overheating BMW M3 1998 E36 Workshop Manual
[x] Cancel search | Manufacturer: BMW, Model Year: 1998, Model line: M3, Model: BMW M3 1998 E36Pages: 759
Page 9 of 759
GENERAL
FUNDAMENTALS
FORTHE
DO-IT
YOURSELF
OWNER
010-1
010
Fundamentals
for
the
Do-lt-Yourself
Owner
GENERAL
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.010-1
TOOLS
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010-8
Basic
Tool
Requirements
......
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010-8
HOW
TO
USE
THIS
MANUAL
.
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010-2
JackStands
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010-9
Warnings,
Cautions
and
Notes
.........
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.
010-2
Oil
Change
Equipment
.
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010-9
GETTING
STARTED
.
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.010-2
Torque
Wrench
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.
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010-10
Feeler
Gauges
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010-10
Safety
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010-2
Digital
Multimeter
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010-10
Lífting
the
Car
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010-3
gMW
Special
Tools
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.
010-11
Raising
car
safely
...
..
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010-3
Working
under
car
safely
...
..
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010-4
EMERGENCIES
.
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010-11
ADVICE
FOR
THE
BEGINNER
.......
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010-4
Changing
a
Tire
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.
.
.
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.
.010-11
Car
Will
Not
Start
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.010-11
Planning
Ahead
....
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.
010-4
Jump
Starting
Car
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010-12
Cleanliness
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010-4
Overheating
.
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010-12
Non-reusable
Fasteners
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.
010-5
Low
Oil
Pressure
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010-13
Tightening
Fasteners
.....
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.
010-5
Brake
Fluid
Level
.
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010-13
Gaskets
and
Seals
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010-5
Check
Engine
Warning
Light
.
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.
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010-13
Electrical
Testing
.
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010-6
pim
Lights
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010-13Wire
Repairs
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010-6
Towíng
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.010-13
BUYINGPARTS
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010-6
Spare
Parts
Kit
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010-14
Genuine
BMW
Parts
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010-6
Non-returnable
Parts
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010-7
TABLES
Information
You
Need
to
Know
.
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010-7
a
.
General
Bolt
Tightening
Torques
SERVICE
.
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010-7
Although
the
BMW
is
a
sophisticated
and
complex
machine,
basic
maintenance
can
be
accomplished
byan
interested
own-
er
with
mechanical
skills
and
the
right
information
.
Most
of
the
preventive
maintenance
that
is
required
in
the
lifetime
of
theav-
erage
BMW
is
weil
within
the
capabilitiesof
the
do-it-yourseifer
.
WARNING
-
Do
not
use
this
manual
unless
you
are
familiar
with
basicautomotive
repair
procedures
and
sale
work-
shop
practices
.
This
manual
illustrates
the
work-
shop
procedures
required
for
most
service
work
;it
is
not
a
substitute
for
full
and
up-to-date
information
from
the
vehicle
manufacturer
or
for
proper
training
asan
automotive
technician
.
Note
that
it
is
not
pos-
sible
for
us
to
anticipate
al¡
of
the
ways
orconditions
underwhich
vehicles
may
be
serviced
or
to
provide
cautions
as
to
all
of
the
possible
hazards
that
may
result
'
in
Nm
(max
.
permissible)
.
..
.
...
............
.
010-5
WARNING
-
Your
common
sense
and
good
judgment
are
crucial
tosale
and
successful
service
work
.
Read
proce-
dures
through
before
starting
them
.
Thinkabout
whether
the
condition
ofyour
car,
your
leve¡
of
me-
chanical
skill,
or
your
leve¡
of
reading
comprehen-
sion
might
result
in
orcontribute
in
some
way
to
an
occurrence
that
might
cause
you
injury
damage
your
car,
or
result
in
an
unsafe
repair
.
lf
you
havedoubts
for
these
or
other
reasonsaboutyour
abilíty
to
perform
sale
repair
work
onyour
car,
have
the
work
done
at
an
authorized
BMW
dealer
or
other
qualified
shop
.
This
section
of
the
manual
is
intended
to
helpthe
beginner
get
started
.
To
begin
with
there
is
a
discussion
on
How
To
Use
This
Manual
.
Tips
on
mechanicas
skills
and
workshop
practic-
es
that
can
help
the
beginner
do
a
faster
and
more
thorough
job
can
be
foundunderGettingStarted
.
The
basic
tools
needed
to
do
most
of
the
procedures
in
this
manual
are
foundunder
Tools
.
The
section
ends
with
a
quick
reference
guide
to
Emer-
gencies,
including
basictroubleshooting
and
information
on
how
to
gauge
the
seriousness
of
a
problem
.
GENERAL
Page 20 of 759
010-12
FUNDAMENTALSFOR
THE
DO-IT
YOURSELF
OWNER
Jump
Starting
Car
Cars
with
discharged
or
dead
batteries
can
be
jump-started
using
the
good
battery
from
another
car
.
