piston BMW 318i 1992 E36 Workshop Manual

GENERAL
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100-1

Cylinder
Block
and
Crankshaft
.
.
.
.
.
.
.
.
.
...
100-1

Connecting
Rods
and
Pistons
.
.
.
.
.
.
.
.
.
.
.
.
.
100-1

Cylinder
Head
and
Valvetrain
.
.
.
.
.
.
.
.
.
.
.
.
.
100-2

VANOS
(Variable
Valve
Timing)
.
.
.
.
.
.
.
.
...
100-2

DISA
(Dual
Resonance
Intake
System)
.
.
.
.
.
100-3

Engine
Management
System
.
.
.
.
.
.
.
.
.
.
.
.
.
100-3

Ignition
......
.
.
.
.........
.
.
.
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.
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.
.
.
.
.
100-5

Fuel
Delivery
..
.
.
.
.....
.
...
.
.
.
.
.
.
.
.
.
.
.
.
100-5

Cooling
System
.
...........
.
.
.
.
.
.....
.
.
100-5

Lubrication
System
.........
.
.
.
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.
.
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.
100-5

MECHANICALTROUBLESHOOTING
.
.
.
.
100-5

Warnings
and
Cautions
..
.
...
.
.
.
.
.
.
.
.
.
.
.
.
100-5

Cylinder
compression,
checking
.
.
.
.
.
.
.
.
.
.
.
100-6

EngineMechanical
Troubleshooting
Table
.
.
.
100-7

DRIVEABILITY
TROUBLESHOOTING
...
100-8

GENERAL

There
are
various
engíne
configurations
used
in
the
1992-

1998
E36
cars
.
See
Table
a
.

On
both
four-
and
6-cylinder
engines,
the
cylinder
block
is

cast
¡ron
with
integral
cyiinders
.
The
cyiinders
are
exposed
on

all
sides
to
circulating
coolant
.

The
fully
counterweighted
crankshaft
rotates
in
replaceable

split-shell
main
bearings
.
Oiiways
drilled
into
the
crankshaft
pro-

vide
bearing
lubrication
.
O¡I
seals
pressed
into
alloy
sea¡
hous-

ings
are
installedat
both
ends
of
the
crankshaft
.

100
Engine-General

Tablea
.
Engine
Specifications

ENGINE-GENERAL
100-1

On-Board
Diagnostics
(OBD)
...
.
.
.
.
.
.
.
.
.
.
.
100-8

Basic
Requirements
....
.
.
.
...
.
.
.
.
.
....
.100-11

Preventive
Maintenance
......
.
.
.
.
.
.....
100-11

Basic
Engine
Settings
..
.
.....
.
.
.
.
.
.....
100-11

Oxygen
Sensors
.
.
.
...
.
.
.
...
.
.
.
.
.
....
.100-11

Air
Flow
Measurement
and
Vacuum
Leaks
.
.100-12

Battery
Voltage
.
.
...........
.
.
.
.
.
.....
100-12

Wiring
and
Harness
Connections
.
.
.
.
.....
100-13

Ground
Connections
...
.
.....
.
.
.
.
.
.....
100-13

Fue¡
Supply
....
.
...........
.
.
..
.....
.100-14

TABLES

a
.
Engine
Specifications
...
...
...........
.
..
..
.100-1

b
.
Engine
Management
Systems
..
..
...........
..
100-5

c
.
Engine
Mechanical
Troubleshooting
..........
.
.
100-8

d
.
OBD
1
Fault
(Blink)
Codes
(1992-1995
models
only)
.
...
..
..
..........
..
.100-9
e
.
Engine
Driveability
Troubleshooting
...........
.100-15
Model



Engine
code



No
.
of



Dispiacement



Compression



Horsepower
cyiinders



liters
(cu
.
in
.)



ratio



SAE
net
@
rpm

318i/is/¡C
1992-1995



M42



4



1
.8
(109
.6)



10
.0
:1



100
@
6000
1996-1998



M44



4



1
.9
(115
.6)



~
10
.0
:1



103
@
6000

323ís/iC
1998



M52



6



2
.5
(152
.2)



