-10



CYLINDER
HEAD
REMOVAL
AND
INSTALLATION

Tightening
Torques

"
Coolant
drain
plug
to
cylinder
block
.
.
25
Nm
(18
ft-1b)

"
Intake
manifold
support
to
manifold
.
.
15
Nm
(11
ft-Ib)

"
Lower
intake
manifold

to
cylinder
head
.
..........
.
..
...



15
Nm
(11
ft-Ib)

"
Lower
intake
manifold

to
upper
manifold
..........
.
..
...
15
Nm
(11
ft-Ib)

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

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

CYLINDER
HEAD,
6-CYLINDER

For
ease
of
use
this
procedure
is
broken
into
subsections,

as
follows
:

General
Coolingsystem,
draining
Cyiinder
head
cover,
removing

Intake
manifold,
removing

Timing
chains,
uncoupling

Cylinder
head
assembly,
removing

WARNING
-

Allow
the
engine
to
cool
before
beginning
this
pro-
cedure
.

General

1
.
Working
inside
luggage
compartment,
disconnect
neg-
ative
(-)
battery
cable
.

CAUTION-

"
Prior
to
disconnectiog
the
battery,
read
the
bat-
tery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
vi¡¡
.

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

2
.
Remove
front
exhaust
pipes
from
manifolds
.
Discard
nuts
.

3
.
Remove
air
filter
housing
complete
with
mass
air
flow
sensor
and
intake
air
ducting
.
Disconnect
vacuum
hos-
es
from
throttle
housing
.

4
.
On
M52
and
S52US
engines
:
Remove
secondary
air
injection
check-valve
from
front
of
engine
and
set
aside
.

CYLINDER
HEAD,
6-CYLINDER

Coolingsystem,
draining

5
.
Drain
engine
coolant
and
Rmove
coolant
hoses
from

thermostat
housing
.
Drain
engine
block
by
removing

block
drain
.
See
170
Radiator
and
Cooling
System
.

NOTE-

The
block
drain
is
on
the
exhaust
side
of
the
engine,
near
cylinder
no
.
5
.

6
.
Remove
radiator
cooling
fan
and
fan
shroud
.
See
170

Radiator
and
Cooling
System
.

NOTE-

The
radiator
cooling
fannut(32
mm
wrench)
has
left-
hand
threads
.

Cylinder
head,
removing

(6-cylinder
engine)



7
.
Disconnect
heater
hoses
at
rear
of
cylinder
head
.
See

Fig
.
26
.

'i

8
.
Remove
alternator
cooling
duct
.

Cylinder
head
cover,
removing

0012687

Fig
.
26
.
Disconnect
heater
hoses
at
heater
valve
(A)
and
heater
core
(B)
.

9
.
Remove
air
plenum
from
rear
of
engine
compartment
.

See640
Heating
and
Air
Conditioning
.

10
.
Remove
plastic
cylinder
head
covers
from
above
fuel
injectors
and
ignition
coils
.
Pull
larger
cover
forward

when
removing
.
See
Fig
.
27
.

11
.
Disconnect
crankcase
ventílation
hose
fitting
from
cyl-
inder
head
cover
.

12
.
Disconnect
ignition
coil
harness
connectors
from
coiis
.

Remove
ignition
coiis
and
spark
plugs
.
See
120
Igni-
tion
System
.

113-12



CYLINDER
HEAD
REMOVAL
AND
INSTALLATION

18
.
Working
from
underside
of
intake
manifold,
disconnect



21
.
Detach
oil
dipstick
guide
tube
from
manifold
.
Disconharness
connectors,
vent
hoses,
and
air
bypass



nectvent
hose
at
base
of
dipstick
.
hoses)
.

22
.
Remove
intake
manifold
from
engine
byremoving
sev-19
.
Working
at
rear
of
intake
manifold,
label
and
disconnect



en
mounting
nuts
from
above
andtwo
support
bracket
fuel
supply
and
fuel
return
lines
.
Remove
fuelline
hold



bolts
from
below
.
See
Fig
.
32
.
down
bracket
to
free
lines
.
See
Fig
.
31
.

