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11 7-50
/Camshaft Timing Chain
Timing chains assembly
(M52 TU and M54 engines)
1. Impulse wheel mounting nut
2. Camshaft impulse wheel
(exh.)
3. Spring plate
4. Thrust spacer (T
= 3.5 mm)
5. Primary chain tensioner
6. Torx screw
7. Exhaust secondary sprocket
8. Splined shaft
9. Secondary timing chain
10. Splined sleeve
11. Primary sprocket
12. Threaded stud
13. Secondary chain tensioner
14. Sprocket mounting nut
15. Spring plate
16. Splined shaft
17. Intake camshaft sprocket
18. Secondary chain lower guide
19. Thrust spacer
20. Camshaft impulse wheel
(intake)
21. Chain tensioner rail
22. Crankshaft sprocket
23. Threaded stud
24. Primary chain
25. Threaded stud
26. Guide rail
27. Threaded stud
28. Woodruff key
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... -.
Camshaft Timing chain1
Timing chains, removing
(M52 TU and M54 engines)
Camshaft timing chain removal requires that the oil pan be re-
moved. See
119 Lubrication System. Also required is re-
moval of the VANOS control
unit and disassembly of the
intake and exhaust camshaft sprocket assemblies as de-
scribed earlier in this repair group.
Special BMW
service tools are needed for timing chain re-
moval and installation. The special tools assure proper timing
of the valvetrain. Precise
marlts to set the timing on the cam:
shafts are not provided for reassembly. Read the procedures
through before beginning the job.
CA
UTION-
If the camshafts are not properly timed, the pistons can con-
tact the valves.
- D~sconnect negative (-) cable from battery.
CAUTION-
* Disconnecting the battery may erase fault code@) stored in
control module memory. Check for fault codes using spe-
cial
BMW diagnostic equipment.
Prior to disconnecting the battery, read the battery dis-
connection
cautfons given in 001 General Cautions
and
Warninqs.
- Remove VANOS control unit. See VANOS control unit, re-
moving
(M52 TU and M54 engines).
Remove sealing plug from crankcase below starter and se-
cure crankshaft with
BMW special tool ll 2 300.
Drain engine cooling system. See 170 Radiator and Cool-
ing System.
Remove belt driven cooling fan, fan shroud, and thermostat
housing. See
170 Radiator and Cooling System.
Remove drive belts. See
020 Maintenance.
NOTE-
Mark direction of belt rotation if reusing belt.
- Remove water pump pulley fasteners and pulley.
- Drain engine oil and remove oil pan as described in 119
Lubrication System.
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11 7-55
Camshaft Timing Chain
< Set timing chain on exhaust camshaft end
< Working in cylinder head cavity, remove timing chain cover
bolts
(arrows).
< Remove secondary chain lower guide bolts (arrows). Re-
move chain guide.
NOTE-
Bolt on intake camshaft side is long and extends into timing
chain cover.
- Remove crankshaft loclting tool from transmission bellhous-
ing.
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~ ~~ ~
I Camshaft Timing Chain I --
lnstall crankshaft holding tool (BMW special tool 11 8 190/11
8 200). Make sure cut outs in tool engages openings in
damper assembly. While counterholding crankshaft with
special tool, remove crankshaft center bolt (A).
CAUTION-
Do not use flywheel locking tool to hold crankshaft stationary
NOTE-
The crankshaft hub centerbolt is tightened to a torque of 410
Nm (300 ft-lb).
4 Install crankshaft damper puller (BMW special tool 11 8 210)
to 11 8 200. and (A) remove damper from crankshaft.
The crankshaft must not be allowed to rotate when the timing
chains are loosened or removed. The pistons can contact the
valves. Use appropriate crankshaft holding tool when loosen-
ing crankshaft hub center bolt.
Using a drift of less than
5 mm diameter, drive two locating
dowels in left and right sides of lower timing
cham cover to-
ward engine. Remove cover mounting bolts
(arrows) and
carefully lift cover off.
CA
UTION-
* Use care when removing the cover from the cylinder heao
gasket. If the cover is stuck, use a sharp
knife to separate
it from the headgasket.
If cylinder liead gasket Is damaged, remove cylinder
head and replace head gasket. See
113 Cylinder
head and valvetrain.
NOTE-
- The chain cover can be removed with the coolant pump in-
stalled.
Use care when removing the cover from the coolant pipe
at rear.
- Push primary chain tensioner guide rail aside and remove
chain.
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... -.
rpp- --- Camshaft Timing Chain1
Timing chains, installing
(M52 TU and M54 engines)
CAUTIOI\C
The procedure outlined below assumes that the camshaits
are lockedin the
TDC installation position with speciallocling
tools as shown earliel:
- inspect timing chain sprockets. Inspect guide rail and ten-
sioner rail for damage. Replace any part that is worn
or dam-
aged.
NOTE-
If any sprockets are being replaced due to wear, the chain
should also be replaced.
4 Primary timing chain assembly
1. Primary chain tensioner
2. Chain tensioner rail
3. Cranltshaft sprocket
4. Exhaust camshaft sprocket
5. Primary chain
6. Anchor bolt
7. Guide rail
8. Anchor bolt
9. Woodruff key
- Install primary timing chain to crankshaft sprocltet and hang
upper end from exhaust camshaft.