10
.5
:1



168
@
5,500

325i/is/iC
1992-1995



M50



6



2
.5
(152
.2)



10
.0
:1



110
@
5,900

328i/is/iC
1996-1998



M52



6



2
.8
(170
.4)



10
.2
:1



190
@
5,300

M3
1995



S50US



6



3
.0
(182
.5)



10
.5:1



240
@
6,000
1996-1998



S52US



6



3
.2
(192
.3)



10
.5:1



240
@
6,000
Cylinder
Block
and
Crankshaft



Connecting
Rods
and
Pistons

The
forged
connecting
rods
use
replaceable
split-shell

bearings
at
the
crankshaft
endand
solid
bushings
at
the
pis-

ton
pin
end
.
The
pistonsare
of
the
three-ring
typewith
two
up-
per
compression
rings
and
a
lowerone-piece
o¡i
scraper
ring
.

Fui¡-floating
piston
pins
are
retained
with
circlips
.

GENERAL

100-2
ENGINE-GENERAL

Cylinder
Head
and
Valvetrain

The
aluminum
cylinder
head
uses
chain-driven
double
overhead
camshafts
and
four
valves
per
cylinder
.
See
Fig
.
1
.

The
cylinder
head
employs
a
crossflow
design
for
greater

power
and
efficiency
.
Intake
air
enters
the
combustion
cham-

ber
from
one
side
while
exhaust
gasses
exit
from
the
other
.

Oílways
in
the
head
provide
lubrication
for
the
camshafts)
and
valvetrain
.

Fig
.
1
.



M52
twin-cam,
4-valve-per-cylinder
engine
with
hydraulíc
lift-
ers
.

On
all
engines
exceptthe
M44
engine,
valveclearance
is
by
seif-adjusting
hydraulic
lifters
.
On
M44
engines,
instead
of
hy-

draulic
lifters,
hydraulic
pedestaisare
used
in
combination
with
roller
rocker
arms
to
actuate
the
valves
.
Hydraulic
pedes-
tals
have
the
same
function
as
hydraulic
lifters,
which
ís
to
maintain
zero
valve
clearance,
reduce
valve
noise,
and
elimí-
nate
routíne
adjustment
.
See
Fig
.
2
.

VANOS
(Variable
Valve
Timing)

GENERAL

1
.
Camshafts
2
.
Rocker
arms
3
.
Hydraulic
valve
adjusters
(HVA)
4
.
Valve
and
conical
valve
spring

4

Fig
.
2
.



Cross
sectionof
M44
twin-cam,
4-valve-per-cylinder
head
.
Note
function
of
hydraulíc
pedestal
in
combination
with
rock-er
arm
(with
roller
bearing
for
reduced
friction)
.

The
main
components
of
the
VANOS
system
arethe
piston

housing
with
integral
spool
valve
and
solenoid,
and
the
modi-

fied
intake
camshaft
and
sprocket
assembly
.
See
Fig
.
3
.

1993
and
later
6-cylinder
engines
are
equipped
with
a
vari-



B11001

able
intake
valve
timing
system,
known
as
VANOS
(from
the
German
words
Variable
Nockenwellen
Steuerung)
.
The



Fig
.
3
.
VANOS
(variable
intake
valve
timing)
systemusedon
M52
en-
VANOS
system
electro-hydraulically
adjusts
intake
valve
tim-



gine
.
When
solenoid
is
actuated,
oíl
pressure
is
directed
to
ingfor
enhanced
mid-range
performance
.
The
VANOS
sys-



front
side
of
gear
cup
piston
.
This
forces
gear
cup
finto
camtem
is
controlled
by
the
engine
control
module
(ECM),
using



shaft
to
advance
intake
valve
timing
.
enginespeed,engine
load
and
engine
temperature
asthe
pri-
mary
inputs
.