When
jump-starting
the
engine,
always
note
the
following
warnings
.
WARNING
-
"
Battery
acid
(electrolyte)
can
cause
severe
burns,
and
will
damage
the
car
and
clothing
.
lf
electrolyte
is
spilled,
wash
the
surface
with
large
quantities
of
water
.
lfit
gets
finto
eyes,
flush
them
with
water
for
severa¡
minutes
and
cal¡
a
doctor
.
"
Batteries
produce
explosive
and
noxious
gas-
ses
.
Keep
sparks
and
flames
away
.
Do
not
smoke
near
batteries
.
"
Do
not
jump-start
the
engine
if
you
suspect
that
the
battery
is
frozen
.
Trapped
gas
may
explode
.
Allow
the
battery
to
thaw
first
.
"
Do
not
quick-charge
the
battery
(for
boost
start-
ing)for
longer
than
one
minute,
and
donot
ex-
ceed
15
volts
at
the
battery
with
the
boosting
cables
attached
.
Wait
at
least
one
minutebefore
boosting
the
battery
a
second
time
.
"
Some
electrical
system
'comfort"
features
may
not
function
correctly
once
battery
power
is
restored
.
For
example,
the
front
window
one-touch-up
func-
tion
may
be
disabled
.
Some
electrical
systems
will
need
to
be
reinitialized
Consult
the
appropriate
re-
pairgroup
formore
specific
information
.
1
.
Place
cars
close
together,
but
do
not
allow
them
to'touch
each
other
.
Turn
off
the
engine
of
thecar
with
the
good
battery
.
2
.
Connect
oneend
of
the
positive
(+)
cable
to
the
positive
(+)
post
of
the
good
battery
.
Remove
the
coverfromthe
positive
(B+)
junction
post
in
the
engine
compartment
of
the
dead
car
and
connect
the
other
end
of
the
posi-
tive
(+)
cable
to
the
junction
post
.
See
Fig
.
17
.
EMERGENCIES
3
.
Connect
one
end
of
the
negative
(-)
cable
to
the
nega-
tive
(-)
battery
post
of
the
good
battery
.
Connect
oppo-
site
end
of
the
negative
cable
(-)
to
the
engine
block
of
thecar
with
the
dead
battery
.
4
.
Start
thecar
with
the
good
battery
and
runthe
engine
at
about2,000
rpm,
then
start
the
car
with
the
dead
bat-
tery
.
5
.
With
the
engine
at
¡dle,
switch
on
the
headlights,
blower
motor
and
rear
window
defogger
to
avoid
damaging
the
cars
electrical
system
.
Carefully
disconnect
the
jumper
cables,
starting
with
the
negative
cable
on
the
engine
block
.
Turn
all
electrical
consumers
off
.
NOTE-
The
engineshould
be
run
for
at
least
an
hour
to
re-
charge
the
battery
.
Overheating
lf
the
temperature
gauge
needle
goes
into
the
red
band
on
the
gauge
face,
the
coolant
temperature
is
too
high
.
Find
a
safe
place
to
stop
and
turn
the
engine
off
.
Open
the
hood
and
allow
the
engine
to
cool
until
the
temperature
gauge
needle
is
at
the
lower
thirdof
the
scale
.
Continuing
to
drive
an
overheated
car
can
cause
extensive
engine
damage
.
WARNING
-
Do
not
remove
the
coolant
reservoir
or
radíator
cap
with
the
engine
hot
.
Undoing
either
couldspray
hot
coolant
and
cause
burns
or
damage
the
engine
.
CAUTION-
Do
not
add
cold
water
or
coolant
to
a
hot
engine
.
Engine
damage
could
result
from
the
sudden
tem-
perature
change
.
NOTE-
If
the
enginecannot
be
safely
tumed
off,
make
sure
the
air
condifioner
isoff
and
turn
the
heater
to
high
.
This
will
helo
cool
the
engine
until
a
salestopping
place
canbe
reached
.
Overheating
may
be
caused
bylow
coolant
leve¡
or
a
dam-aged
engine
drive
belt
.
Visually
check
the
coolant
leve¡
and
en-
gine
belts
as
described
in
020
Maintenance
Program
.
lf
the
coolant
leve¡
is
low,
check
the
filler
cap,hoses,
clamps
and
ra-
diator
for
signs
of
leakage
.
Check
for
leaks
at
the
water
pump
on
the
frontof
theengine
.
lf
no
leaks
are
found,
add
coolant
after
the
engine
has
cooled
.
The
carcan
be
driven,
but
have
the
cooling
system
thoroughly
checked
assoonas
possible
.
lf
replacement
cool
0013245
-
ant
is
not
available,
then
plain
water
canbe
used,
butthe
cool-
antshould
later
be
drained
and
refilled
with
theproper
mixture
Fig
.
17
.
