1996 BMW M3 check oil

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-
1
8



CYLINDER
HEAD
REMOVAL
AND
INSTALLATION

CYLINDER
HEAD,
6-CYLINDER

Fig
.
46
.
Primary
chaintensioner
being
installed
.
Piston
cutout
must
engage
chain
rail
.

22
.
Install
intake
cam
cover
and
then
install
cylinder
head

cover
.
Check
for
correct
seating
of
half-moons
in
back

of
cylinder
head
cover
.
Use
a
small
amount
of
3-Bond
O

1209
orequivalent
seaiant
at
corners
of
half-moon
cut-

outs
.

23
.
Install
front
exhaust
pipes
to
manifolds
using
new
gas-
kets
and
nuts
.
Coat
manifold
studs
with
copper
paste
prior
to
installing
nuts
.

24
.
Installationof
remaining
parts
is
reverse
of
removal
.

Refill
cooling
system
as
described
in
170
Radiator
and

Cooling
System
.
Change
engine
oil
and
filter
as
de

scribed
in
020
Maintenance
Program
.
Check
adjust-

ment
of
accelerator
cable
.
Additional
tightening
torques

are
given
below
.
Reconnect
battery
last
.

25
.
Installationof
remaining
parts
is
reverse
of
removal,

noting
the
following
:

"
Make
sure
all
sealing
surfaces
are
clean
and
free
of
old

gasket
material
.
Insta¡¡
new
intake
manifold
gasket
.

"
Reinstall
harness
connectors
for
oil
pressure
switch

and
coolant
temperature
sensor
before
installing
in-

take
manifold
.

"
Refill
cooling
systemas
described
in
170
Radiator

and
Cooling
System
.

"
Change
engine
oil
and
filter
as
described
in
020
Main-

tenance
Program
.

"
If
necessary,
adjust
accelerator
cable
.

"
Reconnect
battery
last
.

CAUTION-

To
prevent
damaging
engine
electronic
systems,
be
sure
to
install
all
ground
wirespreviously
re-
moved,
including
the
ground
wires
at
the
cylinder
head
for
the
ignition
coils
.

Tightening
Torque



Tightening
Torques

"
Cylinder
head
cover



"
Coglant
drain
plug
to
cylinder
block
.
.
25
Nm
(18
ft-Ib)

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



"
Intake
manifold
to
cylinder
head
.
...
.
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)

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

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-
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

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