1995 BMW M3 fig 27

170-10



RADIATOR
AND
COOLING
SYSTEM

Coolant
pump,
replacing

The
engine
coolant
pump
is
mounted
in
the
frontof
the
en-

gine
on
the
timing
cover
.
See
Fig
.
16
.

Fig
.
16
.
Coolant
pump
mounted
on
timing
cover
.

NOTE-

Onlyreplacement
coolant
pumps
with
metal
¡mpellers
should
be
installed
.
Pumps
with
plastic
impellers
should
not
be
used
.

1.
Drain
cooling
system
as
described
earlier
.

0013197

WARNING
-

Allow
cool¡ng
system
to
cool
before
open¡ngor
drain¡ng
system
.

2
.
Remove
primary
cooling
fan
shroud
and
cooling
fan
(belt-driven
or
electric)
as
described
earlier
.

Fig
.
17
.
Engine
drive
belt
tensioner
being
released
on
M44
engine
.
Pry
off
tensioner
cover
and
then
lever
tensioner
in
counterciock-
wise
direction
(as
facing
engine)
and
slip
belt
off
pulleys
.

Fig
.
18
.
Drive
belt
tensioner
being
released
on
M52
engine
.
Pry
off
3
.
Disconnect
hoses
from
thermostat
housing
.
Unbolt



tensioner
cover
and
then
lever
tensioner
clockwise
(as
facing
thermostat
housing
from
front
of
cylinder
head
.



engine)torelease
belt
tension
.

4
.
Remove
coolant
pump
drive
belt
.
See
Fig
.
17
or
Fig
.
18
.

NOTE-

-
Mark
direction
of
drive
belt
rotation
if
reusing
belt
.



"
The
6-cylinder
coolant
pump
¡s
mounted
on
studs
and
retained
by
nuts
.
"
Severa¡
drive
belt
and
tensioner
configurations
havebeenused
in
E36
models
.
Refer
to
020
Maintenance
Program
and
640
Heating
and
Air
Conditioning
.

5
.
Remove
coolant
pump
pulley
from
pump
.

6
.
Remove
mounting
fasteners
from
pump
.

COOLING
SYSTEM
SERVICE

NOTE-

"
The
4-cylinder
coolant
pump
¡s
mounted
us¡ng
two
dif-
terent
length
bolts
.
Note
where
thelonger
bolt
fits
dur-
ing
disassembly
.

0011989

7
.
Insert
twoscrews
(M6)
in
tapped
bores
and
tighten
uni-
formly
until
pump
is
free
from
timing
chain
cover
.
See
Fig
.
19
.

Fig
.
19
.
Coolant
pump
being
removed
.
Thread
two
M6
bolts
(arrows)
in
evenly
to
withdraw
pump
.
(Thermostat
and
hoseshavebeen
removed
tor
visual
access
.)

8
.
Installation
is
reverse
of
removal
.

"
Be
sure
to
replace
O-ring
and
gaskets
.

"
Coat
O-ring
with
lubricant
during
installation
.

Tightening
Torque

"
Coolant
pump
to
timing
chaincover

M6
...
.
...................
..
.
.
10
Nm
(89
in-lb)

M8
.
..
.
....................
.
.
.
22
Nm
(17
ft-Ib)

"
Coolant
pump
pulley

to
coolant
pump
.................
10
Nm
(89
in-lb)

RADIATOR
SERVICE

Radiator,
removing
and
installing

1
.
Drain
radiator
as
described
earlier
.

WARNING
-

Allow
cooling
system
to
cool
before
opening
ordraining
system
.

2
.
Remove
primary
cooling
fan
(belt-driven
or
electric)
as

described
earlier
.

3
.
Disconnect
coolingfan
and
leve¡
sensor
harness
con-

nectors
from
bottom
of
radiator,
where
applicable

4
.
Disconnect
harness
connector
from
auxiliary
fandual

temperature
switch
.
See
Fig
.
20
.

5
.
Disconnect
all
coolant
hoses
from
radiator
.

RADIATOR
AND
COOLING
SYSTEM



170-11

0012500

Fig
.
20
.
Cooling
fan
dual
temperatura
switch
(arrow)
on
right
sido
of
radiator
.

6
.
Where
applicable,
disconnectautomatic
transmission
fluid
(ATF)
cooler
lines
from
radiator
.
See
Fig
.
21
.

Fig
.
21
.
Automatic
transmission
fluid
(ATF)
linos
at
radiator
.

7
.
Carefully
pryout
radiator
retaining
clips
from
top
of
ra-

diator
.
See
Fig
.
22
.

8
.
Pul¡
radiator
up
and
out
of
car
.

NOTE-

The
radiator
rests
ontwo
rubber
mounts
.
Check
that

the
mounts
do
not
stick
to
the
bottomof
the
radiator
.

