1995 BMW M3 engine removal

160-
4



FUEL
TANK
AND
FUEL
PUMP

Fig
.
4
.



Pinch
off
supply
and
retum
fuel
hoses
(arrows)
before
dis-
connecting
from
rigid
metal
lines
.

0013143

Fig
.
5
.
After
removing
exhaustsystem,
remove
heat
shield
screws
(arrows)
and
heat
shield
.

9
.
Working
underneath
car,
loosen
hose
clamp
and
dis-

connect
filler
hose
.

10
.
Support
tank
from
below
.
Remove
tank
strap
mounting

bolts
.
Lower
and
remove
tank,
disconnecting
right
side



TheE36
model
uses
a
two-lobed
fuel
tank
and
each
lobeof
vent
and
other
hoses/electrical
connectors
as
neces-



the
tank
has
its
own
fuel
level
sending
unit
.
sary
.

11
.
Installation
is
reverse
of
removal
.

"
Always
use
new
seals,
gaskets,
O-rings,
and
hose
clamps
.

"
Inspect
hoses
and
replace
any
that
are
chafed,
dried

outor
cracked
.

"
Inspect
heat
shield
and
replace
if
corroded
.

"
Inspect
rubber
buffers
and
liners
on
fuel
tank,
support
straps
and
on
underside
of
body
.
Replace
rubber

parts
that
are
hardened
or
damaged
.

FUEL
LEVEL
SENDERS

CAUTION-

"
Before
starting
the
engine,
fill
the
fuel
tank
with
at
least
1.5
gallons
(5
liters)
of
fuel
to
prevent

damaging
a
dry
fuel
pump
.

"
If
the
filler
neck
has
been
removed
from
the
body,
be
sure
toreattach
theneck's
grounding
screw
(where
applicable)
.
Check
electrical
resistance
between
the
ground
tab
and
wheel
hub
.
The
re-
sistance
shouldbeno
higher
than
0
.6
ohms
.

Tightening
Torques

"
Fuel
tank
to
body
.............
...
23
Nm
(17
ft-Ib)

"
Hose
clamps
(10
mm-16
mm
día
.)
..
2
.0
Nm
(18
in-lb)

Fuel
Tank
Evaporative
Control
System

The
fuel
tank
evaporative
control
system
is
used
to
vent
the

fuel
tank
to
a
charcoal
canister,
which
is
then
purgedby
en-

gine
vacuum
during
normal
engine
operatíon
.
This
controls

emission
of
raw
hydrocarbons
(fuel)
to
the
atmosphere
.
See

Fig
.
1
.

A
fuel
expansion
tank,
located
under
the
right
rear
fender,

traps
overflow
fuel
and
incorporates
extra
fuel
tank
plumbing
.

Startingwith
1996
models,
OBD
II
standards
require
that

the
fuel
tank
evaporative
control
system
be
monitored
for

leaks
.
This
is
accomplished
usingthe
fuel
tankpressuresen-

sor,
the
ventshut
off
valve,
and
the
evaporative
purge
valve
.

NOTE-

On
most
early
cars(1992-1995),
the
charcoal
canister

is
in
the
engine
compartment
.
On
latercars,
the
char-
coal
canister
is
under
the
spare
tire
in
the
luggage
com-
partment
.

FUEL
LEVEL
SENDERS

The
right
side
fuel
leve¡
sender
is
integrated
with
the
fuel

pump
.
Each
senderhas
a
float
connected
to
a
variable
resis-

tance
for
fuel
leve¡
.
When
replacing
the
sender/pump
assem-

bly
always
replace
hose
clamps,gaskets
and
O-rings
.

WARNING
-

When
removing
the
fuel
level
sender
or
the
fuel
pump,
the
fuel
tank
should
be
emptied
.

Fuel
leve¡
senders,
testing



Fuel
leve¡
sender
(right
side)

The
left
and
right
fuelleve¡
sending
units
are
wired
in
series
.



and
fuel
pump,
removing
and
installing

The
fuel
gauge
receives
a
signal
that
is
the
average
of
the
two



1
.
Disconnect
negative
(-)
cable
from
battery
.

input
values
.

