hydraulic BMW 325i 1993 E36 User Guide

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
.

116-
6



CYLINDER
HEAD
AND
VALVETRAIN

9
.
Camshaft
installation
is
reverse
of
removal,noting
the

following
:

"
Prior
to
installation,
check
al¡
components
for
wear
as
described
below
under
Cylinder
Head
and
Val-

vetrain
Reconditioning
.

"
Crankshaft
must
be
at
least
45°
away
from
MC
before

installing
camshafts
to
cylinder
head
.

"
Lubricate
camshafts
prior
to
installation
.
"
Insta¡¡
camshafts
into
cylinder
head
with
lobes
for
cyl-
inder
no
.
1
pointing
up
and
towards
each
other
.
See
Fig
.
8
.

"
After
installing
camshaft(s),
observe
specified
waiting

time
for
hydraulic
cam
followers
to
fully
compress
be-

fore
bringing
crankshaft
back
to
TDC
.

Fig
.
8
.



Camshaft
correctly
positioned
for
reassembly
so
thatcylinder
no
.
1
lobes
(arrows)
face
each
other
.

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
chaintensioner
to
cylinder
head-see
117
Camshaft
Timing
Chain
"
Spark
plugs
(M12)
.............
.
.
23
Nm
(17
ft-Ib)

"
Timing
chain
sprocket
to
camshaft
flange
(M6)-see
117
Camshaft
Timing
Chain

CYLINDER
HEAD,
DISASSEMBLYAND
ASSEMBLY

Valves,
removing
and
installing

1
.
Remove
cylinder
head
as
described
in
113
Cylinder

HeadRemoval
and
Installation
.
Remove
exhaust

manifold(s)
.

2
.
Remove
camshafts
using
special
tools
as
descríbed

earlier
.

3
.
On
M42
and
al¡
6-cylinder
engines
:
Remove
camshaft

carriers
by
pulling
them
straight
up
off
mounting
studs
.

CAUTION-

"
Do
not
let
the
hydraulic
cam
followers
fa¡¡
out
as
the
camshaft
carrier
is
removed
.
Special
suction
cupsare
available
from
BMW
to
hold
the
hydrau-
lic
cam
followers
in
place
during
carrier
removal
.
Camshaft
installation
waiting
times

"
at
or
above
68°F
(20
0
C)
....
..
.
..
......
10
minutes

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

"
32-50°F
(0-10°C)
....
.
..
....
.
..
......
75
minutes
4
.
On
M44
engines
:
Remove
all
hydraulic
valve
adjusters
.
See
Hydraulicvalve
adjusters,
checking
and
re-
"
Reinstall
timing
chainsprockets
and
tensioner
as
spe-



placing
(M44
engine),
later
in
this
section
.
cifically
described
in
117
Camshaft
Timing
Chain
.
"
Waít
at
least
10
minutes
before
cranking
engine
over



CAUTION-
withstarter
motor
for
the
first
time
.



Hydraulic
valve
adjusters
should
be
stored
in
an
upright
position
.
lf
necessary,
use
amagnetic
tool
to
aid
in
removal
of
the
adjusters
.

"
Hydraulic
cam
followers
shouldbe
stored
in
an
upright
position
.

5
.
Remove
valves
using
a
valve
spring
compressor
.

NOTE-

"
The
M44
cylinder
head
has
recessed
valve
stems
.
This
requires
the
use
of
a
special
valve
spring
com-
pressor
tool
.

"
Label
each
valve
assembly
as
it
is
removed
so
it
can
be
installed
in
its
original
position
.

6
.
Remove
and
discard
valve
stem
oil
seals
from
valve
guides
.
See
Valve
stem
oil
seals
later
in
this
section
.

7
.
Valve
installation
is
reverse
of
removal
.

"
Reinstall
exhaust
manifold(s)
with
new
gaskets
.
Use
Molycote
HSC'
5
or
equivalent
anti-seize
thread
com-
pound
on
fasteners
.

