1994 BMW 325i timing chain

7
.
Lightly
lubricate
new
cylinder
head
bolts
.
Loosely
instan
bolts
and
their
washers,
then
thread
them
in
until
they
are
finger
tight
.

NOTE-

Check
that
all
washers
for
the
cylinder
head
bolts
are
in
place
before
installing
the
bolts
.

8
.
Tighten
cylinder
head
bolts
in
correct
sequence
.
See
Fig
.
17
.

UU125U2

Fig
.
17
.
Cylinder
head
bolt
tightening
sequence
for
4-cylinder
en-
gines
.
Note
oil
supply
tube
seal
(arrow)
on
M44
engine
.

WARNING
-

The
bolts
should
be
tightennd
in
three
stages
as
líst-
ed
below
.
The
final
stages
require
the
use
of
a
spe-

cial
tool
(BMW
tool
No
.
11
2
110)
ora
suitable

protractor
to
tighten
the
bolts
to
a
specified
torqueangle
.
See
Fig
.
18
.

Tightening
Torques

"
Cylinder
head
to
engine
block
(Torx
El2
M10
bolts)

Stage
1



.
.
.....
.
.
.............
30
Nm
(22
ft-Ib)

Stage
2



.
...
...
.
.
...................
..
.
+90°

Stage
3
.....
...
.
..
...................
..
+90°

9
.
Carefully
rotate
crankshaft
in
direction
of
engine
rota-
tion
and
lock
it
at
TDC
by
inserting
BMW
special
tool

no
.
11
2
300
through
transmission
bellhousing
.
See

Fig
.
19
.

CYLINDER
HEAD
REMOVAL
AND
INSTALLATION



113-
7

Fig
.
18
.
Protractor
and
pointer
being
used
to
tighten
bolts
to
specified
torqueangle
(6-cylinder
engine
shown)
.

Fig
.
19
.
BMW
special
tool
11
2
300
inserted
through
bellhousing
hole
and
finto
flywheel
(arrow)
to
lockcrankshaft
at
TDC
.

10
.
Turn
left
chainguide
adjusting
sleeve
in
until
it
just
con-

tacts
the
cylinder
head
(See
Fig
.
14
.)
.
Insert
chain
guide
retaining
screw
and
tighten
.

CAUTION-



11
.
Placechain
sprockets
with
chains
oncamshaftsso
that
Be
sure
timing
chain
does
not
bind
oncrank
gear

when
turning
crankshaft
.



arrowson
sprockets
point
up
and
elongated
holes
in

sprocketsare
centered
to
tapped
holes
in
camshafts
.

See
Fig
.
20
.

CYLINDER
HEAD,
4-CYLINDER

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

113-10



CYLINDER
HEAD
REMOVAL
AND
INSTALLATION

Tightening
Torques

"
Coolant
drain
plug
to
cylinder
block
.
.
25
Nm
(18
ft-1b)

"
Intake
manifold
support
to
manifold
.
.
15
Nm
(11
ft-Ib)

"
Lower
intake
manifold

to
cylinder
head
.
..........
.
..
...



15
Nm
(11
ft-Ib)

"
Lower
intake
manifold

to
upper
manifold
..........
.
..
...
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)

CYLINDER
HEAD,
6-CYLINDER

For
ease
of
use
this
procedure
is
broken
into
subsections,

as
follows
:

General
Coolingsystem,
draining
Cyiinder
head
cover,
removing

Intake
manifold,
removing

Timing
chains,
uncoupling

Cylinder
head
assembly,
removing

WARNING
-

Allow
the
engine
to
cool
before
beginning
this
pro-
cedure
.

General

1
.
Working
inside
luggage
compartment,
disconnect
neg-
ative
(-)
battery
cable
.

CAUTION-

"
Prior
to
disconnectiog
the
battery,
read
the
bat-
tery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
vi¡¡
.

"
Disconnecting
the
battery
may
erase
fault
code(s)
stored
in
control
module
memory
.
Check
for
fault
codes
using
special
BMW
diagnostic
equipment

2
.
Remove
front
exhaust
pipes
from
manifolds
.
Discard
nuts
.

3
.
Remove
air
filter
housing
complete
with
mass
air
flow
sensor
and
intake
air
ducting
.
Disconnect
vacuum
hos-
es
from
throttle
housing
.

4
.
On
M52
and
S52US
engines
:
Remove
secondary
air
injection
check-valve
from
front
of
engine
and
set
aside
.

