ESP BMW 328i 1993 E36 User Guide

020-2



MAINTENANCE
PROGRAM

GENERAL

The
information
given
in
this
repair
group
includes
the
routine

checks
and
maintenance
steps
that
are
both
required
by
BMW

under
the
terms
of
the
vehicle
warranty
protection
and
recom-

mended
by
BMW
to
ensure
long
and
reliable
vehicle
operation
.

GENERAL

NOTE-

Aside
from
keeping
yourcar
in
the
bestpossible
condi-
tion,
proper
maintenance
plays
a
role
in
maintaining
full
protection
under
BMWs
new-car
warranty
coverage
.
If
in
doubtabout
the
terms
and
conditions
of
yourcark
warranty,
an
authorized
BMW
dealer
should
be
able
to
explain
them
.

NOTE-

BMW
is
constantly
updating
their
recommended
main-
tenance
procedures
and
requirements
.
The
informa-
tion
contained
here
is
as
accurate
as
possible
at
the
time
of
publication
.
If
hhere
is
any
doubt
aboutwhat
pro-
cedures
apply
to
a
specific
model
or
model
year,
or
what
intervals
should
be
followed,
remember
that
an
authorized
BMW
dealer
has
the
latest
information
on
factory-recommended
maintenance
.

BMW
Service
Indicator

The
BMW
Service
Indicator
notifies
the
driver
when
mainte-
nance
is
required
.
The
service
indicator
consístsof
multiple
light
emitting
diodes
(lEDs)-typically
five
green,
one
yellow,
andone
red-as
well
as
OIL
SERVICE
and
INSPECTION
indi-
cators
.

When
the
ignition
is
tumed
on,the
green
LEDs
come
on
.
They
go
out
when
the
engine
is
started
.
After
the
Service
Indi-
cator
is
reset,
al¡
green
LEDs
will
be
illuminatedwith
the
keyon
.
As
thecar
is
driven
in
normal
use,
fewer
and
fewer
green
LEDs
will
be
illuminated
before
start-up,indicating
that
the
next
main-
tenance
interval
is
approaching
.

When
thecar
has
accumulated
sufficient
use
to
require
the
next
maintenance
interval,
the
yellow
LED
will
come
on
along
with
either
the
OIL
SERVICE
indicator
or
the
INSPECTION
in-
dicator
.
These
LEDs
will
stay
on
after
the
engine
is
started
.
If
maintenance
service
is
delayed,
thered
LED
will
also
illuminate
as
a
reminder
that
maintenance
service
is
overdue
.

An
OIL
SERVICE
interval
will
alwaysbe
followed
by
an
IN-
SPECTION
interval,
which
will
then
be
followed
byan
OIL
SER-VICE
interval,
andsoon
.
See
Fig
.
1
.

'
80
100/

60
II

"
1

,



ló
1
,
4
`20
140s



#
X120
100
leo
A
O
,



80



km/h`F



*101
200
,
,
~60

BMW
has
taken
a
unique
approach
to
establishing
mainte-

nance
intervals
.
BMW's
Service
Indicator
System
computes

maintenance
intervais
based
not
only
on
elapsed
mileage,
but



Fig
.
1
.



Service
indicator
display
in
lower
section
of
speedometer
.
also
on
such
inputs
as
enginespeed,engine
temperature,
number
of
starts,
and
length
oftrips
.
At
the
appropriate
time,
the
system
indicates,
through
lights
in
the
instrument
cluster,
when



Oil
Service

the
next
routine
maintenance
is
due
.

The
Oil
Service
indicator
signals
the
need
for
the
most
basic
levelof
routine
maintenance
.
BMW's
required
oil
service
speci-
fies
changing
the
engine
lubricating
oil
and
the
engine
oil
filter

after
the
engine
has
been
warmed
up
.
BMW-recommended
ad-

ditional
maintenance
for
this
service
is
listed
in
Table
a
.

NOTE-

For
reference,
the
BMW
Oil
Service
requirements
are
approximately
equivalent
to
the
maintenance
that
other
European
manufacturers
specify
at
intervals
with
a
maximum
of
every
7,500
miles
or6
months
.

CAUTION-

Be
sure
to
follow
the
ínstructions
forresetting
the
Oil
Service
indicator
fight
.
The
Inspection
indica-
tor
can
be
accidentally
reset
rendering
its
function
inaccurate
.

