1999 BMW 525i Workshop Manual

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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)

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Camshaft Timing chain/
Fit top sprocltet to primary timing chain and install on exhaust
camshaft so that pointer (arrow) on sprocltet lines up with
cylinder head sealing surface.
Position sprocket so that chain slack is on tensioner rail side.
4 Insert BMW special tool 11 4 220 in cylinder head and screw
in adjustment screw
by hand just until it contacts tensioning
rail and chain slack is removed.
NOTE-
BMW special tool 71 4 220 is an adjustable primary chain
tensioner that simulates the function of the tensioner.
- Make sure arrow on top primary sprocket is still lined up with
upper edge of cylinder head. Reposition sprocket if neces-
sary.

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11 7-60
Camshaft Timing Chain
< Install and tighten down threaded locating studs (arrows) in
end of exhaust camshaft.
Tightening torque Exhaust camshaft locating
stud 20 Nrn (15 ft-lb)
4 Install secondary chain tensioner on cylinder head.
- Make sure tensioner is locked in compressed position as
described earlier.
Fit exhaust camshaft splined sleeve, aligning gap in sleeve
splines with corresponding gap on
camshaft splines
(arrows).