1993 BMW 325i Workshop Manual

22
.
Move
A/C
compressor
out
of
the
way
without
distorting



26
.
Carefully
raise
engine
out
ofcar,
checking
for
any
wir-
or
damaging
any
lines
.
Support
compressor
by
hanging



ing,fuel
lines,
or
mechanical
parts
that
might
become
it
from
chassis
using
stiff
wire
.



snagged
as
engine
is
removed
.

23
.
Disconnect
wiring
from
starter
and
alternator
.
Move



27
.
Installation
is
reverse
of
removal,
noting
the
following
:
wiring
harness
out
of
the
way
.
See
121
Battery,
Start-
Replace
al¡
gaskets,
O-rings
and
seals
.
er,
Alternator
.



"
Change
engine
oil
and
filter
and
check
all
other
fluid

24
.
Remove
Fontexhaust
pipe
fromexhaust
manifold
.
See



levels
.
See
020
Maintenance
Program
.
"
Refill
and
bleed
cooling
system
.
See
170
Radiator
Fig
.
16
.



and
Cooling
System
.

"
Check
that
engine
drivebelts
properly
engage
the
pul-

ley
grooves
.

"
Install
the
Font
exhaust
pipesusing
new
gaskets
and
seif-locking
nuts
.
Use
copper
paste
on
threads
.
See
180
Exhaust
System
.

0012525

Fig
.
16
.
Front
exhaust
pipeto
exhaust
manifolds
mounting
nuts
on
6-

cylinder
engine
(arrows)
.

25
.
Install
an
engine
lifting
device
and
raise
engine
until
its

weight
is
supported
.
Remove
nuts
and
ground
strap

from
left
and
right
engine
mounts
.

ENGINE
REMOVAL
AND
INSTALLATION



110-
7

Tightening
Torques

"
Coolant
drain
plug
to
cylinder
block
.
25
Nm
(18
ft-Ib)
"
Engine
mount
to
subframe
M10
..
.
.
.
...
..............
..
.
45
Nm
(33
ft-Ib)

M8
..
..
.
..
................
...
22
Nm
(16
ft-Ib)

"
Intake
manifold
to
cylinder
head

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

M8
...
.
..
...
................
.
22
Nm
(16
ft-Ib)
"
Radiator
cooling
fan
to
coolant
pump40
Nm
(30
ft-Ib)

"
Radiator
drain
screw
to
radíator
...
2
.5
Nm
(22
in-lb)
"
Wiring
to
alternator
(M8
nut)
........
12
Nm
(9
ft-Ib)

"
Wiring
to
starter

M6
nut



.
..
...
..................
5
Nm
(44
in-lb)

M8
nut
.....
..
.
.
.
.
.............
12
Nm
(9
ft-Ib)

ENGINE
REMOVAL
AND
INSTALLATION

113
Cylinder
Head
Removal
and
Installation

GENERAL
.
...............
.
.
.
.
.
.......
113-1



CYLINDER
HEAD,
6-CYLINDER
.
.
.
.
.
.
.
113-10

Cylinder
head,
removing
(6-cylinder
engine)
..
113-10
CYLINDER
HEAD,
4-CYLINDER
..
.
...
.
.
113-1



Cylinder
head,
installing
(6-cylinder
engine)
...
113-15
Cylinder
head,
removing
(4-cylinder
engine)
...
113-1



E
Cylinder
head,
installing
(4-cylinder
engine)
...
113-6

GENERAL



CYLINDER
HEAD,
4-CYLINDER

The
information
given
inthis
repair
group
assumes
that
the

engine
is
installed
in
the
engine
bay
.
For
cylinder
head,
cam-



Cylinder
head,
removing

shaft,
and
valvetrain
disassembly
and
reconditioning
informa-



(4-cylinder
engine)
tion,
see116
Cylinder
Head
and
Valvetrain
.

For
ease
of
use
this
removal
procedure
is
broken
into
sub-
In
the
procedures
given
below,
engines
are
referred
to
by



sections,
as
follows
:
engine
code
.
If
necessary,
see100
Engine-General
for
en-

gine
code
and
application
information
.

NOTE-

If
a
head
gasket
problem
is
suspected,
acompression
test
will
usually
detectthe
fault
.
See
100
Engine-Gen-
eral
for
compression
testing
information
.

