2012 BMW Z4 problems

• N20B20B 184 hp (135 kW, 2011-2017)

  184 hp · N20B20, N20B20B

  It shares with the rest of the N20 family the risk of wear to the timing chain guides and tensioner on units built before 2015.^[2]

  With caution

• N20B20A 245 hp (180 kW, 2011-2017)

  245 hp · N20B20, N20B20A

  It shares with the rest of the N20 family the risk of wear to the timing chain guides and tensioner on units built before 2015.^[2]

  With caution

Faults that affect 2012 cars

• Critical severityFrequency: CommonTimingTiming chain guide and tensioner wear (2011-2015)Yes: on BMW N20s built mainly between 2011 and 2015, the timing chain guides and tensioner wear out early; if the chain jumps teeth it can put pistons and valves out of sync and cause catastrophic damage. BMW revised the design in 2015, without a formal recall.Appears at around 129,000 km
• Critical severityFrequency: OccasionalCoolingElectric water pump failure (BMW campaign in the US over fire risk)The N20 has an electric water pump whose connector can suffer ingress of blow-by liquid; a short circuit can cause local overheating and, very rarely, a fire. BMW recalled 720,000 vehicles in the US in 2024, not including the European Union or Spain.
• Medium severityFrequency: CommonLubricationOil leaks from the rocker cover gasket and the filter housingYes: with the years and heat cycles, the rocker cover gasket and the oil filter housing or cooler gasket on the N20 start to weep oil; it is not an acute defect but expected wear that is worth watching before the oil level drops too low.
• Medium severityFrequency: OccasionalTurboWastegate noise and plastic charge pipe breakageThe N20's single TwinScroll turbo is not, in itself, a frequent point of failure, but over the years wastegate noise or rattle and a loss of pressure can appear, and the plastic pipe that carries air from the turbo to the intercooler can crack, especially with poor maintenance or on modified engines.
• Medium severityFrequency: OccasionalInjectionHigh-pressure fuel pump (HPFP) failureThe high-pressure pump that feeds the N20's direct injection (High Precision Injection) can fail, especially on high-mileage units, leaving the car with hard starting, jerking or, in the worst case, unable to start.

• N54 322 hp (2008-2013)

  322 hp · N54B30

  It is the engine with the most documented faults in the family: high-pressure pump, injectors and wastegates; check which parts have already been replaced.^[3][6][7]

  With caution

• N55B30M0 302 hp (2009-2018)

  302 hp · N55B30M0

  Simpler than the N54 (one turbo and solenoid injectors), but it keeps the oil leaks from the filter housing and the electric water pump; check both.^[5][8][9]

  With caution

• N55B30 315 hp (2011-2018)

  315 hp · N55B30

  Simpler than the N54 (one turbo and solenoid injectors), but it keeps the oil leaks from the filter housing and the electric water pump; check both.^[5][8][9]

  With caution

Faults that affect 2012 cars

• Medium severityFrequency: CommonInjectionN54 piezoelectric injector failureThe N54's piezoelectric injectors can clog or leak and cause intermittent misfires. The N55 has solenoid injectors, so it does not share this weak point.
• Medium severityFrequency: CommonTurboTurbo wastegate noise and failureOn the N54 the wastegate rods work loose and produce a metallic rattle; over time they reduce boost pressure. On the N55 it is the electric actuator that fails.
• Medium severityFrequency: CommonCoolingElectric water pump and thermostat failureThe electric water pump on the N54 and N55 fails without warning, at around 100,000-150,000 km, and is usually replaced together with the thermostat. If not dealt with, the engine overheats.
• Medium severityFrequency: CommonLubricationOil leak from the oil filter housing gasketThe oil filter housing gasket on the N54 and N55 leaks oil as it ages; the oil can drip onto the auxiliary drive belt, and there are also leaks from the valve cover.
• Medium severityFrequency: CommonIgnitionOil in the spark plug wells from the rocker cover gasketOn the N54 and N55 the rocker cover gasket hardens with age and lets oil seep into the spark plug wells. Guides treat it as a known fault: it smells of burnt oil and can damage spark plugs and coils.

• N52B30 3.0 (2004-2015)

  215–268 hp · N52B30, N51B30

  Same weak points as the N52B25; units from before the end of 2008 may have noisy hydraulic lifters.^[10][11]

  With caution

Faults that affect 2012 cars

• Medium severityFrequency: CommonCoolingElectric water pump and thermostat failureThe N52's plastic electric water pump cracks or fails sooner than a mechanical one, and the thermostat usually goes with it; it is recommended to replace it as a precaution at around 80,000-100,000 km.Repair (garage): €350–€600Appears at around 80,000 km
• Medium severityFrequency: CommonLubricationOil leak from the oil filter housing gasketThe oil filter housing gasket hardens over time and leaks oil on all N52 engines; the leak can soil the engine and damage nearby parts.
• Low severityFrequency: CommonLubricationValve cover and crankcase ventilation valveThe N52's plastic valve cover cracks with heat cycles and the crankcase ventilation system fails, causing whistling, leaks and oil consumption.Repair (garage): €200–€350

• Medium severityFrequency: OccasionalBodywork and interiorRetractable hardtop sensor, actuator and motor failureAccording to the reports collected by fiches-auto.fr, the retractable hardtop on the Z4 E89 can become temperamental: sensors, actuators or motors fail and the roof gets stuck or does not close, with cases at 84,000 and 147,000 km.
• Low severityFrequency: RareElectronics and infotainmentComfort Access and door handle failureAccording to the reports collected by fiches-auto.fr, on the Z4 E89 the Comfort Access handle or antenna can stop communicating with the car, and in some cases the sat nav screen does not fold away.
• Low severityFrequency: RareElectrical systemErratic operation of the frameless window regulatorsAccording to the reports collected by fiches-auto.fr, the frameless window regulators on the Z4 E89 can work erratically, with a risk of water getting in on a convertible.