18 40 030 Removing and installing/replacing both exhaust manifolds (M54)

WARNING: This page is about a different car, the 2005 BMW Z4, 2004 BMW Z4, and 2003 BMW Z4. However, it is still accessible from the selected car via links, so may be relevant.

Necessary preliminary tasks:

Secure engine in installation position
Remove front engine underguard
Remove reinforcement plate
Remove entire exhaust system .
Remove bracket between exhaust manifold and transmission
Detach grounding cable from body
Remove right engine support arm with engine mount
Release nuts on heat shield at bottom
Remove right tension strut . See 51 23 265 REMOVING AND INSTALLING/REPLACING LEFT AND RIGHT GAS STRUT SHOCKS .
Remove air pump
Release heat shield at top and remove

NOTE: The oxygen sensors are in danger of being damaged when the exhaust manifolds are removed and installed.

Remove oxygen control sensors .

Remove cover from injection valves.

NOTE: Do not mix up oxygen monitor sensors for cylinders 1 to 3 and 4 to 6 at plug connection to wiring harness.
Mark plug connections.
Unclip the cable from the retainer. Disconnect plug connection.
Unclip cable on rear side of engine from cable guide.

Remove oxygen monitor sensor from cylinders 1 to 3 from above.

Fig 1: [Removing Cover From Injection Valves]

Courtesy of BMW OF NORTH AMERICA, INC.

NOTE: Rear exhaust manifold with catalytic converter can only be removed after front exhaust manifold with catalytic converter has first been removed.

Remove front exhaust manifold with catalytic converter.

Remove oxygen monitor sensor from cylinders 4 to 6.

Unscrew nuts.

Remove exhaust manifold (1).

Installation:

Clean sealing faces, replace gaskets.

Coat threads with copper paste.

Replace nuts.

Tightening torque, see 11 62 1AZ in ENGINE - TIGHTENING TORQUES .

Fig 2: Removing Exhaust Manifold

Courtesy of BMW OF NORTH AMERICA, INC.