1999 BMW 525i Workshop Manual

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Cylinder Head and valvetrain1
< Place intake and exhaust sprockets in BMW special tool
11 6 180. Position spline gap on intake sprocket (arrow) as
shown and place secondary chain on
sprocitets.
< Remove chain and sprockets from tool and slide sprockets
on camshafts. Confirm that gap in intalte sprocket splines
lines up with corresponding gap in camshaft splines (arrow).
CAUTIOI\C
Do not alter position of sprockets with respect to chain when
removinq from saecial tool 11 6 180.
4 While aligning locating tooth of shaft with spline gaps on
camshaft and sprocket, slide spiined
shaft onto intalte carn-
shaft until approx. 1 mm (0.04 in.) of splines (arrows) are
visible.
4 lnstall intake camshaft spring plate so that FRONT mark is
visible. install mounting nuts (arrows) finger tight.

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/Cylinder Head and Valvetrain
4 Insert sprocket mounting bolts (arrows) on exhaust side
carnshaft assembly.
Initially tighten to approx.
5 Nrn (44 in-lb) and then back off
by half a turn.
4 Fit thrust spacer (A) on exhaust
camshaft.
4 Install spring plate (A) to exhaust camshaft. Make sure that
(F) mark is visible.
NOTE-
If F marlc is no longer visible, install spring plate as shown in
inset.

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. .
Cylinder Head and Valvetrain
Install exhaust camshaft impulse wheel, aligning pointer (B)
with top edge of cylinder head (A). Install mounting nuts (ar-
rows) finger tight.
4 Pull out exhaust camshaft splined shaft to stop.
- Press down on secondary chain tensioner and remove ten-
sioner lock-down tool.
Preload primary chain:
- Tighten adjusting screw on BMW special tool 11 4 220 to
specified torque.
Tightening torque Primary chain tensioner preload
0.7 Nm (6 in-lb)

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1 16-36
I Cylinder Head and Valvetrain
4 Preload exhaust camshaft spring plate by pressing on im-
pulse wheel while tightening mounting nuts (arrows)
fingel
tight.
4 Install BMW special tool 11 6 150 (VANOS setup bracket) to
front of cylinder head timing case. Install nuts (arrows) finger
tight, then tighten down uniformly until special tool is in full
contact with cylinder head.
CAUTION--
Male sure aNgas1ef material Is removed from face of cyiin-
der head. Clean sealing face and keep free of oil.
4 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 (B) 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 carnshaft
M7 tom screws (A) 20 Nm (15 ft-lb)
M6 mounting sciew (6) I0 Nm (8 ft-lb) - - -
- - Remove crankshaft locking tool from crankcase.
- Remove camshaft locking tools from cylinder head.

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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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I Cylinder Head and Valvetrain
- Remove adjustable primary timing chain tensioner tool and
reinstall primary chain tensioner cylinder to cylinder head.
Tightening torque
Primary chain tensioner cylinder
to 70 Nm (52 ft-lb)
cylinder head
- Remove flywheel locking tool from crankcase. Replace spe-
cial tool bore sealing plug.
- Remove camshaft locking tools from cylinder head
Install intake camshaft cover and 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
8 1209 or equivalent
sealing compound at corners
(B) of half-moon cutouts.
Seat gasket and seal corners at VANOS unit with Three
Bond
@ 1209.
Tightening torque Cylinder head cover to cylinder head
(M6) 10 Nm (89 in-lb)
- Installation of the remaininq parts is reverse or removal, not- -
ing the following:
Change engine
011 and f~lter as descr~bed in 020 Mainte-
nance.
Reconnect battery.
To prevent damaging the engine electronic systems, install
all ground wire previously removed, including the ground
wires for the ignition coils.
Tightening torque
-
Radiator cooling fan to coolant pump 40 Nm
(30 ft-ib)
Spark plug to cylinder head
25 Nm (18 ft-ib)

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Cylinder Head and valvetrain1
Camshaft removal and installation
(M62 engine)
Camshafts, removing (M62 engine)
Special
BMW service tools should always be used to remove
and install the camshafts. Removal of the camshafts without
the special tools can result in personal injury and lor cylinder
head damage.
NOTE-
Cylinder bank 1-4 is referred to as the right cylinder bank
and is located on the passenger side. Cylinder bank 5-8 is
referred to as the left cylinder bank and is located on the driv-
er's side.
WARNING-
Allow enqine to cool before beqinninq this procedure. 1
- Disconnect negative (-) cable from battery.
CAUTION-
Prior to disconnecting the battery, read the battery discon-
nection cautions
in 001 General Cautions and Warnings.
- Dra~n coolant. See 170 Radiator and Cooling System.
Remove plastic engine covers:
Press down on locking pins (arrows) and remove top
cover.
Pry out
trlm caps (A) from covers.
Remove fasteners from beneath
trlm caps and remove
side covers.
4 Remove left and right interior ventilation filter housing (lefl
side shown):
Release locking tabs
(A) or locking strap (early models,
not shown).
Rotate duct inward (arrow) to disconnect.
- Release spring lock (6) to unloclc ventilation housing.
Disconnect electrical harness from hood switch
(C).
Release locking clip and remove ventilation filter cover (0).
Remove filter housing.
Removal of right side ventilation duct is similar.

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-. .
Cylinder Head and Valvetrain -- v . -- --- --
4 Remove air filter housing and ducts:
Loosen hose clamps as necessary and disconnect electri-
cal harnesses.
- Remove air filter housing mounting fastener (arrow).
Loosen hose clamp at throttle body.
Remove air filter housing with mass air flow sensor and
duct.
Disconnect the following electrical harness connectors.
Knoclc sensors (A).
Thermostat housing (B).
Throttle position sensor/throttle position switch and idle
valve
(C).
Camshaft position sensor (D).
* Ignition coils (E).
Remove mounting nuts (arrows)
ducting. from
wiring harness