Before disconnecting the battery, there are battery disconnection cautions that have to be read first. First, safely lift up the car and secure it on a stand then, take off the lower engine cover panel. After that let the engine cool to drain the engine coolant. Then pull out the air filter housing and with the help of BMW special tools fit and uninstall the cooling fan shield and clutch bonded with the coolant pump very carefully as the 32mm cooling fan nut has the left thread. Once the fan cowl is unbolted from the radiator, unbolt and gank off both head cowl covers and remove the spark plugs and plug spark plug holes with copper gaskets to avoid fluid getting into the engine crankcase. Continue to take of the
Timing Chain tensioner located on the right side upper timing chain cover, in addition to the right and left upper timing chain covers. Take out the right and left VANOS units and make certain that the cams and the crank are at TDC employing specific tools. It is followed changing the VANOS oil distributor of the right intake camshaft with the removal of mounting Torx bolts and detachment from the camshaft sealing rings. On the right side of the cylinder head remove the profile gasket at the front of the cylinder head carefully to avoid damaging the oil check-valve and take out the latter but do not drop it. Follow the same procedure for the left cylinder head which is placed at the left-hand side of the car. Once the, crankshaft locking tools have been withdrawn, raise the timing chain and maintain some tension while turning the crankshaft anti clockwise until the 45 marked on the crankshaft vibration damper aligns with the boss on the lower timing chain cover. Taking off the camshaft locking tools and positioning the camshafts for removal is done by pulling on the two green tabs using a 27mm open end wrench and rotating in the anticlockwise direction as required. Turn the right exhaust camshaft until the cylinder 2 exhaust lobes are up, the right intake camshaft until the cylinder 1 intake lobes are up, the left exhaust camshaft until the cylinder 6 exhaust lobes are up and the left intake until the cylinder 8 intake lobes are up. Slightly loosen the left intake camshaft bearing cap nuts by turning them anti-clockwise as far as possible in steps which should be half turns so as not to damage the cap nuts then ensure that the caps are not mixed by labeling them or using some method which will help you remember their positions and orientations. Last, dismantle the left exhaust camshaft as was done and then the camshafts from the cylinder head then the right cylinder head.