Special
BMW
service
tools
are
required
to
properly
remove
and
install
the
cylinder
head
on
both
the
4-cylinder
and
6-cyl-

inder
engines
.
The
special
tools
are
used
to
time
the
val-

vetrain
to
the
crankshaft
and
to
remove
the
Torx
(El
2)
head

bolts
.
Read
the
procedure
through
before
beginning
thejob
.

Cover
al¡
painted
surfaces
before
beginning
the
removal

procedure
.
As
an
aid
to
installation,
label
all
components,

wires,
and
hoses
before
removing
them
.
Do
not
reuse
gas-

kets,
O-rings
or
seals
during
reassembly
.

WARNING
-

Due
to
risk
of
personal
injury,
be
sure
the
engine
is
cold
before
beginning
the
removalprocedure
.

CYLINDER
HEAD
REMOVAL
AND
INSTALLATION



113-1

General
Coolingsystem,
draining
Cylinder
head
cover,
removing

Intake
manifold,
removing

Timing
chains,
uncoupling

Cylinder
head
assembly,
removing

WARNING
-

Allow
engine
to
cool
before
beginning
this
proce-
dure
.

General

1
.
Disconnect
negative
(-)
cable
from
battery
.

CAUTION
-

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

"
Disconnecting
the
battery
may
erase
fault
codees)

stored
in
control
module
memory
.
Check
for
fault

codes
using
special
BMW
diagnostic
equipment
.

NOTE-

The
battery
is
mounted
in
the
luggage
compartment
behind
the
right
side
trim
panel
.

2
.
Working
underneath
vehicle,
remove
front
exhaust
pipe

from
exhaust
manifold
.
See
Fig
.
1
.

3
.
Disconnect
vacuum
hose
fitting
from
brake
booster
on

rear
bulkhead
.
Plug
opening
in
booster
and
hose
end
.

CYLINDER
HEAD,
4-CYLINDER

113-2



CYLINDER
HEAD
REMOVAL
AND
INSTALLATION

0011s6i



-

0Fig
.
1
.



Front
exhaust
pipe
to
exhaust
manifold
mountíng
nuts
(arrows)
.
-1



~~
0013023

4
.
Remove
air
filter
housing
complete
with
mass
air
flow



Fig
.
3
.



Coolant
hose
connection
beneath
intake
manifold
on
M42

sensor
and
attached
hoses
and
ducting
.
See
Fig
.
2
.



engine
(arrow)
.

0011969

Fig
.
2
.



Air
filter
housing/air
intake
connections
on
M44
engine
with
traction
control
.
Clamp
atthrottle
housing
(A)
;
mass
air
flow
sensor
connector
(B)
;
and
clips
at
upper
air
filter
housing
(C)
.

Coolingsystem,
draining

5
.
Draincoolant
from
engine
block
and
radiator
.
See
170

Radiator
and
Cooling
System
.

NOTE-

"
The
block
drain
is
on
the
exhaust
sideof
the
engine,
near
cylinder
no
.
4
.

6
.
Disconnect
hoses
from
coolant
flange/thermostat
hous-
ing
on
frontof
cylinder
head
.
Unbolt
thermostat
housing
from
cylinder
head
.

CYLINDER
HEAD,
4-CYLINDER

7
.
On
M42
engines,
disconnect
hose
from
coolant
pipe
on

left
side
of
engine
.
See
Fig
.
3
.

8
.
Disconnect
heater
hoses
from
coolant
flange
on
rear
of
cylinder
head
.

Cylinder
head
cover,
removing

9
.
Remove
ignition
coil
pack
from
rightstrut
tower
.
See

Fig
.
4
.

0011995
"
The
radiator
drain
plug
is
on
the
bottomof
the
radiator



Fig
.
4
.



Cylinder
head
cover
showing
location
of
engine
breather
hose
on
the
driver's
side
.
Remove
small
plastic
lock
clipto



(A),
wiring
harness
duct
(B),
and
ignition
coil
pack
(C)
.
M44
pull
radiator
drain
plug
out
completely
.



engine
shown
.
Cover
on
M42
engine
is
similar
.

10
.
Disconnect
engine
breather
hose
from
cylinder
head
cover
.

11
.
Detach
wiring
harness
duct
at
rear
bulkhead
panel
and
pull
complete
duct
forward
and
up
to
allow
access
to
rear
of
cylinder
head
cover
.