Battery
jump
starting
posts
(arrows)
behind
right
frontstrut
of
anti-freeze
and
water
.
tower
.
Lift
cover
to
access
positive
post
.
Page 50 of 759
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
.
Page 140 of 759
121-
4
BATTERY,
STARTER,
ALTERNATOR
BatteryOpen-Circuit
Voltage
Test
Battery
Charging
Before
making
the
test,
load
the
battery
with
15
amperes
for
Discharged
batteries
can
be
recharged
using
a
battery
one
minute
with
a
batteryload-tester
or
turn
on
the
headlights
charger
.
The
battery
should
be
removed
from
the
luggage
for
about
one
minute
without
the
engine
running
.Then
discon-
compartment
during
charging
.
nect
the
battery
negative
(-)
cable
and
connect
a
digital
volt-
meter
acrossthe
battery
terminals
.
Open-circuit
voltage
Prolonged
charging
causes
electrolyte
evaporation
to
a
lev
levels
are
given
in
Table
c
.
el
that
can
damage
the
battery
.
Itis
bestto
use
a
low-current
charger
(6
amperes
or
less)
to
prevent
battery
damage
If
the
open-circuit
voltage
ís
OK
butthe
battery
still
lacks
caused
by
overheating
.
power
for
starting,
make
a
load
voltage
test
.
If
the
open-circuit
voltage
is
below
12
.4
volts,
recharge
the
battery
and
retest
.
WARNING
-
Hydrogen
gas
given
off
by
the
battery
duringcharg-
Table
c
.
Open-Circuit
Voltage
and
Battery
Charge
ing
is
explosive
.
Do
not
smoke
.
Keep
open
llames
away
from
the
top
of
the
battery,
and
prevent
elec
Open-circuit
voltage
State
of
charge
trical
sparks
by
turning
offthe
battery
charger
be-
12
.6
V
or
more
Fully
charged
fore
connecting
or
disconnecting
it
.
12
.4
V
1
75%
charged
12
.2
V
50%
charged
CAUTION-
12
.0
V
25%
charged
"
Battery
electrolyte
(sulfuric
acid)
can
damage
the
car
.
If
electrolyte
isspilled,
clean
the
area
11
.7
V
or
less
Fully
discharged
with
a
solution
of
baking
soda
and
water
.
Battery
Load
Voltage
Test
A
battery
load
tester
is
required
for
a
load
voltage
test
.
The
-
Always
disconnect
both
battery
cables
and
re-
test
is
made
by
applying
a
high
resistive
load
to
the
battery
ter-
move
battery
from
vehicle
during
battery
charg-
ing
.
Do
not
exceed
16
.5volts
at
the
battery
.
minals
and
then
measuring
battery
voltage
.
The
battery
should
be
fully
charged
for
the
most
accurate
results
.
The
battery
ca-
bles
mustbe
disconnected
before
making
the
test
.
If
the
volt-
ALTERNATOR
$ERVICE
age
is
below
that
listed
in
Table
d,
the
battery
should
be
replaced
.
WARNING
-
Always
wear
protective
goggles
and
clothing
when
performing
aload
test
.
Table
d
.
Battery
Load
Test-Minimum
Voltage
(apply
200
amp
load
for
15
seconds)
Ambient
temperature
Voltage
80°F
(27°C)
9
.6
V
60°F
(16°C)
9
.5
V
40°F
(4°C)
9
.3
V
20°F
(-7°C)
8
.9
V
0°F
(-18°C)
8
.5
V
ALTERNATOR
SERVICE
"
Always
allow
a
frozen
battery
to
thaw
before
at-
tempting
to
recharge
it
.
Before
checking
the
alternator
and
regulator,
make
sure
the
battery
is
fully
charged
and
capable
of
holding
acharge
.
Check
that
the
battery
terminals
are
clean
and
tight
and
the
al-
ternator
drive
belt
is
properly
tensioned
and
not
severely
worn
.
Charging
system,
checking
CAUTION-
Do
not
disconnect
the
battery
while
the
engine
is
running,
.
Damage
to
the
alternator
andlorengine
electronic
systems
may
result
.
1.
Turn
ignition
key
on
.
Check
that
the
chargewarning
lamp
comes
on
.
NOTE-
If
the
warning
light
does
not
come
on,
repair
any
wiring
or
bulb
faults
before
continuing
to
check
the
charging
system
.
Page 191 of 759
Fig
.
9
.
Fuel
pump
relay
terminal
identification
.
Fuel
Pump
Electrical
Tests
Troubleshooting
of
any
fuel
pump
fault
should
begin
with
checking
the
fuel
pump
fuse
and
the
fuel
pump
relay
.
The
DME
main
relay
should
also
be
checked
.
NOTE-
Special
tools
are
requíred
for
some
of
the
tests
de-
scribed
here
.
Fuel
pump
electrical
circuit,
testing
The
fuel
pump
electrical
circuit
diagram
is
shown
in
Fig
.
