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MotorFiable

BMW B58 vs Rover K-Series: which engine is more reliable?

According to our risk index, the BMW B58 carries less risk than the Rover K-Series: 38/100 versus 46/100 (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 Rover K-Series has 2 documented serious faults, the main one being «Head gasket failure».

Risk index

BMW B58

38

Moderate risk · 1 serious fault

Lower risk

Risk index

Rover K-Series

46

Moderate risk · 2 serious faults

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

14 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 Rover K-Series reliable?

The Rover K-Series has one very well-known fault: the head gasket, which according to Diariomotor can fail at under 100,000 km and which technical sources link to a small cooling circuit and a badly placed thermostat. The usual repair uses the multi-layer (MLS) gasket developed for the Freelander; the other two documented faults (sunken liners and coolant leaks) are related to that same circuit.[5][6][7][8]

See the 3 of the Rover K-Series faults

Side-by-side comparison

Comparison of BMW B58 and Rover K-Series
BMW B58Rover K-Series
Technical data
TypeEngineEngine
FuelPetrolPetrol
Displacement2,998 cm³—
TimingChainTiming belt (dry)
Power290–441 hp60–160 hp
Productionsince 2015[9][10]1990–2005[6][11]
Reliability
Risk index (what is it?)38Moderate risk46Moderate risk
Documented faults63
Of high or critical severity12
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: Head gasket failure
  2. High severity: Sunken cylinder liners and warped head after overheating
  3. Medium severity: Coolant leaks: expansion tank cap, rear block rail and hoses
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][12]
  • B58 340-360 hp (B58B30M0, 2016-2019)[2][3][12]
  • B58TU 333-340 hp (B58B30M1, since 2018)[2][3]
  • B58TU 374 hp (B58B30O1, M340i, M440i and M240i, since 2019)[3]
  • 1.1 K8 60 hp / K16 75 hp (Rover 25, 1998-2005)[5][8]
  • 1.4 8V/16V 74-103 hp (14K2F / 14K4F, 1995-2005)[5][7]
  • 1.6 16V 109-116 hp (16K4F, 1995-2005)[5][7]
  • 1.8 16V 117-136 hp (18K4F, 1995-2005)[5][7][13]
  • 1.8 VVC 145-160 hp (18K4K, 1995-2005)[13][14]
  • 1.8 T turbo 150-160 hp (18K4T, 2002-2005)[5][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

Rover K-Series

See the 12 models with the Rover K-Series

Other comparisons

With the BMW B58

With the Rover K-Series

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. Guía de compra del MG TF de segunda manoDiariomotor · Motoring press · published 7 November 2023 · consulted 8 October 2026 · in Spanish
  6. MG TF (2002)Wikipedia (en) · Other source · consulted 8 October 2026
  7. Choosing the correct K Series Head Gasket KitDMGRS · Technical documentation · consulted 8 October 2026
  8. Cooling and heating (K-Series: ZR, ZS, ZT, MGF, TF)MGOC Spares · Technical documentation · consulted 8 October 2026
  9. BMW B58Wikipedia (inglés) · Other source · consulted 9 October 2026
  10. BMW B58Wikipedia (alemán) · Other source · consulted 9 October 2026 · in German
  11. Rover K-series engineWikipedia (en) · Other source · consulted 8 October 2026
  12. 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
  13. MG ZR ZS ZT & Modern Engine & FuelMGOC Spares · Technical documentation · consulted 8 October 2026
  14. MGF & TF Headgasket Repair KitsMGOC Spares · Technical documentation · consulted 8 October 2026