vacuum BMW 318i 1995 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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100-5

Fuel
Delivery
..
.
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.
.....
.
...
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.
.
.
.
.
.
.
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

camshaft
secondary
drive,
causing
thecamshaft
to
"advance"

12
.5°
.
The
helical
gears
are
cut
so
that
forward
motion
of
the

gear
cup
is
transiated
into
rotational
motion
of
the
camshaft
.

See
117
Camshaft
Timing
Chain
for
testing
and
repair
infor-
mation
on
the
VANOS
system
.

DISA
(Dual
Resonance
Intake
System)

DISA,usedon
4-cylinder
engines,
is
a
dual
intake
runner

system
that
effectively
provides
the
advantages
of
both
short

and
long
intake
runners
within
the
same
engine
.
For
best
per-

formance,
long
intake
runners
aremost
beneficial
atlow-
and
mid-engine
speeds
(below
4,200
rpm),
and
short
intake
run-
ners
enhance
torque
at
high
engine
speeds
(above4,200
rpm)
.

NOTE-

The
term
DISA
comes
from
the
German
words
Differ-
enzierte
Sauganlage,
and
can
roughty
be
transiated
as
a
differing
intake
manifold
configuration
.

The
DISA
solenoid
valve
is
controlled
by
the
DME
control

module,
using
engine
speed
as
the
primary
input
.
The
main

components
of
the
system
are
the
modified
twin-section
in-

takemanifoldwith
change-over
valve,
the
twin-barrel
throttle

body,
and
the
electrical/pneumatic
actuating
components
.

See
Fig
.
4
.

r

I

I

I

?
,
in
UpPer,
take
-1
manifold

1
-1
Throttle
housing
(Heated)

q
:lZU

Fig
.
4
.



DISA
system
components
.
DISA
changes
the
intake
runner

length
based
on
engine
speed
.

The
DISA
system
electro-pneumatically
changes
the
intake
runner
length
through
the
twin-section
intake
manifold
and
a
change-over
butterfly
valve
.
The
change-over
valve
is
located
at
a
point
in
the
intake
manifold
where
four
pipes
come
into
two
.
When
the
change-over
valve
is
closed,
the
4-way
primary
intake
manifold
and
the
2-way
ram
air
manifold
areconnected
to
make
the
"long"
configuration
.
When
the
change-overvalve
opens,
intake
air
flow
is
redirected
through
only
the
short
4-

way
primary
intake
manifold
.

The
change-over
valve
is
held
in
the
normally
open
position
bya
spring
.
Thisallows
for
an
open
valve
in
the
event
of
sys-
tem
failure
.
During
low
andmid
enginespeeds,
the
DME
con-

trol
module
supplies
power
to
the
solenoid
valve,
which
in
turn

allows
vacuum
to
be
applied
lo
the
vacuum
diaphragm
.
This

causes
the
valve
to
close
(long-pipe
configuration)
.
When
en-
gine
speed
reaches
approximately
4,800
rpm,
the
DME
con-
trol
module
electrically
signals
the
solenoid
valve
and
the
valve
opens,
creating
the
short
pipe
configuration
:

Further
detafs
on
DISA
canbefound
in
130
Fuel
Injection
.

Engine
Management
System

Al¡
enginescoveredby
this
manual
usean
advanced
engine

management
system
called
Digital
Motor
Electronics
(DME)
.

In
the
DME
system,
advancedOn-Board
Diagnostics
(OBD),

fuel
injection,
ignition,
and
otherfunctions,
are
combined
under

the
control
of
theEngine
Control
Module
(ECM)
.
See
Fig
.
5
.

-



Lower
intake
manifold

DISAvacuum
'
~servo

EíY1z

ENGINE-GENERAL
100-
3

le

-
DISA
solenoid
valve

0012591

/
with
butterfly
va¡

GENERAL

ignition

Table
b
.
Engine
Management
Systems



engine
has
high
mileage
.