10
.
3
.
If
fuel
pump
does
not
run,
disconnect
black
harness
connector
from
tank
sender
unit
.
With
jumper
wire
con-
nectedas
described
in
step
2
above,
check
for
positive
(+)
batteryvoltage
at
harness
connector
terminals
.
See
Fig
.
11
.
FUEL
TANK
AND
FUEL
PUMP
160-
7
From
Main
Relay
(+15
power
with
key
in
run
From
B+juretion
point
orstartposition)
(batteryvoRageatalltirnes)
'
.5
RD/Nrr
1
.5
RD
1
.5
GNNI
From
Engine
2
.5
GNNI
Control
Module
15
2
.5
GNNI
Ground
(below
center
console)
Fig
.
10
.
Fuel
pump
electrical
circuit
.
30
-~
Relay
Fuel
Pump
8~T
I
1
s
ám
61
Front
Power
I
a
1
Distribution
Box
I_
16
WIRING
COLOR
CODE
BK
-
BLACK
BR
-
BROWN
Fuel
Pump
RD
-
RED
(in-tank)
M
YL
YELLOWGN
-
GREENBU
-
BLUE
1
VI
-
VIOLET
GY
-
GREY
WT
-
WHITE
PK
-
PINK
0011946
4
.
If
voltage
and
groundare
present,
fuel
pump
is
proba-
bly
faulty
.
If
there
is
no
voltage,
check
wiring
From
fuel
pump
Reay
and
make
sure
Reay
is
functioning
correctly
.
CAUTION-
Fuseandrelaylocationsmayvary
.
Usecara
when
Fuel
pump
power
consumption,
testing
troubleshooting
the
electrical
system
at
the
fuselrelay
panel
.
To
resolve
problems
in
identify-
NOTE-
ing
a
relay,
see
en
authorízed
BMW
dealer
.
"
To
achieveaccurate
testresults,
fhe
battery
voltage
at
the
connector
should
be
approximately
13
volts
.
1.
Remove
rearseat
cushion,
pull
right
side
insulation
mat
Charge
the
battery
asnecessary
.
back
to
expose
fuel
tank
accesscover
.
Remove
cover
.
q
higher
than
normal
power
consumption
usually
fin-
to
expose
wiring
connections
.
dicates
a
worn
fuel
pump,
which
may
cause
intermit-
tentfuel
starvation
due
lo
pump
overheating
and
2
.
Remove
fuel
pump
relay
and
opérate
fuel
pump
as
de-
seizure
.
The
only
remedy
is
pump
replacement
.
Be
scribed
under
Operating
fuel
pump
for
tests
earlier
.
sure
to
check
that
thereturn
fine
and
the
pump
pickup
Pump
should
run
.
Disconnect
jumper
wire
when
fin-
are
not
obstructed
before
replacing
the
pump
.
ished
.
1
.
Remove
rear
seat
cushion,
pull
right
side
insulation
mal
back
to
expose
fuel
tank
accesscover
.
Remove
cover
to
expose
wiring
connections
.
2
.
Disconnect
(black)
harness
connector
from
fuel
pump
.
3
.
Connect
an
ammeter
and
an
insulated
jumper
wire
be-
tween
terminals
in
connector
and
corresponding
pump
terminals
.
See
Fig
.
12
.
FUEL
PUMP
Page 196 of 759
170-2
RADIATOR
AND
COOLING
SYSTEM
Cooling
Fans
TROUBLESHOOTING
Belt-driven
coolingfan
.
The
primary
cooling
fan
is
belt-
driven
.
It
is
mounted
to
the
frontof
the
coolant
pump
through
a
fan
clutch
.
The
fan
clutch
is
a
viscous
fluid
coupling
that
con-
trols
the
speed
of
thefan
based
on
engine
compartment
tem-
perature
.
Electric
cooling
fan
.
Models
with
M44
engine
and
stan-
dard
transmission
substitute
an
electric
fan
for
the
belt-driven
viscous
fan
.
This
is
attached
to
the
rear
of
the
radiator
and
controlledvia
the
DME
5
.2
engine
management
system
.
NOTE-
The
electric
cooling
fan
in
these
models
is
activated
by
the
engine
control
module
(ECM)
.
Auxiliary
coolingfan
.
In
al¡
models
a
two-speed
electric
auxiliary
cooling
fan
is
mounted
behind
the
front
grill
and
in
front
of
the
radiator
.
This
fan
is
primarily
used
for
the
A/C
sys-
tem,
but
also
operates
when
the
coolant
temperature
ex-
ceeds
a
predetermined
leve¡
.
Warnings
and
Cautions
The
following
warnings
and
Cautions
should
beobserved
when
working
on
the
cooling
system
.
WARNING
-
"
Atnormal
operating
temperature
the
cooling
sys-
tem
is
pressurized
.
