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N42 and N45 1.6, 1.8 and 2.0 vs 1.4 and 1.6 16v: which engine is more reliable?

According to our risk index, the 1.4 and 1.6 16v carries less risk than the N42 and N45 1.6, 1.8 and 2.0: 45/100 (moderate risk) versus 57/100 (high risk). The N42 and N45 1.6, 1.8 and 2.0 has 1 documented serious fault, the main one being «Timing chain stretch and tensioner wear»; the 1.4 and 1.6 16v has 1 documented serious fault, the main one being «Timing belt breakage or premature failure».

Risk index

N42 and N45 1.6, 1.8 and 2.0

57

High risk · 1 serious fault

Risk index

1.4 and 1.6 16v

45

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

20 sourcesHow we work

Is the N42 and N45 1.6, 1.8 and 2.0 reliable?

The N42 (2001-2004, E46) and the N45 (2003-2011, 116i and 316i) are four-cylinder 16-valve petrol engines with double VANOS and a timing chain; only the N42 has Valvetronic. The most cited weakness is chain stretch caused by the tensioner, followed by oil leaks and, on the N42, Valvetronic faults.[1][2][3]

See the 5 of the N42 and N45 1.6, 1.8 and 2.0 faults

Is the 1.4 and 1.6 16v reliable?

The K4J (1.4) and K4M (1.6), both naturally aspirated 16-valve units, are simple and generally reliable petrol engines: no source consulted documents oil consumption or faults that destroy the block. Their most-cited weak point is the ignition coils, followed by the crankshaft sensor and, on versions with a variable valve timing unit, its pulley; a neglected belt can cause serious damage, as one case in the Renault Laguna II documents.[4][5][6][7]

See the 6 of the 1.4 and 1.6 16v faults

Side-by-side comparison

Comparison of N42 and N45 1.6, 1.8 and 2.0 and 1.4 and 1.6 16v
N42 and N45 1.6, 1.8 and 2.01.4 and 1.6 16v
Technical data
TypeEngineEngine
FuelPetrolPetrol
Displacement——
TimingChainTiming belt (dry)
Power115–143 hp75–135 hp
Production2001–2011[1][2][8][9][10][11]since 1998[12][13][14]
Reliability
Risk index (what is it?)57High risk45Moderate risk
Documented faults56
Of high or critical severity11
Worst severityCritical severityHigh severity
Main faults
  1. Critical severity: Timing chain stretch and tensioner wear
  2. Medium severity: Oil leaks from the rocker cover and oil consumption
  3. Medium severity: Eccentric shaft sensor and Valvetronic motor faults (N42)
  1. Medium severity: Ignition coil failure
  2. High severity: Timing belt breakage or premature failure
  3. Medium severity: Crankshaft position sensor failure
Most expensive documented repairNo reliable dataNo reliable data
Which versions to buy
BuyRecommended versionsNone
  • 1.6 16V 105-110 hp Dacia, without variable valve timing unit (K4M, 2004-2020)[7][15]
With cautionVersions to be cautious about
  • N42B18, 1.8 litres with Valvetronic (115 hp; 2001-2004)[1][3]
  • N42B20, 2.0 litres with Valvetronic (143 hp; 2001-2004)[1][3][16]
  • N45B16 and N45NB16, 1.6 litres without Valvetronic (116 hp; 2003-2011)[2]
  • 1.4 16V 75-100 hp (K4J, 1999-2012)[17][18]
  • 1.6 16V 110-135 hp with variable valve timing unit (K4M, 1998-2020)[6][19][20]
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

N42 and N45 1.6, 1.8 and 2.0

1.4 and 1.6 16v

See the 13 models with the 1.4 and 1.6 16v

Other comparisons

With the N42 and N45 1.6, 1.8 and 2.0

With the 1.4 and 1.6 16v

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. BMW N42 Probleme und HaltbarkeitGebrauchtwagenberater · Motoring press · consulted 2 November 2026 · in German
  2. BMW N45 Probleme und HaltbarkeitGebrauchtwagenberater · Motoring press · consulted 2 November 2026 · in German
  3. BMW N42 Engine Guide: Reliability, Efficiency, Tuning, Pros and ConsBMWBlog · Motoring press · published 21 November 2025 · consulted 2 November 2026
  4. Fiabilité et pannes de la Renault Mégane 1Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  5. Fiabilité et pannes du Renault Scénic 1Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  6. Fiabilité et pannes de la Renault Laguna 2Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  7. Fiabilité et pannes du Dacia Duster 1Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  8. BMW N42Wikipedia (inglés) · Other source · consulted 2 November 2026
  9. BMW N42Wikipedia (alemán) · Other source · consulted 2 November 2026 · in German
  10. BMW N45Wikipedia (inglés) · Other source · consulted 2 November 2026
  11. BMW N45Wikipedia (alemán) · Other source · consulted 2 November 2026 · in German
  12. Renault K-Type engineWikipedia (inglés) · Other source · consulted 27 September 2026
  13. Moteur K RenaultWikipedia (francés) · Other source · consulted 27 September 2026 · in French
  14. Anexo:Motores de RenaultWikipedia (español) · Other source · consulted 27 September 2026 · in Spanish
  15. Fiabilité et pannes du Dacia Logan 1Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  16. N42 2.0 Motoru: kronik sorunlarAraclo · Other source · consulted 2 November 2026 · in another language
  17. Fiabilité et pannes de la Renault Clio 2Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  18. Fiabilité et pannes de la Renault Clio 3Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  19. Fiabilité et pannes de la Renault Mégane 2Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  20. Fiabilité et pannes du Renault Scénic 2Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French