NOTE-

On
M52IS52US
engines,
a
special
fitting
is
used
to
re-tain
the
fuel
fines
to
the
fuel
rail
.
Use
BMW
special
tool
no
.
16
1
050
to
expand
the
locking
clip
inside
the
end
of
the
fuellíne
fittings
.

WARNING
-

"
The
fuel
system
is
desígned
to
retan
pressure
even
wheh
the
ignition
is
off
.
When
working
with
the
fuel
system,
loosen
the
fuel
lines
slowly
toal-
low
residual
fuel
pressure
to
dissipate
gradually
.
Avoid
spraying
fuel
.

"
Fuel
is
highly
flammable
.
When
working
around
fuel,
do
not
disconnect
any
wires
that
could
cause
electrfcal
sparks
.
Do
not
smoke
orwork
near
heaters
or
other
fire
hazards
.

"
Always
unscrew
the
fuel
tank
cap
to
release
pres-
sure
in
the
tank
before
working
on
the
tank
or
lines
.

20
.
Remove
mountingscrews
and
release
wiring
harness
duct
at
rear
bulkhead
and
move
aside
.
Remove
wiring
harness
brackets
frombulkhead
.

CYLINDER
HEAD,
6-CYLINDER

Fig
.
32
.
Intake
manifoldnuts
and
support
bracket
bolts
(arrows)
.

CAUTION-

Stuff
clean
rags
into
the
open
intake
ports
topre-
001269s



vent
any
ports
from
falfing
into
the
engine
.
Fig
.
31
.
Fuel
lines
at
intake
manifold
on
M52/S52
engine
.
Use
BMW
special
tool
16
1
050
to
release
locking
fittings
at
ends
of
fuel
enes
.



1



Timing
chains,
uncoupling

23
.
Remove
VANOS
unit
from
frontof
cylinder
head
.
See
VANOS
section
in
117
Camshaft
Timing
Chain
.

24
.
Setengine
to
approximate
TDC
by
rotating
in
normal
operating
direction
until
camshaft
lobes
at
cylinder
no
.
1
are
facing
each
other
.
Arrows
on
camshaft
sprockets
should
be
pointing
up
.

NOTE-

To
confirm
that
the
crankshaft
is
set
to
the
TDC
posi-
tion,
check
that
the
OIT
mark
(0°
TDC)on
the
front
low-
er
timing
chain
cover
ís
aligned
with
the
víbration
damperSee
Fig
.
33
.

25
.
Lock
crankshaft
at
TDC
.

"
Insert
BMW
special
tool
no
.
11
2
300
through
transmis-
sion
bellhousing
and
finto
hole
in
flywheelor
drive
plate
.
See
Fig
.
34
.

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
.

113-16



CYLINDER
HEAD
REMOVAL
AND
INSTALLATION

NOTE-

Check
that
all
washers
for
the
cylinder
head
bolts
are
in
place
before
installlng
the
bolts
.
Some
of
the
washers
may
be
staked
to
the
cylinder
head
.

6
.
Tighten
cylinder
head
bolts
in
correct
sequence
.
See
Fig
.
41
.

Fig
.
41
.
Cylinder
head
bolt
tightening
sequence
for
M50
engine
.

Fig
.
42
.
Protractor
and
pointer
being
used
to
tighten
bolts
to
specified
torque
angle
.

WARNING
-

The
bolts
should
be
tightened
in
three
stages
as
list-
ed
below
.
The
final
stages
require
the
use
of
aspe-
cial
tool
(BMW
tool
No
.
11
2
110)
ora
suitable
protractor
to
tighten
the
bolts
to
a
specified
torque
angle
.
See
Fig
.
42
.

CYLINDER
HEAD,
6-CYLINDER

7
.
Install
and
tighten
cylinder
head-to-lower
timing
chain

cover
bolts
.