Tightening
Torque

"
Exhaust
manifold
to
cylinder
head
M7
............
..
...
....
.
...
..
20
Nm
(15
ft-Ib)

116-
8



CYLINDER
HEAD
AND
VALVETRAIN

0012502

Fig
.
10
.
Location
of
camshaft
oil
sprayer
tube
sea¡
in
M44
cylinder
head
(arrow)
.

Hydraulic
valve
adjusters,

checking
and
replacing
(M44
engine)

The
M44
engine
uses
hydraulic
valveadjusters
(HVA)
to
keep
valve
clearances
within
a
limited
working
range
.
See
Fig
.
11
.
HVAs
are
sealed
units
and
require
no
maintenance
.

1
.
Camshafts
2
.
Rocker
arms
3
.
Hydraulic
valve
adjusters
(HVA)
4
.
Valve
and
conical
valve
spring

Fig
.
11
.
Cutaway
view
of
M44
cylinder
head
.

Under
some
circumstances,
such
as
a
cold
start,
thehy-
draulic
units
may
become
noisy
.
Hydraulic
valve
adjusternoise
is
usually
ahigh-pitched
tapping
or
chattering
noise
.
In
most
instances,
this
is
consídered
normal
aslong
as
the
noise
goes
away
in
a
few
minutes
(maximum20
minutes)
.
If
thenoise
does
not
go
away,
either
the
hydraulic
unit
is
faulty
orthe
oil
pressure
tothe
adjuster(s)
is
low
.

CYLINDER
HEAD
AND
VALVETRAIN,
RECONDITIONING

NOTE-

8efore
checking
valveadjusters,
make
sure
engine
oil
is
fresh
and
at
proper
level
.

1
.
Run
engine
until
it
reaches
normal
operating
tempera-

ture
.

2
.
Turn
engine
off
and
remove
top
engine
cover,
spark

plugs,
and
cylinder
head
cover
.
See
113
Cylinder
Head
Removal
and
Installation
.

3
.
Use
a
plastic
or
wooden
stick
to
press
down
on
top
of

rocker
armend
(side
away
from
camshaft)
.
If
any
play
can
be
detected,the
HVA
is
faulty
and
should
be
re-

placed
.

NOTE-

When
checking
the
HVA,
make
sure
the
camshaft
lobe
is
facing
upso
that
there
is
no
valve
spring
pressure
on
the
adjuster
.

4
.
To
remove
an
HVA,
turn
engine
over
until
camshaft
lobe

points
straight
up
.
Using
BMW
special
tool
no
.
11
5
130,
depress
valvespring
and
remove
rocker
arm
from
under
camshaft
.
See
Fig
.
12
.

Fig
.
12
.
BMW
special
tool
no
.
115
130
(arrow)
being
used
to
depress
valve
stem
to
remove
rocker
arm
.

WARNING
-

Removed
rocker
armsmustbe
reinstalled
in
the
same
locations
.

5
.
Pull
hydraulic
valve
adjuster
straight
out
of
cylinder

head
.
See
Fig
.
13
.

Fig
.
13
.
Remove
hydraulic
valve
adjuster
by
pulling
straight
out
ofcyl-
inder
head
(arrow)
.

6
.
Installation
is
reverse
of
removal
.
Be
sure
to
inspect

HVA
bore
in
the
cylinder
head
for
wear
or
scoring
.

Tightening
Torque

"
Cylinder
head
cover
to
cylinder
head/timing
chain
cover

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

M7
bolt
.......
.
.
..
...
.
...
.
.....
15
Nm
(11
ft-Ib)

Hydraulic
cam
followers,

checking
and
replacing

(M42
and
al¡
6-cylinder
engines)

The
M42
engine
and
al¡
6-cylinder
engines
use
self-adjust-

ing
hydraulic
cam
followers
to
keep
the
valveclearances
with-

ina
limited
working
range
.
The
cam
followers
are
sealed
units

and
require
no
maintenance
.
See
Fig
.
14
.
.

