1996 BMW 325i Measure

010-10



FUNDAMENTALS
FOR
THE
DO-IT
YOURSELF
OWNER

TOOLS

Torque
Wrench

B021FNG

Fig
.
12
.
Jack
stand
for
safely
supporting
car
to
work
underneath
.

B022FNG

Fig
.
13
.
Oil
change
equipment
includesdrainplug
wrench
(17mm),
8
qt
.
drain
pan,
and
funnel
.

A
torque
wrench
is
used
to
precisely
tighten
threaded
fasten-



Fig
.
15
.
Feeler
gauge
set
.
ers
to
a
predetermined
value
.
Many
of
the
repair
procedures
in
this
manual
include
BMW-specified
torquevalues
in
Newton-
meters
(Nm)
and
the
equivalent
values
in
foot-pounds
(ft-Ib)
.



Digital
Multimeter

A
torque
wrench
with
a
range
up
to
about
150
Nm
(185
ft-lb)
has
adequate
capacity
for
most
of
the
repairs
covered
in
this
manual
.
For
recommended
torque
values
of
10
Nm
or
below,the
English
system
equivalent
is
given
in
inch-pounds
(in-lb)
.
These
small
values
may
be
most
easily
reached
using
a
torque
wrench
calibrated
in
inch-pounds
.
To
convert
inch-pounds
to
foot-pounds,
divide
by12
.

Fig
.
14
.
Torque
wrenches
.
Inexpensive
beam-type
(top)
is
adequate
but
must
be
read
visually
.
Ratchet-type
(bottom)
can
be
pre-
set
to
índicate
(click)
when
torquevalue
has
been
reached
.

Feeler
Gauges

B018FNG

Feeler
gauges
are
thin
metal
strips
of
precise
thickness,

used
to
measure
small
clearances
.
They
are
normally
available

as
a
set,
covering
a
range
of
sizes
.
See
Fig
.
15
.

Several
types
of
torque
wrenches
are
available
.
They
al¡
do



Many
of
the
electrical
tests
in
Chis
manual
cal¡
for
the
mea-
the
same
job,
bu¡
óffer
different
convenience
features
at
differ-



surement
of
resistance
(ohms)
or
voltage
values
.
For
safe
and
ent
prices
.
Two
typical
torque
wrenches
are
shown
in
Fig
.
14
.



accurate
tests
of
ignition,
fuel
injection,
and
emission
control
The
most
convenient
ones
have
a
built-in
ratchet,
and
can
be



systems,
the
multi-meter,
shown
in
Fig
.
16,
should
be
digital,
preset
to
indicate
when
a
specific
torque
value
has
been



with
high
(at
least
10,000
ohms)
input
impedance
.
Some
reached
.
Followthe
wrench
manufacturer's
directions
for
use



meters
have
automotive
functions
suchas
dweil
and
pulse
to
achieve
the
greatest
accuracy
.



width
that
are
useful
fortroubleshooting
ignition
and
fuel
injec-
tion
problems
.

CAUTION-

The
DME
system,
central
body
electronics,
and
other
electronic
systems
may
be
damaged
by
the
high
current
draw
of
a
test
fight
with
a
normal
in-
candescent
bulb
.
As
a
general
rule,
usea
high
ím-
pedance
digital
multimeter
or
an
LED
test
fightforall
electrfcal
testfng
.

B020FNG

020-
1
4



MAINTENANCE
PROGRAM

uu11989

Fig
.
14
.
Engine
drive
belt
tensíoner
being
released
on
late
4-cylinder
engine
.
Pry
off
tensioner
cover
and
then
lever
tensioner
in
clockwise
direction
(as
facing
engine)
and
slip
beltoff
pulleys
.



Fig
.
17
.
Engine
drive
belt
routing
for
late
4-cylinder
engine
with
poly-
ribbed
drivebelts
.

CA
UTION-

Use
only
BMW
approved
phosphate-free
anti-
freeze
when
filling
the
cooling
system
.
Use
of
anti-

B11177



freeze
containing
phosphates
!s
considerad
to
be

Fig
.
15
.
Engine
drive
belt
tensioner
being
released
on
6-cylinder
en-



harmful
to
the
cooling
system
.

gine
.
Pry
off
tensioner
cover
and
then
lever
tensioner
in
clock-
wise
direction
(as
facing
engine)
and
slipbelt
off
pulleys
.