1
.
Remove
rear
seat
cushion,
lift
up
insulation
mats,
andremove
both
fuel
tank
access
covers
.

2
.
Disconnect
white
plug
on
each
sending
unit
.
See
Fig
.
6
.

3
.
Check
resistance
value
of
eachsending
unit
.
Values
should
be
the
same
.

5
.
If
valuesare
different,
remove
sending
units
as
described

below,
and
check
resistance
valuésacross
terminals
.
Table
a

lists
resistance
values
for
senders
at
various
float
positions
.

Table
a
.
Fuel
Leve¡
Sender
Resistances

Float
position



Test
result
(ohms)

Right
side
empty



10
ohm
t2

Right
side
full



250
ohm
±
5
Left
side
empty



10
ohm
t
2

Left
side
fui¡



250
ohm
±
5

FUEL
TANK
AND
FUEL
PUMP



160-
5

CAUTION
-

Prior
to
disconnecting
the
battery,
read
the
battery
disconnection
cautionsglven
at
the
front
of
this
manual
onpage
viii
.

2
.
Drain
fuel
from
tank
as
described
earlier
.

WARNING
-

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

3
.
Remove
rear
seat
cushion
and
pull
back
insulation
pad
under
right
side
.

4
.
Remove
screws
holding
rightfuel
tank
accesscover
.

Remove
cover
.

5
.
Label
fuel
hoses
.
Disconnect
hoses
and
harness
con-

nectors
from
fuel
sending
unit
and
fuel
pump
.

6
.
Unscrew
threaded
collar
from
fuel
pumplfuel
leve¡
sender
.
Slowly
withdraw
assembly
from
tank,allowing

fuelto
drain
off
.
See
Fig
.
7
.
0013187
&
0013194

Fig
.
6
.



Fuel
pump/leve¡
sender
terminal
identification
.
Check
resis-
tance
at
terminals
of
white
connectors
(arrows)
.



"
If
necessary,
push
leve¡
sender
arm
toward
fuel
pump

assembly
to
facilitate
removal
.

NOTE
-

BMW
special
tool
no
.
16
1
020
should
beused
to
re-
move
and
install
the
threaded
collar
.
Damage
to
the
collar
may
result
if
the
special
tool
is
not
used

WARNING
-

NOTE-



Fuel
may
be
spilled
.
Do
not
smoke
or
work
near

The
compensating
siphon
pump
(Fig
.
1)
maintains
the



heaters
or
other
fire
hazards
.

fuel
leve¡
between
the
right
and
left
tank
lobes
.
If
the
re-
sistances
are
different
between
the
left
and
right
send-
ers,
remove
the
senders
and
visually
inspect
the
leve)
in



7
.
Using
a
new
sealing
ring,
install
pump
and
sending
each
lobe
.
If
the
leve¡
is
different,
check
the
siphon
com-



unit,
being
sure
that
fuel
line
connections
point
in
same

pensating
pump
.



direction
as
they
carne
out
.

8
.
Reconnect
harnessconnector
and
hoses
.
Fill
tank
and

check
for
leaks
by
running
engine
.
Insta¡¡
access
cover

and
its
mountingscrews
.
Reconnect
negative
(-)
cable

to
battery
.

CAUTION
-

Before
starting
the
engine,
fill
the
fuel
tank
with
at
least
1
.5
gallons
(5liters)
of
fuel
.
The
pump
will
be
damaged
if
you
run
it
without
fuel
.

FUEL
LEVEL
SENDERS

160-
6



FUEL
TANK
AND
FUEL
PUMP

Fig
.
7
.



Fuel
sender
and
pump
assembly
.

To
operate
the
fuel
pump
for
testing
purposes
without
hav-
Fuel
leve¡
sender
(left
side),



ing
to
runthe
engine,
the
fuel
pump
relay
can
be
bypassed
to

removing
and
installing



powerthe
pump
directly
.

