2001 BMW 525i Pg 240

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I Cylinder Head Removal and Installation
4 Check that two locating dowels are correctly positioned in
block and are not damaged.
- Apply permanently elastic sealing compound Three Bond
1209 8 to joints where cylinder block joins timing case cover.
- Place new cylinder head gasket on cylinder block.
NOTE-
The word "OBEN" or 'TOP': printed on the gasket, should
face up. The cylinder head
gasket will fit correctly in only one
orientation.
- With camshafts locked in TDC oosition with BMW soecial
tools as described during cylinder head removal,
seicylinder
head in position, guiding primary chain through cylinder head
opening.
NOTE-
* The camshafts must be locl(ed in the TDC position at the
rear of the cylinder head with
BMW special tool I1 3 240
before installing the cylinder head.
Make sure the
cranksha% which had been rotated approx-
imately
30" opposite the direction of engine rotation, is still
in that position before lowering the cylinder head into posi-
tion.
- Lightly lubricate new cylinder head bolts. Loosely install bolts
and their washers, then thread them in until they are finger
tight.
NOTE-
. Torx-type cylinder head bolts should not be reused. They
are stretch-type bolts and must always be replaced when-
ever loosened.
Check that all washers for the cylinder head bolts are in
place before installing the bolts. Some of the washers may
be
stalced to the cylinder head.
CAUTIOI\C
Cylinder head bolts for a cast iron engine block are different
length and require different tightening torque than bolts for an
aluminum cylinder bloclc engines
(95 rnm versus 110 rnm
bolts).
- Install cylinder head-to-lower timing chain cover bolts finger
tight.
< Tighten cylinder head bolts in correct sequence to initial
torque value.

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--
Cylinder Head Removal and Installation
NOTE-
BMW special tool 11 4 220 is an adjustable primary chain
tensioner and simulates the function of the hydraulic
tensioner.
- Check that elongated holes in primary sprocket are now cen-
tered to bolt holes in camshaft and chain is free of slack. If
not, reposition sprocket to chain and reinstall.
- lnstall secondary timing chain guide and secondary chain
tensioner. Tighten mounting bolts (tensioner remains locked
down for now using
BMW special tool 11 3 292).
- Install cylinder identification trigger plate to front of intake
camshaft with studs.
- Install spacer to front of intake camshaft.
- Install secondary chain sprockets and chain as an assembly
so that arrows on sprockets are pointing up. Center mounting
holes in sprockets to bolt holes in camshafts.
4 lnstall thrust washers and diaphragm spring to intake cam
sprocket.
I 2hm thrust washer I
- Install shim and torx bolts to exhaust camshaft. Tighten fin-
ger tight; do not torque down.
- Tighten intake sprocket nuts.
CA UTIOG
Hold the camshaft stationary (at hex on camshaft) when loos-
enino or tiahtenino sorocket mounting bolts and studs.
Tightening torque
Intake s~rocket nuts to studs 10 +l Nm (89 +9 in-lb)
- Turn crankshaft approx. 30" in direction of rotation to bring
engine to TDC. Lock crankshaft in TDC position with BMW
special tool
11 2 300.
CAUTION-
The camshafts andcranlshaft must be lockedin the TDCpo-
sition using BMW special tools 11 2 300 and 11 3 240. If the
camshafts and cranl(shaft are not at TDC, the valves can
contact the pistons.

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11 3-31
Cylinder Head Removal and Installation
Remove sealing plug from special tool bore on lower left side
of engine block near flywheel. Secure crankshaft in TDC po-
sition with
BMW special tool l l 2 300 (arrow).
4 Unscrew and remove two cylinder head cover studs
(arrows) at rear of cylinder head.
4 Secure camshafts in TDC position using BMW special tool
set
11 3 240.
- Disconnect compressed air line, leaving compressed air fit
ting attached to VANOS unit.
4 Unscrew sealing plugs (arrows) from VANOS unit.