Tightening
Torques

"
Cylinder
head
to
engine
block(Torx
El
2
Ml
0
bolts)

Stage
1
.........
..
.
.
.
...
.
...
..
30
Nm
(22
ft-Ib)

Stage
2
.........
..
..
....
.
...
..........



+90°

Stage
3
...
.
.....
..
.
.
.
...
.
...
..........
.+90°

"
Cylinder
head
lo
lower
timing

chaincover
.......
..
..
..
...
.
....
10
Nm
(89
in-lb)

8
.
Carefully
rotate
crankshaft
in
direction
of
engine
rota-tion
and
lock
it
at
TDC
by
inserting
BMW
special
tool
no
.
11
2
300
through
transmission
bellhousing
.
Guide
primary
timing
chain
to
keep
it
from
jamming
on
crank
gear
.

9
.
Mount
primary
chain
sprocketto
primary
chain
so
that

arrowon
sprocket
faces
up
.
Mount
sprocket
to
exhaust
camshaftso
tapped
holes
in
camshaft
are
on
left
most
side
of
elongated
holes
in
sprocket
.
See
Fig
.
43
.

Fig
.
43
.
Primary
chain
sprocket
correctly
afgned
to
exhaust
cam-
shaft
.
Camshaft
holes
should
be
on
left
most
sideof
sprocket
holes
.

10
.
Install
timing
chain
guide
and
secondary
chain
tension-er
.
Tighten
mounting
bolts
.

11
.
Install
asan
assembly,
secondary
chain
sprockets
and
chain
so
that
arrow(s)
on
sprockt(s)
are
pointing
up
.
Centermounting
holes
in
sprockets
tobolt
holes
in
camshafts
.
See
Fig
.
44
.

12
.
Install
thrust
washers
and
spring
plate
(if
applicable)
to
sprockets
.
See
Fig
.
45
.

GENERAL

CYLINDER
HEAD,

DISASSEMBLY
AND
ASSEMBLY
CYLINDER
HEAD
AND
VALVETRAIN



116-1

116
Cylinder
Head
and
Valvetrai
n

GENERAL
.
.....
.
.
.
...
.
.
.
.
.
.
.
.
.
.......
116-1



Hydraulic
cam
followers,
checking
and
replacing
(M42
and
al¡
6-cylinder
engines)
.
...
.....
.
..
116-9
CYLINDER
HEAD,



Valve
guides
.
.
.
...
.
.
.
.
.
.
...
.
.
.
.
.
.
.
.
.
.
116-10
DISASSEMBLY
AND
ASSEMBLY
...
.
...
116-1



Valves
.
.
.
.
.
.
.
.
.
.
.
.
.
...
.
...
.
.
.
.
.
...
.
.
116-11
Camshafts,
removing
and
installing

(M42
engine)
....
.
....
.
.
.
.
.
.
.
.
.
.....
.
.
116-1



Valves,
leak
test
.
.
.
.
.
.
.
.
.
.
...
.
.
.
.
.
.
.
.
.
.
116-11

Camshafts,
removing
and
installing



Valve
stem
oil
seals
.
.
.
.......
.
.
.
.
.
...
.
.
116-11

(M44
engine)
.........
.
.
.
.
.
.
.
.
.
.......



116-3



Valve
seats



.
.
.
.
.
.
.
.
.
...
.
...
.
.
.
.
.
...
.
.116-12

Camshafts,
removing
and
installing



Valve
springs
.
.
.
.
.
.
.
.
...
.
...
.
.
.
.
.
.....
116-12

(6-cylinder
engine)
.....
.
.
.
.
.
.
.
.
.
.......
116-4

Valves,
removing
and
installing
........
.
....
116-6



TABLES

CYLINDER
HEAD
AND
VALVETRAIN,



a
.
Cylinder
Head
Height
........
....
.
..
..........
116-7

RECONDITIONING
.
...
.
.
.
.
.
.
.
.
.
.......
116-7



b
.
Camshaft
Specifications
.......
..
.
..
........
.116-7

Cylinder
head
...
.
.
.
...
.
.
.
.
.
.
.
.
.
....
.
..
116-7



c
.
Valve
Guide
Specifications
....
...
.
..
........
116-10
d
.
Valve
Specifications
...........
..
.
..
........
116-11
Camshaft
.
.
.
.
.
.
.
.
.
.
.
.
.
.
...
.
.
.
.
.
.......
116-7



