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Cylinder Head and Valvetrain
Remove torx
(arrows). screws
from
exhausl
: camshaft : sprocket
Lift off exhaust and intalte sprockets together with secondary
chain, thrust spacer
(A) from exhaust camshaft, and splined
shaft (B) from intake camshaft.
CAUTIOf+
Splined shafts share the same part number for both intake
and exhaust camshafts. Used splined shafts must be rein-
stalled in their
oriqinal locations.
Place intalte and exhaust sprockets in
BMW special tool 11 6
/ 180. Position spline gap on intake sprocket (arrow) as
shown.
4 Remove exhaust camshaft splined sleeve (A) and shaft (B).
Page 198 of 1002
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11 6-22
Cylinder Head and Valvetrain
Remove secondary chain tensioner mounting bolts (arrows)
and remove tensioner with locking tool in place.
Remove primary chain sprocket mounting studs
(arrows) on
exhaust camshaft.
NOTE-
Counterhold camshafts when loosening.
Lifl primary chain sprocket off exhaust camshaft. Remove
sprocket from chain.
Page 199 of 1002
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11 6-23
Cylinder Head and Valvetrain
Place timing
chain on end of exhaust camshaft
4 Do not remove end spline retaining screws from camshafts
(arrows).
CAUTION-
The end spline retaining screws precisely locate the end
splines to the camshafts. Do not loosen these screws.
Remove locating studs (arrows) from
intake camshaft. Lift
off intake
camshaft thrust spacer (A) and impulse wheel (B)
4 Remove cylinder head cover mounting studs (arrows) from
center of cylinder head.
- Remove crankshaft locking tool (BMW special tool 11 2 300)
from cranltcase.
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I Cylinder Head and Valvetrain - I
4 Lift primary chain and hold under tension, rotate engine
against direction of rotation (counterclockwise) approximate-
ly 30".
To prevent damaging valves while
worlcing on camshafts, no
aistons should be in the TDC position.
- Remove BMW special tool set 1 I 3 240 from rear of cylinder
head.
Remove retaining nuts (arrows) and bearing cap
1 of intake
camshaft.
Intake camshaft bearing cap
1 is centered with adapter
sleeves. To avoid camshaft damage, it must be removed be-
fore anv other caos.
4 Fit BMW special tools 11 3 260 (A) and 11 3 270 (B) to cylin-
der head and screw long bolts (aiiows) into spark plug
threads. Tensioners will align with the bearing caps on the in-
take camshaft.
CA UTION--
Do not over torque bolts into spark plug holes. 1
4 Turn eccentric shaft of special tool to pretension intake carn-
shaft bearing caps. Remove nuts on remaining bearing caps.
- Slowly release tension on eccentric shaft and remove BMW
special tools. Remove bearing caps and set aside in order.
Remove camshaft and store safely.
CA U TIOW-
Camshaft bearing caps must be installed in their original lo-
cations.
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Cylinder Head and Valvetrain
NOTE-
The camshaft bearing caps are coded with a letter and a
number. For example, "A
1" is the first exhaust camshaft
bearing cap
at the front of the engine, and "El "is the intake
camshaft bearing cap at the front of the engine.
-. -
The camshafts are stamped with a code letter - "E for the
intake side and
'X" for the exhaust side.
"E is for Einlap. (German for intake) and 'XA7s for Auspuff.
(German for exhaust).
- Repeat procedure for exhaust camshaft
< Secure hydraulic lifters in lifter bores using BMW special tool
11 3 250, or remove lifters using a magnetic pick-up tool.
I CAUTION-
Used liydraulic lifters must be reinstalled in original lifter
1 bores.
4 Remove lower camshaft bearing carriers from cylinder head.
CAUTION- Camshaft bearing carriers must be reinstalled in their original
locations
(E for intalce and A for exhaust).
NOTE- Do not allow hydraulic lifters to fall out of camshaft carriers.
Hydraulic lifters should be stored in an upright position.
Camshafts and lifters, installing (M52TU and M54 engine)
Lubricate camshafts, camshaft carriers, bearing caps, hy-
draulic lifters, friction washers, splined shafts and
spline hubs
with assembly
lubricant before installation.
CAUTION-
Make sure the crankshaft, which had been rotated approxi-
mately
30" opposite the direction of engine rotation from
TDC, is
stillin thatposition before lowering the camshafts into
position. Allpistons must be out of
TDCposition to prevent
valve/piston inteiference when the carnshafis are installed.
- Lift timing chain and place exhaust cam onto exhaust cam-
shaft carriers. Place
intake camshaft on camshaft carrier.
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11 6-28
Cylinder Head and Valvetrain
Double
VANOS timing
chain components
1. Impulse wheel mounting nut
2. Exhaust camshaft impulse
wheel
3. Spring plate, exhaust
4. Thrust spacer (T
= 3.5 mm)
5. Splined shaft
6. Torx screw
7. Exhaust camshaft secondary
sprocket
8. Secondary timing chain
9. Splined sleeve
10. Primary sprocket
11. Threaded stud
12. Secondary chain tensioner
13. Secondary chain lower guide
14. Sprocket mounting nut
15. Spring plate, intake
16. Splined shaft
17. Intake camshaft sprocket
18. Locating stud
19. Thrust spacer
20. lntake camshaft impulse wheel
Page 205 of 1002
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Cylinder Head and valvetrain1
Double VANOS secondary timing chain components,
installing
(M52 TU, M54 engine)
< Secure camshafts in TDC position using BMW special tool
set
11 3 240.
4 If necessary, turn camshaft so that special tools are squarely
seated on cylinder head.
4 Lift timing chain and hold under tension
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Cylinder Head and Valvetrain .-
4 While maintaining tension on timing chain, rotate crankshaft
at vibration dampener from
30" before TDC in direction of ro-
tation (clockwise) until number
1 cylinder is at TDC position
with line between the OIT mark (arrow) on front pulley
aligned with boss on lower timing chain cover.
4 Secure crankshaft in TDC position with BMW special tool
11 2 300 (arrow).
Slide impulse wheel on intake camshaft, aligning boss with
raised portion on camshaft (arrow).
Fit thrust spacer
(A) to intalte camshaft and tighten down with
threaded locating studs (arrows). Place longer threaded por-
tion of studs into camshaft.
Tightening torque
Impulse wheel studs to intake camshaft (M7)
20 Nm (15 ft-lb)