When
the
engine
is
running,
the
piston
housing
is
supplied
with
pressurized
engine
oil
víathe
solenoid-actuatedspool
At
low
speeds,
the
intake
valves
open
late
to
ensure
smooth



valve
.
Depending
on
the
position
of
the
spool
valve,
oil
isdi
engine
operation
.
At
mid-rangespeeds,
thevalves
open
early



rected
to
either
the
front
or
back
side
of
the
gear
cup
piston
.
(valvetiming
advanced,
VANOS
actuated)
for
increased
torque,
improved
driveability,
and
reduced
emissions
.
And
at



When
the
solenoid
isin
the
off
position,
engine
oíl
is
direct-
high
speeds,
the
valves
again
open
late
for
optimum
power



ed
to
the
back
side
of
the
piston
.
This
holds
the
gear
cup
for-
and
performance
.



ward
and
valve
timing
is
maintained
at
the
normal
"late"
position
.
When
the
solenoid
is
energized,
the
spoolvalve
is
moved
forward
and
oil
pressure
is
directed
to
the
front
side
of
the
piston
.
This
in
turn
moves
thegear
cup
further
into
the

eiioo4

Fig
.
9
.



Remove
ignition
coils
on
6-cylinder
engine
by
disconnecting
harness
connector
and
removing
mounting
bolts
(arrows)
.

NOTE-

"
The
compression
gauge
reading
shoutd
increase
with
each
compression
stroke
and
reach
near
its
maxi-
mum
reading
in
about
4-6
strokes
.

"All
cylinders
shoutdreach
maximum
compression
in
the
same
number
of
strokes
.
If
a
cylinder
needs
sig-
nificantly
more
strokes
to
reach
maximum
compres-

sion,
there
is
a
problem
.

7
.
Release
the
pressure
at
the
compression
gauge
valve,

then
remove
the
gauge
from
the
spark
plughole
.
Re-

peat
the
test
for
each
of
the
other
cylinders
and
com-

pare
the
results
with
the
values
given
below
.

ENGINE-GENERAL
1
:00-
7

Compression
Pressure

"
Minimum
..........
.
.
..
..
10-11
bar
(142-156
psi)

"
Maximum
difference
between
cylinders
..
.....
.........
0
.5
bar
(7
psi)

Reinstall
the
spark
plugs
and
spark
plug
wires
or
ignition

cofs
.
The
remainder
of
installation
is
the
reverse
of
removal
.
Be
sure
to
reihstall
al¡
wires
disconnected
during
the
test,
especial-

¡y
ground
wires
at
the
coils
and
cylinder
head
cover
(where
ap-
plicable)
.

Tightening
Torque

"
Spark
plug
to
cylinder
head
.......
25
Nm
(18
ft-Ib)

Low
compression
indicates
a
poorly
sealed
combustion

6
.
With
the
parking
brake
set,
the
transmission
in
Park
or



chamber
.
Relatively
even
pressures
that
are
below
specification

Neutral,
and
the
accelerator
pedal
pressed
to
the
floor,



normally
indicate
worn
piston
rings
and/or
cylinder
walls
.
Erratic

crank
the
engine
with
the
starter
.
Record
the
highest



values
tend
to
indicate
valve
leakage
.
Dramatic
differences
be

value
indicated
by
the
gauge
.



tween
cylinders
are
often
the
sign
of
a
failed
head
gasket,

bumed
valve,
or
broken
piston
ring
.

Engine
Mechanical
Troubleshooting
Table

Table
c
lists
the
symptoms
of
common
engine
mechanical

problems,
their
probable
causes
and
the
suggested
corrective

actions
.
The
bold
type
indicates
the
repair
groups
where
appli-

cable
test
and
repair
procedures
can
befound
.

MECHANICAL
TROUBLESHOOTING

100-8
ENGINE-GENERAL

Symptom



1



Probable
cause
and
correctiveaction

1
.
Engine
will
not
start
or
run
.
Starter
cranks



a
.



No
fuel
reaching
engine
.
Check
forfuelin
tank
.

engine
at
normal
speed
.



Fuel
pump
notoperating
.
Repair
Group
160

b
.
No
spark
.
Check
ignition
system
.
Repair
Group
120

c
.
Incorrect
valve
timing
.
Check
timing
chain
.
Repair
Group
117

2
.
Check
Engine
warning
light
illuminated
.



a
.
DME
engine
management
system
self-diagnostic
fault
detected
.
Sea
an
authorized
BMW
dealer
or
other
qualified
shop
for
OBD
II
fault
code
diagnosis
.
See
also
On-
board
Diagnostics(OBD),
given
later
inthis
repair
group
.