e
.
Valve
Seat
Dimensions
.........
.
..
..
......
.116-12
Hydraulic
valve
adjusters,

checking
and
replacing
(M44
engine)
..
.
.
.
116-8

Camshafts,
removing
and
installing

(M42
engine)

This
repair
group
covers
cylinder
head
and
valvetrain
ser-
vice
and
repair
.
Most
of
the
repairs
described
here
require
that



The
camshafts
can
be
removed
with
the
cylinder
head
the
cylinder
head
first
be
removed
as
described
in
113
Cylin-



mounted
on
the
engine
.
The
first
step
is
to
remove
the
cylinder
der
HeadRemoval
and
Installation
.



head
cover
.
See
113
Cylinder
HeadRemoval
and
Installa-

tion
.

NOTE-



Special
BMW
service
tools
should
always
be
used
to
remove

"
For
timing
chain
and
VANOS
repair
information,
see



and
install
the
camshafts
.
Removal
and
installation
of
the
cam-
117
Camshaft
Timing
Chain
.



shafts
without
the
special
tools
can
result
in
camshaft
and
valve

"
If
it
is
determined
that
the
cylinder
head
will
require



train
damage
.

significant
reconditioning
work,
a
remanufactured
cyl-

inder
head
may
bea
good
alternative
.
Remanufac-



WARNING-

tured
cylinder
heads
are
available
froman
authorized



The
process
of
evenly
loosening
the
camshaftbear

BMW
dealer
.



ing
cap
nuts
is
NOT
an
acceptable
method
of
re-
moving
the
camshafts
.
Be
sure
to
read
the

The
information
given
in
this
repair
group
is
organized
ac-



procedure
through
before
starting
the¡ob
.

cording
to
engine
code
.
For
engine
applicationinformation,

see100
Engine-General
.



1
.
Disconnect
negative
(-)
battery
cable
.

CAUTION-

Prior
to
disconnectiog
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manualonpage
viii
.

BMW
special
tools
are
required
for
most
cylinder
head
ser-



2
.
Remove
radiator
cooling
fan
shroud
and
cooling
fan
.
vice
described
in
this
repair
group
.
Many
of
these
tools
areex-



See
170
Radiator
and
Cooling
System
.
pensive
and
only
available
through
an
authorized
BMW
dealer
.
If

the
special
tools
are
not
available,
one
altematve
is
to
remove

the
cylinder
head
and
have
it
disassembled
byan
authorized



CAUTION-

BMW
dealer
.
Be
sure
to
read
each
procedure
thoroughlybefore



Radiator
fa
n
has
left
hand
threads
.

starting
a
job
to
determinewhich
special
tools
and
equipment
will

be
necessary
.

CYLINDER
HEAD,
DISASSEMBLYANDASSEMBLY

Camshaft
installation
waíting
times

"
Ator
above
68°F
(20°C)
............
.
..
10
minutes

"
50-68°F
(10-20°C)
................
..
.
30
minutes

"
32-50°F
(0-10°C)
.
.......
.
.........
..
.
75minutes
"
Reinstall
timing
chain
sprockets
and
tensioner
as
spe-

cifically
described
in
117
Camshaft
Timing
Chain
.



i

"
Wait
at
least
10minutes
before
cranking
engine
over

with
starter
motor
for
the
fi+



1
1/
/~~
.0
time
.

