Camshaft and Cam Follower, Remove and Install (Cylinder Head Installed)
 Remove, Disconnect Remove front toothed belt cover - see operation "Front Toothed Belt Cover, Remove and Install (X 16 SZR)" or "Front Toothed Belt Cover, Remove and Install (16 LZ2 and 20 NEJ)".
 Adjust Before removing toothed belt - at the fastening bolt of the toothed belt drive gear turn the crankshaft slowly and smoothly in direction of engine rotation 60 ° (dimension I) in front of TDC mark. For X 16 SZR: move toothed belt tension roller upwards against the spring force until the bore holes coincide - install toothed belt tension roller with suitable drift (1). For 16 LZ2 and 20 NEJ: release fastening bolt for toothed belt tension roller and turn adjustment eccentric in direction of arrow (clockwise) until indicator (2) bears against left stop.
Remove, Disconnect Remove toothed belt. | 
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Remove, Disconnect Remove battery support - see operation "Battery Support, Remove and Install" in group "A". Detach engine vent hoses from camshaft housing cover. Remove wiring trough from camshaft housing. Detach camshaft housing cover from cylinder head. Remove camshaft sprocket - counterhold at hex of camshaft with an open-ended wrench. Remove gasket or seal ring out of rear camshaft housing - see operation "Seal Ring - Rear Camshaft Housing, Replace (X 16 SZR)", "Seal Ring - Rear Camshaft Housing, Replace (16 LZ2)" or "Gasket - Rear Camshaft Housing, Replace (20 NEJ)". Remove pressure plate (1) from camshaft housing.
 Important! Carefully cover oil return bore holes in cylinder head during assembly, so that thrust pieces cannot fall in. | 
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Remove, Disconnect X 16 SZR: install Valve Depressor MKM-891 at camshaft housing. With 16 LZ2 and 20 NEJ: Install Valve Lifter Depressor MKM-890 at camshaft housing. Press down all rocker arms uniformly. Carefully remove camshaft (1) from camshaft housing. Release tension in valve lifter depressor and remove from camshaft housing. Remove rocker arms and thrust pieces and lay aside in correct order to ensure that they can be allocated to the individual valves on reinstallation.
 Inspect Check all parts for damage and wear, replace if necessary. When replacing camshaft, replace all rocker arms. Before installing, check that crankshaft is at 60 ° in front of TDC mark.
 Install, Connect Insert thrust pieces and rocker arms - ensure correct installation position and allocation. Attach valve depressor to camshaft housing and press down all rocker arms uniformly. Coat sliding surfaces lightly with MoS 2 lubricating paste (grey) Insert camshaft carefully into camshaft housing. | 
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Install, Connect Install pressure plate (1) at camshaft housing - 8 Nm / 6 lbf. ft. Release tension in valve lifter depressor and remove from camshaft housing. Install gasket or seal ring in rear camshaft housing - see operation "Seal Ring - Rear Camshaft Housing, Replace (X 16 SZR)", "Seal Ring - Rear Camshaft Housing, Replace (16 LZ2)" or "Gasket - Rear Camshaft Housing, Replace (20 NEJ)". Install camshaft pulley - see operation "Seal Ring in Camshaft Housing, Front, Replace".
Important! Before installing the toothed belt, the marks on the toothed belt drive gear and the oil pump housing, as well as the notches on the camshaft sprocket and the rear toothed belt cover must be aligned.
Install, Connect Install battery support - see operation "Battery Support, Remove and Install" in group "A". | 
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