BMW E46 330i (M54B30) engine oil leak - causes and solutions

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BMW E46 330i (M54B30) engine oil leak - causes and solutions

Common leak sources:

• Valve cover gasket
• Oil filter housing gasket
• Oil pan gasket
• Rear main seal
• VANOS seals

Diagnostic steps:

• Clean the engine thoroughly
• Run the engine and inspect for fresh oil leaks
• Use UV dye for hard-to-spot leaks

Solutions:

• Valve cover gasket replacement:
  - Remove valve cover and replace gasket
  - Torque bolts to 10 Nm
• Oil filter housing gasket replacement:
  - Remove oil filter housing and replace O-rings and gaskets
  - Torque bolts to 22 Nm
• Oil pan gasket replacement:
  - Support engine, remove front subframe
  - Replace gasket and torque bolts to 12 Nm

Note: Address oil leaks promptly to prevent engine damage and environmental issues.