Tightening
Torques

"
Camshaft
bearing
caps

to
cylinder
head
(M7)
.............
15
Nm
(11
ft-Ib)

"
Cylinder
head
cover

to
cylinder
head
(M6)
.............
10
Nm
(89
in-lb)

"
Primary
timing
chain
tensioner
plug

to
cylinder
head
..
..
..
...........
40
Nm
(30
ft-Ib)

(see
117
Camshaft
Timing
Chain)

"
Spark
plugs
(M12)
..
.
.............
23
Nm
(17
ft-Ib

"
Timing
chain
cover
(upper)

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

"
Timing
chainsprockets
to
camshaft

M6
........
.
...
.
..
.



..........
10
Nm
(7.5
ft-Ib)

M7



............
.
..
..
...........
15
Nm
(11
ft
.lb)

(see
117
Camshaft
Timing
Chain)

Camshafts,
removing
and
installing

(M44
engine)

Special
BMW
service
tools
should
always
be
used
to
remove

and
install
the
camshafts
.
Removal
and
installation
of
the
cam-

shafts
without
the
special
tools
can
result
in
camshaft
and
val-

vetrain
damage
.

1.
Disconnect
negative
(-)
battery
cable
.

CAUTION-

Prior
to
disconnecting
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this

manual
on
page
vi¡¡
.

CYLINDER
HEAD
AND
VALVETRAIN



116-
3

2
.
Remove
spark
plugs
.
See
1201gnition
System
.

3
.
Rotateengine
until
a
pair
of
camshaft
lobes
are
point-
ing
up
.
Using
BMW
special
tool
115
130,
depresseach
valve
and
valve
spring
enough
to
remove
rocker
arms
.

Rotate
engine
for
the
next
pair
of
rocker
arms
.
See
Fig
.

3
.

cover
.

Fig
.
3
.



BMW
special
tool
no
.
11
5130
(arrow)
being
used
to
depress
valve
stem
to
remove
rocker
arm
.

WARNING
-

Removed
rocker
arms
must
be
reinstalled
in
the
same
locations
.

4
.
Remove
primary
timing
chain
tensioner
from
right
side

of
cylinder
head
.

The
camshafts
can
be
removed
with
the
cylinder
head



5
.
Remove
upper
timing
chaincover
.

mounted
onthe
engine
.
The
first
step
is
to
remove
the
cylinder

head
cover
.
See
113
Cylinder
HeadRemoval
and
Installa-



NOTE-

tion
.



lt
is
not
necessary
to
remove
the
lower
timing
chain

6
.
Remove
timing
chain
sprockets
with
timing
chains
from

front
of
camshafts
.
See
117
Camshaft
Timing
Chain
.

Remove
upper
timing
chain
guide
from
cylinder
head
.

WARNING-



7
.
Remove
camshaft
bearing
caes
and
remove
cam
The
process
of
evenly
loosening
the
camshaft
bear-



shafts
.
ing
cap
nuts
is
NOT
an
acceptable
method
of
re-

moving
the
camshafts
.
Be
sure
to
read
the



CAUTION-
procedure
through
before
starting
the
job
.
Camshaft
bearing
capsmust
be
reinstalled
intheir

original
locations
.

CYLINDER
HEAD,
DISASSEMBLYAND
ASSEMBLY

116-
4



CYLINDER
HEAD
AND
VALVETRAIN

NOTE-

"
The
camshaft
bearing
caps
are
coded
with
a
letter
anda
number
.
Forexample,
'541"is
the
exhaustcam-
shaft
bearing
cap
at
the
front
of
the
engine,
and
`El"
is
the
intake
camshaft
bearing
cap
at
the
front
of
the
engine
.

"
Camshafts
are
stamped
with
a
code
letter-'E"
for
the
intakeside
and
A"
for
the
exhaust
side
.

"
"E"
isfor
Einla3,
(German
for
intake)
and
A"
is
for
Auspuff,
(Germen
for
exhaust)
.

"
The
front
of
the
engine
is
at
the
front
of
the
car
.

