2001 BMW 525i 300

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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
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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116-15
Cylinder Head and Valvetrain
4 Remove primary timing chain tensioner plug (arrow) and pri-
mary tensioner.
CAUTION-
Primary timinq chain tensioner is under sarina aressure.
4 Remove primary timing chain sprocket and timing chain from
exhaust camshaft.
- Remove crankshaft locking tool (BMW 11 2 300) from
flywheel (installed during
VANOS removal).
Lift timing chain (holding under tension) and rotate engine
counterclockwise 30" from
TDC.
- Suspend timing chain with mechanic's wire

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11 6-23
Cylinder Head and Valvetrain
Place timing
chain on end of exhaust camshaft
4 Do not remove end spline retaining screws from camshafts
(arrows).
CAUTION-
The end spline retaining screws precisely locate the end
splines to the camshafts. Do not loosen these screws.
Remove locating studs (arrows) from
intake camshaft. Lift
off intake
camshaft thrust spacer (A) and impulse wheel (B)
4 Remove cylinder head cover mounting studs (arrows) from
center of cylinder head.
- Remove crankshaft locking tool (BMW special tool 11 2 300)
from cranltcase.

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~ ~. --
Cylinder Head and Valvetrain .-
4 While maintaining tension on timing chain, rotate crankshaft
at vibration dampener from
30" before TDC in direction of ro-
tation (clockwise) until number
1 cylinder is at TDC position
with line between the OIT mark (arrow) on front pulley
aligned with boss on lower timing chain cover.
4 Secure crankshaft in TDC position with BMW special tool
11 2 300 (arrow).
Slide impulse wheel on intake camshaft, aligning boss with
raised portion on camshaft (arrow).
Fit thrust spacer
(A) to intalte camshaft and tighten down with
threaded locating studs (arrows). Place longer threaded por-
tion of studs into camshaft.
Tightening torque
Impulse wheel studs to intake camshaft (M7)
20 Nm (15 ft-lb)

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-
. - - -- Cylinder Head and valvetrain]
Turn engine over twice in direction of rotation until cylinder 1
intake and exhaust camshaft lobes (arrows) face each other.
- Lock 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.
NOTE-
@ If the exhaust side of the tool (A) is not flush with the head,
camshaft timing is incorrect. Reset camshaft timing as de-
scribed in 11
7 Camshaft Timing Chain.
Due to flexible sprocket design, VANOS unit tolerances
and play in the VANOS splines, when the camshaft timing
is set correctly, the intake side of special tool set
11 3 240
(B) may be up to 1 mm (0.04 in.) above the suiface of the
cylinder head. This is normal. Reassemble engine. Other-
wise, reset camshaft timing as describedin 1
l?Camshaft
Timing Chain.
- Remove BMW special tool 11 6 150 from front of cylinder
head.
4 Clean contact edges of cylinder head face and VANOS unit
and apply a thin coat of Three Bond
12090 or equivalent
sealing compound to surfaces.
CAUTION-
Male sure all gasket material is removed from face of cyl-
inder head. Clean sealing face and keep free of oil.
Check locating dowel
(A) and dowel sleeve (B) at top
of cylinder head for damage or incorrect installation.
- Using a new steel gasket, install VANOS unit to front of cyi-
inder head. See 117 Camshaft Timing Chain.
NOTE-
If VANOS control unit is being replaced, be sure to check and
adjust camshaft timing as described in 117 Camshaft Tim-
ing Chain.
- Reinstall engine lifting eye.
- Reconnect electrical harness connectors to camshaft posi-
tion sensors and
VANOS solenoid valves.

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ICylinder Head and Valvetrain -.
Rotate engine clockwise (arrow) from 45" before TDC to
TDC position.
Secure crankshaft in
TDC position with BMW special tool
11 2 300.
4 Fit sprocket with primary chain to intaite camshaft on right
cylinder head:
Press timing chain tensioner rail against timing chain
(white arrow) to check that fastener holes are centered in
sprocket slots (black arrows) when slack is removed from
timing chain.
If necessary, remove sprocket and reposition.
Fit sprocket with chain to intake camshaft
5-8 with long bores aligned centrally.
Install bolts (arrows) and finger tighten cylinder
head