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BMW B58 vs 1.8 T 20v: which engine is more reliable?

According to our risk index, the 1.8 T 20v carries less risk than the BMW B58: 32/100 versus 38/100 (both moderate risk). The BMW B58 has 1 documented serious fault, the main one being «Failure of the oil pump with a plastic rotor housing»; the 1.8 T 20v has 1 documented serious fault, the main one being «Turbo wear and oil consumption».

Risk index

BMW B58

38

Moderate risk · 1 serious fault

Risk index

1.8 T 20v

32

Moderate risk · 1 serious fault

Lower risk

The index (0–100) weights the severity and frequency of the three most serious documented faults. How it is calculated

17 sourcesHow we work

Is the BMW B58 reliable?

The B58 (3.0 turbo straight-six, since 2015) is considered robust and less troublesome than the N54/N55 it replaced, and the sources do not document widespread internal failures. The known faults are on the periphery: the plastic oil filter housing, crankcase ventilation, gaskets and coolant. On units built before 2021 there are also US reports of an oil pump with a plastic housing.[1][2][3][4]

See the 6 of the BMW B58 faults

Is the 1.8 T 20v reliable?

With up-to-date maintenance, the 20-valve 1.8T has a reputation as a powerful, durable engine for its time, but owner reports document recurring faults: ignition coils (especially on 2001 to 2003 units), water pump and air mass meter, and less often the turbo -sometimes linked to growing oil consumption- and the timing chain tensioner.[5][6][7][8][9][10]

See the 5 of the 1.8 T 20v faults

Side-by-side comparison

Comparison of BMW B58 and 1.8 T 20v
BMW B581.8 T 20v
Technical data
TypeEngineEngine
FuelPetrolPetrol
Displacement2,998 cm³1,781 cm³
TimingChainTiming belt (dry)
Power290–441 hp150–225 hp
Productionsince 2015[11][12]1996–2006[13][14][15][16]
Reliability
Risk index (what is it?)38Moderate risk32Moderate risk
Documented faults65
Of high or critical severity11
Worst severityHigh severityHigh severity
Main faults
  1. High severity: Failure of the oil pump with a plastic rotor housing
  2. Medium severity: Oil and coolant leak from the plastic oil filter housing
  3. Medium severity: Failure of the crankcase ventilation PCV valve (integrated in the valve cover)
  1. High severity: Turbo wear and oil consumption
  2. Medium severity: Water pump failure
  3. Medium severity: Timing chain tensioner noise and wear
Most expensive documented repairNo reliable dataNo reliable data
Which versions to buy
BuyRecommended versions
  • B58TU2 381 hp (B58B30M2, since 2022)[2][3]
None
With cautionVersions to be cautious about
  • B58 326 hp (B58B30M0, 2015-2019)[2][3][17]
  • B58 340-360 hp (B58B30M0, 2016-2019)[2][3][17]
  • B58TU 333-340 hp (B58B30M1, since 2018)[2][3]
  • B58TU 374 hp (B58B30O1, M340i, M440i and M240i, since 2019)[3]
  • 1.8 T 20v 150 hp (AEB/AGU/ARZ/AUM, 1996-2005)[6][10]
  • 1.8 T 20v 180 hp (AUQ, 1998-2006)[7][8]
  • 1.8 T 20v 225 hp quattro (BAM, 1999-2006)[8]
AvoidVersions to avoidNoneNone

Severity of each fault: green, low; amber, medium; red, high; dark red, critical. How we rate them

Cars that each one is fitted to

BMW B58

See the 16 models with the BMW B58

1.8 T 20v

See the 11 models with the 1.8 T 20v

Other comparisons

With the BMW B58

With the 1.8 T 20v

Compare other engines

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Sources

Every fact on this page links to its source. If you find an error, let us know.

  1. The 5 Most Common BMW B58 Engine ProblemsBMW Tuning · Technical documentation · published 7 February 2020 · consulted 9 October 2026
  2. BMW B58 EngineFCP Euro · Technical documentation · consulted 9 October 2026
  3. The Popular BMW B58 Inline-Six Engine Has One Big Achilles HeelThe Autopian · Motoring press · published 14 June 2024 · consulted 9 October 2026
  4. ¿En qué se diferencian los motores B58 y S58 de BMW?Diariomotor · Motoring press · published 27 April 2024 · consulted 9 October 2026 · in Spanish
  5. Fiabilité et pannes Volkswagen Golf IVFiches-auto.fr · Other source · consulted 27 September 2026 · in French
  6. Fiabilité et pannes Volkswagen PassatFiches-auto.fr · Other source · consulted 27 September 2026 · in French
  7. Fiabilité et pannes Audi A3Fiches-auto.fr · Other source · consulted 27 September 2026 · in French
  8. Fiabilité et pannes Audi TTFiches-auto.fr · Other source · consulted 27 September 2026 · in French
  9. Fiabilité et pannes Seat LeónFiches-auto.fr · Other source · consulted 27 September 2026 · in French
  10. Seat Leon Mk1: Probleme, Schwachstellen, ErfahrungenGebrauchtwagenberater.de · Other source · consulted 27 September 2026 · in German
  11. BMW B58Wikipedia (inglés) · Other source · consulted 9 October 2026
  12. BMW B58Wikipedia (alemán) · Other source · consulted 9 October 2026 · in German
  13. List of Volkswagen Group petrol enginesWikipedia · Other source · consulted 27 September 2026
  14. Audi TTWikipedia · Other source · consulted 27 September 2026
  15. SEAT LeónWikipedia · Other source · consulted 27 September 2026
  16. SEAT ToledoWikipedia · Other source · consulted 27 September 2026
  17. How A Plastic Part On BMW's B58 Engine Can Turn An Oil Change Into A $3,000 RepairThe Autopian · Motoring press · published 28 March 2025 · consulted 9 October 2026