RADIATOR
SERVICE

170-12



RADIATOR
AND
COOLING
SYSTEM

Fig
.
22
.
Radiator
retaining
clip
being
removed
.
Push
down
and
pulí
screwdriver
forward
to
release
clip
.

9
.
Installation
is
reverse
of
removal
.

"
Fill
radiator
and
cooling
system
as
described
under
Coolant,
draining
and
filling
.
"
Check
ATF
leve¡
and,
if
necessary,
top
up
.
See
240
Au-
tomatic
Transmission
.

RADIATORSERVICE

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

180-2



EXHAUST
SYSTEM

a

EXHAUST
SYSTEM
REPLACEMENT

Fig
.
2
.



Exhaust
systemon
1992-1995
6-cylinder
engines
.
3251
(M50)
exhaust
system
shown
.

E~

)l-,malo
m~=

i

32592-95

1
.



Front
pipe
with
catalytic
convertor



6
.



Bracket



11
.



Bracket/clamp
(2)



16
.



Rear
pipewith
muffler
2
.



Gasket
(2)



7
.



Bracket
(2)



12
.



Rubber
mounting
ring
(2)



17
.



Rubber
mount
3
.



Exhaust
manifold



8
.



Bracket



13
.



Flange



18
.



Support4
.



Exhaust
manifold



9
.



Bracket



14
.



Gasket
(48mm)



19
.



Bracket
5
.
Manifold
gasket



10
.
Oxygen
sensor



15
.
Gasket
(48mm)

eme°"



k
:I>
-
8a

1
.



Exhaust
manifold



7
.



Front
pipe
with
catalytic
con-



9
.



Bolt
(M8X90)



14
.



Brackets
(rear
muffier)
2
.



Nut
(M10)



vertor



10
.



Compression
spring



15
.



Rear
muffler
and
pipe
3
.
Gasket
(clty
.
2)



8
.



Oxygen
sensor
(regulating)



11
.



Self-lockingnut
(M8



16
.



Bracket
(transmission)
4
.
Gasket



-tightento
55
Nm
(41
ft-Ib)



-always
replace



17
.



Brackets
(transmission)
5
.



Nut



8a
.



Oxygen
sensor
(monitoring)



12
.



Bracket
(rear
pipe)
6
.



Bolt
(M8X55)



-tightento
55
Nm
(41
ft-Ib)



13
.



Rubber
mounting
ring
(9ty
2)

Fig
.
3
.



Exhaust
systemon
1996-1998
4-cylinder
(M44)
engine
.1992-1995
4-cylinder
engine
exhaust
system
is
similar
.

1
.



Gaskets



5
.



Front
pipe
with
catalytic
con-



8
.



Flange
2
.



Exhaust
manifold



verter



9
.



Bolt
(M8x55)

3
.
Exhaust
manifold



6
.
Oxygen
sensor
(monitoring)



10
.
Rubber
mounting
ring
(48mm)
4
.



Oxygen
sensor
(regulating)



7
.



Nut
(M8)



11
.



Rear
pipewith
mufflers

Fig
.
4
.



Exhaust
systemon
1996-1998
6-cylinder
engines
.
M3
(S50US)
exhaust
system
shown
.

Exhaust
system,
removing
and
installing



NOTE-

The
automatic
transmission
will
be
supported
by
the

This
section
covers
removing
the
exhaust
system
as
a
com-



rear
crossmember
once
the
brace
is
removed
.

plete
unit
.
Once
the
system
is
removed
from
the
car,
individual

pipes
and
mufflers
can
be
more
easily
replaced
.

1.
With
exhaust
system
fully
cold,raise
and
support
car

for
access
to
exhaustsystem
.

WARNING
-

Do
not
work
undera
lifted
car
unless
it
is
solidly

supported
on
jack
stands
designed
for
that
pur-
pose
.
Never
work
under
a
car
that
is
supported
solely
by
a
jack
.

2
.
Disconnect
oxygen
sensor
connector(s)
.

NOTE
-

On
1996
and
later
cars
with
multiple
oxygen
sensors,

label
the
oxygen
sensor
connectorsbefore
disconnect-
ing
.

4
.
Where
applicable,
remove
support
brace
from
trans-

mission
.
See
Fig
.
5
.

EXHAUSTSYSTEM



180-
3

3
.
Loosen
andremove
bolts
holding
front
exhaust
pipes
to

exhaust
manifolds
.



transmission
.
See
Fig
.
6
.

0011940

Fig
.
5
.



Crossbracemounting
bolts
(arrows)
.

5
.
Disconnect
exhaust
support
bracket
assembly
from

6
.
Supportexhaustsystem
from
below
and
dísconnect

rubbersupports/rubber
rings
from
exhaust
system
.
Re-

move
exhaust
system
from
below
.
See
Fig
.
7
.

EXHAUST
SYSTEM
REPLACEMENT

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