Under
some
circumstances,
suchasa
cold
start,
the
cam

followers
may
become
noisy
.
Hydraulic
cam
follower
noise
is

usually
a
high-pitched
tapping
or
chattering
noise
.
In
most
in-

stances,
this
is
considered
normalas
long
as
the
noise
goes

away
in
a
fewminutes
(maximum
20
minutes)
.
lf
the
noise

does
not
go
away,
either
the
follower
is
faulty
or
the
oil
pres-

sure
to
the
follower
is
low
.
Hydraulic
cam
follower
replace-

ment
requires
that
the
camshaft
first
be
removed
.

NOTE-

Before
checking
valve
adjusters,
make
sure
engine
oil

ís
fresh
and
at
proper
level
.

CYLINDER
HEAD
AND
VALVETRAIN



116-
9

Fig
.
14
.
Section
view
of
camshaft
(A),
hydraulic
cam
follower
(B),
and
valvewith
conical
valvespring
(C)
usedon
M52
engine
.

1.
Run
engine
until
it
reachesnormal
operating
tempera-

ture
.

2
.
Turn
engine
off
and
remove
top
engine
covers,
ignition

coils,
and
cylinder
head
covers
.
See
113
Cylinder

Head
Removal
and
Installation
.

3
.
Use
a
plastic
or
wooden
stickto
press
down
on
top
of

cam
follower
.
See
Fig
.
15
.
If
there
is
any
noticeable

clearance,
the
follower
is
faulty
and
should
be
replaced
.

811107

Fig
.
15
.
Hydraulic
cam
follower
in
M52
enginebeing
checked
.
Note

that
camshaft
lobe
is
pointing
up
.

CYLINDER
HEAD
AND
VALVETRAIN,
RECONDITIONING

116-
1
0



CYLINDER
HEADAND
VALVETRAIN

NOTE-

When
checking
a
cam
follower,
make
sure
the
corre-
sponding
camshaft
lobe
ís
facing
up
so
that
there
is
no
valve
spring
pressure
on
the
follower
.

4
.
To
replace
a
cam
follower,
remove
appropriate
cam-

shaft
.
Refer
to
camshaft
removal
procedures
given
ear-
lier
.

5
.
Once
camshaft
is
out
of
way,
withdraw
faulty
cam
fol-

lower
and
replace
with
new
one
.
Inspect
cam
follower

bores
for
wear
and
scoring
.

6
.
Camshaft,
timing
chain
and
cylinder
head
cover
reas-
sembly
is
reverse
of
disassembly
.

Tightening
Torques

"
Camshaft
bearing
caps
to
cylinder
head

M7
....
.
..
.
......
.
.....
...
.
..
.
15
Nm
(11
ft-Ib)

"
Cylinder
head
cover
to
cylinder
headltiming
chain
cover
M6
....
.
..
.
.
.
..........
...
.
.
..
10
Nm
(89
in-lb)

"
Timing
chain
hydraulic
tensioner
to

cylinder
head-see
117
Camshaft
Timing
Chain

"
Timing
chain
sprocket
to
camshaft

flange
(M6)-see
117
Camshaft
Timing
Chain

CYLINDER
HEAD
AND
VALVETRAIN,
RECONDITIONING

Table
c
.
Valve
Guide
Specifications

Fig
.
16
.
Valveguide
wear
being
checked
with
dial
indicator
.
Insert
new
valve
until
stem
end
is
flush
with
end
of
guide(white
arrow)
.
See
Table
c
for
wear
limits
.

NOTE-

Valve
guides



"
Intemational
Organization
for
Standardization
(ASO)
tolerance
classes
are
Gsted
in
Table
c
.
ISO
allowanc

BMW
does
notsupply
valve
guides
as
replacement
parts
.
If



esare
based
on
nominal
sizes
and
should
beused
to

a
valve
guide
is
excessively
worn,
it
should
be
reamed
to
ac-



determine
proper
fit
.
Most
machine
shops
should

cept
oversized
valve
stems
.
Valve
guide
specifications
are



have
thís
informationavailable

listed
in
Table
c
.