Allow
the
system
to
cool
as
long
as
possible
before
opening-a
minimum
of
an
hour-then
release
the
cap
slowly
to
allow
sale
release
of
pressure
.
"
Releasing
the
cooling
system
pressure
lowers
the
coolants
boiling
point
and
the
coolant
may
boíl
suddenly
.
Use
heavy
gloves
and
wear
eye
and
laceprotection
to
guard
against
scalding
.
"
Use
extreme
care
when
draining
and
disposing
of
engine
coolant
.
Coolant
is
poisonous
and
lethal
to
humans
and
pets
.
Pets
are
attracted
to
coolant
because
of
its
sweet
smell
and
taste
.
Consult
a
veterinarian
immediately
if
coolant
is
ingested
byan
animal
.
CAUTION-
"
Avoidadding
cold
water
to
the
coolant
while
the
engine
is
hot
or
overheated
.
If
it
is
necessary
to
add
coolant
to
ahot
system,
do
so
only
with
the
engine
running
and
coolant
pump
tuming
.
"
Prior
to
disconnecting
the
battery,
read
the
bat-
tery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
viii
.
TROUBLESHOOTING
Most
cooling
system
faults
can
be
grouped
into
one
of
three
categories
:
"
Cooling
system
leaks
"
Poor
coolant
circulation
"
Radiator
cooling
fan
faults
When
investigating
the
cause
of
overheating
or
coolant
loss,
begin
with
a
visual
inspection
.
Be
sure
to
check
the
con-
dition
and
tension
of
the
coolant
pump
drive
belt
.
Check
hoses
for
cracks
or
softness
.
Check
clamps
for
looseness
.
Check
the
coolant
leve¡
and
check
for
evidence
of
coolantleaks
from
the
engine
.
Check
that
the
radiator
fins
are
not
blocked
with
dirt
or
de-
bris
.
Clean
the
radiator
using
low-pressure
water
or
com-
pressed
air
.
Blow
outward,
fromthe
engine
side
out
.
Inspect
the
coolant
pump
by
first
removing
the
drive
belt
from
the
pump
.
Firmly
grasp
opposite
sídes
of
the
pulley
and
check
for
play
in
all
directions
.
Spin
the
pulley
and
check
that
the
shaft
runs
smoothly
.
NOTE-
The
coolant
provides
lubrication
for
the
pump
shaft,
soan
occasional
drop
of
coolant
leaking
from
the
pump
is
acceptable
.
If
coolant
drips
steadily
from
the
vent
hole,
the
pump
should
be
replaced
.
The
cooling
system
becomes
pressurized
at
normal
operat-
ing
temperature,
which
raises
the
boiling
point
of
the
coolant
.
Leaks
may
prevent
the
system
from
becoming
pressurized,
allowing
the
coolant
to
boil
at
a
lower
temperature
.
If
visual
ev-
idence
is
inconclusive,
a
cooling
system
pressure
test
can
help
to
pinpointhard-to-find
leaks
.
If
the
cooling
system
is
full
of
coolant
and
holds
pressure,
the
next
most
probable
cause
of
overheating
are
:
"
Faulty
radiator
fan
"
Loose
or
worn
drive
belt
"
Failed
thermostat
or
coolant
pump
"
Clogged/plugged
radiator
or
coolant
passages
.
NOTE
-
"
Some
early
style
coolant
pumps
were
fitted
wíth
fi-
berlplastic
type
impellers
.
Over
time,
this
impeller
can
wear
away
and
result
in
overheating
.
The
plastic
im-
peller
can
also
slip
or
free-wheel
on
the
pump
shaft
.
If
the
engine
overheats
and
no
other
faults
canbe
found,
theold
style
impeller
may
be
the
cause
of
the
problem
.
"
Only
pumps
with
the
updated
metal
impeller
should
be
used
for
replacement
.
Page 197 of 759
Cooling
System
Pressure
Test
If
the
engine
overheats
and
no
other
cooling
system
testsindicate
trouble,
the
radiator
may
have
some
pluggedpassag-
A
cooling
system
pressure
test
is
used
to
check
for
internal
es
that
are
restricting
coolant
flow
.
leaks
.
Some
of
the
common
sources
ofinternal
leaks
are
a
faulty
cylinder
head
gasket,
a
cracked
cylinder
head,
or
a
Temperature
Gauge
Quick
Check
cracked
cylinder
block
.
The
coolant
temperature
sensor
is
located
on
the
intake
To
doa
cooling
system
pressure
test,
a
special
pressure
manifold
(left)
side
of
the
cylinder
head,
under
the
intake
man-
tester
is
needed
.
ifold
runners
.
See
Fig
.
2
.
WARNING
-
At
normal
operating
temperature
-
the
cooling
sys-
tem
is
pressurized
.
Allow
the
system
to
cool
before
opening
.
Release
the
cap
slowly
to
allow
sale
re-
tease
of
pressure
.
