
Fig
.
23
.
When
reinstalling
chain
tensioner
on
M44
engine,
old
oil
in
tensioner
piston
mustbe
expelled
bycompressing
piston
in
vise
.
When
compressing
piston,
only
compress
up
to
end
cir-
clip
(arrow)
.
21
.
Turn
engine
overby
hand
in
direction
of
rotation
at
least
two
fui¡
rotations
.
Reinstall
camshaft
and
crankshaft
locking
tools
to
check
engíne
timing
.
Remove
locking
tools
if
no
faults
are
found
.
22
.
Insta¡¡
upper
timingchain
cover
.
"
Install
gaskets
and
instan
cover
using
two
mounting
Tightening
Torque
bolts
.
Using
a
screwdriver,
lever
down
on
front
cover
"
Cylinder
head
cover
until
cover
gasket
surface
is
flush
with
cylinder
head
to
cylinder
head
(M6
screws)
.......
10
Nm
(89
in-lb)
gasket
surface
.
See
Fig
.
24
.
Tighten
two
bolis
.
"
Insta¡¡
and
tighten
remainder
of
bolis
.
23
.
Install
cylinder
head
cover
.
CYLINDER
HEAD
REMOVAL
AND
INSTALLATION
113-
9
0012507
Fig
.
24
.
Install
upper
timing
case
cover
with
two
bolis,
then
press
down
on
cover
so
that
top
surface
is
flush
withcylinder
head
(arrow)
.
Hold
cover
in
position
and
tighten
bolis
.
"
Clean
old
gasket
glue
from
sealing
surfaces
.
Usea
small
amount
of
3-Bond
®
1209
adhesive
or
equivalent
at
corners
of
half-moon
cut-outs
at
back
of
cylinder
head
.
See
Fig
.
25
.
NOTE-
OnM44
engines,
reptace
sea¡
for
oil
supply
tube
.
See
Fig
.
17
.)
Fig
.
25
.
Rear
of
cylinder
head
cover
showing
area
where
sealant
(ar-
rows)
should
be
applied
.
Inset
shows
cylinder
head
cover
mounting
bolt
and
insulator
assembly
:
M6
screw
(1),
rubber
damper
(2),
washer
(3)
.
24
.
Installation
of
remaining
parts
is
reverseofremoval,
noting
the
following
:
"
Make
sure
al¡
sealing
surfaces
are
clean
and
free
of
old
gasket
material
.
Install
new
intake
manifold
gasket
.
"
On
M44
engine
:
Replace
seals
above
and
below
crankcase
ventvalve
.
"
When
installing
lower
intake
manifold,
make
sure
hol-
low
locating
bushings
are
on
two
lower
studs
.
"
Reinstall
harness
connectors
for
oil
pressure
switch
and
coolant
temperature
sensor
before
installing
in-
take
manifold
.
Tighten
manifold
nuts
in
stages
.
"
Refill
cooling
system
as
described
in
170
Radiator
and
Cooling
System
.
"
Change
engine
oil
and
filter
as
described
in
020
Main-
tenance
Program
.
"
If
necessary,
adjust
accelerator
cable
.
"
Run
engine
at
approx
.
3,500
rpm
for
about
20
seconds
to
allow
hydraulic
chain
tensioner
to
fill
with
oil
.
"
Reconnect
battery
last
.
CYLINDER
HEAD,-CYLINDER

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)

116-2
CYLINDER
HEADAND
VALVETRAIN
3
.
Remove
timing
chain
sprockets
and
timing
chains
from
7
.
Slowly
release
pressure
oncamshaft
bearing
capsby
camshafts
.
Remove
upper
timing
chain
guidefrom
cyl-
turningeccentric
shaft
.
Remove
bearing
caps
and
inder
head
.
See117
Camshaft
Timing
Chain
.
camshaft
.
Repeat
procedureon
remaining
camshaft
.
NOTE-
It
is
not
necessary
lo
remove
the
lower
timing
chain
cover
.
4
.
Remove
spark
plugs
and
instaf
BMW
special
tool
11
3
260
to
cylinder
head
.
Tighten
tool
retaining
bolts
in
spark
plug
holes
.
Do
not
over-tighten
bolts
.
See
Fig
.
1
.
6
.
Remove
bearing
cap
mounting
nuts
.
0013033
5
.
Turn
eccentric
shaft
on
special
tool
until
pressure
is
ap-
plied
to
camshaft
bearing
caps
.
See
Fig
.
2
.
Fig
.
2
.
Special
tool
(eccentric
shaft)
being
turned
to
apply
pressure
to
camshaft
bearing
caps
.
CYLINDER
HEAD,
DISASSEMBLYAND
ASSEMBLY
CAUTION-
Camshaft
bearing
caps
mustbe
reinstalled
intheir
original
locations
.
NOTE-
"
The
camshaft
bearing
caps
are
coded
wíth
a
letter
anda
number
.
Forexample,
"Al
"ís
the
exhaust
cam-
shaft
bearing
cap
at
the
front
of
the
engíne,
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"forthe
exhaust
side
.
"
"E"
isforEinlal3,
(German
for
íntake)
and
A"
isfor
Auspuff,
(German
for
exhaust)
.
"
The
front
of
the
engine
is
at
the
front
of
thecar
.
8
.
Camshaft
installation
is
reverse
of
removal,noting
the
following
:
"
Prior
to
installation,
check
al¡
components
for
wear
as
described
below
underCylinder
Head
and
Va¡-
Fig
.1
.
Special
BMW
tool
no
.
11
3
260
.
Tool
mounting
bolts
(arrows)
vetrain,
Reconditioning
.
thread
into
spark
plug
holes
.
"
Crankshaft
must
be
at
least
45°
away
from
TDC
before
installing
camshafts
to
cylinder
head
.
"
Lubricate
camshafts
prior
to
installation
.
Tightening
Torque
"
Install
camshafts
into
cylinder
head
with
lobes
for
cyl-
"
BMW
special
tool
11
1
260
inder
no
.
1
pointing
up
and
towards
each
other
.
to
cylinder
head
.
...
.
.
...........
23
Nm
(17
ft-Ib)
"
After
installing
camshafts),observe
specified
waiting
time
for
hydraulic
cam
followers
to
fully
compress
be-
fore
bringing
crankshaft
back
to
TDC
.

