1998 BMW 528i Cylinder head

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1 17-2
Camshaft Timing Chain
This repair group covers timing chain and VANOS repair
information for the following engines:
M52 (Single VANOS 6-cylinder engine)
M52
TU and M54 (Double VANOS engines)
M62 (Non VANOS
V-8 engine)
NOTE-
The M62 TU V-8 engine with VANOS Variable Camshaft
Timing repair information is not included.
NOTE-
See 100 Engine General for engine code and application
information.
Worn timing chains and sprocltets can lead to noisy operation
and erratic valve timing. Afaulty tensionercan also cause tim-
ing chain noises.
For specific repair procedures, refer to the appropriate repair
group:
020 Maintenance
113 Cylinder Head Removal and Installation
119 Lubrication System
121 Ignition System
170 Radiator and Cooling System
Special tools
Special BMW service tools are needed to perform the service
and repairs procedures covered in this repair group. Many of
these tools are expensive and only available through an au-
thorized BMW dealer. Be sure to read each procedure thor-
oughly before starting a job to determine which special tools
will be necessary.
In addition, Double VANOS system diagnosis can only be
carried out by using BMW specific electronic scan tools, such
as BMW
DISplus, MoDiC or equivalent.
4 Torque wrench wl flex extension
(Tool No. BMW 00
9 250)

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Camshaft Timina chain1
- Remove viscous clutch cooling fan. See 170 Radiator and
Cooling
System.
CA UTlOEIC
The radiator cooling fan nut (32mm wrench) has left- hand
threads.
.
< Remove engine trim covers:
Pry out plastic trim caps (arrows).
. Remove cover fasteners and covers.
4 Remove ignition coils:
0 Disconnect ignition coil electrical harness connectors
Remove
coil mounting fasteners and remove coils.
Remove spark plugs.
NOTE-
Make note of ignition coil ground strap locations.
Disconnect VANOS electrical harness connector
(A) and oil
line fitting
(B) from VANOS control unit.
NOTE-
Wrap the VANOS oil line fitting with a shop rag to absorb
leaking oil.
- Disconnect cranltcase breather by squeezing at arrows,
- Remove cylinder cover mounting fasteners and remove
cylinder head cover.
NOTE-
The cylinder head cover mounting bolt insulators and gas.
kets should be reinstalled in their original positions. Make
note of their arrangement during removal.

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Camshaft Timing Chain
4 Unscrew and remove cylinder head cover studs (arrows) at
rear of cylinder head.
% Secure camshafts in TDC position using BMW special tool
set
11 3 240.
4 Remove access plugs (arrows) from VANOS control unit.

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117-18
Camshaft Timing Chain
4 Loosen 4 bolts (arrows) from exhaust camshait sprocket
(Torx E10).
Press down on secondary chain tensioner and lock into place
using BMW special tool
11 3 292 or a similar size pin.
NOTE-
Two types of secondary timing chain tensioners are used;
one with two holes, and one with a single hole for the
locl pin tool.
Remove VANOS control unit mounting fasteners at front of
cylinder head.
4 Install sprocltet rotating tool (BMW special tool 11 5 490) on
exhaust camshaft.
- Rotate exhaust camshaft sprocket clockwise while sliding
VANOS control unit forward to remove from cylinder head.

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Camshaft Timing chain1
VANOS control unit, installing (M52 engine)
CAUTION-
Incorrect installation of the VANOS control unit may result in
damage to the engine.
- Make sure camshafts and crankshaft are loclted in TDC po-
sition with BMW special tools as described during VANOS
removal.
< Rotate exhaust camshaft sprocket clocltwise (as viewed from
front of engine) using BMW special tool
11 5 490, until detent
position stop is reached.
4 Apply a small amount of liquid gasket sealer (Three Bond
1209
8 or equivalent) to VANOS housing alignment dowels
on front of cylinder head. Install a new
gasket.
< Push VANOS piston gear cup (arrow) into VANOS housing
until it bottoms out. Position VANOS control unit in front of
camshafts, but do not engage splines on gear cup.

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11 7-20
Camshaft Timing Chain
4 lnstall BMW special tool 1 I 5 490 on exhaust camshaft.
- Insert the helical-toothed splined shafl (arrow) into the heli-
cal-toothed sprocket while rotating gears and chain counter-
clockwise with special tool.
CAUTION- Ensure
that the first available tooth engages. It is important
that the exhaust camshaft sprocket be turned only the mini-
mum amount necessary to engage the gear cup. If this pro-
cedure is done
incorrectlq: the VANOS system may not fully
function.
- Install and tighten down VANOS control unit fasteners
Tightening torques
VANOS control unit to cylinder head
M6 nuts 10 Nm (89 in-lb)
M8 bolts 22 Nrn (17 ft-lbj
- Press down on secondary timing chain tensioner and remove
lock tool.
Remove primary timing chain tensioner
(arrow)
CAUTION-
Timing chain tensioner is under spring tension.
lnstall adjustable primary chain tensioner
(BMW special tool
11 4 220) and preload timing chain by tightening to 1.3 Nm
(I I in-lb).

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Camshaft Timing Chain/ - - - - - - . - - . - .
Tighten exhaust camshaft sprocket mounting bolts (arrows)
alternately in two stages.
Tightening torques
Secondary timing chain sprocltets to camshafts
Stage
1
Stage 2
5 Nm (44 in-lb)
22 Nm (17 ft-lb)
- Remove crankshaft locking tool and camshaft locking tool
set.
- install camshaft gear bolt access plugs using new sealing
washers and tighten.
- Remove timing chain tensioning tool from side of cylinder
head. Install primary chain tensioner with new sealing wash-
er and tighten.
Tightening torques
Access plugs to VANOS control unit 50 Nm (37 ft-lb)
Primary timing chain tensioner
plug to 70 Nm (52 ft-lb)
tensioner sleeve
- Check adjustment VANOS system, see VANOS timing,
checking and adjusting
(M52 engine).

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Camshaft Timing Chain
4 Disconnect VANOS electrical harness connector (A) and oil
line fitting
(B) from VANOS control unit.
NOTE-
Wrap the VANOS oil line fitting with a shop rag to absorb
leaking oil.
Disconnect cranltcase breather by squeezing at arrows.
- Remove cylinder cover mounting fasteners and remove
cylinder head cover.
NOTE-
The cylinder head cover mounting bolt insulators andgas-
lets should be reinstalled in their original positions. Make
note of their arrangement during removal.
4 Remove oil baffle cover from intake camshaft