3
.
White
exhaust
smoke
(steam)
.



a
.
Failed
cylinder
head
gasket
(probably
accompanied
bylowcompression
readings)
.

Replace
gasket
and
resurface
cylinder
head
if
necessary
.
Repair
Group
113
4
.
Blue-gray
exhaust
smoke
and
oily
spark



a
.
Contaminated
or
gasoline-diluted
engine
oil
.
Change
engine
oil
and
replace
oil
filter
.
plugs
.
Indicates
oii
burning
in
combustion
.



Repair
Group
020

b
.
Faulty
valve
guide
seals
or
valve
guides
.
Replace
valve
guide
oil
seals
or
overhaul
cylinder
head
.
Repair
Group
116

5
.
Pinging
or
rattling
when
under
load,



a
.
Ignition
timing
too
advanced
.
Ignition
knocksensors
faulty
(CheckEngine
light
traveling
uphill,
or
accelerating,
especially



illuminated)
.
Repair
Group
120fromlow
speeds
.
Indicates
pre-ignition
or



b
.
Fuel
octane
leve¡
toolow
.
detonation
.



c
.
Engine
running
too
hot
or
overheating
.
Check
cooling
system
.
Repair
Group
170

6
.
Light
metallic
tapping
that
varies
directly
with
engine
speed
.
Oil
pressure
warning
light
not
illuminated
.

7
.
Light
metallic
knock
that
varies
directly
with
enginespeed
.
Oil
pressure
warning
light
blinking
or
fully
illuminated
;
may
be
most
noticeable
during
hard
stops
or
cornering
.

8
.
Screeching
or
squealing
under
load
that



a
.
Loose,worn,
or
damaged
drive
belt
.
Inspect
belt(s)
.
Repair
Group
020
goesaway
when
coasting
.

9
.
Growling
or
rumbling
that
varieswith
engine



a
.
Remove
drive
belt(s)toidentifyfaulty
component
.
Check
for
play,
bearing
roughness,
rpm
.
Indicates
abad
bearing
or
bushing
in



and
loose
mountings
.
Refer
to
appropriate
repair
group
for
repair
procedures
.
an
engine-driven
accessory
.

DRIVEABILITY
TROUBLESHOOTING



On-Board
Diagnostics
(OBD)

On-Board
Diagnostics
is
incorporated
into
al¡
engine
man-



Two
generations
of
OBD
are
usedon
thecars
covered
by
agement
systems
used
on
the
cars
covered
by
this
manual
.



this
manual
:
Therefore,
checking
for
fault
codes
should
be
the
first
step
in
troubleshootinga
driveability
problem
.
For
additional
informa-



On-Board
Diagnostics
tion
on
engine
management
and
repair
see130
Fuel
Injec-
tion
.



"
1992-1995models
....
.
..
....
.
..
.......
OBD
I

"
1996-1998models
.
....
..
.
.
.
..
.
........
OBD
II

DRIVEABILITY
TROUBLESHOOTING

Tablec
.
Engine
Mechanical
Troubleshooting

b
.
Warped
or
cracked
cylinder
head
.
Resurface
or
replace
cylinder
head
.
Repair
Group
113

c
.
Cracked
cylinder
block
.
Replace
engine
or
short
block
.

c
.
Worn
piston
rings
.
Overhaul
or
replace
engine
.

d
.
Failed
cylinder
head
gasket
.
Replace
gasket
.
Repair
Group
113

d
.
Air/fuel
mixture
too
lean
(Check
Engine
light
illuminated)
.
Repair
Group
130

a
.
Valveclearances
excessive
.
Check
hydraulic
valve
adjusters
.
Repair
Group
116

b
.
Low
oil
pressure
orpossibly
defective
warning
light
circuit
.
Check
oil
pressure
andwarning
light
circuit
.
Repair
Group
119
c
.
Dirty
oil
.
Change
oil
.
Repair
Group
020
.

a
.
Low
oil
leve¡
.
Check
and
correct
oil
leve¡
.