Inspection
l
and
Inspection
II

The
Inspection
indicator
signals
the
need
for
more
compre-
hensive
maintenance
and
Inspection
.
There
are
two
sets
of
in-
spection
requirements,
Inspection
I
and
Inspection
ll
.
These
inspections
alternate
throughout
a
car's
maintenance
history
.
If
the
last
Inspection
interval
was
Inspection
I,
the
next
Inspection
interval
(following
an
Oil
Service)
will
be
Inspection
ll,
the
next
after
that
will
be
Inspection
I,
and
so
on
.

Inspection
I
tasks
are
listed
in
Table
b
.
Inspection
II
in-
cludes
most
of
the
tasks
from
Inspection
I
with
additional
In-
spection
11
tasks
.
A
complete
listing
of
Inspection
II
tasks
are
listed
in
Table
c
.

020-6



MAINTENANCE
PROGRAM

Group
310/330

Table
c
.
Inspection
II
Service

a
d

d



a



a>



0
d

a



r



.c



mm
L



m
y



L
E

ó
3
E
ó

Maintenance
ítem



l
o-



z



~



c

Engine
compartment
maintenance

Inspect
V-belt
/Poly-ribbeddrive
condition
.
Check
V-belt
tension,
if
applicable
.

Lubricate
throttle
linkage
.

Replace
air
filter
.

Change
oil
and
oil
filter
.

Replacespark
plugs
.
Repair
Group
120

Check
brake/clutch
fluid
leve¡
.

Check
battery
acid
leve¡
and
correct
asnecessary
.
Repair
Group
121

Check
engine
coolant
leve¡
and
anti-freeze
protection
and
add
asnecessary
.
Inspect
for
cooling
system
leaks
.
Repair
Group
170

Under
car
maintenance

Change
automatic
transmission
fluid
.
Repair
Group
240

Change
manual
transmission
oil
.
Repair
Group
230

Check
clutch
plate
for
wear
.
Repair
Group
210

Check
drive
axle
boots
for
leaks
.
Repair
Group
330

Change
final
drive
fluid
(1995
and
later
models
:
change
synthetic
oil
every
2nd
Inspection
II)
.

Replace
fuel
filter
.

Check
fuel
tank,
fuel
lines,
and
af
connections
for
leaks
.

Inspect
exhaust
system
.
Repair
Group
180

Check
steering
gear
and
steering
¡inkages
.
Check
power
steering
system
for
leaks
.
Check
fluidleve¡
.
Repair
Group
320

Inspect
brake
system
for
damaged
hoses
and
lines,
leaks
or
damage
.
Remove
calipers
and
check
brake
pad
wear
.
Check
brake
rotors
for
scoring
damage
.
Repair
Group
340

Check
parking
brake
operation,
adjust
cable
if
necessary
.
Check
thickness
of
parking
brake
lin-
ings
.
Repair
Group
340

Inspect
front
and
rear
suspension,
including
front
and
rear
wheel
bearings,
for
play
.
Repair

Inspect
wheels
and
tires,
including
spare,
check
tire
pressure
and
condition
.

Body
and
Interior
Maintenance

Lubricate
door
hinges
and
hood
latch,
hood
hinges
.

Check
headlight
and
driving
light
aiming
and
adjust
asnecessary
.

Check
operation
of
headlights,
parking
lights,
back-up
lights,
licenseplate
lights,
interior
lights,
glove
box
light,
engine
compartment
light,
trunk
light,
instrument
panel
lights,
turn
signals,
emer-gency
flashers,
stop
lights,
horns,
headlight
flasher
anddimmer
switch
.

Check
active
check
control
panel
forfauits
(where
applicable)
.
6
Electrical
System

MAINTENANCE
TABLES

Continued
on
next
page

Air
filter,
replacing



Spark
plugs,
replacing

The
specified
maintenance
intervals
for
the
air
filter
are



To
access
the
spark
plugs
on
4-cylinder
engines,
remove
the

based
on
normal
use
.
If
thecar
is
operated
primarily
in
dusty



cover
fromatop
the
sparkplugs
.
See
Fig
.
10
.
Using
the
special

conditions,
the
air
filter
should
be
serviced
more
frequently
.



spark
plug
wire
removal
tool
(attached
to
rear
of
cylinder
head

beneath
engine
cover),
gently
pull
the
spark
plugwire
from
the

To
replace
the
air
filter
on
6-cylinder
engines,
unclip
and
sude



spark
plug
.
See
Fig
.
11
.
Blow
away
any
dirt
from
around
the
the
filter
cartridge
assembly
out
of
the
air
boxand
remove
the



base
of
the
plug
to
prevent
it
from
entering
theengine
.
Remove

filter
from
the
frame
assembly
.
See
Fig
.
8
.



and
install
the
spark
plugs
one
at
a
time
.