Engine



1
System

4-cylinder
engines
M42
(1992-1995)



Bosch
DME
Ml
.7
M44
(1996-1998)



Bosch
DME
M5
.2
(OBD
II)

6-cylinder
engines
M50
(1992)



Bosch
DME
M3
.1
M50
VANOS
(1993-1995)



Bosch
DME
M3
.3
.1
M52
(1996-1998)



Siemens
MS41
.1
(OBD
II)
S50US
(1995)



Bosch
DME
M3
.3
.1
S52US
(1996-1998)



Siemens
MS41
.1
(OBD
II)

Both
the
4-cylinder
and
6-cylinder
engines
use
a
distributor-

less
ignition
system
with
individual
ignition
coils
for
each
cylin-

der
.

FuelDelivery

Pressurized
fuel
from
the
in-tank
fuel
pump
is
injected
via

solenoid-type
fuel
injectors
.
The
ECM
controls
the
opening

and
closing
of
the
injectors
by
switchingthe
ground
side
of

each
injector
circuit
.
The
exact
amount
of
fuel
injected
is
de-

termined
by
the
amount
of
timethe
injectors
are
open
.

Cooling
System

Whenever
the
engine
is
running,
acoolant
pump
circulates

coolant
through
the
engine
and,
if
either
heater
control
valves

are
open,
through
the
heater
core
in
the
passenger
compart-

ment
.
The
coolant
absorbs
excess
heat
and
carries
it
to
the
ra-

diator
where
it
is
transferred
into
the
passing
airstream
.
A

thermostat
controls
the
flow
of
coolant
through
the
radiator

based
on
engine
temperature
.

Lubrication
System

The
lubrication
system
is
pressurized
whenever
theengine

is
running
.
The
oil
pump
draws
oil
through
a
pickup
in
the
bot-

tom
of
the
oil
pan,thenforces
it
through
a
replaceable
oil
filter

and
finto
the
engine
oíi
passages
.

On
4-cylinder
engines,
the
oil
pump
is
mounted
to
the
front

engine
cover
.
On
6-cylinder
engines,thechain-driven
oil

pump
is
bolted
to
the
bottom
of
the
cylinder
block
.

A
pressure
relief
valve
limits
the
maximum
system
pres-

sure
.
A
bypass
valve
prevents
the
oil
filter
from
bursting
and

insures
engine
lubrication
should
the
filter
become
plugged
.

See
119
Lubrication
System
for
additional
information
.

ENGINE-GENERAL
100-
5

Various
versions
of
DME
systems
are
usedon
thecars
cov-



MECHANICAL
TROUBLESHOOTING
ered
by
this
manual
.
See
Table
b
.
Each
system
is
highly
adaptive
to
compensate
for
things
suchasengine
wear
and



When
troubleshooting
an
engine
that
fails
to
start
or
runs
vacuum
leaks
.



poorly,
first
check
its
mechanical
condition-particularly
if
the

Warnings
and
Cautions

For
personal
safety,
as
well
asthe
protection
of
sensitive
electronic
components,
the
following
warnings
and
cautions
must
be
adhered
to
during
all
troubleshooting,
maintenance,
and
repairwork
.

WARNING
-

"
The
ignition
system
produces
high
voltages
that
can
be
fatal
.
Avoid
contact
with
exposed
termi-
nals
anduse
extreme
caution
when
working
on
a
car
with
the
ignition
switched
on
or
the
engine
running
.

"
Do
not
touch
or
disconnect
any
high
voltage
ca-
bles
from
the
coil,
distributor,
orspark
plugs
while
the
engine
is
running
or
being
cranked
by
the
starter

"
Connect
and
disconnect
the
engine
manage-
ment
system
wiring
and
test
equipment
leads
only
when
the
ignition
is
switched
off
.

"
Gasoline
is
highly
flammable
and
its
vapors
are
explosive
.
Do
not
smoke
or
work
on
a
car
near
heaters
or
other
fire
hazards
when
diagnosing
and
repairing
fuel
system
problems
.
Have
a
fire
extínguisher
available
in
case
of
an
emergency
.

"
Disconnecting
the
battery
may
erase
fault
code(s)
stored
in
control
module
memory
.
Using
special
BMW
diagnosnnc
equipment,
check
for
fault
codes
prior
to
disconnecting
the
battery
cables
.
If
the
Check
Engine
lightis
illuminated,
see
On-

Board
Diagnostics
(OBD)
forfault
code
infor-
mation
.
If
any
other
system
faults
havebeen
de-tected
(indicated
byan
illuminated
warning
light),
see
an
authorized
BMW
dealer
.