With
the
engine
cold,instan
a
pressure
tester
to
the
expan-
sion
tank
.
Pressurize
thesystem
to
the
specification
listed
be-
low
.
Pressure
should
not
drop
more
than
0
.1
bar
(1
.45
psi)
for
at
leakt
two
minutes
.
If
the
pressure
drops
rapidly
and
there
is
no
sign
of
an
externa¡
leak,
the
cylinder
head
gasket
may
be
faulty
.
Considera
compression
test
as
described
in
100
En-
gine-General
.
The
screw-on
type
expansion
tank
cap
should
also
be
test-
ed
using
a
pressure
tester
and
the
correct
adapter
.
Cooling
System
Test
Pressure
"
Radiator
test
pressure
.........
.
1
.5
bar
(21
.75
psi)
"
Radiator
cap
test
pressure
..
.
........
2
bar
(29
psi)
CA
UTION-
Exceeding
the
speclfied
test
pressure
could
dam-
age
the
radiatoror
other
system
components
.
Carefully
inspect
the
radiator
cap
for
damage
.
Replace
a
faulty
cap
or
a
damaged
cap
gasket
.
Thermostat
Quick
Check
In
later
models,
the
ECT
sensor
and
the
gauge
sender
are
combined
into
one
sender
unit
.
For
wire
colors
refer
to
Table
a
.
To
check
if
the
thermostat
is
opening
and
coolant
is
circulat-
ing
through
the
radiator,
allow
a
cold
engine
to
reach
operat-
ing
temperature
(temperature
gauge
needieapproximately
centered)
.
Shut
off
engine
.
Feel
the
top
radiator
hose
.
If
the
hose
is
hot
to
the
touch,
the
coolant
is
probably
circulating
cor-
rectly
.
If
there
are
any
cool
areas
in
the
hose
or
radiator,
cool-
ant
flow
to
the
radiator
is
probably
restricted
.
Check
for
a
faulty
thermostat
or
aplugged
radiator
.
NOTE-
A
thermostat
that
is
stuck
open
will
cause
the
engine
to
warmup
slowly
and
run
belownormal
temperature
at
highway
speed
.
A
thermostat
that
is
stuck
closed
will
re-
strict
coolant
flow
to
the
radiator
and
cause
overheating
.
RADIATOR
AND
COOLING
SYSTEM
170-
3
U
.¡ig
.v
Fig
.
2
.
Temperature
gauge
sender
on
M44
engine
.
Temperature
gauge
sender
location
is
similar
on
al]
engines
.
In
early
models,
the
engine
coolant
temperature
(ECT)
sen-
sor
for
the
fuel
injection
and
the
coolant
temperature
gauge
sender
are
located
side
by
side
.
Table
a
.
Coolant
Temperature
Sensor
Wire
Colors
Function
Sensor
Terminal
Wire
colors
location
number
Two
sensors
:
Temperature
Rear
1
Brown/violet
gauge
sender
2
Brown/yellow
ECT
sensor
Front
1
Brown/red
2
Brown
or
Brown/black
One
sensor
:
Temperature
Dual
1
Brown/yellow
gauge
sender
sensor
2
Brown/violet
ECT
sensor
3
Brown/red
4
Brown/black
or
Grey/black
TROUBLESHOOTING
Page 198 of 759
170-
4
RADIATOR
AND
COOLING
SYSTEM
A
quick
testat
the
coolant
temperature
gauge
sender
can
The
auxiliary
cooling
fan
comes
on
when
coolant
tempera
determine
if
the
gauge
is
functioning
correctly
.
ture
exceeds
a
predetermined
leve¡
or
whenever
the
air
condi-
tioning
is
on
.
A
dual-range
temperature
switch
for
cooling
fan
lf
the
gauge
needie
remains
at
the
rest
position
with
theen-
control
is
mounted
on
the
right
side
of
the
radiator
.
See
Fig
.
3
.
gine
warm,
remove
the
harness
connector
from
the
sender
and
jumper
the
correct
terminals
in
the
connector
to
simulate
a
high
engine
temperature
.
See
Table
a
.
Turn
the
ignition
on
.
If
the
gauge
needle
moves
upward,
the
sender
is
faulty
.
If
the
gauge
does
not
respond,
the
wiring
to
the
gauge
is
broken
(open
circuit)
or
the
gauge
itselfis
faulty
.
WARNING
-
1996
and
laten
models
are
OBD
11
compliant
.
Dis-
connecting
electrical
connectors
wíth
the
ignition
turned
on
may
set
fault
codes
in
the
ECM
.
It
is
rec-
ommended
that
you
leave
the
diagnosis
of
faults
in
the
coolant
temperature
sensorsystem
to
the
BMW
dealer
service
department
which
has
specialized
OBD
11
scan
tool
equipment
.
If
the
gauge
needle
reads
too
high
when
the
engine
is
cold,
remove
the
harness
connector
from
the
sender
.