The
procedure
for
removing
and
replacing
the
left
side
fuel



To
runthe
fuel
pump,
remove
the
relay
and
connect
the
leve¡
sender
is
similar
tothat
used
for
the
right
side
.
There
is



socket
for
relayterminal
30
to
the
socket
for
relay
terminal
no
.
no
fuel
pump
on
the
left
side
.



87
with
afused
jumper
wire
.
Relay
terminal
identification
is
shown
in
Fig
.
9
.
After
completing
the
tests,
remove
the
jumper

wire
.

FUEL
PUMP

The
electric
fuel
pump
ís
mounted
in
the
fuel
tank
in
tandem
with
the
right
side
fuelleve¡
sender
.
The
fuel
pump
delivers
fuel
at
high
pressure
to
the
fuel
injection
system
.
A
pressure
regulator
maintains
system
pressure
.
The
quantity
of
fuel
sup-
plied
exceeds
demand,
so
excess
fuel
retums
to
the
fuel
tank
via
a
retum
líne
.
See
130
Fuel
Injection
for
more
information
on
system
pressure
and
the
fuel
pressure
regulator
.

NOTE
-

Fuel
pump
removalprocedures
are
given
earlier
under
Fuel
leve¡
sender
(right
side)
and
fuel
pump,
remov-
íng
and
installing
.

Fuel
Pump
Fuse
and
Relay

The
fuel
pump
is
operated
by
a
fuel
pump
relay
located
ín
the
power
distribution
box
.
The
fuel
pump
circuit
is
protected
by
fuse
no
.
18
located
in
the
power
distribution
box
.
See
Fig
8
.

FUEL
PUMP

0013142

Fuel



DM
E
PUMP
main
re
ay



rel
ay

0

aoo
o
~a

aao
ó

Fig
.
8
.



Fuel
pump
relay
location
in
power
distribution
box
.

The
DME
engine
control
module
(ECM)
and
the
DME
main

relay
supply
power
to
the
coi¡
sideof
the
fuel
pump
relay
.
Dur-

ing
starting,
the
fuel
pump
runs
as
long
as
the
ignition
switch
is
in
the
start
position
and
continues
to
run
oncethe
engine

starts
.
If
an
electrical
system
fault
interrupts
power
to
the
fuel
pump,
the
engine
will
notrun
.

Operating
fuel
pump
for
tests

CA
UTION-

Relay
locations
may
vary
.
Use
care
when
identify-
ing
relays
and
when
troubleshooting
the
electrical
system
at
the
fuselrelay
panel
.
The
fuel
pump
re-
¡ay
is
a
four
pin
relay
and
has
a
1.5
mm
2
red
wireat
terminal
30
in
the
relay
socket,
lf
in
doubt,
con-
sult
an
authorized
BMW
dealer
.

NOTE-

Thejumper
wire
shouldbe
1.5
mm2
(14
ga
.)
and
in-
clude
en
in-fine
fuse
holder
with
a16
amp
fuse
.
To
avoid
fuselrelay
panel
damage
fromrepeated
connect-
íng
and
disconnecting,
also
include
a
toggleswitch
.
A
heavy-duty
jumper,
BMW
tool
no
.
613
050,
fs
also
available
from
en
authorized
BMW
dealer
.

0013034,

If
the
pump
does
notrun
with
the
jumper
installed,
the
fault
could
be
in
the
fuel
pump
or
the
wiring
to
the
pump
.
Check
the
pump
and
its
wiring
as
described
below
.

170-8



RADIATOR
AND
COOLING
SYSTEM

Electric
cooling
fan,
replacing

On
late
4-cylinder
models
(M44
engine)
with
manual
trans-
mission,
the
primary
cooling
fan
is
electrically
operated
and
is
mounted
on
the
engine
side
of
the
radiator
.

1
.
If
necessary,
remove
cover
from
top
of
radiator
.
See
Fig
.
10
.

0012505
Fig
.
10
.
Air
cover
in
back
of
radiator
.
Unclip
cover
from
fan
shroud
af-
ter
removing
mounting
screws
.

2
.
Disconnect
fan
harness
connector
at
bottom
left
of
ra-
diator
.

