New cylinder head bolts and a new cylinder head gasket must be fitted each time the procedure is done. It is recommended first to empty the cooling system; afterwards, remove the intake and exhaust manifolds as well as the camshafts and hydraulic lifters. Pull a small, black, and white wire bundle out of one, and two, large, black and green wire bundles from the other end of the two camshaft position sensors and then remove them from the top of the cylinder head. Remove the secondary timing chain guide by removing the Torx screws; remove the bolts holding the lower timing chain cover. Disconnect the coolant pipe from the intake side of the cylinder head, be sure to get the oil pipe sealing washers as well and take out the thermostat. On the left-hand side of the cylinder head remove the electrical connectors of the temperature sensor. Gradually and gradually unscrew and extract the cylinder head bolts and washers, kindly bearings in mind that a number of washers are most likely to be captive. Loosen the cylinder head from the engine block using your hands and rocking it back and forth, do not slide any threaded tool in between the two for they may scrape the faces of the gasket. If possible, two people should stand with the heavy cylinder head assembly and position the timing chain aperture and allow them to drop while another person feed it and support it on the engine block. The first step that you need to undertake is to take off the cylinder head gasket. When inspecting, the surfaces where the cylinder head and block are to mate should be free from gasket and carbons, carbons must be scraped off but not the head surface and avoid using any metallic tools on the head because it is made out of aluminum material. It is necessary to wrap water, oil, and bolt holes in the engine block to exclude debris penetration, and to visually inspect the block for nicks or scratches, which should be smoothed with file if they exist, or by machinist if they are deeper. Examine the block for warpage by running a straight edge across it and cleaning out the bolt holes on the block and make sure they free from oil and water. Check the threads of the engine block for any signs of damage, and if the threads are damaged chase them with the appropriate size tap. For installation, it is required the faces to be mated clean, the threads of the cylinder head bolts to be dry and locating dowels in the correct places. Rotate the crankshaft to position No 1 piston at TDC if not already there, then apply RTV sealant where the engine block meets the timing cover. Drop on a new cylinder head gasket while making sure that it is properly aligned, then place the cylinder head on the block over the dowels. Coat the threads and the washer contact areas with the clean engine oil, then put on the new Cylinder Head Bolts together with the washers and then tighten them lightly. After compressing the upper timing chain, you have to sequence and torque the nut/bolt in that order; finally replace the lower timing chain cover and the secondary timing chain guide. Install back the camshafts and hydraulic lifters; rotate the crankshaft to TDC position; reinsert the locking rod to the flywheel. Last but not the least, carry out the installation's final touches in the same manner as the removal procedures and coolant your car's cooling system.
Posted by BMWPartsDeal Specialist 