0012625

Fig
.
8
.



To
remove
air
filter
cartridge
on
6-cylinder
engines,release
fil-
ter
cartridge
at
sides
(arrows)
and
then
remove
filter
element
insert
from
cartridge
.

To
replace
the
air
filter
elementon
4-cylinder
engines,
sepa-

rate
the
upper
air
filter
housing
section
from
the
lower
section
by

unfastening
the
spring
clips
.
Remove
the
air
filter
element
from

the
air
filter
housing
.
See
Fig
.
9
.
Wipe
the
inside
of
the
air
filter

housing
clean
and
install
the
new
element
.
Reinstall
the
upper

air
filter
housing,
making
sure
that
the
two
halves
are
mated

correctly
.
Refasten
the
spring-clips
.

Fig
.
9
.



Air
filter
element
being
removed
on
4-cylinder
engine
.

MAINTENANCE
PROGRAM



020-
11

NOTE-

Spark
plug
applications
are
often
updated
and
super-
seded
from
the
original
plug
specification
.
Consuff
an
authorized
BMW
parts
department
for
the
latest
parts
_'
information
.
The
sparkplug
fisted
in
the
owners
manu-
al
may
not
be
the
latest
recommend
spark
plug,
espgp
cially
on
older
cars
.

0012631

Fig
.
10
.
To
remove
engine
cover
above
sparkpiugs
on
4-cylinder
en-
gine,
turnretainers
90°
counterclockwise
and
lift
cover
off
.

0012630

Fig
.
11
.
To
remove
spark
plugwirefrom
spark
plug
on
4-cylinder
en-

gine,
sude
special
removal
tool
over
spark
plug
wire
end
(ar-

row)
and
pull
straightoff
.
Usea
screwdriver
for
added

leverage
.
Special
tool
is
stored
at
rear
of
cylinder
head
below

top
cover
.

ENGINE
COMPARTMENT
MAINTENANCE

020-
1
2



MAINTENANCE
PROGRAM

6-cylinder
engines
use
a
coil-on-plug
configuration,
and
re-



Battery
cablesshould
be
tight
.
The
terminals,
the
cable
moval
of
thetop
engine
cover
(between
the
camshafts)
and
ig-



clamps,
and
the
battery
case
should
be
freeof
the
white
deposits
nition
cofs
are
necessary
.
See
Fig
.
12
.
Blow
away
any
dust
or



that
indicate
corrosion
and
acid
salts
.
Even
a
thin
¡ayer
of
dust
dirt
around
the
ignition
coils,
and
then
remove
the
coils
.
Blow



containing
conductive
acid
salts
can
cause
battery
discharge
.
away
any
dustor
dirt
around
the
sparkplugs
.
Remove
the
spark

plugs
.



To
remove
battery
corrosion,
begin
by
disconnecting
theca-

bles
.
Disconnect
the
negative
(-)
cable
first
.
Clean
the
terminal

posts
and
the
cable
clamps
with
a
wire
brush
.
Clean
the
main
chassis
ground
terminal
next
to
the
battery
.
Corrosion
can
be
washedaway
with
a
baking
soda
and
water
solution
that
will
neutralize
the
acid
.
Apply
the
solution
carefully,
though,since
ít
will
also
neutralize
the
acid
inside
the
battery
.
Reconnect
the
ca-
ble
clamps,
positive
(+)
cable
first
.
Lightly
coat
the
outside
of
the

terminals,
hold
down
screws,
and
clamps
with
petroleum
jelly,
grease,
or
a
commercial
battery
terminal
corrosion
inhibitor
.

Fig
.
12
.
Ignition
coil
being
removed
from
spark
plug
on
M52
engine
.

NOTE-

If
necessary,
see
120
Ignition
System
for
more
details
on
coil
removal
.