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Cylinder Head Removal and Installation I
Remove cylinder head cover mounting studs (arrows) from
center of cylinder head.
- Remove crankshaft loclting tool from transmission bell hous-
Ing.
Lift primary chain and hold under tension, then rotate engine
at vibration damper in opposite direction of normal rotation
(counterclocltwise) approximately 30".
CAUTION-
By turning crankshait3O0, pistons are movedaway from top
dead center, to prevent possible valve interference to pistons
during camshaft servicing.
- Remove camshaft loclting tools (BMW special tool set 11 3
240) from rear of cylinder head.
4 Remove camshaft bearing cap 1 on intake camshaft.
4 Fit BMW special tools 11 3 260 (A) and 11 3 270 (B) to cyl-
inder head and screw long bolts (arrows) into spark plug
threads. Tensioning pins on tool will align with the bearing
caps on the
intake camshaft.
CAUJION-
Do not over torque bolts into sparkplug holes.

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11 3-44
I Cylinder Head Removal and Installation
4 Secure camshafts in TDC position using BMW special tool
set
11 3 240.
4 In necessary, turn camshaft slightly so that special tools are
squarely seated on cylinder head.
4 Lift timing chain and hold under tension.

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. .- --
Cylinder Head Removal and Installation
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
(8) on exhaust and intake sprocket
assemblies to approx.
5 Nm (44 in-lb).
Torque down mounting screws (A) and nuts (B) to final
specifications.
Tightening torques
sprocket assembly to camshaft
initial torque
5 Nm (44 in-lb)
Sprocket assembly
wheel to camshaft
M7 torx screws (A) 20 Nm (15 ft-lb)
M6 mounting nuts (5) 10 Nm (8 ft-lb)
- Remove crankshaft locking tool from transmission bell hous-
ing so that crankshaft is no longer secured in
TDC position.
- Remove camshaft locking tools from cylinder head.
4 Turn engine over 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 set 11 3 240 over camshafts and
measure clearances.
CAUTION-
- If the exhaust side of the tool (A) is not flush with tlie head,
camshaft timing is incorrect Reset camshaft timing as de-
scribed in
117 Camshaft Timing Chain.
* Due to flexible sprocket design, VANOS unit tolerances
and play in the VANOS splines, when the camshaft tim-
ing is set correctly, the intake side of special tool
11 3
240 (6) may be up to 1 mm (0.04 in.) above the surface
of the cylinder head. This is normal. Reassemble en-
gine.
Othe~lise, reset camshaft timing as described in
11 7 Camshaft Timing Chain.
- Remove BMW special tool 11 6 150 from front of cylinder
head.

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1 16-3
Cylinder Head and Valvetrain
4 Cranltshaft loclting tool (Tool No. BMW 11 2 300)
4 Camshaft loclting tools set (V-8, cyl. 1-4)
(Tool No.
BMW 11 2 440)
4 Camshaft locking tools set (V-8, cyl. 5-8)
(Tool No. BMW 11 2 440)
4 Camshaft loclting tools set (6-cylinder)
1 (Tool No. BMW 11 3 240)
4 Camshaft bearing cap tensioning jig (6-cylinder)
ITool NO. BMW 11 3 260/27n

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..--.
I Cylinder Head and Valvetrain - I
4 Lift primary chain and hold under tension, rotate engine
against direction of rotation (counterclockwise) approximate-
ly 30".
To prevent damaging valves while
worlcing on camshafts, no
aistons should be in the TDC position.
- Remove BMW special tool set 1 I 3 240 from rear of cylinder
head.
Remove retaining nuts (arrows) and bearing cap
1 of intake
camshaft.
Intake camshaft bearing cap
1 is centered with adapter
sleeves. To avoid camshaft damage, it must be removed be-
fore anv other caos.
4 Fit BMW special tools 11 3 260 (A) and 11 3 270 (B) to cylin-
der head and screw long bolts (aiiows) into spark plug
threads. Tensioners will align with the bearing caps on the in-
take camshaft.
CA UTION--
Do not over torque bolts into spark plug holes. 1
4 Turn eccentric shaft of special tool to pretension intake carn-
shaft bearing caps. Remove nuts on remaining bearing caps.
- Slowly release tension on eccentric shaft and remove BMW
special tools. Remove bearing caps and set aside in order.
Remove camshaft and store safely.
CA U TIOW-
Camshaft bearing caps must be installed in their original lo-
cations.