CYLINDER
HEAD,
6-CYLINDER

Coolingsystem,
draining

5
.
Drain
engine
coolant
and
Rmove
coolant
hoses
from

thermostat
housing
.
Drain
engine
block
by
removing

block
drain
.
See
170
Radiator
and
Cooling
System
.

NOTE-

The
block
drain
is
on
the
exhaust
side
of
the
engine,
near
cylinder
no
.
5
.

6
.
Remove
radiator
cooling
fan
and
fan
shroud
.
See
170

Radiator
and
Cooling
System
.

NOTE-

The
radiator
cooling
fannut(32
mm
wrench)
has
left-
hand
threads
.

Cylinder
head,
removing

(6-cylinder
engine)



7
.
Disconnect
heater
hoses
at
rear
of
cylinder
head
.
See

Fig
.
26
.

'i

8
.
Remove
alternator
cooling
duct
.

Cylinder
head
cover,
removing

0012687

Fig
.
26
.
Disconnect
heater
hoses
at
heater
valve
(A)
and
heater
core
(B)
.

9
.
Remove
air
plenum
from
rear
of
engine
compartment
.

See640
Heating
and
Air
Conditioning
.

10
.
Remove
plastic
cylinder
head
covers
from
above
fuel
injectors
and
ignition
coils
.
Pull
larger
cover
forward

when
removing
.
See
Fig
.
27
.

11
.
Disconnect
crankcase
ventílation
hose
fitting
from
cyl-
inder
head
cover
.

12
.
Disconnect
ignition
coil
harness
connectors
from
coiis
.

Remove
ignition
coiis
and
spark
plugs
.
See
120
Igni-
tion
System
.

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
.

Fig
.
33
.
Crankshaft
is
positioned
at
TDC
when
notch
oh
front
timing
chain
cover
is
alignedwith
0/T
mark
on
víbration
damper
.

CYLINDER
HEAD
REMOVAL
AND
INSTALLATION



113-
1
3

Fig
.
35
.
Camshaft
locking
tool
(BMW
special
tool
no
.
11
3
240)
in-
stalled
on
rear
of
camshafts
.
(M44
engine
shown
.
Other
en-
gines
are
similar
.)

CAUTION-

The
camshafts
must
be
locked
in
the
TDC
position
using
the
special
service
tool
before
removing
the
timing
chain
.
Thearrowson
the
sprockets
should
not
be
used
to
accurately
set
the
engine
to
TDC
.
The
tool
holds
the
camshafts
parallel
to
each
oth-
er
and
perpendicular
to
the
cylinder
head
covergasket
surface
.

27
.
Depress
secondary
timing
chain
tensioner
and
lock
t

down
by
inserting
BMW
special
tool
no
.
113
292
.
Alter-

natively,
a
stiff
piece
of
wire
can
be
used
.
See
Fig
.,36
.

Fig
.
34
.
Crankshaft
locking
tool
(BMW
special
tool
11
2
300)
inserted



Fig
.
36
.
Press
secondary
tensioner
down
fully
and
insert
wire
through
through
bellhousinghole
and
finto
flywheel
(arrow)
.



holes
(arrow)
to
lock
.
Timingchain
tensioner
varies
depend-
ing
on
engine
(M52
engine
tensioner
shown)
.

26
.
Lockcamshafts
at
TDC
.

"
Remove
three
cylinder
head
cover
mounting
studs



28
.
Remove
mounting
nuts
from
front
of
intake
camshaft

from
across
rear
of
head,
if
applicable
.



sprocket
.
Remove
camshaft
sprocket,
thrust
washer(s),

"
Mount
BMW
special
tool
no
.
11
3
240
over
square



and
where
applicable,
spring
plate
.

ends
of
camshafts
.
Check
that
tool
is
squarely
seated

on
cylinder
head
gasket
surface
.
If
necessary,
rotate



NOTE-

camshafts
slightly
using
a
24
mm
wrench
at
hexon



Where
applicable,
make
note
of
thrust
washer
positions
.

camshaft(s)
.
See
Fig
.
35
.



The
thicker
(0
.4
mm)
washer
is
mounted
outermost
.

CYLINDER
HEAD,6-CYLINDER

113-14



CYLINDER
HEAD
REMOVAL
AND
INSTALLATION
29
.
Remove
mounting
nuts
from
front
of
exhaustcamshaft

sprocket
.
Remove
secondary
sprockets
together
with

timing
chain
from
front
of
camshafts
.

CAUTION-

The
crankshaft
must
not
be
allowed
to
rotate
once
the
camshaft
timing
chain
is
removed
.
The
pistons
can
contact
thevalves
.

