Camshaft BMW M3 1993 E36 Owner's Guide

Valves

Valve
specifications
are
listed
in
Table
d
.
Remove
carbon

deposits
from
thevalves
using
a
wire
brush
or
wire
wheel
.

Specification



M42
engine



M42IM44
engines



M50
engine



M50,
M52
engines



S50
USIS52
US
(1992)



(1993-1998)



(1992)



(1993-1998)



I
engine
(1995-1998)

Valve
head
dia
.
Intake



133
.0
mm
(1
.299
in)



133
.0
mm
(1
.299
in)



33
.0
mm
(1
.299
in)



33
.0
mm
(1
.299
in)



130
.0
mm
(1
.181
in)
Exhaust



30
.5
mm
(1
.201
in)



30
.5
mm
(1
.201
in)



30
.5
mm
(1
.201
in)



~
30
.5
mm
(1
.201
in)



27
.0
mm
(1
.063
in)

Valve
stem
dia
.
Standard
Intake



6
.975-0
.015
mm



5
.975-0
.015
mm



6
.975-0
.015
mm



5
.975-0
.015
mm



5
.975-0015
mm
(0
.2746-00006
in)



(0
.2352-00006
in)



(0
.2746-00006
in)



(0
.2352-00006
in)



(0
.2352
-
00006
in)
Exhaust



6
.960-0015
mm



5
.960-0
.015
mm



6
.960
--0
.015
mm



5
.960
-0
.015
mm



5
.960-0
.015
mm
(0
.2740-00006
in)



(0
.2345-0
.0006
in)



(0
.2740--0
.0006
in)



(0
.2345-0
.0006
in)



(0
.2345-0
.0006
in)

Intake



7
.075-0
.015
mm



6
.075-0
.015
mm



7
.075-0
.015
mm



6
.075-0
.015
mm



6
.075-0
.015
mm
(0
.2785-00006
in)



(0
.2392-0
.0006
in)



(0
.2785-00006
in)



(0
.2392
-
00006
in)



(0
.2392-00006
in)
Exhaust



7
.060-0015
mm



6
.060-0015
mm



7
.060-0
.015
mm



6
.060-0015
mm



6
.060-0015
mm
(0
.
2779-0
.0006
in)



(0
.2386-00006
in)



(0
.2779-00006
in)



(0
.2386-00006
in)



(0
.2386-00006
in)

Oversize
2
Intake



7
.175-0
.015
mm



6
.175-0
.015
mm



7
.175-0
.015
mm



6
.175-0
.015
mm



6
.175-0
.015
mm
(0
.2825-00006
in)



(0
.2431-00006
in)



(0
.2825-00006
in)



(0
.2431--0
.0006
in)



(0
.2431-00006
in)
Exhaust



7
.160-0015
mm



6
.160-0015
mm



7
.160-0
.015
mm



6
.160-0015
mm



6
.160-0-015
mm
(0
.2819
-
00006
i
n
)



(0
.2425-00006
in)



(0
.2819-00006
in)



(0
.2425-00006
in)



(0
.2425-00006
in)

Valves,
leak
test
NOTE-

BMW
speclal
tools
are
available
to
remove
the
valve
To
test
thevalves
for
leakage,
the
camshafts
and
camshaft



stem
oil
seals
.
As
an
alternative,
standard
valvesea¡

carriers
(where
applicable)
should
first
be
removed
.
Instali
the



removal
tools
are
available
from
most
automotive
parts

valve
assemblies
and
the
spark
plugs
in
each
cylinder
.
Place



stores
.
See
Flg
.
17
.

the
cylinder
head
on
a
workbench
with
the
combustion
cham-

ber
facing
upward
.
Fill
each
combustion
chamber
with
a
thin

non-flammable
liquid,
suchas
a
parts
cleaning
fluid
.
After
fif-

teenminutes,
check
the
leve¡
of
the
fluid
.
If
the
fluid
level
in
any

cylinder
drops,
thatcylinder
is
not
sealing
properly
.

Valve
Stem
Oil
Seals

The
purpose
of
the
valve
stem
oil
sea¡
is
to
prevent
excess

oil
from
entering
the
combustion
chamber
.
The
sign
offautty

valve
stem
oil
seals
is
excessive
oil
consumption
and
smoke

from
the
exhaust
immediately
after
starting
and
during
decel-

erat¡on

NOTE-

Valve
stem
oil
seals
should
not
be
reused
.
ff
valves
are

removed,
new
valve
stem
oil
seals
should
be
installed
.

Valve
stem
oil
sea¡
replacement
requires
that
the
cylinder

head
be
disassembled
and
thevalves
removed
as
described

above
under
Valves,
removing
and
installing
.

CYLINDER
HEAD
AND
VALVETRAIN



116-
11

Table
d
.
Valve
Specifications

Fig
.
17
.
Valve
stem
oil
sea¡
being
removed
from
valve
guide
.

Lubricate
the
new
seals
and
insta¡]
them
using
hand
pres-

sure
only
.
Be
sure
to
install
the
valve
spring
seat(s)
before
in-

stalling
the
sea¡
.

CYLINDER
HEAD
AND
VALVETRAIN,
RECONDITIONING

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

117-2



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
.

