N55B30

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3.0L Turbo Petrol

N-series • N55 family • 2009–2018

68%

Engine Reliability

The N55 replaced the twin-turbo N54 with a more reliable single twin-scroll turbo design. It eliminated most of the N54's major issues (HPFP, injectors, wastegate) while retaining the 306hp output. Still susceptible to oil leaks and charge pipe failures, but overall a solid and responsive powerplant.

3.0L

Displacement

Layout

306 hp

Power

400 Nm

Torque

Petrol

Fuel

Turbocharged

Aspiration

Technology & Features

TwinPower Turbo (twin-scroll single turbo)Valvetronic IIIDirect injectionDouble-VANOSElectric water pump

Fuel SystemDirect injection

ValvetrainDOHC 24-valve, Valvetronic III, Double-VANOS

Used In 7 Applications

1 Series F20 / F21 M135i, M140i 3 Series F30 / F31 / F34 335i 5 Series F10 / F11 535i 7 Series F01 / F02 740i X5 E70 X5 35i X5 F15 X5 35i M2 F87 M2

Known Issues

Critical

Wear Items

Applications

Known Issues – N55B30

medium Charge Pipe Blow-Off Common (>35%)

Factory plastic charge pipe blows off under high boost, particularly in warm weather or spirited driving. Aftermarket aluminium replacement recommended.

Typical Mileage

40,000–80,000 km

Est. Repair Cost

€100–€250

DIY Friendly

✓ Yes

Sudden power lossBoost leak whistleLimp mode

high Valve Cover / VANOS Gasket Leak Common (>35%)

Valve cover and VANOS solenoid gaskets seep oil over time. Oil can drip onto hot exhaust components causing burning smell and smoke.

Typical Mileage

60,000–120,000 km

Est. Repair Cost

€300–€700

DIY Friendly

✓ Yes

Burning oil smellVisible oil seepageSmoke from engine

high Oil Filter Housing Gasket Leak Common (>35%)

Oil filter housing gasket deteriorates and leaks oil onto belts and other components.

Typical Mileage

60,000–100,000 km

Est. Repair Cost

€250–€400

DIY Friendly

✓ Yes

Oil leakBurning smellOil on engine

high Electric Water Pump Failure Common (~30%)

Electric water pump fails causing overheating. Shared issue with other N-series inline-6 engines.

Typical Mileage

80,000–130,000 km

Est. Repair Cost

€400–€700

DIY Friendly

✓ Yes

OverheatingWarning lightNo heat from vents

Wear & Maintenance – N55B30

Spark Plugs Every 45,000 km

NewReplace

Replacement Cost€100–€180

Wear Factor60%

Ignition Coils 80,000–120,000 km

NewReplace

Replacement Cost€200–€400

Wear Factor50%

Applications (7)

Transmissions (3)

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6-Speed Manual (Getrag)

Getrag • 6-speed manual • 2003–2019

Getrag 6-speed manual used across a wide range of BMWs. Different models handle various torque capacities. Known for precise, mechanical shift action. The GS6-53DZ handles up to 500Nm (used with 335i/M135i).

Known Issues2

medium 2nd Gear Synchro Wear Moderate (~20%)

Second gear synchros can wear, especially on higher-torque applications, causing grinding on fast 2nd gear shifts.

Typical Mileage

100,000–180,000 km

Est. Repair Cost

€800–€1,500

DIY Friendly

✗ Specialist

Grinding into 2nd gearDifficulty downshifting to 2nd

low Clutch Release Bearing Noise Moderate (~25%)

Clutch release (throw-out) bearing develops a chirp or whine when clutch is depressed.

Typical Mileage

80,000–150,000 km

Est. Repair Cost

€400–€800 (usually replaced with clutch)

DIY Friendly

✗ Specialist

Chirping with clutch pressedWhining noiseVibration in pedal

Wear Items

Clutch Assembly 100,000–180,000 km

NewReplace

Replacement Cost€700–€1,500

Wear Factor55%

Dual Mass Flywheel 150,000–250,000 km

NewReplace

Replacement Cost€500–€1,000

Wear Factor45%

Transmission Fluid Every 80,000 km

NewReplace

Replacement Cost€50–€120

Wear Factor30%

Fluid TypeMTF-LT-4 / MTF-LT-5

Service IntervalLifetime fill (recommended every 80,000 km)

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8-Speed Automatic (ZF 8HP)

ZF • 8-speed automatic • 2009–present

Widely considered one of the best automatic transmissions ever made. Lightning-fast shifts, excellent efficiency, and remarkable reliability. Used across BMW's entire range from 1 Series to 7 Series. Even better with regular fluid services. The 8HP70/75 handles V8 and V12 torque.

Known Issues1

medium Mechatronic Sleeve Leak (Early Production) Occasional (~10%)

Early production 8HP units can develop a transmission fluid leak from the mechatronic sleeve connector.

Typical Mileage

80,000–150,000 km

Est. Repair Cost

€200–€500

DIY Friendly

✗ Specialist

Fluid leakLow fluid warningShifting hesitation

Wear Items

Transmission Fluid & Filter Every 80,000–100,000 km

NewReplace

Replacement Cost€300–€600

Wear Factor40%

Fluid TypeZF Lifeguard 8

Service IntervalEvery 80,000–100,000 km

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7-Speed DCT (DKG/M-DCT)

Getrag • 7-speed dct • 2008–present

BMW's dual-clutch transmission, used in performance models and the F40 1 Series. Offers lightning-fast shifts for sporty driving but can judder at low speeds. The wet-clutch design handles high torque but requires regular fluid changes. The M-DCT variant was used in M3/M4.

Known Issues2

medium Low-Speed Judder Common (~30%)

Characteristic DCT judder during low-speed maneuvers, parking, and stop-start traffic. Can sometimes be improved with a software update.

Typical Mileage

20,000–60,000 km

Est. Repair Cost

€0 (software update) – €1,500 (clutch pack)

DIY Friendly

✗ Specialist

Shuddering at low speedHesitant take-offClunking in reverse

high Clutch Pack Wear Moderate (~20%)

Clutch packs wear, especially in urban driving with frequent stop-start. More aggressive driving actually helps keep clutches clean.

Typical Mileage

80,000–150,000 km

Est. Repair Cost

€1,500–€3,000

DIY Friendly

✗ Specialist

SlippingShuddering on accelerationLoss of drive

Wear Items

DCT Fluid Change Every 60,000 km

NewReplace

Replacement Cost€200–€400

Wear Factor50%

Clutch Pack 80,000–150,000 km

NewReplace

Replacement Cost€1,500–€3,000

Wear Factor45%

Fluid TypePentosin FFL-4 / Castrol BOT 130 M

Service IntervalEvery 60,000 km