NOTE-

Do
not
remove
the
sprockets
from
the
chain
unless
these
parts
are
being
replaced
.
Wire
tie
each
sprocket
to
the
chain
to
keep
the
sprockets
timed
to
each
other
.

30
.
Unbolt
secondary
timing
chain
tensioner
from
top
of

cylinder
head
.

31
.
Remove
primary
timing
chaintensioner
from
side
of

cylinder
head
.
See
Fig
.
37
.

Fig
.
37
.
Primary
timing
chain
tensioner
(arrow)
.

WARNING
-

Remove
tensioner
slowly-¡t
ís
under
spring
pres-
sure
.

32
.
Remove
timing
chainguíde
(Tono
E8
socket)
.
See
Fig
.
38
.

33
.
Lift
primary
chain
sprocket
off
exhaust
camshaft
.
Re-
move
sprocket
from
chain
.
Suspend
chainusing
stiff
wire
.

Cylinder
head
assembly,
removing

34
.
Remove
two
mounting
bolts
holding
cylinder
head
to
lower
timing
chaincover
(Torx
E8
socket)
.
See
Fig
.
39
.

CYLINDER
HEAD,
6-CYLINDER

Fig
.
38
.
Timing
chain
guide
mounting
bolts
(arrows)
.
M50
engine
shown
.

Fig
.
39
.
Cylinder
head-to-timing
chain
covermounting
boits(arrows)
.
(Bolt
A
also
retains
secondary
chain
tensioner
.)

35
.
Using
BMMI
special
tool
no
.
11
2
250
or
an
equivalent

tool,
loosen
cylinder
head
bolts
in
several
stages
.
See
Fig
.
40
.
Discard
head
boits
.

CAUTION-

Torx-type
cylinder
head
bolts
should
not
be
re-
used
.
Theyare
stretch-type
bolts
and
must
atwaysbe
replaced
whenever
loosened
.

NOTE-

Cylinder
head,
installing

(6-cylinder
engine)

CAUTION-

If
the
camshafts
were
removed
and
installed
while

the
cylinder
head
was
off,
a
minimum
waiting
time

is
required
after
ínstalling
the
camshafts
.
When

the
camshaftsareremoved,
the
hydraullc
lifters

can
expand
.
This
expansion
can
cause
increased

valve
lift
when
the
camshafts
are
bolted
down,
re-

sulting
in
open
valves
.

Cylinder
head
installation
waiting
times

"
68°F
(20°C)
and
higher
.
.
.
..
..........
10
minutes

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

"
32-50°F
(0-10
°C)
.........
...
........
75
minutes

CYLINDER
HEAD
REMOVAL
AND
INSTALLATION



113-
1
5

1
.
Clean
cylinder
head
and
gasket
surfaces
of
cylinder

block
and
al¡
timing
chain
covers
.

"
Remove
all
foreign
matter
and
any
¡¡quid
from
bolt

holes,
then
clean
with
a
thread
chaser
.

CA
UTION-

Do
not
use
ametal
scraper
or
wire
brush
to
clean

the
aluminum
cylinder
head
or
pistons
.
If
neces-
sary,
use
a
hard
wooden
or
plastic
scraper
.
Also

available
are
abrasive
discs
to
be
used
in
conjunc-
tion
with
an
electric
drill
.
Be
sure
to
use
the
correct
disc
for
the
typeof
metal
being
cleaned
.

2
.
Check
gasket
surface
of
cylinder
head
and
cylinder

block
for
warpage
using
a
straight
edge
.

NOTE-

Fig
.
40
.
Cylinder
head
bolt
loosening
sequence
.



If
the
cylinder
head
has
been
machined,a
special
0
.3

mm
thickergasketshould
be
installed
.
The
thickergas-

ket
is
available
from
an
authorized
BMW
dealer
.

BMW
special
tool
no
.
112250
is
a
thin-walled
Torx
E12

socket
wíth
anextended
reach
.
The
cylinder
head
bolts



3
.
Place
new
cylinder
head
gasket
on
cylinder
block
.

are
recessed
finto
the
head
below
the
camshaft
towers



Check
that
two
locating
dowels
are
correctly
positioned

wíth
liffle
working
space
.



in
block
and
arenot
damaged
.

36
.
Remove
crankshaft
locking
tool
(BMW
special
tool
no
.



