BMW tool 11 3 260 will be required for this operation. Do not attempt to remove and reinstall the camshafts without the aid of this special tool, as expensive damage to the camshafts or bearings may result. Begin by removing the VANOS adjustment unit and the secondary liming chain, followed by the splined shaft and sleeve from the center of the exhaust camshaft sprocket. Unscrew the four bolts to remove the secondary chain tensioner, then take out the three screw-in pins from the exhaust sprocket, lifting the chain to remove the sprocket while noting its installation direction. Remove the crankshaft locking pin and carefully rotate the crankshaft 30 degrees counterclockwise to prevent accidental piston-to-valve contact, securing the primary timing chain to the cylinder head. If necessary, remove the three screw-in pins from the intake camshaft, along with the thrust washer and camshaft sensor wheel. Remove the template from the camshafts and unscrew the spark plugs from the cylinder head. Check the camshaft bearing caps for identification marks, which are numbered from the timing chain end of the engine, with the exhaust camshaft bearing caps marked A1 to A7 and the intake camshaft caps marked E1 to E7. Unscrew the four camshaft cover retaining studs, and as the intake camshaft No 1 bearing cap is located by adapter sleeves, unscrew the nuts and remove the cap to prevent binding during camshaft removal. Assemble BMW special tool 11 3 260 and mount it on the cylinder head, ensuring the plungers are over the relevant camshaft bearing caps. Apply force to the camshaft bearing caps by turning the eccentric shaft on the tool with a wrench, then unscrew the remaining camshaft bearing cap nuts, taking care not to do so without the special tools in place to avoid damage. Slowly turn the special tool shaft to release the force from the bearing caps, unbolt the tool, and lift off the bearing caps in order before removing the camshaft. The camshaft bearing casting can now be lifted from the cylinder head, ensuring the camshaft Lash Adjusters do not fall out and get mixed up, as they must be installed in their original locations. With the bearing casting removed, lift the camshaft Lash Adjusters from the cylinder head, identifying them for location and storing them upright in clean engine oil. Repeat the procedure on the remaining camshaft, marking the camshaft Lash Adjusters as Intake and Exhaust. Clean all components, including the bearing surfaces, and examine them for wear and damage, particularly the bearing and camshaft lobe surfaces for scoring and pitting, replacing components as necessary. If the camshaft lower bearing castings have been removed, ensure the mating faces are clean and that the bearing casting locating dowels are in position. Reinstall the bearing casting(s) and camshaft Lash Adjusters, ideally retaining the lifters in the bearing casting for assembly. Oil the bearing casting contact surfaces of the Lash Adjusters, avoiding oil on the top faces, then install each follower to its original location. Once all Lash Adjusters are installed, retain them in the bearing casting and reinstall the casting to the cylinder head, ensuring the exhaust side casting is marked A and the intake side casting is marked E, with marks facing each other at the timing chain end. To minimize the possibility of piston-to-valve contact, observe specified delays before turning the crankshaft back to the TDC position. Identify the camshafts to ensure correct installation, noting the triangular front flange of the intake camshaft and the circular front flange of the exhaust camshaft, while ensuring the crankshaft is still positioned at 30 degrees counterclockwise from TDC. Position the camshaft on the cylinder head, aligning the tips of the front camshaft lobes and ensuring the square flanges are at right angles to the top surface of the cylinder head. Place the bearing caps in position, noting their identification marks, and reinstall BMW special tool 11 3 260 to the cylinder head. Apply pressure to the bearing caps by turning the eccentric shaft on the tool with a wrench, then reinstall and tighten the bearing cap retaining nuts progressively in a diagonal sequence. Once tightened, unbolt the tool and repeat the procedure on the remaining camshaft. Reinstall the spark plugs and camshaft cover studs, then reinstall the special tool/camshaft holding fixture to check the camshaft positions, turning the camshaft slightly if necessary. Turn the crankshaft back 30 degrees clockwise to the TDC position, re-engaging the locking tool with the flywheel to lock the crankshaft in position, then reinstall the camshaft sprockets and timing chains, followed by the VANOS adjustment unit. To minimize the possibility of piston-to-valve contact after installing the camshaft(s), observe specified delays before cranking the engine.
Posted by BMWPartsDeal Specialist 
