engine overheat BMW 328i 1995 E36 Workshop Manual
[x] Cancel search | Manufacturer: BMW, Model Year: 1995, Model line: 328i, Model: BMW 328i 1995 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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.
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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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......
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...
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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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...
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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 127 of 759
IGNITION
SYSTEM
DIAGNOSTICS
IGNITION
SYSTEM
SERVICE
Poor
driveability
may
have
a
variety
of
causes
.
The
fault
On
4-cylinder
engines,
an
ignition
coil
pack
is
mounted
to
may
lie
with
the
ignition
system,
the
fuel
system,
parts
of
the
the
passenger
side
strut
tower
in
the
engine
compartment
.
emission
control
system,
or
a
combination
of
the
three
.
Be-
The
coil
pack
integrates
4
individual
coils
.
cause
of
these
interrelated
functions
and
their
effects
oneach
other,
it
is
often
difficult
to
know
where
to
begin
looking
for
On
6-cylinder
engines,
an
ignition
coil
is
located
directly
problems
.
above
each
spark
plug
.
For
this
reason,
effective
troubleshooting
should
alwaysbe-
gin
with
an
interrogation
of
the
On-Board
Diagnostic
(OBD)
system
.
The
OBD
system
detects
certain
emissions-related
engine
management
malfunctions
.
When
faults
are
detected,
the
OBD
system
stores
a
Diagnostic
Trouble
Code
(DTC)
in
the
system
ECM
.
In
addition,
the
Check
Enginewarning
light
will
come
on
if
an
emissions-related
fault
is
detected
.
Two
generations
of
OBD
areusedon
the
cars
coveredby
this
manual
.
See
100
Engine-General
for
OBD
information
.
On-Board
Diagnostics
"
1992-1995
models
............
...
.
..
...
OBD
I
"
1996
and
later
models
.........
.......
..
OBD
II
NOTE-
"
On
carswith
OBD
ti,
specialized
OBD
11
scan
tool
equipment
mustbeused
to
access
DTCs,
either
using
the
BMW
special
tool
or
a
`generic"
OBD
11
scan
tool
.
"
The
OBD
11
fault
memory
(including
an
illuminated
Check
Engine
light)
can
only
be
reset
using
the
spe-
cial
scan
tool
.
Removing
the
connector
from
the
ECM
or
dísconnecting
the
battery
will
not
erase
the
fault
memory
.
Basic
Troubleshooting
Principies
An
engine
that
starts
and
runs
indicates
the
ignition
system
is
fundamentally
working-delivering
voltage
toat
least
some
of
the
sparkplugs
.
A
hard-starting
or
poor-running
engine,
however,
may
indicate
ignition
coil
problems,
cracked
or
dete-
riorated
spark
plug
wires
(4-cylinder
engines
only),
and
worn
or
fouled
spark
plugs
.
WARNING
-
Inefficient
combustion
(richair/fuel
mixture)
can
cause
the
catalytic
converter
to
overheat
and
plug
.
An
overheated
catalytic
converter
can
also
bea
tire
hazard
.
Checking
for
Spark
IGNITION
SYSTEM
120-
3
WARNING
-
If
a
spark
test
is
done
incorrectly,
damage
to
theen-
gine
control
module
(ECM)
or
the
ignitioncoil(s)
may
result
.
Checking
for
spark
is
difficult
onengines
with
distributorless
ignition
systems
.
Try
Rmovng
the
plugs
and
inspecting
for
differences
be-
tween
them
.
A
poor-firing
plug
may
be
wet
with
fuel
and/or
black
and
sooty,
butnot
always
.
If
a
coil
is
not
operating,
the
engine
management
system
will
electrically
disable
the
fuel
injectorto
that
cylinder
.
The
key
is
to
look
for
differences
be-
tween
cylinders
.
Ignition
coil,
testing
and
replacing
(4-cylinder
engine)
1.
Disconnect
mainharness
connector
from
coils
:
"
On
M42
engine,
remove
plastic
covering
from
coils
and
disconnect
individual
harness
connectors
.
"
On
M44
engine,
disconnect
main
harness
connectorat
end
of
coil
pack
.
See
Fig
.
3
.
Fig
.
3
.
Ignition
coil
pack
for
M44
engine
(arrow)
.
Coil
harness
con-
nector
shown
at1
.
IGNITION
SYSTEM
SERVICE
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 754 of 759
WARNING
Your
common
sense,
good
judge-
ment,
and
general
alertness
are
cru-
cial
tosafe
and
successful
service
work
.
