Genuine 2008 BMW X3 Timing Chain

2008 BMW X3 Timing Chain Parts Questions & Experts Answers

• Q: What are the essential steps and precautions for camshaft disassembly and timing chain removal in M54 six cylinder engine on 2008 BMW X3?

  A: Specific BMW instruments are required for camshafts dismantling, and timing chain installation as well as removal that aid in the correct synchronization of the valve train. There are no specific features aimed at the reassembly, and it is necessary to read the procedures carefully before beginning. Camshafts must in a right time; otherwise, pistons will hit valves thus causing damage to the engine. First, you should remove the negative battery terminal; however, be careful to follow battery disconnection warnings. To do so, first take off the air filter housing, electric cooling fan and finally the cowl noting the direction of rotation of the engine on the accessory belts before removing these. Subsequently, take off the coolant pump pulley, the engine covers and the cylinder head cover, and the spark plugs which should be plugged to avoid the intrusion of debris on the engine. The VANOS unit is to be taken off, the car has to be lifted and securely positioned for further work to be done on it. Empty the engine cooling system and the oil and take out the oil pan. Engage the camshaft adjuster lock rings to hold the camshafts in the TDC position and make sure that the crankshaft lock is also in place and locked, using the suitable BMW special tools. There is no primary camshaft chain tensioner with the engine on the stand Take this part off the timing chain cover being careful of the tensioner piston as it will spring back into position. Clamp the secondary chain tensioner and take off the nuts of the exhaust camshaft impulse wheel mounting after which you would do away with the impulse wheel and the spring plate. Bolts securing the intake camshaft sprocket must be loosened, and so must be the spring plate, together with the torx bolts on the exhaust camshaft sprocket. Remove the exhaust and intake sprockets, as well as the secondary chain and the thrust spacer and the splined shafts, and make a note of the position of the shafts for reassembly. The exhaust camshaft splined sleeve and shaft should be taken out and the secondary chain tensioner mounting bolts should also be removed but the locking pin should remain fixed. Take out the both of the studs holding the primary chain sprocket on the exhaust camshaft and move the primary chain sprocket aside, the timing chain goes on this end of the exhaust camshaft. Within the cylinder head, unscrew the TIMING CHAIN COVER bolts as well as the secondary chain lower guide mounting bolts the pull out the chain guide carefully and know that the bolt on the intake camshaft side is longer than the other one. Take out the crankshaft vibration damper; do not employ a flywheel locking tool to immobilize the crankshaft. MUST NOT turn crankshaft during the loosening or removal of timing chains to avoid contact between the pistons and valves. Poke two locating dowels in the lower timing cover towards the back of the car, take out the timing cover bolts and pull the cover to the front to unclip it. Care should be taken when undoing the cover on the cylinder head gasket and this may require the use of a sharp knife and the head gasket should be changed if it is damaged. Last of all, in order to gain access to the primary chain tensioner, moving the guide rail out of the way sends the chain on its way out as well.