NOTE-

The
vibration
damper
center
bolt
is
very
tight
.
A
heavy
duty
holding
device,
such
as
BMW
special
tool
no
.
112
150,
should
be
used
to
hold
the
vibration
damper
hub



V
stationary
while
the
bolt
is
loosened
.
v

11
.
Usingloosened
bolt
at
vibration
damper,
turn
crank-

shaft
to
TDC
and
lock
in
position
by
inserting
BMW

special
tool
no
.
11
2
300
through
transmission
bell-



-



p

housing
.
See
Fig
.
5
.



v

O

NOTE-



I\



0011966a

"
If
necessary,
remove
plugfrom
locating
boye
in
lower
edge
of
bell
housing
.

"
Confirm
that
locatng
tool
has
been
correctlyinstalled
by
trying
to
rotate
the
crankshaft
.

Fig
.
7
.



Lower
timing
chain
cover
mounting
bolts
(arrows)
.
Bolts
A

Fig
.
5
.



BMW
special
tool
no
.
11
2300
installed
through
bellhousing



are
installed
through
hollow
locating
dowels
.

and
finto
flywheel
to
lock
crankshaft
at
TDC
(arrow)
.

CA
UTION-

Thecamshafts
mustbe
locked
in
the
MC
position
using
the
specialservice
tool
before
removing
the
timing
chain
.
The
tool
holds
the
camshafts
parallel

to
each
other
and
perpendicular
to
the
valve
cover
gasket
surface
.

12
.
Lockcamshafts
at
TDC
bymounting
BMW
special
tool

no
.
113
240
over
square
ends
of
camshafts
.
See
Fig
.
6
.

"
Check
that
tool
is
squarely
seated
on
cylinder
head

gasket
surface
.
If
necessary,
rotate
camshafts
slightly

using
an
open-end
wrench
at
hexon
camshafts
.

13
.
Remove
lower
timing
chaincover
mounting
bolts
and

carefully
lift
cover
off
.
Clean
sealing
surfaces
and
gas-

ket
grooves
.
See
Fig
.
7
.

14
.
Remove
hydraulic
chaintensioner
from
right
side
of
cyl-

inder
head
.
See
Fig
.
8
.

CAMSHAFT
TIMING
CHAIN



117-
3

Fig
.
6
.



BMW
special
tool
no
.
11
3240
installed
on
rearof
camshafts
to
position
camshafts
at
TDC
.
(M44
camshafts
shown
.
Other
engines
are
similar
.

Fig
.
8
.



Hydraulic
chain
tensionerplug
(arrow)
.

CAMSHAFT
TIMING
CHAIN,
4-CYLINDER

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

M42
Engine

CL
(EM

Fig
.
11
.
Two
versionsof
hydraulic
chaintensioners
.
Original
chain
ten-
sioner
on
M42
engine
(top)
canbe
disassembled
.
Chain
ten-
sioner
on
M44
engine
(bottom)
cannot
be
disassembled
.
Note
differences
in
outer
sleeve
.
Also,
the
M42
tensioner
de-
tent
ring
groove
is
visible
when
tensioner
is
extended
(arrow)
.

Outer
sleeve
Spring

0013024a

Detent

ring

9
.
On
M44
engines
:
Clamp
tensioner
piston
in
vice
(soft

jaws)
and
squeeze
oil
from
it
.
Slowly
compress
piston

only
up
to
end
círclip
.
Repeat
procedure
twice
to
ensure

al¡oil
is
expelled
.
See
Fig
.
13
.

10
.
Insta¡¡
hydraulic
chain
tensioner
lo
cylinder
head
.
Usea
new
sealing
washer
on
tensionerplug
when
installing
.

Tightening
Torque

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

11
.
On
M42
engines
:
Release
early-style
chain
tensioner
by
pressing
chain
guide
against
tensioner
until
it
un-

locks
and
expands
out
.

CAMSHAFT
TIMING
CHAIN



117-
5

0012507

Fig
.
13
.
When
reinstalling
chain
tensiones,
oil
in
tensioner
piston
must

first
be
expelled
by
compressing
piston
in
vise
.
When
com-
pressing
piston,
only
compress
up
to
and
circlip
(arrow)
.

Tightening
Torque

"
Chain
sprocket
lo
camshaft
flange
(M6)
..
.
..
.............
.
..
10
Nm
(89
in-lb)

13
.
Remove
crankshaft
locking
tool
from
bellhousing
and

camshaft
locking
tool
from
rear
of
cylinder
head
.

14
.
Install
lower
timingchain
cover
:

"
Insta¡¡
new
crankshaft
oil
seal
in
cover
.

"
Use
new
gaskets
when
installing
cover
.

"
Thoroughly
clean
profile
gasketgroove
and
all
gasket

sealing
surfaces
on
lowerchaincover
.

"
Apply
a
small
bead
of
silicon
sealer
(3-Bond
1209
or
Snap



equivalent)
lo
joint
corners
where
chaincover
meets

ring



0013024



head
and
block
.
See
Fig
.
14
.

"
Tap
cover
into
position
to
engage
locating
dowels
.

Fig
.
12
.
Disassembled
early-style
chain
tensioner
usadon
M42
en-



"
Tighten
cover
mounting
bolts
alternately
and
in
stages
.

gine
.

12
.
Check
that
chain
is
now
free
of
siack
.
Tighten
down

sprocket
mounting
bolts
.



where
chain
cover
meets
head
and
block
(arrows)
.
Fig
.
14
.
Apply
sealer
(3-Bond
1209
0
or
equivalent)
to
joint
corners

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
.

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-
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
.
.

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