Turn
the
igni-
tion
on
.
lf
the
gauge
needle
position
does
not
change,
the
wir-
ing
or
the
gauge
is
shorted
to
ground
.
If
the
gauge
needle
drops,
the
sender
is
faulty
and
should
be
replaced
.
When
re-
placing
a
faulty
coolant
temperature
sender,
the
gasket
ring
on
the
sender
should
also
be
replaced
.
Tightening
Torque
"
Temperature
gauge
sender
to
engine
18
Nm
(13
ft-Ib)
Cooling
fan,
testing
NOTE-
OnM44
engines
with
manual
transmission,
the
primary
electric
cooling
fan
is
mounted
on
the
engine
side
of
the
radiator
and
is
controlled
by
the
engine
control
module
(ECM)
.
Troubleshooting
thiscircuit
should
be
left
to
an
authorized
BMW
dealer
with
the
proper
diagnostic
equipment
An
otherwise
sound
cooling
system
may
still
overheat,
par-
ticularly
with
prolonged
idling,
due
to
a
failure
of
the
coolíng
fan(s)
.
The
belt-driven
cooling
fan
is
controlled
by
a
temperature
dependent
viscous
clutch
.
A
failed
fan
clutch
may
affect
air
flow
through
the
radiator
resulting
in
overheating
orpossibly
overcooling
.
Speed
Low
sp
High
s
With
the
engine
off,
check
thefan
clutch
by
spinning
thefan
.
eed
The
fan
should
spin
on
the
clutch
with
some
resistance
.
peed
Check
for
signs
of
leaking
fluid
from
the
clutch
.
If
thefan
free-
wheels
with
no
resistance,
cannot
be
tu
rned
by
hand,
or
there
are
signs
of
oil
leakage,
the
clutch
should
be
replaced
.
TROUBLESHOOTING
Fig
.
3
.
Radiatorcooling
fan
temperature
switch
(arrow)
.
WARNING
-
"
Use
caution
when
testing
the
electric
cooling
fan(s)
and
coolant
temperature
switch
.
Keep
hands
and
wires
clear
of
thefan
blades
.
The
cool-
ing
fan(s)
can
run
any
time
the
ignition
is
ON
.
"
For
greatest
safety,
coolíng
fan
and
coolant
tem-perature
switch
tests
shouldbe
performed
on
acoldengine
with
the
air
conditioning
off
.
Table
b
.
Auxiliary
Cooling
Fan
Switching
Temperatures
Switching
temperature
196°F(91°C)
210°F(99°C)
0012506
If
a
faulty
thermostat,
trapped
air,
or
a
restriction
in
the
sys-
tem
is
not
allowing
the
coolant
to
circulate
through
the
radia-
tor,
the
temperature
switch
will
not
close
and
the
auxiliary
cooling
fan
will
not
run
.
Before
making
the
tests
described
be-
low,
make
sure
the
thermostat
is
operating
correctly
as
de-
scribed
earlier
.
The
normal
switching
temperatures
for
the
dual
-speed
switch
are
listed
in
Table
b
.
Page 280 of 759
330-
8
REAR
SUSPENSION
CV
boot,
replacing
NOTE-
"
The
outer
CV
joint
cannot
be
removed
from
the
axle
shaft
.
In
order
to
replace
the
outer
CV
boot,
it
is
nec-
essary
to
remove
the
inner
joint
and
boot
first
.
"
If
the
CV
joints
are
worn
or
defective,
acomplete
re-
built
axle
shaft
is
available
from
an
authorized
BMW
dealerparts
department
.
1
.
Remove
drive
axle
from
car
as
described
above
.
2
.
Remove
inner
and
outer
CV
boot
clamping
bands
and
cut
old
boots
off
joints
and
shaft
.
Clean
grease
from
joints
.
3
.
Lift
off
dust
cover
from
inner
CV
joint
and
remove
circlip
5
.
Clean
all
old
lubricantoff
shaftsplines
and
inner
joint's
retaining
joint
inner
hub
to
axle
shaft
.
See
Fig
.
14
.
splines
.
DRIVE
AXLES
-0
1
,
1
1,1
1
L
"I
C
OYA
Drive
axle-"
e
:>,
)
0006560
CV
joint
Fig
.
15
.
Support
CV
joint
at
inner
hub
duringpressing
operation
(ar-
rows)
.
NOTE-
To
inspect
a
CV
joint,
clean
away
the
grease
and
look
for
galling,pittihg
and
othersigns
of
wear
or
physical
damage
.
Polished
surfaces
or
visible
ball
tracks
alone
are
not
necessarily
cause
for
replacement
.
Discolora-
tion
due
to
overheating
indicates
lackof
lubrication
.
6
.
Place
new
clamping
bands
and
CV
boots
over
drive
ax-
le
.
NOTE-
When
replacing
CV
joint
boots,
usecomplete
CV
joint
boot
repair
kits
.
