M54 crankcase breather valve, replacing (E46)

In the procedure given here, the crankcase breather and all related parts will be replaced.

None of the attached parts will be reused. These parts become brittle over time and should be replaced. None will be reused as they become brittle and can break when removing.

Replacement parts: Pipe to valve cover (A), Crankcase breather (B), Drain hose (C), Pipe to intake manifold (D).

• Disconnect battery negative cable.

• Remove upper engine covers.

• Remove complete air intake housing.

• Remove idle air control valve (if equipped).

• Unbolt and remove throttle body.

• Disconnect breather pipe (arrow) at front of valve cover. Pinch spring collar on pipe to release and pull straight out of the valve cover.

• Working at top of intake manifold, disconnect hose (A) from breather pipe then disconnect breather pipe (B) from intake manifold.

• Disconnect vent valve drain hose from dipstick tube.

• Remove dipstick tube from engine. Check that drain hole is clear of obstructions.

• Disconnect hoses A, B, C from crankcase vent valve (D). Remove crankcase vent valve fasteners (arrows) and remove crankcase vent valve from engine. Note that some plastic fittings may break during removal owing to brittleness.

• Installation is reverse of removal. Be sure to properly route all pipes and hoses.