B11004

Lightlylubricate
the
new
spark
plug
threads
with
a
small
amount
of
anti-seize
compound
.
Thread
the
plugs
into
the
cyl-
inder
head
byhand
to
prevent
cross-threading
.

Tightening
Torque

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

Idie
Speed

Engine
¡dle
speed
canchange
due
to
a
number
of
factors,
in-
cluding
normal
wear
.
The
idle
speed
is
electronically
adaptive
and
non-adjustable
.
See
130
Fuel
Injection
for
more
information
.

Battery,
checking
and
cleaning

The
battery
is
located
in
the
right
side
of
the
luggage
com-
partment
.
Simple
maintenance
of
the
battery
and
its
terminal
connections
will
ensure
maximum
starting
performance,
espe-
cially
in
winter
when
colder
temperaturesreduce
battery
power
.

ENGINE
COMPARTMENT
MAINTENANCE

WARNING
-

"
Prior
to
disconnecting
the
battery,
read
the
bat-
tery
disconnection
cautions
given
at
the
front
of
this
manualonpage
viii
.

"
Battery
acid
is
extremely
dangerous
.
Take
care
to
keep
it
from
contacting
eyes,
skin,
or
clothing
.
Wear
eye
protection
.
Extinguish
all
smoking
ma-
terials
and
do
not
worknear
any
oyen
flames
.

Battery
electrolyte
should
be
maintained
at
the
correct
level
just
above
the
battery
plates
and
their
separators
.
The
correct
leve¡
is
approximately
5
mm
(
1
/4
in
.)
above
thetop
of
battery
plates
orto
thetop
of
the
indicator
marks
(if
applicable)
.
The
battery
plates
and
the
indicator
marks
can
beseen
once
the
fill-
er
caps
are
removed
.
If
the
electrolyte
level
is
low,
replenish
it
by
adding
distilled
water
only
.

Battery,
repiacing

Batteries
are
rated
by
ampere
hours
(Ah),
the
number
of
hoursa
specific
current
draín
can
be
sustained
before
complete
discharge,
or
by
cold
cranking
amps
(CCA),
the
number
of
amps
available
to
crank
the
engine
in
cold
weather
conditions
.
In
general,
replacement
batteries
should
alwaysbe
rated
equal
or
higherthan
the
original
battery
.

CAUTION-

Prior
to
disconnecting
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
thls
manual
on
page
viii
.

The
battery
is
held
in
place
bya
single
hand
screw
and
píate
.
A
secure
battery
hold-down
is
important
in
order
to
prevent
vi-
brations
and
road
shock
from
damaging
the
battery
.

NOTE-
NOTE-
"
Always
disconnect
the
negative
()
cable
first,
and
Design
characteristics
of
the
convertible
body
cause
vi-



connect
ft
last
While
changing
batteries,
clean
away
brations
in
the
trunk
area
.
Therefore,
E36
convertibles



any
corrosion
in
or
around
the
battery
tray
.
require
a
specialbattery
designed
for
constant
vibra-
tion
.
When
repiacing
the
battery,
be
sure
the
replace-



"
Design
characteristics
of
the
convertible
body
cause
ment
is
designed
specffically
for
the
convertible
.



vibrations
to
oscillate
in
the
trunk
area
.
Therefore,
the
convertible
model
uses
a
specialbattery
designed
for
this
constant
vibration
.

020-20



MAINTENANCE
PROGRAM

Seat
Belts



Washing
Chassis

Dirt
and
other
abrasive
particles
will
damage
seat
belt
web-



Periodic
washing
of
the
underside
of
the
car,
especially
in

bing
.
If¡t
is
necessary
to
clean
seat
belts,
use
a
mild
soap
solu-



winter,
will
help
prevent
accumulation
of
road
salt
and
rust
.
The

tion
.
Bleach
and
other
strong
cleaning
agents
may
weaken
the



besttime
to
wash
the
underside
is
just
after
the
car
has
been

belt
webbing
and
should
be
avoided
.



driven
in
wet
conditions
.
Spray
the
chassis
with
a
powerful
jet
of

water
.
Commercial
or
self-service
car
washes
may
not
be
best

WARNING-



for
this,
as
they
may
recycle
the
salt-contaminated
water
.