8
.
Camshaft
installation
is
reverse
of
removal,
noting
the

following
:

"
Prior
to
installation,
check
all
components
for
wear
as

described
below
underCylinder
Head
and
Val-

vetrain
Reconditioning
.
"
Lubricate
camshafts
prior
to
installation
.
"
Reinstall
timing
chain
sprockets
and
tensioner
and
set
valve
timing
before
reinstalling
rocker
arms,as
spe-

cifically
described
in
117
Camshaft
Timing
Chain
.

"
Be
sure
corresponding
camshaft
lobe
is
pointing
up

before
installing
rocker
arms
.
Note
that
each
rocker
arm
angles
away
from
corresponding
spark
plug
hole
.
See
Fig
.
4
.

"
Wait
at
least
10
minutes
for
hydraulic
cam
followers
to
fully
compress
before
cranking
engine
over
with
start-

er
for
the
first
time
.

Tightening
Torques

"
Camshaft
bearing
caps

to
cylinder
head
(M7)
.............
15
Nm
(11
ft-Ib)

"
Cylinder
head
cover

to
cylinder
head
(M6)
.............
10
Nm
(89
in-lb)

"
Primary
timing
chain
tensioner
plug

to
cylinder
head
.
................
40
Nm
(30
ft-lb)
(sea
117
Camshaft
Timing
Chain)

"
Spark
plugs
(M12)
.............
...
23
Nm
(17
ft-lb

Timing
chaincover
(upper)
to
cylinder
head
M6
.....
.
.
...
................
.
10
Nm
(7
.5
ft-Ib)
M7
....
..
.
.
........
.
.....
.
...
.
15
Nm
(11
ft-Ib)

"
Timing
chain
sprockets
to
camshaft

M6
....
.
.
..
..............
.
..
..
10
Nm
(7
.5
ft-Ib)
M7
....
....
..............
.
..
..
.15
Nm
(11
ft
.lb)
(sea
117
Camshaft
Timing
Chain)

Camshafts,
removing
and
installing

(6-cylinder
engine)

Camshafts
on
6-cylinder
engines
can
be
removed
with
the
cylinder
head
mounted
on
the
engine
.
The
first
step
is
to
re-
move
the
cylinder
head
cover
.
See
113
Cylinder
Head
Re-
moval
and
Installation
.

CYLINDER
HEAD,
DISASSEMBLYAND
ASSEMBLY

Fig
.
4
.



Correct
installation
position
ofrocker
arms
(arrows)
on
M44
engine
.

Special
BMW
service
tools
should
always
be
used
to
re-

move
and
instan
the
camshafts
.
Removal
of
camshafts
with-

outthe
special
tools
can
result
in
personal
injury
and/or
cylinder
head
damage
.

WARNING
-

The
processof
evenly
loosening
the
camshaft
bear-
ing
cap
nuts
is
NOT
en
acceptable
method
of
re-
moving
the
camshafts
.
Special
tools
shouldalways
be
used
lo
remove
the
camshafts
.
Be
sure
to
read
the
procedure
through
before
starting
ajob
.

1
.
Disconnect
negative
(-)
battery
cable
.

CAUTION-

Prior
to
disconnectiog
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
onpaga
viii
.

516
2
.
Setengine
to
TDC
and
lock
into
position
by
installing
BMW
special
tool
11
2
300
through
transmission
bell-
housing
and
into
hole
in
flywheel
or
drive
platea
See
Fig
.
5
.

NOTE-

Arrows
on
camshaft
sprockets
shouldbe
pointing
up
.
Sea
117
Camshaft
Timing
Chain
.

3
.
Remove
VANOS
control
unit
from
cylinder
head
.
Re-
move
timing
chainsprockets
from
camshafts
.
See117

Camshaft
Timing
Chain
.

4
.
Remove
sparkplugs
and
insta¡¡
BMW
special
tool
11
3
260/11
3
270
to
cylinder
head
.
Tighten
tool
retaining
bolts
in
spark
plug
holes
.
Do
not
ovar-tighten
bolts
.
See
Fig
.
6
.