A
translucent
expansion
tank,
or
overflow
resenroir,
providesmonitóring
of
coolant
leve¡
.
Because
the
expansion
tank
is
translucent,
thecoolant
level
can
be
checked
visually
without
opening
the
system
.
Always
check
thecoolant
leve¡
with
theen-gine
cold
.
The
coolant
leve¡
should
be
at
the
maximum
mark
on
O



o
'~
I



the
expansion
tank,
as
shown
in
Fig
.
18
.

OO



Hose
connectionhld
b
tiht
s
soueg



an
ddry
.
Coolánt
seepage
indicates
either
that
the
hose
clamp
is
loose,
that
the
pose
is

ENGINE
COMPARTMENT
MAINTENANCE

0012470

Fig
.
16
.
Engine
drive
belt
routing
for
6-cylinder
engine
.
A/C
compres-
sor
drive
belt
not
shown
.

'92

irá
Alternator
belt

Coolant~
0
pp



o0o



Belt
tensioner

Cooling
System
Service

0013000

Cooling
system
maintenance
consists
of
maíntaining
thecoolant
leve¡,
inspecting
hoses
.
Because
the
coolant's
anti-cor-

rosion
and
anti-freeze
additives
gradually
lose
their
effective-
ness,
replacement
of
thecoolant
every
two
years
up
to
1996
models,
and
every
three
years
from
1996
is
recommended
.
Asa
preventive
measure,
replacement
of
the
cooling
system
hos-
es
every
four
years
is
also
recommended
.

damaged,
or
that
the
connection
is
dirty
or
corroded
.
Dried
cool-
ant
has
a
chalky
appearance
.
Hoses
should
be
firm
and
springy
.
Replace
any
hose
that
is
cracked,
that
has
become
soft
and
limp,
or
has
been
contaminated
by
oil
.
See
Fig
.
19
.

Power
steering
fluid,
checking
leve¡

Check
the
power
steering
fluid
level
in
the
fluid
reservoir
.
Park
thecar
on
leve¡
ground
with
the
engine
off
.
The
level
is
cor-
rect
if
it
is
between
the
MIN
and
MAX
marks
on
the
dipstick
.
See
Fig
.
20
.
If
the
leve¡
is
below
the
MIN
mark,
start
the
engine
andadd
fluid
to
the
reservoir
to
bríng
the
leve¡
up
.
Stop
the
engine
and
recheck
the
leve¡
.
Hand-tighten
the
reservoir
cap
.

GENERAL
.
.....
.
.
.
.
.
.
.
...
.
.
.
.
.
.
.
.
.
...
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
......
.
.
.
.........
.
.
.
.
.
.
.
.
.
.
.
.
100-5

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

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

Lubrication
System
.........
.
.
.
.
.
.
.
.
.
.
.
.
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

Graphic
representation
of
flashing
Check
Engine
light
fault
code
:
1221

-
;
5
Seconds
.
~-



2
.5;-

Fault
code
and
meaning



Corrective
action

Code
1286
:
Knock
control
test
pulse
(DME
3
.3
.1
only)



Check
DME
control
module
inputs/outputs
.
Control
module
may
be
faulty
Repair
Group
130

Code
1000
(light
remains
off)
:



End
of
fault
code
output-all
fault
codes
have
been
displayed
.
No

~
corrective
action
necessary
.
Repeat
test
if
necessary

Code
1444
:



No
more
faults
.
No
corrective
action
necessary
.
This
code
must
be
present
lo
erase
fault
memory

Basic
Requirements



Preventive
Maintenance

The
following
list
contains
basic
checks
that
should
be
made
when
experiencing
driveability
problems
.

1
.
Check
intake
(induction)
system
for
leaks
.
Check
for

cracked,
loose,
or
disconnected
hoses
and
duct
work
.

Check
that
all
hose
clamps
are
tight
.

NOTE-

An
air
leak
allows
unmeasured
airto
enter
the
engine,
offen
resulting
in
an
in
overly
lean
fuel
mixture
and
causing
driveability
problems
which
will
cause
the
Check
Engine
light
to
come
on
.