Do
not
clean
the
seat
belt
webbing
using
dry
clean-
ing
or
other
chemicals
.
Allow
wet
belts
to
dry
before
allowing
them
to
retract
.



Speeial
Cleaning

The
condition
of
the
belt
webbing
and
the
function
of
the
re-

tractor
mechanisms
should
be
inspected
.
See720
Seat
Belts
for
seat
belt
inspection
information
.

Exterior
Washing

The
longer
dirt
isleft
on
the
paint,
the
greater
the
risk
of
dam-
aging
the
glossy
finish,
either
by
scratching
or
by
the
chemical
effect
dirt
particles
may
have
on
the
paintedsurface
.

Do
not
wash
the
car
in
direct
sunlight
.
If
the
engine
hood
is

warm,
allow
it
to
cool
.
Beads
of
water
not
only
leavespots
when
dried
rapidly
by
the
sun
or
heat
from
the
engine,
but
also
can
act
as
small
magnifyingglasses
and
burn
spots
into
the
finish
.
Wash
thecar
with
a
mixture
of
lukewarmwater
and
a
car
wash
product
.
Rinse
using
plenty
of
clear
water
.
Wipe
the
body
dry
witha
soft
cloth
towel
or
chamois
to
prevent
water-spotting
.

Waxing

For
a
long-lasting,protective,
and
glossy
finish,
apply
a
hard
wax
after
thecar
has
been
washed
and
dried
.
Use
carnauba
or
synthetic
based
products
.
Waxing
is
not
needed
after
every
washing
.
You
can
tell
when
waxing
is
required
by
looking
at
the
finísh
when
it
is
wet
.
If
the
water
coats
the
paint
in
smooth
sheets
instead
of
forming
beads
that
rol¡
off,
a
new
coat
of
wax
is
needed
.
Wax
shouldnot
be
applied
to
black
trim
pieces,
rub-
ber,or
other
plastic
parts
.

Polishing

Use
paintpolish
only
if
the
finish
assumes
a
dull
lock
after
long
service
.
Polish
can
beused
to
remove
tar
spots
and
tar-
nish,
but
afterwards
a
coat
of
wax
should
be
applied
to
protect
the
clean
finish
.
Do
not
use
abrasive
polish
or
cleaners
on
alu-
minum
trimor
accessories
.

BODYAND
INTERIOR
MAINTENANCE

Cylinder
Head
and
Valvetrain

The
aluminum
cylinder
head
uses
chain-driven
double

overhead
camshafts
and
four
valves
per
cylinder
.
See
Fig
.
1
.
Tha
rvfinriar
hand
nmnlnve
n
ernceflnier
rineinn
fnr
nronter

Tar
spots
canbe
removed
with
a
bugand
tar
remover
.
Never

use
gasoline,
kerosene,
nail
polish
remover,
or
other
unsuitable

solvents
.
Insect
spots
also
respond
to
tar
remover
.
A
bit
of
bak-

ing
soda
dissolved
in
the
wash
water
will
facilitate
their
removal
.
This
method
can
also
beused
to
remove
spotting
from
tree
sap
.

Interior
Care

Dirt
spots
can
usually
be
removed
with
lukewarm
soapy
wa-
ter
or
a
dry
foam
cleaner
.
Use
spot
remover
for
grease
and
o¡I

spots
.
Do
not
pour
the
(quid
directly
on
the
carpetor
fabric,
but
dampen
a
clean
cloth
and
rub
carefully,starting
at
the
edge
of
the
spot
and
working
inward
.
Do
not
use
gasoline,
naptha,
or

other
flammable
substances
.

Leather
Upholstery
and
Trim

Leather
upholstery
and
trim
should
be
periodically
cleaned
using
a
slightly
damp
cotton
or
wool
cloth
.
The
idea
is
to
get
rid
of
the
dirtin
the
creases
and
pores
that
can
cause
brittleness
and
premature
aging
.
On
heavily
soiled
areas,
usea
mild
deter-
gent
(such
as
Woolite®)
or
other
specially
formulated
leather
r

cleaners
.
Use
two
tablespoons
to
one
quart
of
cold
water
.
Dry

the
trim
and
upholstery
completely
using
a
soft
cloth
.
Regular
use
of
agood
quality
leather
conditioner
will
reduce
drying
and
crackingof
the
leather
.

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

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

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

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
.

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