3
.
Remove
fan
shroud
mountingscrews
at
left
and
right
side
of
radiator
.
Lift
fan
assembly
straight
up
and
offra-
diator
.

4
.
Installation
is
reverse
of
removal
.
Be
sure
to
align
side
tabs
on
fan
housíng
with
retaining
tabs
on
radiator
when
reinstalling
fan
.

Auxiliary
cooling
fan,
replacing

The
auxiliary
electric
cooling
fan
is
mounted
behind
the
front
bumper,
in
front
of
the
A/C
condenser
.
There
aretwo
ver-
sions
of
auxiliary
fans
installed,
depending
on
model
and
en-
gine
installed
.

TType
1
(u
p
to
9192)

1
.
Remove
front
radiator
air
shroud
.
See
Fig
.
11
.

2
.
Remove
fan
mountingscrews
.
See
Fig
.
12
.

3
.
Tilt
fan
forward
.
Disconnect
electrical
harness
connec-
tor
before
lifting
fan
up
.

COOLING
SYSTEM
SERVICE

Fig
.
11
.
Front
radiator
air
shroud
fasteners
(arrows)
.

Fig
.
12
.
Version
1
auxiliary
fan
mountingscrews
(arrows)
.

NOTE
-

If
necessary,
remove
front
bumper
or
lowerengine
cov-
erto
access
electrical
harnessconnector
.

4
.
Installation
is
reverse
of
removal
.

l)
Type
2
(from
9192)
2
.
Remove
fan
mounting
screws
.
See
Fig
.
13
.

0013137

1.
Remove
front
bumper
and
radiator
grilles
.
See
510
Ex-
terior
Trim,
Bumpers
.

3
.
Angle
fan
up
and
forward,
disconnecting
electrical
har-
nessconnectorbehind
it
.
Remove
it
through
bumper
opening
.

Fig
.
13
.
Version
2
auxiliary
fan
mounting
screws
(arrows)
.
Front
bumper
hasbeen
removed
.

4
.
Installation
is
reverse
of
removal
.

Thermostat,
replacing

0013146

The
coolant
thermostat
is
instalied
in
a
housing
at
the
front

of
the
cylinder
head
.
See
Fig
.
14
.

Fig
.
14
.
Coolantthermostat
and
housíng
.

NOTE-

On
M44
engines,
the
thermostat
is
integrated
into
the
thermostat
housíng
.
If
the
thermostat
requiresreplace-
ment,
the
complete
thermostathousing
mustbe
replaced
.

RADIATOR
AND
COOLING
SYSTEM



170-
9

WARNING
-

Allow
the
cooling
system
to
cool
before
opening
ordraining
the
system
.

2
.
Remove
belt-driven
cooling
fan
and
fan
shroudas
de-

scribed
earlier
.

3
.
On
M52/S52US
engines
:
Unclip
wiring
duct
retaining
clips
and
remove
duct
from
above
thermostat
housing
.

Also
remove
engine
front
lifting
bracket
.

4
.
Remove
thermostat
housing
from
front
of
engine
.
See
Fig
.
15
.

Fig
.
15
.
Thermostat
housíng
shown
removed
(6-cylinder
engine)
.

NOTE-

Some
thermostats
have
a
direction
arrowor
venthole
near
the
edge
.
Install
the
thermostat
so
that
either
the
arrow
or
hole
are
at
thetop
.

CAUTION
-

Be
sure
to
reconnect
ground
wire(s)
at
thermostat
housing
mounting
bolt,
where
applicable
.

5
.
Remove
thermostat
.
Note
thermostat
direction
and
ori-

entation
before
removing
.

6
.
Insta¡¡
new
thermostat
and/or
thermostat
housing
using

new
O-ring
and
gasket(s)
as
necessary
.

oo131ss



7
.
Installation
is
reverseof
removal
.
Fill
system
with
cool-

ant
as
described
under
Coolant,draining
and
filling
.

