BMW 11627500483 Exhaust Manifold

To avoid damaging oxygen sensors, remove them prior to exhaust manifold removal and ensure not to mix up oxygen sensor connectors by marking them before disassembly. Use new hardware and gaskets when reinstalling exhaust manifolds. Begin by removing the intake manifold cover and separating the post-catalyst oxygen sensor connectors. With the engine fully cooled, work above the exhaust manifolds to separate and remove the precatalyst oxygen sensors. Safely raise and support the car, then remove the front end reinforcement, ensuring to follow the proper procedure to avoid chassis or front end damage. Next, remove the front stabilizer bar mounting brackets and rubber mounts, and detach the stabilizer bar links. Separate the rear mufflers from the center muffler, then remove the center muffler. Proceed to remove the post-catalyst oxygen sensors and the exhaust manifold mounting nuts, followed by the removal of the front and rear exhaust manifolds along with their catalytic converters. For installation, reverse the removal steps, ensuring to clean sealing surfaces, replace gaskets, replace manifold and front pipe mounting nuts, and coat fastener threads with anti-seize paste.

Use new hardware and gaskets when reinstalling the exhaust manifolds. Access to manifolds is extremely limited, and if removing exhaust manifolds as part of additional engine work, it may be easier to first remove the engine. With the exhaust system cold, raise and support the car for access to the exhaust system, then remove the exhaust system. Remove the front end reinforcement, ensuring to read the procedure for its removal, and do not drive the vehicle without it installed to avoid damage to the chassis or front end. Remove the front driveshaft. For the right exhaust manifolds (cylinder bank 1 - 4), remove the MS self-locking nuts securing the exhaust manifolds to the cylinder head and then remove the manifolds from below. For the left exhaust manifold (cylinder bank 5 - 8), remove the MS self-locking nuts securing the exhaust manifold to the cylinder head and then remove the manifold from below. Installation is the reverse of removal, ensuring to replace gaskets with the bead facing the manifold, replace manifold and front pipe mounting nuts, and coat fastener threads with anti-seize paste.