disa BMW 318i 1997 E36 User Guide

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
.

Fig
.
5
.



BMW
special
tool
11
2300
(arrow)
inserted
through
bell-
housing
hole
and
finto
flywheel
.

A

Tightening
Torque

"
BMW
special
tool11
1
260/11
3
270

to
cylinder
head
.................
23
Nm
(17
ft-Ib)

5
.
Remove
intake
camshaft
bearing
cap
no
.
1
.

6
.
Turn
eccentric
shaft
on
special
tool
until
pressure
is
ap-

plied
to
camshaft
bearing
caps
.
See
Fig
.
7
.

7
.
Remove
remaining
bearing
capmounting
nuts
.

CYLINDER
HEAD
AND
VALVETRAIN



116-
5

NOTE-

Fig
.
7
.



Special
tool
(eccentric
shaft)
beingturned
to
apply
pressure
to
camshaft
bearing
caps
.

8
.
Slowly
release
pressure
oncamshaft
bearing
capsby

turning
eccentric
shaft
.
Remove
bearing
caps
and

camshaft
.
Repeat
procedure
on
remaining
camshaft
.

CAUTION-

Camshaft
bearing
capsmust
be
reinstalled
in
their
original
locations
.

"
The
camshaft
bearing
caps
are
coded
with
a
letter

and
a
number
.
For
example,
`A1
"is
the
exhaust
cam-
shaft
bearing
cap
at
the
front
of
the
engine,
and
"E1"
is
the
intake
camshaft
bearing
cap
at
the
front
of
the
engine
.

"
The
camshaftsare
stamped
with
a
code
letter-`E"
for

the
intake
síde
and
`A"
for
the
exhaust
side
.
F19
.6
.



Special
BMW
tool
no
.
11
3260
(A)
with
adapter
ll
3
270
(B)
.

Tool
mounting
bolts
(arrows)
thread
into
spark
plug
holes
.



"
"E"
is
for
Einfal3,
(German
for
intake)
and
`A"
is
for

Auspuff,
(German
for
exhaust)
.

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

CYLINDER
HEAD,
DISASSEMBLYAND
ASSEMBLY

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)

CYLINDER
HEAD
AND
VALVETRAIN,

RECONDITIONING

Thís
section
provides
the
specifications
and
special
recon-
ditioning
information
necessary
to
repair
the
cylinder
heads

covered
by
this
manual
.

If
machine
shop
services
are
not
readily
available,
one
al-

ternative
is
to
install
a
remanufactured
cylinder
head
froman

authorized
BMW
dealer
.

Cylinder
head

NOTE-

When
replacing
the
cylinder
headon
engines
with
re-
movablecamshaft
carriers,
be
sure
to
check
the
cam-
shaft
carrier
bearing
surfaces
for
warpage
.

4-cylinder



1
140
.0
mm
(5
.512
in)



1
139
.55
mm
(5
.494
in)

6-cylinder



1



140
.0
mm
(5
.512
in)



1



139
.7
mm
(5
.500
in)

CYLINDER
HEAD
AND
VALVETRAIN



116-
7

A

The
disassembled
cylinder
head
should
be
inspected
for



Fig
.
9
.



Front
víew
of
cylinder
head
showing
minimum
resurfacing
di-

warpage
and
cracks
.
Check
the
valve
guides
and
valveseats



mension
(A)
.

for
wear
before
machining
a
warped
head
.
Always
decarbon-

ize
and
clean
the
head
before
inspectiog
it
.
A
high-quality



Camshaft

straíght
edge
can
be
used
to
check
for
warpage
.
Camshaft
wear
is
usually
caused
by
insufficient
lubrication
.

Visually
inspect
the
cylinder
head
for
cracks
.
If
acracked



Visually
inspect
the
camshaft
lobes
and
journals
for
wear
.

cylinder
head
is
suspected
and
no
cracks
are
detected



Camshaftwear
specifications
are
given
in
Table
b
.

through
the
visual
inspection,
have
the
head
further
tested
for

cracks
byan
authorized
BMW
dealer
.
A
cracked
cylinder
head



Table
b
.
Camshaft
Specifications

must
be
replaced
.



4-cylinder
engines

Axialplay
M42
engine



0
.065-0
.150
mm
(0
.0025-0
.0059
in)

M44
engine



0
.065-0
.150
mm
(0
.0025-0
.0059
in)

Radial
play(Plastigage)



0
.020-0.061
mm
(0
.0008-0
.0024
in)
M42
engine
M44
engine



0
.040-0
.082
mm
(0
.0016-0
.0032
in)

6-cylinder
engines
A
warped
cylinder
head
can
be
machined
provided
no



Axial
pla
y
more
than
0
.3
mm
(0
.012
in)
of
material
is
removed
.
If
further



All



0
.020-0.054
mm
(0
.0008-0
.0021
in)

machining
is
required,
the
head
should
be
replaced
.
Remov-



Radial
play(Plastigage)
0
.150-0.330
mm
(0
.006-0.013
in)
ing
more
than
this
amount
will
reduce
the
size
of
the
combus-



All

tion
chamber
and
adversely
affect
engine
performance
.
A
0
.3

mm
thicker
gasket
is
available
from
an
authorized
BMW
parts

department
for
machined
heads
.



NOTE-

-
On
M44
engines,
check
the
oil
sprayer
tube
in
the
top
Before
machining
the
head
to
correct
for
warpage,
measure



of
the
cylinder
head
coverand
the
tubesea¡
in
the
cyl-

the
total
height(thicknessof
the
cylinder
head)
.
See
Fig
.
9
.



inderhead
.Acloggedsprayertubeoradefectiveseal

Minimum
height
specifications
are
given
in
Table
a
.



will
reduce
oil
flowto
the
camshaft
.
See
Fig
.
10
.