Table
d
.
OBD
I
Fault
(Blink)
Codes
(continued)

(1992-1995
models
only)

7
-
1
--------------
Check
Engine
light
on

ENGINE-GENERAL
100-
1
1

Check
Engine
light
off

The
condition
of
the
fuel,
ignition
and
emission
controlsys-

tem
components
has
a
directeffect
onengineperformance

and
driveability
.
BMW
specifies
maintenance
of
certain
parts

at
regular
intervals
lo
keep
the
engine
in
proper
tune
.
Extend-
ing
maintenance
intervals
beyond
the
time
or
mileagerecom-
mended
bythe
manufacturer
can
adversely
affect
the
way
the
engine
runs
.
When
troubleshooting
driveability
problems,
a
good
starting
point
is
to
perform
a
major
engine
service,par-

ticularly
if
one
is
overdue
.
For
maintenance
schedules,
major
engine
service
and
other
driveability-related
maintenance

procedures,
see020
Maintenance
Program
.

Basic
Engine
Settings

2
.
Check
that
the
battery
isin
good
condition
.
Check
that

the
cables
are
tight
and
free
of
corrosion
at
both
ends
.



Idle
speed,
idle
mixture
(%CO),
and
ignition
timing
are
not

Check
that
all
related
ground
points
are
firmly
connect-



adjustable
.
The
adaptive
engine
management
system
is
de-

ed
and
in
good
condition
.
Check
al¡
harness
connectors



signed
lo
automatically
compensate
for
changes
in
engine
op-

for
damage
and
corrosion
.



erating
conditions,
although
the
adaptive
range
is
limited
.

Once
these
limits
are
exceeded,
driveability
problems
usually

3
.
Check
for
prwer
and
ground
at
the
Engine
Control



become
noticeable
.

Module
(ECM)
.
Check
the
main
grounds
for
the
ECM
.

See130
Fuel
Injection
.



NOTE-

If
the
DME
adaptive
limits
are
exceeded,
the
Check
En-
4
.
Check
the
fuses
.
Check
for
sufficient
fuel
in
the
tank
.
If



gine
light
will
come
on,
indicating
an
emission
related
the
engine
ranout
of
fuel,
it
will
take
a
little
time
to
re-



fault
.
See
130
Fuel
Injection,
store
fuel
pressure
.
See
160
Fuel
Tank
and
Fuel

Pump
.
Oxygen
Sensors

5
.
Check
for
spark
at
the
spark
plugs
.
If
the
tachometer

needle
bounces
while
the
engine
is
crankedby
the



A
high
oxygen
level
in
the
engine
exhaust
indicates
a
lean

starter
then
the
ignition
system
is
probably
working
cor-



air-fuel
mixture
and
a
low
oxygen
level
indicates
a
rich
mix

rectly
.
See
120
Ignition
System
.



ture
.
The
oxygen
sensor,
shown
in
Fig
.
10,
measures
the
oxy-

gen
content
in
the
exhaust
gasand
generates
a
variable

6
.
Check
for
any
faults
through
the
On-Board
Diagnostics



voltage
signal
.
Using
that
feedback
signal
asan
input,
the

system
.
See
On-Board
Diagnostics
(OBD)
.



DME
control
module
fine
tunes
the
air-fuel
mixture
.

DRIVEABILITY
TROUBLESHOOTING

100-
1
2
ENGINE-GENERAL

NOTE-

The
oxygen
sensor
signal
is
ignored
until
the
engine
reachesa
specified
minimum
temperature
.
Therefore,



The
primary
input
usedby
the
fuel
injection
system
to
deter-

when
troubleshooting
cold
engine
driveability
prob-



mine
how
much
fuel
should
be
delivered
is
the
signal
from
the

lems,
the
oxygensensor
canbe
ruled
out
asa
possible



mass
air
flow
sensor
in
the
intake
air
ductwork
.

cause
.

