N54 / N55 Family

BMW N54 / N55 Family

All Engines

Problems

  • High pressure fuel pump (HPFP) – the car may take a long time to start
  • Carbon deposits

N54

Problems

All Vehicles

  • Turbocharger failure – ~15 hours labor plus parts
  • Valve cover gasket
  • Water pump
  • Turbo chargepipe – generally only fails when car is tuned/modified
  • TSB – Deposits in the injection and induction system:
    • Deposits at the fuel injector’s tip – symptoms include hesitation or stumble during acceleration, loss of power, poor fuel efficiency, increased emissions, and/or CEL due to misfires
    • Carbon deposits at the valves or intake manifold ports – symptoms include loss of power, unstable and/or rough idle, increased emissions, and/or CEL due to misfires
    • Combustion Chamber Deposit Interference (CCDI) – pinging or knocking which may be mistaken for engine knock that first occurs as a cold start noise that fades as the engine reaches temperature; symptoms may also include increased emissions, poor acceleration, and engine idle speed surges

Certain Vehicles

  • MY05-06: VANOS solenoids (fault codes 2A87, 2A88, and 3100)
  • MY09 and earlier: TSB – Slack in the wastegate actuator rod/linkage can cause premature wear of the bypass valve, rattling, engine warning lights, and force the engine into “limp home” mode. This can be identified by a metallic “clanking” noise during deceleration from ~3500rpm or during heavy throttle without a gear engaged. If the noise is still present after reprogramming the DME, both turbocharger wastegate actuators must be replaced.

Usage

N55

Problems

This engine was a vast improvement on the N54 and has no issues specific to it beyond what is listed above in “All Engines.”

Usage