NOTE-

11
2
300)
.
Using
the
crankshaft
vibration
damper
bolt,



The
word
"OBEN",
printed
on
the
gasket,
should
face

turn
engine
opposite
its
normal
direction
of
rotation



up
.Thecylinderheadgasketwillfitcorrectlyinonlyone

(counterclockwise
asviewed
from
the
front)
approxi-



orientation
.

mately
45°
.
This
prevents
accidental
contact
between

valves
and
pistons
during
installation
.



4
.
With
camshafts
locked
in
TDC
positionwith
BMW
spe-

cial
tools
as
described
earlier,
set
cylinder
head
in
po

NOTE-



sition,
guiding
primary
chain
through
cylinder
head
Guide
cam
chain
to
keep
it
from
jamming
when
turning



opening
.

the
crankshaft
.
CA
UTION-

"
The
camshafts
must
be
locked
in
the
MC
posi-

tion
at
the
rear
of
the
cylinder
head
with
BMW

special
tool
no
.
113240
before
installing
the
cyl-

inder
head
.

"
Make
sure
the
crankshaft,
which
had
been
rotat-

ed
approximately
45°
opposite
thedirection
of
engine
rotation,is
still
in
that
position
before
low-
ering
the
cylinder
head
into
position
.

5
.
Lightly
lubricate
new
cylinder
head
bolts
.
Loosely
instan
bolts
and
their
washers,
then
thread
them
in
until
they

are
finger
tight
.
Install
cylinder
head-to-lower
timing

chaincover
boitsfinger
tight
.

CAUTION-

Tonc-type
cylinder
head
bolts
should
not
be
re-

used
.
They
are
stretch-typebolts
and
must
always
be
replaced
whenever
loosened
.

CYLINDER
HEAD,
6-CYLINDER

113-16



CYLINDER
HEAD
REMOVAL
AND
INSTALLATION

NOTE-

Check
that
all
washers
for
the
cylinder
head
bolts
are
in
place
before
installlng
the
bolts
.
Some
of
the
washers
may
be
staked
to
the
cylinder
head
.

6
.
Tighten
cylinder
head
bolts
in
correct
sequence
.
See
Fig
.
41
.

Fig
.
41
.
Cylinder
head
bolt
tightening
sequence
for
M50
engine
.

Fig
.
42
.
Protractor
and
pointer
being
used
to
tighten
bolts
to
specified
torque
angle
.

WARNING
-

The
bolts
should
be
tightened
in
three
stages
as
list-
ed
below
.
The
final
stages
require
the
use
of
aspe-
cial
tool
(BMW
tool
No
.
11
2
110)
ora
suitable
protractor
to
tighten
the
bolts
to
a
specified
torque
angle
.
See
Fig
.
42
.

CYLINDER
HEAD,
6-CYLINDER

7
.
Install
and
tighten
cylinder
head-to-lower
timing
chain

cover
bolts
.

Tightening
Torques

"
Cylinder
head
to
engine
block(Torx
El
2
Ml
0
bolts)

Stage
1
.........
..
.
.
.
...
.
...
..
30
Nm
(22
ft-Ib)

Stage
2
.........
..
..
....
.
...
..........



+90°

Stage
3
...
.
.....
..
.
.
.
...
.
...
..........
.+90°

"
Cylinder
head
lo
lower
timing

chaincover
.......
..
..
..
...
.
....
10
Nm
(89
in-lb)

8
.
Carefully
rotate
crankshaft
in
direction
of
engine
rota-tion
and
lock
it
at
TDC
by
inserting
BMW
special
tool
no
.
11
2
300
through
transmission
bellhousing
.
Guide
primary
timing
chain
to
keep
it
from
jamming
on
crank
gear
.

9
.
Mount
primary
chain
sprocketto
primary
chain
so
that

arrowon
sprocket
faces
up
.
Mount
sprocket
to
exhaust
camshaftso
tapped
holes
in
camshaft
are
on
left
most
side
of
elongated
holes
in
sprocket
.
See
Fig
.
43
.

Fig
.
43
.
Primary
chain
sprocket
correctly
afgned
to
exhaust
cam-
shaft
.
Camshaft
holes
should
be
on
left
most
sideof
sprocket
holes
.

10
.
Install
timing
chain
guide
and
secondary
chain
tension-er
.
Tighten
mounting
bolts
.

11
.
Install
asan
assembly,
secondary
chain
sprockets
and
chain
so
that
arrow(s)
on
sprockt(s)
are
pointing
up
.
Centermounting
holes
in
sprockets
tobolt
holes
in
camshafts
.
See
Fig
.
44
.

12
.
Install
thrust
washers
and
spring
plate
(if
applicable)
to
sprockets
.
See
Fig
.
45
.