Before
attempting
any
work
on
your
BMW,
read
the
warnings
and
cautions
on
page
vi¡
and
the
copyright
page
at
the
frontof
the
manual
.
Review
these
warnings
and
cautions
each
time
you
prepare
to
work
on
your
BMW
.
Please
also
read
any
warnings
and
cautions
that
accom-
pany
the
procedures
in
the
manual
.
Fuel
pressure
regulator
See
Fuel
injection
Fue]
pump
general
information
160-1
electrical
tests
160-7
power
consumption,
testing
160-7
delivery
tests160-8
delivery
volume,
testing
g
160-9
electrical
circuit,
checking
160-7
fuse
and
relay
160-6
level
sender
See
pump/fuel
leve¡
sender
operating
fuel
pump
for
tests
160-6
pump/fuel
level
sender
(left
side),
removing/installing
160-6
pump/fuel
leve¡
sender
(right
side),
removing/installing
160-5
relieving
fuel
pressure
and
connecting
fue¡
pressure
gauge
160-8
Fueltank
and
lines
general
information
160-1
draining
160-2
evaporative
control
system
160-4
leve¡
senders,
testing
160-5
removing/installing
160-3
Fundamentals
for
the
do-it-yourself
owner
general
information
010-1
advice
for
the
beginner
010-4
cleanliness
010-4
electrical
testing
010-6
gaskets
and
seals
010-5
non-reusable
fasteners
010-5
planning
ahead
010-4
tightening
fasteners
010-5
wire
repairs
010-6
buying
parts
010-6
genuine
BMW
parts
010-6
information
you
need
to
know
010-7
non-returnable
parts
010-7
emergencies
010-11brake
fluid
leve¡
010-13
car
will
not
start
010-11
changinga
tire
010-11
check
enginewarning
light
010-13
dim
Iights
010-13
jump
starting
car
010-12
low
o]I
pressure
010-13
overheating
010-12
Emergencies
(cont
.)
spare
parts
kit
010-14
towing
010-13
gettingstarted
010-2
lifting
thecar
010-3
raising
car
safely
010-3
safety
010-2
working
under
car
safely
010-4
how
to
use
this
manual
010-2
warnings,
cautions
and
notes
010-2
service
010-7
tools
010-7
basic
tool
requirements010-8
BMW
specialtools
010-11
feeler
gauges
010-10
jack
stands
010-9
oil
change
equipment
010-9
torque
wrench
010-10
volt-ohm
meter
(VOM)
or
Multi-
meter010-10
Fuses
See
Electrical
component
locations
G
Gaskets
See
Fundamentals
for
the
do-it-
yourself
owner
Gearshift
See
Gearshift
linkage
Gearshift
linkagegeneral
information
250-1
automatic
shiftlock,
checking
function
250-5
automatic
transmission
gearshift
250-
3
gear
position/neutral
safety
switch,
replacing
(automatic
transmission)
250-4
gearshift
lever,
installing
(manual
transmission)
250-2
gearshift
lever,
removing
(manual
transmission)
250-1
gearshift
mechanism,
adjusting
(automatictransmission)
250-3
manual
transmission
gearshift
250-1
shift
interlock,
checking
function
(automatic
transmission)
250-6Glass
See
Door
windows
Glove
compartment
See
Interior
trim
Grille
See
Exterior
trim,
bumpers
Guibo
(flex
disc)
See
Driveshaft
Handle,
door
See
Doors
Hardtop
See
Body-general
Headlight
See
Exterior
lighting
Headlight
switch
See
Switches
and
electrical
accessoriesHeater
box
See
Heating
Heater
core
See
Heating
Heater
valve
See
Heating
Heating
general
information
640-1
air
distribution
motors
640-9
air
distribution
motor,
replacing
(rotary
knob)
640-10
blower
motor,
removing/installing
640-1blower
motor
resistor
pack,
replacing
640-3
control
head
640-7
removing/installing
(digital-display)
640-8
removing/installing
(rotary
knob)
640-7
control
module
removing/installing
(digital-display)
640-8
removing/installing
(rotary
knob)
640-8
heater
box,
removing640-4
heater
core,
replacing
640-6
heater
core
temperature
sensor,
replacing
640-7
heater
valve,
replacing
640-3
rear
window
blower
(convertible
models)
640-10
reas
window
defogger
640-10sensor
fan
forinterior
temperature,
replacing
640-9warnings
and
cautions
640-11
Hood
See
Fenders,
engine
hood
Idle
speed
See
Maintenance
program
Idle
speed
control
valve
See
Fuel
injection
Ignition
switch
See
Switches
and
electrical
accessories
INDEX
5