BMW 11417584079 Chain

The non-turbo and turbo camshaft timing chain, vibration damper (front pulley) and related parts are similar but not interchangeable; repair requires special tools and new parts; refer to the entire procedure before proceeding. Bent valves from piston contact which can be resulted from disassembly, removal and assembly of camshafts or camshaft adjustment units without special tools. During the process it is necessary to keep the crank and the camshafts locked against rotation with BMW special tools. Start with a scan tool to clear or record the fault memory of the ECM and then turn off the engine then take out the key. Go further to take off the upper and lower cabin microfilter housings, the right strut tower brace, ignition coil cover and disconnect the ignition coil connectors and put the harness away. Dis-connect the ignition coils and the cylinder head cover after which the spark plugs are eliminated. For non-turbo engines position the crankshaft in such a way that cylinder 1 is in TDC firing position with the intake camshaft lobe facing upward and the exhaust camshaft lobe facing downward. When the turbo engines are in position to satisfy requirements, cylinder 1 should be set in TDC firing position and the lobes of 6 should be formed downwards and apart from each other. Disconnect the timing chain tensioner, watch for dripping oil and lift the car to have access to the engine compartment splash guard and the accessory belt. Take off the vibration damper and pull out the crankshaft front seal, insert the crankshaft locking tool through the bell housing into the flywheelOil supply to the crankshaft front and main bearings will be eliminated by rotating the crankshaft until the front end of the crank hits the front bearer and lock it at TDC. Pull of the vibration damper hub by using special tools while tightening the counter hold on the hub. Loosen the plugs at the timing chain housing, then take off the chain guide and tensioning rail bolts, and then, with the aid of the special tool set, secure the camshafts. Both the intake and exhaust camshaft adjustment units should be pulled out then the timing chain assembly and crankshaft sprocket lifted out of the housing. The new timing chain has to be fitted on the pulley /variator cover properly while fitting the crankshaft sprocket in the correct position in reference to the timing chain, and the installment of the timing chain assembly must be done under tension. Bolt the vibration damper hub back in its position by new bolts and follows the standard torque procedures in a manner that cannot allow the crankshaft to rotate. Replace the crankshaft front seal and camshaft adjustment unit, if the timing is improper it should be corrected. Last, the chain tensioner should be fitted, along with the new sealing O-ring; the locking tools should be removed; the engine should be rotated two full revolutions; and the camshaft timing should be checked before the reassembly of the engine.

Lower the timing chain and module in place, threading the crankshaft pulley hub through the sprocket, and insert the new hub retaining bolt.

Before attempting this repair, consult an expert if unsure of your abilities.

Before proceeding, remove the spark plugs and valve cover.

Install and torque the timing chain assembly, rail, and guide bolts. With the crankshaft locked, insert a new bolt with the hub for the crankshaft and use an angle protractor to torque the center bolt.

Time the intake to exhaust sprockets using BMW special tool 116180, position the spline gap on the intake sprocket, and place the secondary chain on the sprockets, ensuring not to alter the position of the sprockets with respect to the chain when removing from the special tool.

Use a mirror to check the exhaust camshaft lobe position.

Remove the intake camshaft sprocket mounting nuts and the corresponding spring plate, then take out the torx bolts from the exhaust camshaft sprocket.