"
Replacement
valve
guides
may
be
available
through
aftermarket
suppliers
.
Valve
guide
replacement
re-
Valve
guides
should
be
checked
for
wear
using
a
new



quires
specíal
tools
and
a
press
.
It
is
also
necessary
valve
.
See
Fig
.
16
.
Be
sure
to
thoroughly
inspect
the
cylinder



to
heat
the
cylinder
head
and
chile
the
valve
guides

head
to
ensure
that
it
can
be
reused
before
reworking
the



when
replacing
the
guides
.

guides
.
"
BMW
suppllesoversize
valves
.
Sea
Valves
for
addi-
tional
information
.

Specifications



M42
engine



M421M44
engines



M50
engine



M50,M52,
S50
US,
S52

~
(1992)



~
(1993-1998)



~
(1992)



~
US
engines
(1993-1998)

Valve
guide
wear,
maximum
(valve
tílt
clearance
measured
with
new
valve)



0
.5
mm
(0
.020
in)



0
.5
mm
(0
.020
in)



0
.5
mm
(0
.020
in)



0
.5
mm
(0
.020
in)

Valveguide
inside
diameter,
installed
(tolerance
per
ISO
allowance
H7)
Standard



7
.0
mm
(0
.276
in)



6
.0
mm
(0
.236
in)



7
.0
mm
(0.276
in)



6
.0
mm
(0
.236
in)
Oversize
1



7
.1
mm
(0
.279
in)



6
.1
mm
(0
.240
in)



7
.1
mm
(0.279
in)



6
.1
mm
(0
.240
in)
Oversize
2



7
.2
mm
(0
.283
in)



6
.2
mm
(0
.244
in)



7
.2
mm
(0
.283
in)



6
.2
mm
(0
.244
in)

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

Fig
.
36
.
BMW
special
tool
no
.
11
2
300
installed
through
bellhousing
and
finto
flywheel
.

8
.
Remove
oil
line
fitting
from
VANOS
control
unit
.

NOTE-

Wrap
the
VANOS
oil
line
fitting
with
a
shop
to
absorb
leaking
oil
.

9
.
Using
hollow
bolt
and
seals
from
oil
supply
line,
instan

BMW
special
tool
no
.
11
3
450
(air
line
fitting)
and
con-
nect
a
supply
of
compressed
air
(30-115
psi)
to
VANOS

oil
fitting
.

10
.
Measure
and
record
distance
between
trigger
plate

edge
and
side
of
secondary
timing
chain
tensioner
.

See
Fig
.
37
.

Fig
.
37
.
VANOS
reference
measurement
(dimension
A)
between
trig-
ger
píate
(sender
gear)
and
side
of
secondary
chain
tensioner
.

CAMSHAFT
TIMING
CHAIN



117-
1
5

11
.
Disconnectharness
connector
from
VANOS
solenoid
.
Connect
BMW
special
tool
no
.
12
6
410
(electrical
test
lead)
to
VANOS
solenoid
connector
.

"
Connect
positive
(+)
test
lead
to
positive
(+)
terminal
ofbattery
Connect
negative
(-)
test
leadto
chassis
ground
.
solenoid
should
audibly
click
and
intake
cam-
shaft
should
advance
.

CA
UTION-

"
Be
sure
to
connect
the
test
hamess
polaritycor-
rectly
.
lf
the
polarity
is
reversed,
the
intemal
diode
in
the
VANOS
solenoid
will
be
destroyed
.
Although
the
solenoid
will
still
functionwith
a
faultydiode,
a
fault
code
may
be
set
in
the
ECM
memory
.

"
To
confirm
voltage
polarity,
turn
the
ignition
on
and
check
for
positive
(+)
batteryvoltage
at
the
terminal
corresponding
to
the
redlwhite
wire
in
the
main
harness
connector
.
Check
that
the
pos-
itive
terminal
(+)
in
the
main
connector
corre-
sponds
to
the
same
terminal
in
the
solenoid
connector
that
is
being
connected
to
the
battery
.

12
.
With
solenoid
actuated,
measure
and
record
new
dis-

tance
between
trigger
plate
edge
and
side'of
second-
ary
timing
chain
tensioner,
as
shown
in
Fig
.
37
.