CAUTION-

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

"
Do
notconnect
any
test
equipment
that
delivers
a
12-volt
power
supply
to
terminal15
(+)
of
the
ignition
coil
.
The
current
flow
may
damage
the

ECM
.
In
general,
connect
test
equipment
only
as
specified
by
BMW,
this
manual,
or
the
equip-
ment
maker
.

"
Do
not
disconnect
the
battery
with
the
engine
running
.
Do
notrunthe
engine
with
any
of
the
sparkplug
wires
disconnected
.

MECHANICAL
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
.

110-2



ENGINE
REMOVAL
AND
INSTALLATION

8
.
Drain
engine
coolant
andremove
coolant
hoses
at-



10
.
Remove
radiator
cooling
fan
and
radiator
as
described

tached
to
cylinder
head
.



in
170
Radiator
and
Cooling
System
.

"
Drain
radiator
and
engine
block
.
See
170
Radiator

and
Cooling
System
.



NOTE-

"
Disconnect
hoses
from
thermostat
housing
at
front
of



Some
late
4-cylinder
modelsuse
an
electric
prímary
cylinder
head
.



cooling
fan
.
"
Disconnect
heater
hoses
at
rear
of
engine
.
See
Fig
.
2
.

CAUTION-

NOTE-



On
cars
with
viscous-type
cooling
fans,
the
radia-

"
The
block
drain
plug
is
located
on
the
exhaust
side
to-



tor
fan
has
left
hand
threads
.

wards
rear
of
engine
.

"
Remove
small
plastic
lock
clíp
to
pull
radiator
drain



11
.
Remove
upper
intake
manifold,
unfasten
cable
duct

plug
out
completely
.



from
lower
intake
manifold,
crankcase
vent
valve
hose

(M44
engine
only)

0012687

Fig
.
2
.



Coolant
hoses
at
heater
valve
and
heatercore
to
be
discon-
nected
(arrows)
.

9
.
Remove
air
shroud
from
top
of
radiator
.
See
Fig
.
3
.

ENGINE
REMOVAL
AND
INSTALLATION

12
.
Disconnect
fuel
supply
and
fuel
return
lines,
main
en-

gine
electrical
connectors,
and
lower
intake
manifold
as

described
in
113
Cylinder
HeadRemoval
and
Instal-

lation
.
See
Fig
.
4
.

0012504

Fig
.
4
.



Crankcase
ventvalve
(A)
on
top
of
lower
intake
manifoldof
M44
engine
.
Fueldelivery
and
retum
lines
shown
at
B
.
Engine
harness
and
sensor
connectors
shown
at
C
.

WARNING
-

"
Fuel
may
be
expelled
under
pressure
.
Do
not
smoke
orworknear
heaters
or
other
fire
haz-
ards
.
Keep
a
fire
extinguisher
handy
.
Before
dis-
connecting
fuel
hoses,
wrap
a
cloth
around
fuel
hoses
to
absorb
any
leaking
fuel
.
Plug
all
open
fuel
lines
.

"
Always
unscrew
the
fuel
tank
cap
to
release
pres-
sure
in
the
tank
before
working
on
the
tank
or
lines
.

CAUTION-
0013137



I
Stuff
clean
rags
into
the
open
intake
ports
topre-
Fig
.
3
.



Front
air
shroud
mounting
screws
(arrows)
.



vent
any
parts
from
falling
into
the
engine
intake
.

13
.
Disconnect
vacuum
hose
from
brake
booster
on
bulk-
head
.
Cover
bothhole
in
booster
and
plug
hose
end
.

110-
4



ENGINE
REMOVAL
AND
INSTALLATION

Engine,
removing
and
installing

(6-cylinder
engines)

Engineremoval
procedures
for
the
various
6-cylinder
en-

gines
arecovered
in
this
section
.
Most
steps
in
theproce-

dures
are
similar
or
the
same
for
al¡
engines
.
Specific

differences
that
apply
are
noted
at
the
beginning
of
each
step
.

Be
sure
to
cover
all
painted
surfaces
before
beginning
the

removal
procedure
.
As
an
aid
to
installation,
label
all
compo-

nents,wires,
and
hoses
before
removing
them
.
Do
not
reuse

gaskets,
O-rings
or
seals
during
reassembly
.