As
the
oxygen
sensor
ages,
its
ability
to
react
quickly
to

changing
conditions
deteriorates,
and
it
may
eventually
cease

to
produce
any
signal
at
all
.
To
check
the
operation
of
the
oxy-

gen
sensor,
see
130
Fuel
Injection
:

NOTE-

On
1996
and
latercars,
OBD
11
enhanced
emission
standards
require
the
engine
control
module
(ECM)
to
monitor
the
oxygen
content
in
the
exhaust
both
before
and
after
the
catalytic
converter
.
Thisallows
for
tighter
control
of
the
tail
pipe
emissions
and
also
allowsthe
ECM
to
diagnose
converter
problems
.
If
the
DME
de-
tects
that
catalytic
converter
or
oxygensensor
efficien-
cyhas
degraded
pasta
certain
pre-programmed
limit,
it
will
turn
on
the
Check
Engine
light,
and
store
a
diag-
nostic
trouble
code
(DTC)
in
the
ECM
.

DRIVEABILITY
TROUBLESHOOTING

Catalytic

B9506

Air
Flow
Measurement
and
Vacuum
Leaks

Because
proper
fuel
metering
depends
on
accurate
mea-

surement
of
the
incoming
air,
any
unmeasured
air
that
enters

the
engine
downstream
of
the
mass
air
flow
sensor
will
cause

a
lean
air-fuel
mixture
and
possibly
affectdriveability
.

NOTE-

Fig
.
10
.
Regulating
oxygen
sensor
measures
oxygen
content
of
ex-



gattery
Voltage
hausY
gas
as
indicator
of
.¡_fi
.1
ratio
and
"-k,
.

E-
effi-
ciency
.
Monitoríng
oxygen
sensor
(not
shown)
monitors

If
a
large
air
leak
is
causing
driveability
problems,
the
Check
Engine
light
will
usually
be
illuminated
and
a
fault
will
be
stored
in
the
fault
code
memory
.
See
On
Board
Diagnostics
(OBD)
.

There
are
many
places
for
unmeasured
air
to
enter
theen-

gine
.
First,
inspect
all
hoses,
fittings,
ducts,
seals,
and
gaskets

in
the
intake
air
tract
for
cracks
or
looseness
.
It
may
be
neces-

sary
to
remove
parts
that
cannot
be
fully
checked
in
their
in-

stalled
positions
.
Also
make
sure
all
of
the
intake
manifold
and

throttle
body
mounting
nuts
are
tight
.

In
addition
to
air
leaks,
air
restrictions
can
also
cause
drive-

ability
problems
.
Remove
the
air
filter
and
hold
it
up
to
a
strong

light
source
.
If
the
filter
does
not
pass
light,
it
is
restricted
and

should
be
replaced
.
Also,
remove
the
intake
air
ductwork
and

check
for
oily
deposits
at
the
throttle
plate
.
Buildup
in
this
area

can
cause
an
erratic
idle
.
Clean
away
any
deposits
using
a

cloth
wetted
withcarburetor
cleaner
and
reinstall
the
ductwork
.

CAUTION-

Do
not
spray
carburetor
cleaner
directly
in
the
throt-
tle
anea
.
Spraying
cleaner
may
force
it
into
the
throt-
tle
position
switch
or
sensor
and
cause
damage
.

catalytic
converter
operation
.



All
of
the
electrical
components
in
the
fuelinjection
and
igni-
tion
systems
require
a
minimum
voltage
to
operate
properly
.

When
troubleshooting
engine
driveability
problems,
one
of
Replacement
of
oxygensensors
at
the
specified
intenrals
en-



the
first
checks
should
be
to
make
sure
the
battery
is
fully
sures
that
the
engine
and
emission
control
system
wili
continue



charged
and
capable
of
delivering
allits
power
to
the
electricalto
operate
as
designed
.
As
the
oxygen
sensor
ages,
its
ability
to



system
.
react
quickly
to
changing
conditions
deteriorates,
and
it
may
eventually
cease
to
produceany
signal
at
all
.



To
make
a
quick
check
of
battery
charge,
measure
the
volt-
age
across
the
battery
terminals
with
all
cables
attached
and
As
the
oxygen
sensor
ages,
its
ability
to
react
quickly
to



the
ignition
off
.
A
fully
charged
battery
will
measure
12
.6
volts
changing
conditions
deteriorates,
and
it
may
eventually
cease



or
slightly
more,
compared
to
12
.15
volts
for
a
battery
with
a
to
produce
any
signal
at
all
.
To
check
theoperation
of
the
oxy-



25%
charge
.
gen
sensor,
see130
Fuel
Injection
.