Tightening
Torques

1
.
Drain
radiator
as
described
above
under
Coolant,



"
Thermostat
housing
cover

draining
and
filling
.



to
housing
orcoolant
pump
..
..
....
10
Nm
(89
in-lb)

"
Engine
lifting
bracket
bolt
to
thermostat
housing

(M52/S52US
engine)(M8)
....
..
...
22
Nm
(17
ft-Ib)

COOLING
SYSTEM
SERVICE

GENERAL
.
.
.......
.
......
.
...
.
.
.
.
.
...
180-1



Exhaust
system,
removing
and
installing
.
...
.180-3

EXHAUST
SYSTEM
REPLACEMENT
.
...
180-1



Exhaust
manifolds,
removing
and
installing
.
.
.180-5

GENERAL

The
exhaust
system
is
designed
to
be
maintenance
free,
al-
though
regular
inspection
is
warranted
due
to
the
harsh
oper-
atingconditions
.
Under
normal
conditions,
the
catalytic

converter
does
not
require
replacement
unless
it
is
damaged
.

On
1996
and
later
cars,
a
pre-
and
post-catalytic
converter

oxygen
sensor
is
used
at
each
catalytic
converter
.
Be
sure
to

take
care
when
removingthe
system
not
to
damage
the
sen-



EXHAUST
SYSTEMREPLACEMENT
sors
.

See
130
Fuel
Injection
for
information
on
testing
oxygen

sensors
.

NOTE-

OnM52
engines,
two
resonator
pípes
(short
and
long)
are
incorporated
into
the
rear
muffler
assembly
.
See
Fíg
.
1
.
An
exhaust
flap
is
integrated
into
the
outlet
side
of
the
short
pipe
.
The
flap
is
operated
by
a
vacuum
ac-
tuator
via
the
Siemens
MS
41
.1
engine
control
mod-
ule)
.
The
flap
is
closed
at
engine
speeds
below
2,500
rpm
.
This
allows
exhaust
gasses
to
flow
through
the
long
resonator
pipe
and
reduce
noise
.
Above
2,500rpm,
the
exhaust
flap
is
open
(no
vacuum
applied
to
the
actuator)
and
allows
exhaust
gasses
to
flow
through
the
short
pipe
for
maximum
performance
.

180
Exhaust
System

0013101

Fig
.
1
.



Rear
muffler
(active
silencer
usedon
M52
engines)
.
Vacuum

operated
flap
(A)
changesbetween
short
and
long
pipes,
de-

pending
on
engine
speed
.

EXHAUST
SYSTEM



180-1

WARNING
-

Exhaust
gases
are
colorless,
odorless,
and
very
toxic
.
Run
the
engine
only
ín
a
well-ventilated
area
.
Immediately
repair
any
leaks
in
the
exhaust
system
or
structural
damage
to
the
car
body
that
might
al-
lowexhaust
gases
to
enter
the
passenger
compart-
ment
.

Exhaustsystem
components
are
detailed
in
Fig
.
2
through

Fig
.
4
.

New
fasteners,
clamps,rubber
mounts,
and
gaskets
should

be
used
when
replacing
exhaust
components
.
A
liberal
appli-
cationof
penetrating
oil
to
the
exhaustsystem
nuts
and
bolts
in
advance
may
make
removal
easier
.

WARNING
-

"
The
exhaust
system
and
catalytic
converter
op-
erate
at
high
temperatures
.
Allow
components
to
cool
before
servicing
.
Wear
protectíve
clothíng
to
prevent
bums
.
Do
not
use
flammable
chemicals
near
a
hot
catalytic
converter
.

"
Old,
corroded
exhaust
system
components
crumble
easíly
and
often
have
exposed
sharp
edges
.
To
avoid
injury,
wear
eye
protection
and
heavy
gloves
when
working
with
old
exhaust
parts
.

EXHAUST
SYSTEM
REPLACEMENT

T

180-
4



EXHAUST
SYSTEM

Fig
.
6
.



Exhaust
system
support
bracket
on
6-cylinder
engine
.
Re-
move
bolts
(arrows)
to
separate
from
exhaust
pipe
.

Fig
.
7
.



Rubber
exhaust
system
hangers
.
Remove
hanger
by
prying
off
bracket
(arrows)
.

