Variable Valve Timing Control Module: Service and Repair

Take off plastic cover. Lift out lock and remove plastic cover for the intake camshaft.







Crank engine in direction of rotation until cam peaks of intake and exhaust cams in cylinder No.1 face each other







Hold crankshaft in TDC position with Special Tool 11 2 300.


CAUTION! Remove special tool prior to operating engine.







Secure camshaft with special tool 11 3 240.







Screw plugs out of control unit.







Unscrew bolts of sprocket on the exhaust camshaft.







Press down top of chain tensioner and lock off with special tool 11 3 290.







Unscrew nuts.
Remove VANOS control unit.







Installation;
Check for dowel sleeves (1).
Apply 3 Bond 1209 (refer to BMW Parts Service) liquid sealing compound at the corners of the joint between the cylinder head and VANOS control unit. Replace seal.







Unscrew nuts of intake camshaft.







Remove thrust washer.







Remove sprockets together with chain.







If applicable for other work on cylinder head later, unscrew thrust washer bolts.
Remove thrust washer.







If applicable, remove sensor gear.







Unscrew secondary tensioner.







Unscrew chain guide.







Unscrew bolt 3.


CAUTION! Strong spring force.
Remove spring (2) and plunger (1).

Installation:
Insert chain tensioner piston (1) in such a way that the guide tabs engage in the tensioning rail.
Install spring (2) and bolt (3).
Replace sealing ring.







Lift off sprocket with chain.







NOTE: Prevent chain from slipping down with a piece of wire.