WARNING
-

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

1
.
Disconnect
negative
(-)
battery
cable
in
luggage
com-

partment
.

CAUTION-

Prior
to
disconnecting
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
onpage
vi¡¡
.

2
.
Remove
engine
hood
or
place
hood
in
service
position
.

See410
Fenders,
Engine
Hood
.

NOTE-

1t
is
not
necessary
to
remove
the
engine
hood,
but
it
is
helpful
and
will
make
engine
removal
and
installation
easier
.

3
.
Remove
splash
guardunder
engine,
if
applicable
.

4
.
Remove
transmission
from
car
.
See
230
Manual

Transmission
or
240Automatic
Transmission
.

5
.
Remove
vacuum
hosefrom
brake
booster
on
bulkhead
.

Cover
hole
in
booster
and
plug
hose
end
.

6
.
Remove
intake
air
plenum
panel
in
rear
of
engine
com-
partment
.
See
640
Heating
and
AirConditioning
.

7
.
Remove
ground
strap
from
timing
case
cover,
if
appli-

cable
.

8
.
Remove
top
enginecovers
and
disconnect
ignition
coil
harness
connectors
.
Working
at
fuel
injectors,
pry
open
small
wire
clipsat
each
injector
.
Remove
main
harness

hold-down
nuts
and
lift
completeharness
away
.
See
Fig
.
7
.

ENGINE
REMOVAL
AND
INSTALLATION

Fig
.
7
.



Remove
mainharnessfrom
top
engine
and
place
at
base
of

windshield
.

0012703

Fig
.
8
.



Mass
air
flow
sensor
connector
air
duct
hose
clamp,
and
air
cleaner
housing
mounting
bolts
(arrows)
.

9
.
Unbolt
andremove
complete
air
cleaner
housing
with



10
.
On
cars
with
automatic
transmission,
remove
front
and
mass
air
flow
sensor,
disconnecting
and
labeling
con-



rearbrackets
holding
transmission
cooler
linesto
side
nectors,
ducting
and
hoses
asnecessary
.
See
Fig
.
8
.



of
engine
.

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

113-10



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
.

Fig
.
27
.
Remove
top
enginecovers
by
prying
out
plugs
and
removing

nuts
(A)
.
Make
sure
rubber
insulators
on
either
side
of
large

cover
do
not
fall
off
during
cover
removal
(B)
.

Fig
.
28
.
Fuel
injection
harness
beíng
lifted
off
engine
to
be
placed
at

base
of
windshield
(A)
.
Ignitioncoils
are
also
visible
(B)
.
M50

engine
shown,
other
6-cylinder
engines
are
similar
.

14
.
Remove
cylinder
head
cover
mounting
bolts
and
re-

move
cylinder
head
cover
.

CYLINDER
HEAD
REMOVAL
AND
INSTALLATION



113-
11

15
.
Remove
oil
baffle
cover
from
above
intake
camshaft
.

See
Fig
.
29
.

Fig
.
29
.
Camshaft
oil
baffle
coverbeing
removed
.

NOTE-

The
cylinder
head
cover
mounting
bolt
insulators
and

13
.
Remove
hold
down
nuts/bolts
from
fuel
injection
har-



gaskets
should
be
reinstalled
in
the
same
order
.
Make

ness
.
Pry
back
injector
connector
retaining
clips
and
lift



note
of
their
arrangement
during
removal
.

entire
harness
off
engine
.
See
Fig
.
28
.

Intake
manifold,
removing

811119

16
.
Disconnect
vacuum
hose
from
brake
system
vacuum

booster
.
Plug
opening
in
booster
.

17
.
Remove
throttle
housing
mounting
bolts
and
remove

throttle
housing
.
Set
throttle
housing
aside
without
dis-

connecting
cablesor
coolant
hoses
.
See
Fig
.
30
.

Fig
.
30
.
Remove
4
comer
bolts
(arrows)
from
throttle
housing
and

unbolt
complete
assembly
from
intake
manifold
.
Remove

complete
throttle
assembly
without
disconnecting
connec-

tors,
hoses
or
cables
.
(M50
engine
shown
.)

