2001 BMW 525i cylinder head bolt

Downloaded from www.Manualslib.com manuals search engine
11 6-54
Cylinder Head and Valvetrain
Replace primary timing chain tensioner O-ring (arrow) in
right cylinder head.
- lnstall right upper timing cover to engine:
Remove old gasket from right timing cover.
Clean gasket groove and install new gasket.
Apply Three Bond
12098sealant to joint between cylinder
head and timing cover. Install remaining timing cover bolts
finger tight.
lnstall left upper timing chain cover to engine:
Remove old gasket from right timing chain cover.
Clean gasket groove and install new gasket.
Insert lower cover timing chain cover retaining bolt (arrow)
to cover, then fit cover to cylinder head.
Apply Three Bond 12098 sealant to joint between cylinder
head and timing chain cover. lnstall upper timing cover
bolts finger tight.
4 Remove cylinder head cover sealing gaskets from right cyl-
inder head cover. lnstall BMW special tool 11
1 41 1 into gas-
ket groove of cylinder head cover.
lnstall right cylinder head cover with BMW special tool
11
1 41 1 to right cylinder head. Fit cylinder head cover retain-
ing nuts to cylinder head cover studs at cylinders
1 and 2
(first two cylinders on right cylinder head).
Tighten nuts uniformly in
'I2 turn steps.
NOTE-
BMW special tool 11 1 41 1 presses upper timing chain cover
to level of cylinder head.
Tightening torque Cylinder head cover nuts
10 Nm (7.5 n-lb)
- Tighten right upper timing cover retaining bolts in two passes.
Tightening torque
Timing chain cover to head
10 Nm (7.5 ft-lb)

Downloaded from www.Manualslib.com manuals search engine
11 6-55
Cvlinder Head and valvetrain1
4 Remove cylinder head cover sealing gasltets from left cylin-
der head cover. Install BMW special tool 11 1 412 into gasket
groove of cylinder head cover.
Install left cylinder head cover. Fit cylinder head cover re-
taining nuts to cylinder head cover studs at cylinders
5 and
6 (first two cylinders on left side cylinder bank).
* Tighten nuts uniformly in 'I? turn steps.
NOTE-
BMW special tool 11 1 4 12presses upper timing chain cover
to level of cylinder head.
Tightening torque Cylinder head cover
nuts 10 Nm (7.5 it-lb)
- Tighten left upper timing chain cover retaining bolts in two
passes.
Tightening torque
Timing chain cover to head
10 Nm (7.5 ft-lb)
- Remove cylinder head covers and remove BMW special
tools 11 4 41 11412 from cylinder head covers.
- Fit new gasket to cylinder head cover without strain.
- Apply Three Bond@ 1209 sealant to joints between cylinder
head and timing cover.
4 Malte sure half-moon cutouts (A) at rear of cylinder heads fit
correctly to cylinder head sealing surface. Apply Three
Bond@ 1209 sealant at corners of half-moon cutouts (B).
- Remainder of installation is reverse of removal.

Downloaded from www.Manualslib.com manuals search engine
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.

Downloaded from www.Manualslib.com manuals search engine
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.

Downloaded from www.Manualslib.com manuals search engine
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).

Downloaded from www.Manualslib.com manuals search engine
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).

Downloaded from www.Manualslib.com manuals search engine
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

Downloaded from www.Manualslib.com manuals search engine
Camshaft Timing Chain Timing chains, removing
(M52 engine)
Camshaft timing chain removal on M52 engines requires en-
gine oil pan removal.
Special
BMW sewice tools are needed for timing chain re-
moval and installation procedures. The special tools assure
propertiming of thevalvetrain. Precise marks to
setthe timing
on the camshafts are not provided for reassembly. Read the
procedures through before beginning the job.
NOTE-
If the camshafts are not properly timed, the pistons can con-
tact the valves.
- Remove VANOS control unit. See VANOS control unit, re-
moving (M52 engine).
- Remove radiator cooling fan and shroud. See 170 Radiator
and Cooling System.
- Drain cooling system. See 170 Radiator and Cooling Sys-
tem.
- Remove coolant hoses from thermostat housing and remove
thermostat housing from front of cylinder head.
- Loosen bolts for coolant pump pulley.
- Remove drive belts for alternator and AIC compressor. See
020 Maintenance.
- Remove coolant pump pulley.
Remove drive belt tensioner mounting bolts (arrows) and re-
move tensioner from front of engine.
- Remove engine speed sensor from lower timing chain cover.