-
If
the
camshaft
is
being
replaced
due
to
cam
lobe
Table
a
.
Cylinder
Head
Height



wear,
the
corresponding
rockerarms
orcam
followers

Engine



New



Minimum
height



shouId
also
be
replaced
to
avofd
damaglng
the
new

(dimension
A)



camshaft
.

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)

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

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

GENERAL
.
........
.
...........
.
.
.
.
.
.
.
120-1



Camshaft
Position
(CMP)
Sensor
....
.
.
.
...
120-6

Disabling
Ignition
System
.
.
.
.
.....
.
.
.
.
.
.
.
120-2



Camshaft
position
(CMP)
sensor,
replacing

Warnings
and
Cautions
.
.
.
.
.
.
.....
.
.
.
.
.
.
.
120-2



(4-cylinder
engine)
..
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
...
120-6

Camshaft
position
(CMP)
sensor,
replacing

IGNITION
SYSTEM
DIAGNOSTICS
.
.
.
.
.
.
120-3



(6-cylinder
engine)
..
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
120-7
Basic
Troubleshooting
Principles
...
.
.
.
.
.
.
.
120-3



Knock
sensors,
replacing
.
.
...
.
.
.
.
.
.
.
.
.
.
.
.
120-7

Ignition
Firing
Order
.....
.
...
.
.
.
.....
.
.
.
.120-7

IGNITION
SYSTEM
SERVICE
.
.........
.
120-3

Checking
for
Spark
..
.
.
.
.
.
.
.
.
.
.......
.
.
.
120-3

Ignition
coil,
testing
and
replacing

(4-cylinder
engine)
.
.
.
.
.
.
.
.
.
.
.........
.
120-3

Ignition
coil,
testing
and
replacing

(6-cylinder
engine)
.........
.
..........
120-4

Crankshaft
Positionlrpm
Sensor
.......
.
...
120-5

Crankshaft
position/rpm
sensor,
testing
and

replacing
(front
mounted)
.........
.
.
.
.
.
.
120-6

Crankshaft
position/rpm
sensor,replacing

(rear
mounted)
.....
.
.....
.
.....
.
.
.
.
.
.
120-6

GENERAL



Troubleshooting
and
testing
of
the
engine
management

system
should
be
carried
out
using
the
BMW
specialized
ser

This
repair
group
covers
repair
andcomponent
replace-



vice
tester
(scan
tool)
.

ment
information
for
the
ignition
system
.
All
engines
use
a
distributorless
ignition
system
with
indívid-

ual
ignitioncoils
for
each
cylinder
.
There
is
no
distributor
cap

NOTE-



or
ignition
rotor
.
Each
coil
can
be
selectively
controlled
by
the

"
Spark
plug
replacement
is
covered
in
020
Mainte-



engine
control
module
on
a
cylinder-by-cylinder
basis
.
On
later

nance
Program
.



systems,
knock
sensors
are
used
to
monitor
and
control
igni-

"
For
fuel
related
troubleshooting
and
testing,
see
130



tion
knock
(ping)
and
adjusttiming
accordingly
.

Fuel
lnjection
.
Ignition
timing
is
electronically
controlled
and
not
adjust-

All
engines
covered
by
this
manual
use
an
advanced
en-



able
.
The
engine
control
module
(ECM)
usesengine
load,
en-

gine
management
system
.
The
engine
management
system



gine
speed,
coolant
temperature,
and
intake
air
temperature

incorporates
on-board
diagnostics,
fuel
injection,
ignition
and



as
the
basic
inputs
for
timing
control
.
Knock
detection
is
also

other
advanced
engine
control
functions
.



an
input
to
the
control
module,
where
applicable
.

Table
a
.
Engine
Management
System
Variants

Engine
code



1
System

4-cylinder
M42
(1.8
I)



Bosch
DME
Ml
.7
M44
(1
.9
I)



Bosch
DME
M5
.2
(OBD
II)

6-cylinder
M50
1992
(2.5
I)



Bosch
DME
M8
.1
1993-1995
(2
.5
I)



Bosch
DME
M33
.1
M52
1996-1998
(2.8
I)



Siemens
MS
41
.1
(OBD
II)

1998
(2
.5
I)



Siemens
MS
41
.1
(013D
11)
S50US
(3.0
I)



Bosch
DME
M3
.3.1
S52US
(3.2
I)



Siemens
MS
41
.1
(OBD
II)

120
Ignition
System

IGNITION
SYSTEM



120-1

IGNITION
SYSTEM
SCHEMATICS
...
.
.
.
.120-7

TABLES

a
.
Engine
Management
System
Variants
......
120-1

b
.
Ignition
Coil
Resistance
(M42
engine)
......
120-4

c
.
Ignition
Coil
Resistance
(M44
engine)
......
120-4

d
.
Ignition
Coil
Resistance

(6-cylinder
engine)
..
.
.
.
.
.
.
.
.
.
.
.
.....
.
..
120-5

NOTE-

All
engines
coveredby
this
manual,
with
theexception

of
the
1992
M50,
incorporate
knocksensors
as
part
of

the
engine
management
system
.

The
initial
ignition
point
is
determined
by
the
crankshaft
po-

sition/rpm
sensor
during
cranking
.
Once
the
engine
is
run-

ning,
timing
is
continually
adjusted
based
on
operating

conditions
.
A
characteristic
ignition
map
is
shown
in
Fig
.
1
.
A

map
similar
to
the
one
shown
is
digitally
stored
in
the
engine

control
module
.

GENERAL