CYLINDER
HEAD,
6-CYLINDER

119-2



LUBRICATION
SYSTEM

NOTE-
Component
Location



If
the
light
does
not
go
out,
thewiring
to
theswitch
is"
Oil
pressure
switch



most
likely
grounded
somewhere
between
the
switch

all
engines
.......
...
.
..
......
ora
oil
filter
housing



terminal
and
the
warning
light
.
Sea
Electrical
Wiring

Diagrams
atrearof
manual
for
electrical
schematics
.

CAUTION-

Some
oil
may
drain
out
as
the
oil
pressure
switch
is
removed
.
Use
a
rag
to
soak
up
any
spills
.

2
.
Install
pressure
gauge
in
place
of
switch
.

3
.
With
gauge
instalied,
start
engine
and
allow
to
reach

operating
temperature
.
Check
oil
pressureboth
cold

and
hot
.

NOTE-

For
the
most
accurate
test
results,
the
engine
oil
(and
filter)
shouldbe
newand
of
the
correct
grade
.

Oil
Pressure

"
¡dle
(mínimum)
..
.
.
..............
.
.
0
.5
bar
(7psi)

"
Regulated
pressure
(elevated
engine
speed)

4-cylinder
engines
..
......
4
.3
±
0
.2
bar
(63
t3
psi)

6-cylinder
engines
.
.
.............
.
4
.0
bar
(59
psi)

4
.
Remove
pressure
gauge
and
reinstall
pressure
switch
.

If
testing
shows
low
oil
pressure,
one
or
more
of
the
follow-

ing
conditions
may
be
indicated
:
OIL
PAN

"
Worn
or
faulty
oii
pump
.

"
Worn
or
faulty
engine
bearings



The
oil
pancan
be
removed
with
the
engine
instalied,
al-

Severe
engine
wear
.



though
specíal
enginesupport
equipment
will
be
needed
.

Al¡
of
these
conditionsindicate
the
need
for
major
repairs
.

Oil
pressure
warning
system,
testing

When
the
ignition
is
tumed
ora,
the
oil
pressure
warning
light

comes
ora
.
When
the
engine
ís
started
and
the
oil
pressure
ris-

es
slightly,
the
oil
pressure
switch
opens
and
thewarning
light

goes
out
.
Make
sure
the
oil
leve¡
is
correct
before
making

tests
.

1
.
Turra
ignition
switch
ora
.

"
Warning
light
ora
instrument
panel
must
light
up
.

2
.
Remove
connector
from
oil
pressure
switch
.

"
Warning
light
ora
instrument
panel
must
go
out
.

OIL
PAN

3
.
If
warning
light
does
not
light
when
ignition
is
ora,
re-

move
connector
from
oil
pressure
switch
anduse
a

jumper
wire
to
ground
connector
terminal
to
a
clean

metal
surface
.

NOTE
-

If
the
warning
light
comes
ora,
check
the
switch
as
de-
scríbed
in
the
nextstep
.
If
the
warning
light
does
not
come
ora,
thewiring
to
the
instrument
cluster
or
to
the

light
itself
isfaulty
.

4
.
To
test
switch,
connect
ara
ohmmeter
between
terminal

in
switch
body
and
ground
.
With
engine
off,
these

should
be
continuity
.
With
engine
running,
oil
pressure

should
opera
switch
and
there
should
beno
continuity

Replace
a
faulty
switch
.

WARNING
-

Keep
in
mind
that
low
oil
pressure
may
be
prevent-

ing
the
switch
from
tuming
the
light
out
.
If
the
light

remains
ora
while
the
engine
is
running,
check
the

oil
pressure
asdescribed
earlier
.
Do
not
drive
the
car
until
the
problem
is
corrected
.
Theengine
may
be
severely
damaged
.

Oil
pan,
removing
and
installing

(4-cylinder
engines)

1
.
Raise
car
arad
place
securely
ora
jackstands
.

2
.
Remove
splash
shíeld(s)
from
under
engine,
where
ap-

plicable
.

3
.
Drain
engine
oil
as
described
in
020
Maintenance
Pro-
gram
.

4
.
Disconnect
vacuum
hose
adapter
from
vacuum
brake

booster
at
rear
of
engine
compartment
.

5
.
Remove
oil
dipstick
guide
tube
mounting
nut
and
pull
guide
tube
from
oil
pan
.
See
Fig
.
2
.