A
kit
will
include
a
new
boot,
clamping
bands,
special
lubricant,
and
anew
inner
CV
joint
cir-
clip
.
The
kit
is
available
from
an
authorized
BMW
dealer
parts
department
.
7
.
Apply
Loctite
®
270
or
an
equívalent
heavy-duty
lockíng
compound
to
drive
axlesplines
.
Position
new
CV
joint
on
shaft
so
that
raisedor
taller
side
of
hub
is
facing
shaft
.
WARNING
-
Fig
.
14
.
Dust
cover
shown
removed
from
inner
CV
joint
.
Clean
away
Do
not
let
the
locking
compound
contact
the
balls
in
grease
and
remove
circlip
(arrow)
from
shaft
end
.
the
joint
.
Apply
only
a
thin
coat
to
cover
the
splines
.
4
.
While
supporting
inner
hub,
press
axle
shaft
out
of
joint
.
8
.
While
supporting
axle
shaft,
press
inner
hub
of
CV
joint
See
Fig
.
15
.
onto
shaft
.
Install
new
circlip
.
NOTE-
Do
not
let
the
ball
hub
pivot
more
than
20°
in
the
outer
ring
of
the
joint
.
The
halls
will
fall
out
if
the
hub
ís
pivoted
too
far
.
Page 295 of 759
6
.
Remove
brake
pads
from
caliper
.
Where
applicable,
carefully
pry
pad
wear
sensor
from
pad
.
See
Fig
.
5
.
Fig
.
5
.
Removing
brake
pad
wear
sensor
.
7
.
Inspect
brake
caliper
for
signs
of
leakage
.
Check
that
the
caliper
piston
slides
smoothly
into
caliper
.
Replace
caliper
if
any
faults
are
found
.
CAUTION-
With
the
pads
removed,
residual
hydreulic
pres-
sure
may
cause
the
caliper
piston
to
slide
out
.
Use
a
wooden
block
to
hold
the
piston
in
place
.
8
.
fnsert
brake
pad
wear
sensor
into
cutout
in
new
pad
where
applicable
.
14
.
Place
inner
brake
pad
(with
locating
spring)
ontobrake
NOTE-
caliper
piston
.
Route
pad
wear
sensor
wiring
through
lf
the
brake
lining
indicator
light
illuminated
prior
to
caliper
opening
and
bleeder
dust
cap
.
brake
pad
replacement,
the
wear
sensor
should
be
re-
placed
.
15
.
The
remainder
of
installation
is
reverse
of
removal
.
"
Do
not
lubricate
guide
boits
.
9
.
Slowly
press
piston
back
into
caliper
.
Use
cace
not
to
"
Once
brake
assembly
is
installed
depress
brakepedal
damage
piston
dust
sea¡
.
See
Fig
.
6
.
severa¡
times
before
driving
vehicle
.
NOTE-
"
Open
caliper
bleeder
screw
when
pressing
piston
Tightening
Torques
back
into
caliper
.
Catch
expelled
fluidin
appropriate
"
Brake
caliper
to
brake
pad
container
.
This
procedure
is
highly
recommended
in
carrier
(guide
bolt)
..........
...
.
.
30
Nm
(22
ft-Ib)
the
case
of
cars
with
ABS
.
"
Road
wheel
to
hub
.....
.
..
100±10
Nm
(74±7
ft-Ib)
"
Open
the
bleeder
screw
only
when
applying
force
to
the
piston
.
Do
not
allow
airto
be
drawn
in
through
the
bleeder
screw
.
"
Pressing
the
caliper
piston
in
may
cause
the
brake
flu-
id
reservoir
to
overflow
.
To
prevent
this,
use
a
clean
syringe
to
first
remove
some
fluid
from
the
reservoir
.
BRAKES
340-
5
0012157
Fig
.
6
.
Brake
caliper
piston
being
pressed
into
caliper
to
make
room
for
new
pads
.
Usea
rag
toprotect
caliper
piston
and
seals
.
10
.
Thoroughly
clean
inner
and
outer
surfaces
of
brake
ro-
tor
.
Inspect
rotor
for
cracks,
signs
of
overheating
and
0012156
scoring
.
11
.
Measure
thickness
of
rotor
.
See
Table
b
.
If
rotor
does
not
pass
minimum
thickness
requirements,
or
is
dam-
aged,
replace
as
described
later
.
12
.
Thoroughly
clean
all
contact
points
on
caliper
and
brake
pad
carrier
.
Clean
guide
bolts
and
make
surethey
slide
freely
13
.
Lightly
coat
pad
contact
points
with
brake
anti-squeal
paste
.
Place
outer
brake
pad
onto
caliper
.
Applya
small
amount
of
grease
to
thetop
and
bottom
contact
points
where
the
caliper
contacts
the
pad
carrier
.
BRAKE
PADS,CALIPERS,
ANDROTORS