13
.
Difference
between
first
measurement
(step
10)
andsecond
measurement
(step12)
should
be
at
least
8
.5
mm
(0
.3346
in
.)
.
lf
any
faults
arefound,
solenoid
may

be
faulty,
or
hydraulic
control
unit
may
be
faulty
or
incor-
rectly
installed
.

14
.
Check
VANOS
solenoid
byremoving
it
from
control
unit
.
Check
that
solenoid
plunger
and
control
unit

plunger
move
freely
.
Install
solenoid
using
tighteníng

torque
given
below
.

NOTE-

"
The
solenoid
is
available
asareplacement
part
.
lf
the
control
unit
plunger
is
sticking,
the
complete
control
unit
will
have
to
be
replaced
.

"lf
the
VANOS
system
does
not
advance
correctly
and
no
other
faults
can
be
found,
itis
possible
that
the
VANOS
control
unit
may
Nave
been
fnstalled
incor-
rectly-especially
if
the
camshaft
sprockets
have
pre-
víously
been
removed
for
other
repairs
.
Check
the
installation
by
removing
and
reinstalling
the
control
unit
as
described
later
.

VANOS
(VARIABLE
VALVE
TIMING)

2
.
Remove
cooling
duct
or
terminal
cover
from
rear
of
al-



2
.
Remove
air
cleaner
upper
section
with
mass
air
flow
ternator
.



sensor
.

3
.
Check
for
battery
voltage
between
ground
and
terminal



3
.
Remove
terminal
cover
from
rear
of
alternator
.
Discon
B+
at
back
of
alternator
.
Then
turn
ignition
on
and



nect
wiring
.
check
for
battery
voltage
between
terminal
D+
and
ground
.
See
Fig
.
3
.
lf
voltage
is
not
present
at
either



4
.
Remove
drive
belt
from
alternator
pulley
.
See
020
point,
check
wiring
for
faults
.



Maintenance
program
.

001
¡987
Fig
.
3
.



Terminal
B+
is
supplied
battery
voltage
directly
from
the
bat-
tery
.
Terminal
D+
is
supplied
battery
voltage
via
the
charge
warning
bulb
when
thekey
is
on
or
the
engine
is
running
.

4
.
lf
no
faults
are
foundup
to
thispoint,test
alternator
out-

put
using
a
load
tester
.

5
.
If
a
load
tester
is
not
available,
a
crude
output
test
can
be
done
by
running
engine
at
about
2000
rpmand
turn-
ing
on
electrical
loads
(fans,
lights
and
rear
window
de-
froster,
wipers)
.
With
al¡
accessories
on,
battery
voltage
should
be
above
12
.0
VDC
.

A
replacement
alternator
should
have
the
same
rating
as
the
original
.
Alternator
manufacturer
and
ampere
rating
are
normally
marked
on
the
alternator
housing
.
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¡¡
.

BATTERY,
STARTER,
ALTERNATOR



121-
5

6
.
Remove
upper
and
lower
mounting
bolts
and
lift
out
al-
ternator
.
See
Fig
.
4
.

NOTE
-

If
reusing
drive
belt,
mark
direction
of
rotation
on
belt
before
removing
.

5
.
On
M44
engine
with
hydraulic
belt
tensioner
:
Remove
tensioner
idler
pulley
(upper
roller)
from
alternator

bracket
.

Fig
.
4
.



Alternator
mounting
bolts
(arrows)
.

O



u
J
S
v~~

U

I



1
i
n
-12
.22

Alternator,
removing
and
installing



7
.
Installation
is
reverse
of
removal
.
Install
drive
belt
as

(4-cylinder
engine)



described
in
020
Maintenance
Program
.

Tightening
Torques

"
D+
vire
to
alternator
(M6
nut)
.
...
.
.
.
7
Nm
(53
in-lb)

"
B+
wire
to
alternator
(M8
nut)
..
.
.
.
.
.
13
Nm
(10
ft-Ib)

"
Pulley
to
alternator
(M16
nut)
...
..
..
60
Nm
(44
ft-Ib)

ALTERNATOR
SERVICE