BMW M73 User Manual

Details the M73 engine's design basis on the M70 and its application in E38/E31 models.

Highlights M73 technical advancements, dual Motronic M5.2 control, and EML IIIs throttle system.

Presents a graphical comparison of M73 and M70 engine power and torque outputs.

Covers cylinder block, main bearing caps, crankshaft, pistons, and associated specifications.

Details connecting rod installation and the M73's redesigned vibration damper.

Explains flywheel's incremental gear wheel and cylinder head components, including knock sensors.

Details valve springs, valves, roller rocker arms, and camshafts, including manufacturing.

Covers camshaft drive, position sensor disc, and crankcase ventilation valve operation.

Discusses modifications to timing chain covers for sensors and housing.

Notes the M73 rear oil seal plate is identical to the M60 engine part.

Explains the housing's function and absence of M70 temperature sensors.

Explains emission compliance requirements and the 12V electric air pump's function.

Details non-return valves, vacuum/vent valve, reservoir, and check valve roles.

Details twin-walled steel manifolds, heat-up properties, and air injection supply unions.

Describes double-walled pipes, converter volume, and monitoring via oxygen sensors.

Provides engine type, application, power, torque, bore, stroke, displacement, and compression ratio.

Details valve dimensions, spring rates, piston material, and exhaust manifold specs.

Emphasizes personally verifying the customer's reported complaint.

Guides on using DIS for fault code checks, test schedules, and diagnostic procedures.

Provides contact information for BMW Technical Assistance Hotline for complex system problems.