12
.
Remove
spark
plugs
and
spark
plugwire
loom
.

"
Remove
plastic
cover
from
top
of
cylinder
head
.

"
Disconnect
spark
plug
wires
fromspark
plugs
and
re-

move
spark
plugs
.
"
Unbolt
spark
plug
cable
harness
and
heat
shield
from
right
side
of
cylinder
head
cover
and
set
aside
.

13
.
Unscrew
andremove
cylinder
head
cover
cap
screws

and
remove
cover
.
See
Fig
.
5
.

CAUTION-

Two
of
the
cover
hold-down
screws
are
under
the
spark
plug
cable
duct
.

NOTE-

Make
note
of
the
arrangement
of
cap
screws,
washers
and
rubber
grommets
holding
the
cylinder
head
cover
in
place
.

Fig
.
5
.



Cylinder
head
cover
mounting
points
(arrows)
.

Fig
.
7
.



M44
fuel
rail
air
connection
(A)
and
fuel
supply
and
return
lines
Intake
manifold,
removing



(B)
.

14
.
On
late
engines,
disconnect
injector
air
shrouding
hose

from
fitting
at
center
of
upper
intake
manifold
.



18
.
Disconnect
fuel
supply
and
return
lines
from
fuel
rail
.

15
.
Remove
upper
section
of
intake
manifold
.

"
Disconnect
ali
cables
harness
connectors
from
throttle

housing
and
intake
manifold
.

"
Disconnect
fuel
tank
vent
hose
fromvent
valve
on
low-

er
sitie
of
manifold
.

"
Remove
manifold
support
brackets
.
See
Fig
.
6
.

"
Remove
upper-to-lower
manifold
fasteners
(1
bolt,
2

nuts)
and
separate
upper
manifold
from
lowermani-

fold
.

Note
locating
dowei
sleeves
on
lower
to
upper
manifold
mounting
studs
.
Remove
dowels
and
set
aside
.
See
Fig
.
8
.

CYLINDER
HEAD
REMOVAL
AND
INSTALLATION



113-3

0012686

Fig
.
6
.



Intake
manifold
support
brackets
and
mountinghardware
.
Manifold
for
M44
engine
shows
.

16
.
Disconnect
oil
dipstick
tube
bracket
from
lower
manifold
section
.

17
.
On
M44
engine,
relieve
fuel
pressure
using
com-

pressed
air
(maximum
3
bar
pressure)
at
schroeder

valve
on
fuel
rail
.
Briefly
apply
air
pressure
to
force
fuel

back
intofuel
tank
.
See
Fig
.
7
.

WARNING
-

"
The
fuel
system
retains
fuel
pressure
when
the
engine
is
off
(up
to
75
psi)
.
Use
care
when
dis-
connecting
fuel
lines
.
Unscrew
the
fuel
tank
cap
to
retease
pressure
in
the
tank
.
Wrap
a
clean
shop
towel
around
the
fitting
when
loosening
.

"
Fuel
is
highly
flammable
.
When
working
around
fuel,
do
not
disconnect
any
wires
that
could
cause
electrical
sparks
.
Do
not
smoke
or
worknear
heaters
or
other
tire
hazards
.
Placea
tire
extin-
guisher
in
the
vicinity
of
the
work
area
.

19
.
Disconnect
coolant
hoses
from
vent
valve
on
lower
intake

manifold
.
Remove
crankcase
vent
valve
from
manifold
.

CYLINDER
HEAD,
4-CYLINDER

113-4



CYLINDER
HEAD
REMOVAL
AND
INSTALLATION

20
.
Disconnect
main
engine
wiring
harness
connector
.
La-

bel
and
disconnect
harness
connectors
for
crankshaft

and
camshaft
sensors
.
See
Fig
.
8
.

0012504

Fig
..
Crankcase
vent
valve
(A),
camshaft
and
crankshaft
sensor
harness
connectors
(B),
locating
bushings
(C),
main
engine
wiring
harnessconnector
(D)
.
M44
engine
shown
.

NOTE-

Early
engines
do
not
havea
maín
disconnect
at
the
lower
intake
manifold
harness
.
lf
necessary,
remove
the
cable
ducting
bolts
and
set
harness
ducting
aside
.

21
.
Remové
lower
section
of
intake
manifold
.