EXHAUST
SYSTEM
REPLACEMENT

7
.
Installation
is
reverse
of
removal
.

"
Where
necessary,
transfer
parts
from
old
system
to
re-
placement
system
.

"
Coat
manifold
studs
with
copper
paste
before
installing

nuts
.

"
Where
applicable,
tighten
front
pípewith
semi-flexible

compensator
last
when
installing
front
pipe
to
mani-

folds
.

"
Make
sure
there
is
at
least
20
mm
(
3
/4
in
.)
of
clearance

between
exhaust
systemand
car
body
at
every
point
.
"
Loosely
install
all
exhaust
system
mountinghardware
and
hangers
before
tightening
fasteners
to
their
final
torque
.

"
On
4-cylinder
engines
:
Tighten
center
mounting
flange
nuts
evenly
until
correct
dimension
is
obtained
.
See

Fig
.
8
.

ri

J%JJ

w

~~~JJJJ

1

Fig
.
8
.



On
4-cylinder
engines,
tighten
nuts
evenly
so
that
spríngs
are
preloaded
to
Dimension
A
.

NOTE-

To
prevent
exhaust
system
rattles
and
vibration,
pre-load
the
rear
clamping
brackets
in
the
íonaard
direction
.
See
Fig
.
9
.

0011937

Tightening
Torques

"
Cross
brace
to
chassis



..
.
...
.
..
..
21
Nm
(17
ft-Ib)

"
Exhaust
support
bracket

to
transmission
.
.
.
.
.......
.....,.
21
Nm
(17
ft-Ib)
"
Exhaust
system
mounting
clamps
...
15
Nm
(11
ft-Ib)

"
Front
exhaust
pipeto
exhaust
manifold
M10
nut
.
.
.
...
.
..
..............
30
Nm
(22
ft-Ib)

"
Front
exhaust
pipe
torear
pipe

M8
bolt/nut
..
....
.
..............
22
Nm
(16
ft-Ib)
with
compression
spring
................
See
Fig
.
8
"
Oxygen
sensor
to
exhaust
pipe
.....
55
Nm
(41
ft-Ib)

Dimension
A=15mm
(0
.60
in
.)

Fig
.
9
.



Preload
rear
clamping
bracket
as
specifíed
tohelp
prevent
system
rattling
.

Exhaust
manifolds,
removing
and

installing

WARNING
-

Do
not
work
under
a
lifted
car
unfess
itis
solidly
supportedonjackstands
designed
for
that
pur-
pose
.
Never
work
underacar
that
is
supported
solely
by
ajack
.

EXHAUST
SYSTEM



180-
5

2
.
On
1996
and
later
6-cylinder
engines,
disconnect
the
secondary
air
check
valve
and
eipe
from
the
exhaust
manifold
.

3
.
Unbolt
front
exhaust
pipe(s)
from
exhaust
manifold(s)
.

4
.
Remove
exhaustsupport
bracket
from
transmission
.

5
.
Loosen
andremove
nuts
fromexhaust
manifolds
and
remove
manifolds
.
Discard
nuts
and
gaskets
.

NOTE-

On
cars
wíth
oxygen
sensors
mounted
in
the
exhaust
manifolds,
usecare
when
removing
manifolds
.
Tobe
safe,
remove
the
sensors
from
the
manifolds
before
re-
moving
manifolds
.

6
.
Installation
is
reverse
of
removal
.

"
Coatexhaust
manifold
mounting
studs
with
copper
paste
before
installing
new
nuts
.
"
Insta¡¡
manifold
gaskets
with
arched
side
facing
mani-
folds
.

Always
use
new
retaining
nuts
and
gaskets
when
removing



Tightening
Torques

and
installing
the
exhaust
manifolds
.



"
Exhaust
manifold
to
cylinder
head

4-cylinder
engine
(M7
nut)
........
15
Nm
(11
ft-Ib)

1
.
With
exhaust
system
cold,raise
and
support
car
for
ac-



6-cylinder
engine
(M7
nut)
........
20
Nm
(15
ft-Ib)
cess
lo
exhaust
system
.

EXHAUST
SYSTEM
REPLACEMENT