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1.0 EcoBoost vs M43 1.6, 1.8 and 1.9: which engine is more reliable?

According to our risk index, the M43 1.6, 1.8 and 1.9 carries less risk than the 1.0 EcoBoost: 42/100 (moderate risk) versus 71/100 (high risk). The 1.0 EcoBoost has 3 documented serious faults, the main one being «Degradation of the timing belt running in oil»; the M43 1.6, 1.8 and 1.9 has 1 documented serious fault, the main one being «Failure of the plastic parts in the cooling system».

Risk index

1.0 EcoBoost

71

High risk · 3 serious faults

Risk index

M43 1.6, 1.8 and 1.9

42

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

18 sourcesHow we work

Is the 1.0 EcoBoost reliable?

It is a turbocharged direct-injection three-cylinder that has won Engine of the Year several times, but it has two very well-documented weak points: two belts running in oil (timing and oil pump) that can disintegrate and seize the engine, and cases of coolant leaks and overheating in early units. It is best bought with a service history and the belts checked or replaced on time.[1][2][3][4]

See the 4 of the 1.0 EcoBoost faults

Is the M43 1.6, 1.8 and 1.9 reliable?

The M43 (1993-2002) is an 8-valve petrol four-cylinder with a timing chain that Autohints describes as one of BMW’s most durable engines of the nineties. The faults the sources cite are with ancillaries: plastic cooling parts, oil leaks from the gaskets, rough idle, ignition and, in some versions, the DISA valve.[5][6][7]

See the 5 of the M43 1.6, 1.8 and 1.9 faults

Side-by-side comparison

Comparison of 1.0 EcoBoost and M43 1.6, 1.8 and 1.9
1.0 EcoBoostM43 1.6, 1.8 and 1.9
Technical data
TypeEngineEngine
FuelPetrolPetrol
Displacement999 cm³—
TimingWet belt (belt-in-oil)Chain
Power100–155 hp102–118 hp
Productionsince 2012[1][8][9][10]1993–2002[6][11][12]
Reliability
Risk index (what is it?)71High risk42Moderate risk
Documented faults45
Of high or critical severity31
Worst severityCritical severityHigh severity
Main faults
  1. Critical severity: Degradation of the timing belt running in oil
  2. Critical severity: Oil pump belt and tensioner failure
  3. Critical severity: Coolant leaks and overheating from the turbo hose
  1. High severity: Failure of the plastic parts in the cooling system
  2. Medium severity: DISA intake manifold valve with play and noise
  3. Low severity: Oil leaks from gaskets (rocker cover, front cover and crankcase breather)
Most expensive documented repairup to €1,200Degradation of the timing belt running in oilPublished figure[2]No reliable data
Which versions to buy
BuyRecommended versionsNoneNone
With cautionVersions to be cautious about
  • 1.0 EcoBoost 100/125 (Fox, 2012-2017)[2][3][13]
  • 1.0 EcoBoost 100/125/140 with cylinder deactivation (from ~2017)[14][15]
  • 1.0 EcoBoost Hybrid 48V mild hybrid (125/155 hp, from 2019)[1][16]
  • M43B16, 1.6 litre (102 hp; 1993-1999)[5][6][7]
  • M43B18, 1.8 litre (115 hp; 1993-1999)[5][17]
  • M43TUB19, 1.9 litre (105 hp; 1998-2002)[5][7][18]
  • M43TUB19, 1.9 litre (118 hp; 1998-2002)[5][7][18]
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

1.0 EcoBoost

See the 12 models with the 1.0 EcoBoost

M43 1.6, 1.8 and 1.9

Other comparisons

With the 1.0 EcoBoost

With the M43 1.6, 1.8 and 1.9

Compare other engines

That is the comparison you are viewing: change one of the two engines.

Sources

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

  1. Ford EcoBoost engineWikipedia · Other source · consulted 26 September 2026
  2. Alerta Ford: la correa de distribución del 1.0 EcoBoost puede romper el motor y la NHTSA ya investigaMotor16 · Motoring press · consulted 26 September 2026 · in Spanish
  3. Los Ford 1.0 EcoBoost tricilíndricos están dando problemas de correas bañadas que recuerdan al caso PureTechMotor.es · Motoring press · consulted 26 September 2026 · in Spanish
  4. Gripa el motor por problema en el manguito se queda sin refrigeranteOpinautos · Owners' forum · consulted 26 September 2026 · in Spanish
  5. BMW M43B18 1.8L 115hp inline-4 cylinder engineAutoHints · Technical documentation · consulted 2 November 2026
  6. Der BMW M43 Motor: Technische Daten, Probleme, Haltbarkeit & FahrzeuglisteCarWiki.de · Other source · consulted 2 November 2026 · in German
  7. BMW M43: problemas conocidosEnginescope · Other source · consulted 2 November 2026
  8. Prueba: Ford Fiesta 1.0 EcoBoost 100 CV (2013)km77 · Motoring press · consulted 26 September 2026 · in Spanish
  9. Ford Mondeo Berlina Trend 1.0 EcoBoost 92 kW (125 CV) (2015-2018): precio y ficha técnicakm77 · Technical documentation · consulted 26 September 2026 · in Spanish
  10. Ford B-MAX Trend 1.0 EcoBoost 100 CV (2012-2018): precio y ficha técnicakm77 · Technical documentation · consulted 26 September 2026 · in Spanish
  11. BMW M43Wikipedia (inglés) · Other source · consulted 2 November 2026
  12. BMW M43Wikipedia (alemán) · Other source · consulted 2 November 2026 · in German
  13. Ford EcoBoost engines: reliability, problems and should you buy one?Carbuyer · Motoring press · consulted 26 September 2026
  14. Ford's Self-Clogging 1.0-Liter EcoBoost Engine Is Finally Getting RecalledThe Drive · Motoring press · consulted 26 September 2026
  15. The Largest Ford EcoBoost Recalls In 15 Years Of ProductionCarBuzz · Motoring press · consulted 26 September 2026
  16. Stellantis no es el único afectado por la correa de distribución bañada en aceiteAutofácil · Motoring press · consulted 26 September 2026 · in Spanish
  17. BMW 3 Series E36 Reliability Guide: Everything You Need to Know Before BuyingEuro Premium Parts · Technical documentation · consulted 2 November 2026
  18. 316i M43: 17 Jahre, Standhaftigkeit erhöhen (E46)BMW-Syndikat (foro) · Owners' forum · consulted 2 November 2026 · in German