"
Remove
Y
shaped
supportbracket
from
underside
of
manifold
.
(See
Fig
.
6
.)
"
Unbolt
support
brackets
from
alternator
and
starter
.
"
Remove
nuts
holding
manifold
to
cylinder
head
and
pull
manifold
back
until
harness
connectors
for
oil

pressure
switch
and
coolant
temperature
sensorare

accessible
.
Label
and
disconnect
connectors,
then
re-

move
manifold
and
set
aside
.

Timing
chains,
uncoupling



26
.
Lock
crankshaft
in
TDC
position
by
insertíng
BMW
spe-

22
.
On
M42
engines,
remove
thermostat
housing
from
up-



cial
tool
no
.
11
2
300
through
bore
and
into
hole
infly-

per
timing
chaincover
.



wheel
or
driveplate
.
See
Fig
.
11
.

23
.
On
late
M44
engines
(January
1997
and
later),
remove



NOTE-
secondary
air
injection
check-valve
from
front
of
engine



"
If
necessary,
remove
plug
from
locating
bore
in
lower
and
lay
aside
.



edge
of
bell
housing
to
insert
locking
tool
.

24
.
Remove
cylinder
identification
sensor
from
upper
tim-
ing
chaincover
.
Remove
upper
timing
chaincover
.
See
Fig
.
9
.

25
.
Set
engine
to
approximate
TDC
by
rotating
in
normal
operating
direction
until
camshaft
lobes
at
cylinder
no
.
1
are
facing
each
other
.
See
Fig
.
10
.

CYLINDER
HEAD,
4-CYLINDER

Fig
.
9
.



Upper
timing
chain
cover
bolts
(arrows)
.
Remove
secondary
air
injection
check
valve
fromhose
(A)
on
M44
engine
.
Re-
move
cylinder
identification
sensor
from
chaincover
(B)
.

0011998

Fig
.
10
.
Engine
set
to
approximate
TDC
.
Cylinder
no
.
1
camshaft
lobes
face
in
and
arrows
on
sprockets
poínt
up
(arrows)
.

"
Confirm
that
the
locking
tool
has
been
correctly
in-
stalled
by
trying
to
rotate
the
crankshaft
.

27
.
Lock
camshafts
at
TDC
by
mounting
BMW
specíal
tool
no
.
113
240
over
square
ends
of
camshafts
.
See
Fig
.
12
.

NOTE-

Check
that
tool
is
squarely
seated
on
cylinder
head
gasket
surface
.
If
necessary,
rotate
camshafts
slightly
using
an
open-end
wrench
at
hex
oncamshafts
.

Fig
.
11
.
BMW
special
tool
no
.
11
2300
installed
through
bellhousin
and
finto
flywheel
(arrow)
tolockcrankshaft
at
TDC
.

Fig
.
12
.
BMW
special
tool
no
.
11
3
240
installed
on
rear
of
camshafts
tohold
them
at
TDC
.
(M44
engine
shown
.
Other
engínes
are

similar
.)

CAUTION-

The
camshafts
must
be
locked
in
the
TDC
position

using
the
special
service
tool,
or
equivalent,
be-

fore
removing
the
timing
chaín
.
The
tool
holds
the
camshafts
parallel
to
each
other
and
perpendicu-
larto
the
valve
covergasket
surface
.

CYLINDER
HEAD
REMOVAL
AND
INSTALLATION



113-5

6011966

28
.
Remove
hydraulic
chain
tensiones
from
right
side
ofcyl-

inder
head
.
See
Fig
.
13
.

Fig
.
13
.
Hydraulic
chain
tensioner
(arrow)
.

NOTE-

It
is
not
necessary
to
remove
the
cam
sprockets
from

the
chainuntessthese
parts
are
being
reptaced
.
tire
tie
each
sprocket
to
the
chain
to
keep
the
sprockets
timed
to
each
other
.
Keeping
the
sprockets
timed
will
símplífy
instaftation
.

uu
11999

Fig
.
14
.
Chainguide
and
guide
adjusting
sleeve
(arrow)
.
Allen-head
retaining
screwhasbeen
removed
.
Use
slotted
screwdriver
to
loosen
adjusting
sleeve
.