b
.
Low
oil
pressure/worn
or
faulty
oil
pump
.
Oil
pump
pickup
restricted/clogged
.
Check
oil
pressure
.
Repair
Group
119

The
OBD
system
detects
emissions-related
engine
manage-
ment
malfunctions
and
tucos
on
the
Check
Engíne
lightin
the
in-
strument
cluster
.
TheCheck
Engine
light
will
stay
on
until
the
code(s)are
called
up
and
the
memory
is
erased
.
When
faulty
are
detected,
the
OBD
system
stores
a
Diagnostic
Trouble
Code
(DTC)
in
the
system
ECM
.
In
addition,
the
Check
Engine
warn-
ing
light
will
come
on
if
an
emissions-related
fault
is
detected
.

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
.

113-8



CYLINDER
HEAD
REMOVAL
AND
INSTALLATION

IW?
-
L
'/~f
W



~
4r

"

-
"



;,s
1

12
.
On
M44
engine
:
Place
sensor
wheel
on
intake
cam-
shaft
sprocket
so
that
arrowon
sensor
wheel
points
up
.

13
.
Instan
and
hand-tighten
sprocket
mounting
bolts
.

CAUTION-

Different
hydraulic
chaintensioners
were
used
during
manufacture,
depending
onengine
type
.
See
Fig
.
21
.
Note
that
the
late
style
tensioner
can
be
retrofitted
to
the
earlier
engine,
so
be
sure
to
identify
the
version
of
tensioner
installed
as
insta-lation
instructions
vary
between
the
two
.

14
.
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
.
22
.

M42
Engine

up
and
camshaft
threaded
holes
centered
in
siotted
holes
.

CYLINDER
HEAD,
4-CYLINDER

0013024a

Outer
sl
eve



Detent

ring

Spri
g

Fig
.
22
.
Disassembled
chain
tensioner
for
M42
engine
.

15
.
On
M42
engine
:
Clamp
tensioner
piston
in
vice
(soft

jaws)
.
Slowly
compress
piston,
making
sure
detent
ring

fits
into
taper
of
outer
sleeve
.
If
necessary,
press
ends

of
detent
ring
together
.
Slowly
continuepressing
ten-

sioner
together
until
snap
ring
audibly
clicksinto
outer

sleeve
.
Measure
overall
lengthof
tensioner
to
confirm

correct
assembly
:
68
.5
mm
(2.7
in
.)
.

NOTE-

i

Snap

ring

/0
.13024

The
late-style
tensioner
on
the
M44
engíne
canbe
ret-
rofitted
to
the
M42
engine
.

Tightening
Torque

"Chain
tensioner
plug
to
cylinder
head
.....
.-~
..........
40
Nm
(30
ft-Ib)

16
.
On
M44
engíne
:
Clamp
tensioner
píston
in
vice
(soft

jaws)
and
squeeze
oil
from
it
.
Slowly
compress
piston
only
up
to
end
circlip
.
Repeat
procedure
twice
to
ensure

all
oil
is
expelled
.
See
Fig
.
23
.

17
.
Instan
hydraulic
chain
tensioner
to
cylinder
head
.
Use
a
new
sealing
washer
on
tensioner
when
installing
.

18
.
On
M42
engine
:
Unlock
chain
tensioner
by
pressing
chain
rail
against
tensioner
until
it
expands
out
.

19
.
Check
that
chain
is
free
of
slack
.
Tighten
sprocket
mounting
bolts
.
Fig
.
21
.
Two
versions
of
hydraulic
chain
tensioners
.
Original
chainten-
sioner
on
M42
engine
(top)
can
be
disassembled
.
Chain
ten
sioner
on
M44
engine
(bottom)
cannotbe
disassembled
.



Tightening
Torque
Note
differences
in
outer
sleeve
.
Also,
the
M42
tensioner
de-



"
Chain
sprocket
to
camshaft
flange
.
..
10
Nm
(89
in-lb)
tent
ring
groove
(arrow)
is
visible
when
tensioner
is
extended
.

20
.
Remove
crankshaft
locking
tool
from
bellhousing
and
camshaft
locking
tool
from
rear
of
cylinder
head
.

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

113-14



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