Check basic position of camshafts - AR05.20-P-6010MM

ENGINES 157, 278 in MODEL 216, 221

ENGINES 276 in MODEL 221

Engine 276 with a 53° marking

Fig 1: Identifying Camshafts Position (Engine 276 With 53° Marking)

Courtesy of MERCEDES-BENZ USA

Engine 276 without a 53° marking

Fig 2: Identifying Camshafts Position (Engine 276 Without 53° Marking)

Courtesy of MERCEDES-BENZ USA

Engine 157, 278 with a 53° marking

Fig 3: Identifying Camshafts Position (Engine 157, 278 With 53° Marking)

Courtesy of MERCEDES-BENZ USA

Engine 157, 278 without a 53° marking

Fig 4: Identifying Camshafts Position (Engine 157, 278 Without 53° Marking)

Courtesy of MERCEDES-BENZ USA

Fig 5: Checking Camshafts Position

Courtesy of MERCEDES-BENZ USA

Shown on engine 276 without a 53° marking

Fig 6: Checking Camshafts Position (Shown On Engine 276 Without 53° Marking)

Courtesy of MERCEDES-BENZ USA

Right cylinder head (A)

Left cylinder head (B)

	Remove/Install
1	Remove all Hall sensors on camshafts	Engine 276	AR15.10-P-2000MMA
1	Remove all Hall sensors on camshafts	Engine 157, 278	AR15.10-P-2000MMB
2	Remove the front and central sections of the lower engine compartment paneling	Vehicles with engine 157, 278	AR61.20-P-1105SX
	Checking
3	Check whether there is a 53 ° marking on the belt pulley/vibration damper (10)
4	Attach replacement marking for a 53 ° marking on belt pulley/vibration damper (10)	Engine without a 53° marking on belt pulley/vibration damper (10) Attach adhesive strips (11) with a length of 17 mm on the 40 ° marking to the belt pulley/vibration damper (10). The end of the adhesive strip (11) marks the missing 53 ° marking on the belt pulley/vibration damper (10).
5.1	Rotate engine at crankshaft center bolt in direction of rotation of engine to a 53 ° crankshaft angle after top dead center (TDC) on cylinder 1	Engine with a 53° marking on belt pulley/vibration damper (10) The engine must not be turned against direction of rotation of engine; otherwise the timing chain can skip. Rotate engine at the crankshaft in direction of rotation of engine until scribe mark 53° on pulley/vibration damper (10) corresponds with reference edge (10a). The reference edge (10a) for engine 276 is located on the coolant pump and for engines 157, 278 on the poly-V belt tensioning device.
5.2	Rotate engine at crankshaft center bolt in direction of rotation of engine at the end of the adhesive strip (11) (53 ° CKA (KW) after top dead center (OT) on cylinder 1 (ignition TDC))	Engine without a 53° marking on belt pulley/vibration damper (10) The engine must not be turned against direction of rotation of engine; otherwise the timing chain can skip. Rotate engine at the crankshaft in direction of rotation of engine until scribe mark 53° on pulley/vibration damper (10) corresponds with reference edge (10a). The reference edge (10a) for engine 276 is located on the coolant pump and for engines 157, 278 on the poly-V belt tensioning device.
	Checking
6	Check basic position of camshafts	The basic position of the camshafts is checked through visual inspection over the Hall sensor openings on the cylinder head covers (2l, 2r). The edges of partial segments (1a) of the segmented discs (1) must be visible in the middle in the Hall sensor openings (Fig 6) on the cylinder head covers (2l, 2r). If the basic setting is not correct: ↓
6	Check basic position of camshafts	Set basic position of camshafts.	AR05.20-P-6020MMB
7	Install in the reverse order