Introduction: The Valvetronic layout incorporates a conventional inlet camshaft and a secondary eccentric shaft, with intermediate lever and follower, activated by a stepper motor. The stepper motor changes the phase of the eccentric shaft, altering the action of the inlet valve. These are positioned in a camshaft carrier bracket in the cylinder head. BMW N42 & N46 engine setting/locking tool kit covers: * Engine timing - checking and adjustment * Vanos unit - removal, installation and alignment Camshaft/Carrier Bracket Remover & Installer Tool Kit is for removal and installation of camshafts, and plus dismantling and re-building of the camshaft carrier bracket / Valvetronic assembly. Application: BMW: 118i E81/82/87/88 (04-12), 120i E81/82/87/88 (04-12), 316/ti Compact E46 (01-07), 318/ti Compact E46 (01-07), 318i E90/91/92/93 (05-12), 320i E90/91/92/93 (05-12), 520i E60/61 (07-10), Z4 2.0 E85/86 (04-09), X1 sDrive 18i E84 (10-12), X1 xDrive 18i E84 (10-12), X3 2.0 E83 (05-10) Engine Code: N42/N46/N46T: B18, B18A, B20, B20A, B20B, B20BD, B20BZ, B202