2004 BMW 3 Series 325ci M54B25 (E46)

Engine identity

Oils and fluids

Service and parts data

Common and chronic problems

• Rear subframe cracking under high mileage
• Window regulator failure
• Cooling system leaks due to plastic components aging

First checks

• Inspect rear subframe for cracks
• Check cooling system hoses and water pump
• Verify timing chain tensioner noise

Avant de remplacer des pièces

• Save fault codes and freeze-frame data before clearing anything.
• Check engine oil, coolant and transmission fluid using the correct temperature and service procedure.
• Verify power, ground, connectors, hoses, leaks and live data before replacing expensive parts.

Important notes

• Engine specs consistent globally though power output may vary by market emissions rules.
• Oil capacity includes filter change; recommended to replace filter at each oil change.