1999 BMW 525i Workshop Manual

Downloaded from www.Manualslib.com manuals search engine
Camshaft Timing chain1
< With compressed air line connected, turn engine at least
twice in direction of rotation until cylinder
1 intake and ex-
haust camshaft lobes (arrows) face each other.
Do not rotate engine counterclockwise to reach the top dead
center position. Instead, complete another two complete ro-
Remove sealing plug from bore at bellhousing. Secure crank-
shaft in
TDC position with BMW special tool 11 2 300 (ar-
row).
- Remove cylinder head cover studs at rear of cylinder head.
< Place BMW special tool 11 3 240 over camshafts ends and
measure clearance of tool to cylinder head surface.
NOTE-
If the exhaust side of the tool (A) is not flush with the head,
adjust camshaft timing as described below.
Due to flexible sprocket design and VANOS control unit tol-
erances and play, the
intake side of special tool 11 3 240
(B) may be up to 1 mm (0.04 in) above the surface of the
cylinder head. This is normal. Reassemble engine. Other-
wise, adjust camshaft timing as described below.
- Remove double VANOS control unit. See VANOS control
unit, removing
(M52 TU and M54 engines).
< Press down on secondary chain tensionerand lock into place
using BMW special tool
11 3 292 or equivalent pin or drift.

Downloaded from www.Manualslib.com manuals search engine
1 17-46
Camshaft Timing Chain
4 Loosen intake camshaft sprocket mounting nuts (arrows) by
1 turn.
Loosen exhaust camshaft sprocltet mounting bolts:
Release bolts
(A) 112 turn
Release nuts
(B) 2 turns
Pull out intake camshaft splined shaft out approx.
1 mm
(0.04 in) of splines (arrows) can be seen.

Downloaded from www.Manualslib.com manuals search engine
Camshaft Timing chain]
4 Pull out exhaust camshaft splined shaft to stop.
- Make sure camshafts are secured in TDC position using
BMW soecial tools 11 3 240 and 11 3 244.
4 Preload primary chain tensioning rail:
Tighten adjusting screw on
BMW special tool 11 4 220.
Tightening torque
Primary chain tensioner preload
0.7 Nm (6 in-lb)
4 Preload exhaust camshaft spring plate by pressing on im-
pulse wheel. Tighten mounting nuts
(arrows) by hand. Do
not tighten fully.

Downloaded from www.Manualslib.com manuals search engine
-
I Camshaft Timing Chain - --
Install BMW special tool 11 6 150 (VANOS setup bracket) to
front of cylinder head timing case. Tighten nuts
(arrows) by
hand, and then tighten down uniformly until special tool is in
full contact with cylinder head.
CAUTION-
Male sure all gasket material is removed from face of cylin-
der head. Clean
sealins face and keep free of oil.
Secure camshaft impulse sprockets and wheels:
Pretighten Torx screws
(A) on exhaust camshaft impulse
wheel to approx.
5 Nm (44 in-lb).
Pretighten mounting nuts
(B) on exhaust and intake
sprocket assemblies to approx.
5 Nm (44 in-lb).
- Torque down Torx screws (A) and nuts (8) to flnal
specifications.
Tightening torques Sprocket assembly
to camshaft
initial torque
5 Nm (44 in-lb)
Sprocket assembly to camshaft
M7 Torx screw (A) 20 Nm (15 fl-lb)
ivl6 mounting nut (B) 10 tdm (89 in-lb)
- Remove flywheel locking tool from transmission bellhousing
so that crankshaft is no longer locked.
- Remove camshaft locking tools from rear of cylinder head.
- Crank engine over twice by hand in direction of rotation until
cylinder
1 intake and exhaust camshaft lobes face each other - again.
- Secure crankshaft with BMW special tool 11 2 300.
4 Place BMW special tool 11 3 240 over camshaft ends and
measure clearance of tool to cylinder head surface.
NOJE-
If the exhaust side of the tool (A) is not flush with the head,
camshaft timing
Is incorrect. Repeat camshaft timing pro-
cedure.
* Due to flexible sprocket design and VANOS control unit tol-
erances and play, the
intake side of special tool 11 3 240
(6) may be up to 1 mm (0.04 in) above the sudace of the
cylinder head. This is normal. Otherwise, repeat camshaft
timing procedure.

