BMW 1989-1995 525i Service Manual page 111

CYLINDER HEAD AND VALVETRAIN
116-13
CAUTlON -
A
minimum waiting time must be observed before
installing the cylinder head to the block. When the
cemshett is remo ved. the hydraulic cam followers
expand sfightly. This expansion causes increased
valve lift. resulting in open valves.
Cylinder head install ati on waiting times
(after cylinder head reassembly)
• at or above 68°F (20°C) 10 minutes
• 50-68°F (1 0-20°C) 30 minutes
• 32-50°F (O- 1O°C) 75 minutes
NOTE-
• 8e sure all parts are reinstalled in their original posi-
tions. The camshaft bearing caps are coded with a let·
ter and
a
cylinder number. For example.
"A t
• is the
exhaust camshaft cap for cylinder no.
1
and "E I" is
the intake camsha ft bearing cap for cylinder no.
1.
Similarly. the camshafts and the camshaft carriers are
stamped with
a
code letter-"E' for the intake side
and "A •
lor the exhaust side.
• "E" is for EinlaB. (German for intake) and "A " is for
Auspuff. (German for exhaust).
• Cylinder no. 1 is at the front of the engine.
Tightening Torques
• Camshaft bearing caps
to cylinder head 15 Nm (11 ft-Ib)
• Exhaust manifold to cylinder head 20 Nm (15 ft-Ib)
• Intake manifold to cylinder head 15 Nm (11 tt-lb)
To disassemble cylinder head
(M60 engine)
Special BMW service tools are highly recommended for reo
moving and installing the camshafts and disassembling the
M60 cylinder head.
WARNING -
Removal of the camshafts without the special tools
can result in personal injury and/or cylinder head
damage. 8 e sure to read the procedure through be-
fore starting
a
job.
CAUTION -
The process of evenly loosening the camshaft
bearing cap nuts is NOT an acceptable method of
removing the camshafts. The special tools should
afways be used to remove the camshafts.
1. Remove the cylinder head as described in 113 Cylin-
der Head Removal and Installation.
2. With the cylinder head mounted to an appropriate work
stand. remove the exhaust camsha ft sprocket mount-
ing bolts.
3. Depress chain tensioner and lock in position using
BMW special tool no. 11 3 420, or appropriate stiff wire.
See Fig. 29.
00 11508
Fig . 29. Camshaft chain tensloner locked in position with BMW special
1 001 no. 11 3 420. Tensioner mounting nuts shown at arrows.
4. Slide sprocket and chain assembly from camshafts.
5. Remove chain tensioner mounting nuts and remove
tensioner.
6. Carefully turn camshafts so that cutouts in camshaft
flanges are positioned as shown in Fig. 30 or Fig. 3 1.
NOTE -
A
special jig (BMW special tool no.
11 2
430) is avail·
able to cnecs the removal and installation pos itions of
the camshafts.
7. Loosen bearing cap mounting nuts in stages (1/2 turn
per stage). working from outside to inside until valve
spring pressure is relieved.
8. Remove camshaft bearing caps. Remove camshafts .
9. Carefully remove hydraulic cam followers. Label each
cam follower as it is removed.
CAUTION -
• Use care not to damage the cam follower bores
when removing the cam followers. Special sue-
tion cups are available from BMW (special tool
no.
11 3
250) to remove the followers from the
cylinder head.
• The remo ved cam followers should be stored in
an upright position.
CYLINDER HEAD DISASSEMBLY AND ASSEMBLY