- If necessary, replace crankshaft radial seal in cover. See
Crankshaft oil seal, replacing (M52 TU and M54 engines).
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(camshaft Timing Chain
- To install lower timing case cover:
- Clean cover and cylinder block sealing surfaces
Use new
gaskets and coolant pipe O-ring.
Remove timing chain cover dowel pins from engine block.
Drive timing cover dowels in until they just protrude slightly
from sealing surface.
Apply a small bead of silicon sealer (Three Bond 1209
63
or equivalent) to corners of cylinder head where timing
cover meets cylinder head and engine block.
Tap cover into position until firmly seated.
lnstall all bolts hand tight, including two Torx bolts from
above.
Install secondary chain lower guide.
Tighten cover mounting bolts alternately and in stages.
Tightening torque
Lower timing cover to cylinder
bloclc (M6) 10 Nrn (89 in-lb)
- Install oil pan with new gasket. See 119 Lubrication Sys-
tem.
Tightening torque
Oil pan
to engine bloclc (M6)
8.8 grade
10.9 grade 10 Nrn (89 in-lb)
12 Nm
(9 ft-lb)
- Align damper assembly with lteyway and tap into place. In-
sert new center bolt with washer.
CAUTION-
Inspect woodruff key for damage before installing hub
assembly.
- Attach special tools 11 8 20011 1 8 190 to damper assembly.
Counterhold damper with
11 8 190 while tightening center
bolt.
CAUTION-
Do not use BMW special tool 1 I 2 300 to hold crankshaft
stationary to tighten cranl(shaft hub center bolt. Use only
the special tools specified, or equivalent hub holding tool.
Have a second person hold special tool
11 8 190 while
tightening center crankshaft bolt.
Tightening torque Crankshaft hub to crankshaft 410 Nrn
(300
ft-lb)
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Cp-- Camshaft -- Timing Chain
Secure camshaft sprockets and impulse wheels:
Tighten mounting screws
(A) on exhaust camshaft impulse
wheel to approx.
5 Nm (44 in-lb).
Tighten mounting nuts
(6) on exhaust and intake sprocket
assemblies to approx.
5 Nm (44 in-lb).
Torque down mounting screws (A) and nuts
(6) to iinal
specifications.
Tightening torques Sprocket assembly
to camshaft
initial torque
5 Nrn (44 in-lb)
Sprocket assembly to camshaft
M7 Torx screw (A) 20 Nm (I5 it-lb)
M6 mounting nut (8) 10 Nm (89 in-lb)
- Remove flywheel locking tool from transmission bellhousing
so that crankshaft is no longer secured.
- Remove camshaft loclting tools from rear of camshafts.
4 Crank engine over by hand twice in direction of rotation until
cylinder
1 intake and exhaust camshaft lobes (arrows) face
each other.
- Secure crankshaft in TDC position with BMW special tool
11 2 300.
4 Place BMW special tool 11 3 240 over camshaft ends and
measure clearance of tool to cylinder head surface.
NOTE-
* If the exhaust side of the tool is not flush with the head (gap
A), retime the camshafts as described laler in this repair
group.
Due to flexible sprocket design and VANOS control unit tol-
erances and play, the
intake side of special tool 71 3 240
may be up to
I mm (0.04 in) above the suriace of the cyl-
inder head (gap
B). This is normal. Otherwise, retime the
camshafts as described in
VANOS timing, checking and
adjusting (M52 TU and 11154 engines).
- Remove VANOS setup bracket from front of cylinder head
- Install VANOS control unit. See VANOS control unit, in-
stalling
(01152 TU and M54 engines).
- Install intake camshaft oil baffle
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11 7-66
I Camshaft Timing Chain
4 install cylinder head cover:
Check for correct seating of half-moon seals
(A) in back of
cylinder head cover.
Use a small amount of Three Bond
1209 8 or equivalent
sealant at corners
(B) of half-moon cutouts. Seal corners
in front of cylinder head at VANOS control unit.
Tightening torque
Cylinder head cover to cylinder head
10 Nm (89 in-lb)
- Remainder of reassembly is reverse of removal, noting the
following:
Secure all coolant hoses, thermostat housing, engine cool-
ant drains.
Install new engine oil filter and oil. See
119 Lubrication
System.
Refill and bleed cooling system as described in
170 Radi-
ator and Cooling system.
Use scan tool to check VANOS operation with engine
idling.
Tightening torques Coolant drain plug to cylinder block
25 Nm (18 ft-lb)
Radiator cooling fan (viscous clutch)
to coolant pump
40 Nm (30 ft-lb)
Radiator drain screw to radrator 2.5 Nm (22 in-lb)
Vibration damper hub to crankshaft 41 0 Nm
(300 ft-ib)
TIMING CHAIN
(M62 ENGINE TO 911998)
Timing chains, removing
(M62 engine to 911 998)
Camshaft timing chain removal requires that the engine oil
pan be removed.
Special
BMW service tools are needed for timing chain re-
moval and installation procedures. The special tools assure
propertiming of thevaivetrain. Precise marks to set the timing
on the camshafts are not provided for reassembly. Read the
procedures through before beginning the job.
CAUTION-
Special BMW service tools are needed for this procedure.
Read the procedure through before beginning the job. If the
camshafts are notproperly timed, the pistons can contact the
valves.