Downloaded from www.Manualslib.com manuals search engine
-- - -- - -- Camshaft Timing chain1
- Remove camshaft locking tools from rear of camshafts
- Remove BMW special tool 11 4 220 (adjustable primary
chain tensioner). Reinstall primary chain tensioner.
Tightening torque Primary chain tensioner to cylinder head
70
Nm (52 it-lb)
- Remove crankshaft locking tool from transmission bellhous-
ing. Reinstall sealing plug.
- Remove VANOS setup bracket from front of cylinder head
- lnstall VANOS control unit as described earlier in this group.
- Remove compressed air fitting (BMW special tool 11 3 450)
from VANOS control unit.
- Fit VANOS oil line banjo bolt with new seals. Attach oil line to
VANOS control unit.
Tightening torque
Oil line to VANOS control unit (banjo bolt) 32 Nm (24 H-lb)
- Remainder of installation is reverse of removal, noting the fol-
lowing:
lnstall spark plugs.
* lnstall intake camshaft plastic baffle prior to installing cylin-
der head cover. lnstall ignition coil packs and connect elec-
trical harness connectors.
Install radiator cooling fan.
- lnstall air filter housing and top engine cover.
Tightening torque Radiator cooling fan
(VISCOUS clutch) to 40 Nm (30 ft-lb)
coolant pump
Cyitnder head cover to cylinder head 10 Nm (89 in-lb)
Sparlc plug to cylinder head 25 Nm (18 ft-lb)

Downloaded from www.Manualslib.com manuals search engine
11 7-50
/Camshaft Timing Chain
Timing chains assembly
(M52 TU and M54 engines)
1. Impulse wheel mounting nut
2. Camshaft impulse wheel
(exh.)
3. Spring plate
4. Thrust spacer (T
= 3.5 mm)
5. Primary chain tensioner
6. Torx screw
7. Exhaust secondary sprocket
8. Splined shaft
9. Secondary timing chain
10. Splined sleeve
11. Primary sprocket
12. Threaded stud
13. Secondary chain tensioner
14. Sprocket mounting nut
15. Spring plate
16. Splined shaft
17. Intake camshaft sprocket
18. Secondary chain lower guide
19. Thrust spacer
20. Camshaft impulse wheel
(intake)
21. Chain tensioner rail
22. Crankshaft sprocket
23. Threaded stud
24. Primary chain
25. Threaded stud
26. Guide rail
27. Threaded stud
28. Woodruff key

Downloaded from www.Manualslib.com manuals search engine
... -.
Camshaft Timing chain1
Timing chains, removing
(M52 TU and M54 engines)
Camshaft timing chain removal requires that the oil pan be re-
moved. See
119 Lubrication System. Also required is re-
moval of the VANOS control
unit and disassembly of the
intake and exhaust camshaft sprocket assemblies as de-
scribed earlier in this repair group.
Special BMW
service tools are needed for timing chain re-
moval and installation. The special tools assure proper timing
of the valvetrain. Precise
marlts to set the timing on the cam:
shafts are not provided for reassembly. Read the procedures
through before beginning the job.
CA
UTION-
If the camshafts are not properly timed, the pistons can con-
tact the valves.
- D~sconnect negative (-) cable from battery.
CAUTION-
* Disconnecting the battery may erase fault code@) stored in
control module memory. Check for fault codes using spe-
cial
BMW diagnostic equipment.
Prior to disconnecting the battery, read the battery dis-
connection
cautfons given in 001 General Cautions
and
Warninqs.
- Remove VANOS control unit. See VANOS control unit, re-
moving
(M52 TU and M54 engines).
Remove sealing plug from crankcase below starter and se-
cure crankshaft with
BMW special tool ll 2 300.
Drain engine cooling system. See 170 Radiator and Cool-
ing System.
Remove belt driven cooling fan, fan shroud, and thermostat
housing. See
170 Radiator and Cooling System.
Remove drive belts. See
020 Maintenance.
NOTE-
Mark direction of belt rotation if reusing belt.
- Remove water pump pulley fasteners and pulley.
- Drain engine oil and remove oil pan as described in 119
Lubrication System.

Downloaded from www.Manualslib.com manuals search engine
11 7-52
Camshaft Timing Chain
Remove primary camshaft chain tensioner (arrow) from tim-
ing chain cover.
CAUTIOIG
Primary camshaft chain tensioning piston is under spring
pressure.
Press down on secondary chain tensionerand lock into place
using
BMW special tool 11 3 292 or a similar size wire.
Remove exhaust camshaft impulse wheel
rows). Remove impulse wheel (A).
4 Remove spring plate (A). mounting
nuts
(ar-