29
.
Remove
mounting
bolts
from
left
and
right
camshaft

sprockets
.
Then
remove
camshaft
sprockets
from
cam-



_



Cylinder
head
assembly,
removing

shafts
.
On
M44
engines,
note
orientation
of
sensor



31
.
Remove
crankshaft
locking
tool
(BMW
special
tool
no
.
wheel
.



11
2
300)
.
Usingthe
crankshaft
vibration
damper
bolt,

30
.
Remove
upper
bolt
from
left
chainguide
.
Loosen
chain



turn
engine
opposite
its
normal
direction
of
rotation

guide
adjusting
sleeve
approximately
two
turns
.
See



(counterclockwise
asviewed
from
the
front)
approxi

Fig
.
14
.



mately
45°
.
This
prevents
accidental
contact
between

valves
and
pistons
during
installation
.

CYLINDER
HEAD,
4-CYLINDER

113-
6



CYLINDER
HEAD
REMOVAL
AND
INSTALLATION

32
.
Using
Torx
E12
socket,
remove
cylinder
head
bolts
in



2
.
Check
gasket
surface
of
cylinder
head
and
cylinder

the
sequence
indicated
.
See
Fig
.
15
.
Remove
cylinder



block
for
warpage
using
a
straight
edge
.

head
and
head
gasket
.
Discard
head
boits
.



3
.
On
M42
engine
:
Be
sure
oil
feed
check
valve
and
spac-

er
are
correctly
positioned
in
block
.
See
Fig
.
16
.

0012502

Fig
.
15
.
Cylinder
head
bolt
loosening
sequence
.
Use
Torx
El
2
socket
.

Cylinder
head,
installing

(4-cylinder
engine)

CAUTION-

If
the
camshafts
were
removedrínstalled
while
the
cylinder
head
was
off,
a
minimum
wafting
time
ís
requíred
after
installing
the
camshafts
.
When
the
camshafts
are
removed,
the
hydraulic
lifters
canexpand
.
This
expansion
can
cause
fncreased
valve
lift,
resultíng
in
open
valves
and
pfston
con-
tact

Cylinder
head
installation
waiting
times

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

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

1
.
Clean
cylinder
head
and
gasket
surfaces
of
cylinder
block
and
al¡
timing
chain
covers
.

"
Remove
al¡
foreign
matter
and
any
¡¡quid
from
bolt
holes,
then
clean
with
a
thread
chaser
.

CAUTION-

Do
not
useametal
scraper
or
wire
brush
to
clean
the
alumfnum
cylinder
head
or
pistons
.
If
neces-
sary,
useahard
wooden
or
plastic
scraper
.
Also
available
are
abrasivediscs
to
be
used
ín
conjunc-
tionwíth
an
electric
dril¡
.
Be
sure
to
use
the
correct
disc
for
the
type
of
metalbeingcleaned
.

CYLINDER
HEAD,
4-CYLINDER

Fig
.
16
.
Oil
feed
check
valve
and
spacer
used
on
M42
engine
.
Install
check
valvewíth
collar
(arrow)
facing
down
.

CAUTION-

If
the
check
valve
is
not
installed
correctly,
oil
flow
to
the
cylinder
head
would
be
restrícted
.

4
.
Place
new
cylinder
head
gasket
on
surface
of
cylinder

block
.
Check
that
two
locating
dowels
are
correctly
po-

sitioned
in
block
and
not
damaged
.

CAUTION-

The
word
"OBEN",
prfnted
on
the
gasket,
should
face
up
.

5
.
Place
new
rubber
profile
gasket
in
groove
of
front
cover
.

6
.
With
camshafts
locked
in
TDC
positionwith
BMW
spe-
cial
tool
as
described
earlier,
set
cylinder
head
in
posi-
tion
.

CAUTION-

"
The
camshafts
mustbe
focked
in
the
TDC
posi-
tion
at
the
rear
of
the
cylinder
head
with
BMW
specfal
tool
no
.
113240
before
installing
the
cyl-
inder
head
.

"
Make
sure
the
crankshaft,
which
had
been
rotat-
ed
approximately
45°
opposite
the
dfrection
of
engine
rotation,
is
still
in
thatposition
before
low-
ering
the
cyffnder
head
ínto
position
.

"
Torx-type
cylinder
head
bolts
should
not
be
re-
used
.
They
are
stretch-type
bolts
and
must
al-
waysbe
replaced
whenever
loosened
.