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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 7-52
Camshaft Timing Chain
Remove primary camshaft chain tensioner (arrow) from tim-
ing chain cover.
CAUTIOIG
Primary camshaft chain tensioning piston is under spring
pressure.
Press down on secondary chain tensionerand lock into place
using
BMW special tool 11 3 292 or a similar size wire.
Remove exhaust camshaft impulse wheel
rows). Remove impulse wheel (A).
4 Remove spring plate (A). mounting
nuts
(ar-
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-
Camshaft Timing chain1
< Remove intake camshaft sprocket mounting nuts (arrows)
and remove spring plate (labelled
FRONT).
Remove tom screws from exhaust camshaft sprocket
(arrows).
Lift off exhaust and intake sprockets with secondary chain,
thrust spacer
(A) and splined shaft (B).
CAUTION-
Splined shafts for both intake and exhaust camshafts share
the same part
numbe,: Remove and mark used splined
shafts in order to reinstall in original locations.
4 Remove exhaust camshaft splined sleeve (A) and shaft (8).
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1 17-54
Camshaft Timing Chain
4 Remove secondary chain tensioner mounting bolts (ar-
rows).
Remove tensioner while keeping locking pin in place.
4 Remove primary chain sprocket mounting studs (arrows) on
exhaust camshaft.
4 Lift primary chain sprocltet off exhaust camshaft. Remove
sprocket from chain.
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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)