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-
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
.

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)

9)
B11126
Fig
.
29
.
Lower
timing
chain
cover
mounting
bolts
(arrows)
anddowel
locations
(A)
.
Coolant
hose
fitting
B
is
replaced
by
coolant
pipe
pressure
fitting
in
later
models
.
28
.
Remove
remaining
Torx
bolt
from
timing
chain
guide
.
See
Fig
.
30
.
Fig
.
30
.
Timing
chainguide
mounting
bolt(A)
.
CAMSHAFT
TIMING
CHAIN
117-
11
29
.
Lift
primary
chain
sprocket
off
exhaust
camshaft
and
remove
chain
.
NOTE-
"
If
any
of
the
sprockets
are
being
replaced
due
to
wear,
the
chain
should
also
be
replaced
.
"
If
the
crankshaft
sprocket
requires
replacement,
the
oil
pump
drive
sprocket
and
chain
must
be
removed
as
described
under
119
Lubrication
System
.
Camshaft
timing
chains,
installing
(6-cylinder
engines)
Inspecttiming
chainsprockets
.
Sprockets
that
haveworn
or
missing
teeth
should
be
replaced
.
Inspect
guide
rail
and
ten-
sioner
rail
for
deep
grooves
caused
by
chain
contact
.
Replace
any
parí
that
is
worn
.
The
procedure
outlined
below
assumes
that
the
camshafts
and
the
crankshaft
are
locked
in
the
TDC
installation
position
with
special
tools
(shown
earlier
in
Fig
.
23
and
Fig
.
24)
.
NOTE-
NOTE-
On
pre-VANOS
engines
(engines
built
up
to
8-92),
the
"
The
timing
chain
cover
can
be
removed
with
the
cool-
camshaft
locking
tool
(Fig
.
24)should
be
raised
upon
ant
pump
installed
.
eitherside
by
3mm
(use
feeler
gauge
or
dril¡
bits)
.
Be
sure
the
clamping
bolts
on
tool
are
loose
and
thecenter
"
Use
care
when
removing
the
chain
cover
from
the
of
the
tool
is
contacting
the
cylinder
head
surface
.
This
coolant
pipe
or
hose
at
the
rearof
the
cover
.
service
campaign
helps
improve
idle
characteristics
by
reducing
valve
overlap
.
1
.
Install
primary
timing
chain
to
crankshaft
sprocket
and
tie
it
up
through
cylinder
head
opening
.
2
.
Using
new
gaskets
and
coolant
pipe
O-ring
;
insta¡¡
low-
ertiming
chain
cover
:
"
Drive
timing
cover
doweis
inuntil
they
just
protrude
slightly
from
sealing
surface
.
"
Apply
a
small
bead
of
silicon
sealer
(3-Bond
1209
©
or
equivalent)
to
corners
of
cylinder
head
where
timing
cover
meets
cylinder
head
and
engine
block
.
"
Tap
cover
into
position
to
engage
doweis
.
"
Install
mounting
bolts
hand
tight,
including
two
outer
Torx
bolts
from
above
.
"
Drive
doweis
in
flush
to
front
of
cover
.
"
Tighten
cover
mounting
bolts
alternately
and
in
stages
.
Tightening
Torque
"
Lower
timing
cover
to
cylinder
block
M7
................
...
..
.
.....
15
Nm
(11
ft-Ib)
M8
.............
.
.
...
.........
20
Nm
(15
ft-Ib)
3
.
Insta¡¡
oil
pan
using
a
new
gasket
.
See
119
Lubrication
Systern
.
CAMSHAFT
TIMINGCHAINS,
6-CYLINDER