Even
a
fully
charged
battery
cannot
deliver
power
unless
it

is
properly
connected
to
the
electrical
system
.
Check
the
bat-
tery
terminals
for
corrosion
and
loosecableconnections
.
If
the
battery
does
not
maintain
the
proper
voltage,
the
charging
system
may
be
atfault
.
See
121
Battery,
Starter,
Alternator
.

If
a
battery
cableconnection
hasno
visible
faults,
but
is
still
suspect,
measure
the
voltage
drop
across
the
connection
.
A
large
drop
indicates
excessive
resistance,
meaning
the
con-
nection
is
corroded,
dirty,
or
damaged
.
Clean
or
repair
the
connection
and
retest
.

NOTE-

For
instructions
on
conducting
a
voltage
drop
test,
and
other
general
electrical
troubleshooting
information,
see600
Electrical
System-General
.

Wiring
and
Harness
Connections

The
electronic
fuel
injection
and
ignition
systems
operate
at

low
voltage
and
current
values,
making
them
sensitive
to

small
increases
in
resistance
.
The
electrical
system
is
routine-

ly
subjected
to
corrosion,
vibration
and
wear,
so
faults
or
cor-

rosion
in
the
wiring
harness
and
connectors
are
common
causes
of
driveability
problems
.

Visually
inspect
all
wiring,
connectors,
switches
and
fuses
in
the
system
.
Loose
or
damaged
connectors
can
cause
inter-

mittent
problems,
especially
the
smallterminals
in
the
ECM

connectors
.
Disconnect
the
wiring
harness
connectors
to

check
for
corrosion
;
and
use
electrical
cleaning
spray
to
re-

move
contaminants
.
Often,
simply
disconnecting
and
recon-

necting
a
dirty
connector
several
times
will
clean
the
terminals
and
help
to
reestablish
good
electrical
contact
.

If
a
wiring
harnessconnectorhasno
visible
faults,
but
is
still

suspect,
measure
the
voltage
drop
across
the
connector
.
A

large
drop
indicates
excessive
resistance,
meaning
the
con-

nector
is
corroded,
dirty
or
damaged
.
Clean
or
repair
the
con-

nector
and
retest
.

Ground
Connections

For
any
electrical
circuit
to
work,
it
must
make
acomplete

path,
beginning
at
the
positive
(+)
battery
terminal
and
ending

at
the
negative
(-)
terminal
.
The
negative
(-)
battery
cable
is

attached
to
the
car's
chassis
.
Therefore,
any
wireor
metal

part
attached
to
the
chassis
provides
a
good
ground
path
back

to
the
negative
(-)
battery
terminal
.

Poorground
connections
are
amajor
source
of
driveabílity

problems
.
If
any
of
themainground
connections
for
the
igni-
tion
system
or
the
fuelinjection
system
are
faulty,
the
in-

creased
resistance
in
that
circuit
will
cause
problems
.

Visually
inspect
al¡
ground
wires
and
connections
for

breaks,
looseness
or
corrosion
.
Be
careful
because
wires

sometimes
break
internally
or
in
areas
not
easily
visible
.
The

main
grounds
for
the
DME
system
are
shown
in
Fig
.
11,Fig
.

12,
and
Fig
.
13
.
Also
check
the
main
fuel
pump
ground
in
the
center
console,
below
the
emergency
brake
handle
.

If
a
ground
connection
has
no
visiblefaults,
but
is
still
suspect,

measure
the
voltage
drop
acrossthe
connection
.
A
large
drop

indicates
high
resistance,
meaning
the
connection
is
corroded,

dirty
or
damaged
.
Clean
or
repair
the
connection
and
retest
.

ENGINE-GENERAL
100-
1
3

UU,~uyi

Fig
.
11
.
Mainground
(arrow)
for
engine
management
system
.
Grounds
are
in
right
rear
of
engine
compartment
.

Fig
.
12
.
Mainground
for
ignition
coils
on
MS
41
.1
engine
manage-
ment
system
(arrow)
.

DRIVEABILITY
TROLIBLESHOOTING

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
.

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