BMW B58 engine: faults and reliability

• B58 326 hp (B58B30M0, 2015-2019)

  2015–2019 · 326 hp · B58B30M0

  With caution

  This is the series in which the PCV valve prone to failure, the plastic oil filter housing and, before 2021, the oil pump with a plastic housing are documented; ask for invoices for these repairs.^[2][3][7]

• B58 340-360 hp (B58B30M0, 2016-2019)

  2016–2019 · 340–360 hp · B58B30M0

  With caution

  It shares the weak points of the first series (PCV valve, oil filter housing and pre-2021 oil pump); check which parts have already been replaced.^[2][3][7]

• B58TU 333-340 hp (B58B30M1, since 2018)

  since 2018 · 333–340 hp · B58B30M1, B58B30C

  With caution

  FCP Euro notes that the TU gives fewer PCV problems, but units built before 2021 may have the oil pump with a plastic housing, and the oil filter housing remains a part to watch.^[2][3]

• B58TU 374 hp (B58B30O1, M340i, M440i and M240i, since 2019)

  since 2019 · 374 hp · B58B30O1

  With caution

  The Autopian notes that the first M340i models (2019-2020) without the ZTK package have the oil pump with a plastic housing, with some failures before 30,000 miles; check that it has been replaced.^[3]

• B58TU2 381 hp (B58B30M2, since 2022)

  since 2022 · 381 hp · B58B30M2

  Buy

  The documented failures relate to the first series and to units built before 2021; we have found no faults specific to the TU2, although it has only been on the road for a few years and there is little real-world experience.^[2][3]

Buy: No known serious faults, or they have already been corrected, in this version. With caution: Worth buying if something specific is verified: history, a replaced part or a completed campaign. Avoid: High risk of a serious fault that is hard to check for or prevent.

1. 1High severityFrequency: OccasionalLubricationFailure of the oil pump with a plastic rotor housingB58s built before 2021 have an oil pump with a plastic rotor housing which, according to US press and retailers, can fail: abnormal oil pressure, a whine and warnings. It is cited on 2019-2020 M340i models without the ZTK package and on X5 and X7 models built before mid-2020.
2. 2Medium severityFrequency: CommonLubricationOil and coolant leak from the plastic oil filter housingThe B58's plastic oil filter housing can crack or lose its seal with heat and age, letting oil, coolant or both escape. One parts retailer puts the failure between 60,000 and 100,000 miles (roughly 97,000-161,000 km).Appears at around 97,000 km
3. 3Medium severityFrequency: CommonLubricationFailure of the crankcase ventilation PCV valve (integrated in the valve cover)On the first-generation B58 the PCV valve, integrated in the valve cover, can tear its diaphragm and stop separating oil from the crankcase gases. It causes blue or white smoke, a whistling noise, higher oil consumption and misfires; the whole cover is usually replaced.
4. 4Medium severityFrequency: CommonLubricationOil leak from the valve cover gasketThe rubber gasket on the B58's valve cover hardens with heat cycles and eventually leaks oil: a burning smell, smoke near the cover and oil on the spark plugs. Guides place it between 60,000 and 100,000 miles (97,000-161,000 km).Appears at around 97,000 km
5. 5Medium severityFrequency: OccasionalCoolingCoolant loss from the cap or the expansion tankCoolant loss is one of the most repeated problems in B58 guides. Workshops first suspect the expansion tank cap and also check the intercooler tank, the pipes and the pump before thinking about the head gasket.
6. 6Medium severityFrequency: OccasionalCoolingWater pump and thermostat module (thermal management) leakOn the B58 the water pump and the thermostat module (thermal management) can leak coolant, with a low-level warning and traces of fluid at the back of the engine. Guides place pump failures between 75,000 and 120,000 miles and module failures from around 40,000.Appears at around 120,000 km

Severity colours: low, medium, high, critical. How we rate them

Manufacturer

BMW

Family

B58 (familia modular B38/B48/B58)

Fuel

Petrol

Displacement

2,998 cm³

Cylinders

6

Fuel system

Turbo

Injection

Direct injection

Timing

Chain

Power

290–441 hp

Peak torque

571 Nm

Production

since 2015

Makes

BMW and Toyota

Technical data^[5][6]

1. 2015–2019

   B58 326 hp (B58B30M0, 2015-2019)

   First series of the B58 straight-six, replacing the N55 and debuting in the 340i: 326 hp (240 kW) and 450 N·m with a twin-scroll turbo, direct injection at 200 bar and a timing chain.^[5][6]

2. 2016–2019

   B58 340-360 hp (B58B30M0, 2016-2019)

   Power steps of the first series: 340 hp (250 kW) with 450 or 500 N·m in the M140i, M240i and 540i, and 360 hp (265 kW) and 500 N·m in the X3 M40i, X4 M40i and with the M Performance Power & Sound kit.^[5][6]

3. since 2018

   B58TU 333-340 hp (B58B30M1, since 2018)

   2018 TU update: injection pressure raised from 200 to 350 bar, one-piece timing chain, petrol particulate filter, exhaust manifold integrated into the head and separate cooling of head and block; 340 hp (333 hp in some cars since 2020 according to German Wikipedia).^[5][6]

4. since 2019

   B58TU 374 hp (B58B30O1, M340i, M440i and M240i, since 2019)

   High step of the TU: 374 hp (275 kW) and 500 N·m in the M340i xDrive, the M440i and the M240i (G42) according to German Wikipedia; English Wikipedia lists the B58B30O1 variant at 387 hp, which German Wikipedia assigns to the M340i outside Europe.^[5][6]

5. since 2022

   B58TU2 381 hp (B58B30M2, since 2022)

   Second update (2022): Miller cycle, electric VANOS and low-pressure indirect injection added to the direct injection; 381 hp (280 kW) and 520 N·m. German Wikipedia lists the M340i, M440i and M240i xDrive with this version as 48 V mild hybrids.^[5][6]