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1.5 dCi vs 1.8 TDCi: which engine is more reliable?

According to our risk index, the 1.8 TDCi carries less risk than the 1.5 dCi: 48/100 (moderate risk) versus 63/100 (high risk). The 1.5 dCi has 4 documented serious faults, the main one being «Wear and seizure of the big-end bearings»; the 1.8 TDCi has 1 documented serious fault, the main one being «Breakage of the timing belt or of the high-pressure pump's belt (running in oil)».

Risk index

1.5 dCi

63

High risk · 4 serious faults

Risk index

1.8 TDCi

48

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

28 sourcesHow we work

Is the 1.5 dCi reliable?

The post-2010 1.5 dCi engines, especially the 90 hp, have a good record. The Euro 3 and Euro 4 units (2001-2010) carry serious faults: big-end bearings that can wreck the engine, a Delphi pump that fills the injection system with metal filings and, in some 105/110 hp versions, a timing belt and dual-mass flywheel that fail early.[1][2][3][4]

See the 8 of the 1.5 dCi faults

Is the 1.8 TDCi reliable?

The 1.8 TDCi (codename Lynx) was Ford's standard diesel between 2001 and 2014, with Delphi common-rail injection and a variable-geometry turbo. It is an engine with well-documented faults: the dual-mass flywheel and clutch are by far its weakest point, followed by the injectors, the EGR valve and, to a lesser extent, the turbo hoses and the timing drive itself.[5][6][7][8]

See the 5 of the 1.8 TDCi faults

Side-by-side comparison

Comparison of 1.5 dCi and 1.8 TDCi
1.5 dCi1.8 TDCi
Technical data
TypeEngineEngine
FuelDieselDiesel
Displacement1,461 cm³1,753 cm³
TimingTiming belt (dry)Timing belt (dry)
Power55–116 hp75–125 hp
Productionsince 2001[1][9][10][11][12][13][14]2001–2014[5][15][16]
Reliability
Risk index (what is it?)63High risk48Moderate risk
Documented faults85
Of high or critical severity41
Worst severityCritical severityCritical severity
Main faults
  1. Critical severity: Wear and seizure of the big-end bearings
  2. Critical severity: Premature timing belt failure
  3. High severity: Delphi high-pressure pump that sheds filings and damages the injection
  1. Critical severity: Breakage of the timing belt or of the high-pressure pump's belt (running in oil)
  2. Medium severity: Premature wear of the dual-mass flywheel and clutch
  3. Medium severity: Delphi injector failure (leaks, cracks or poor spray pattern)
Most expensive documented repairup to €2,000Premature dual-mass flywheel failure and clutch problemsPublished figure[17][18]No reliable data
Which versions to buy
BuyRecommended versions
  • 1.5 dCi Energy Euro 6 with NOx trap (90 and 110 hp, 2015-2018)[19][20][21]
  • 1.5 dCi in Mercedes-Benz and Infiniti (OM 607 / OM 608, 2012-2020)[14][22]
None
With cautionVersions to be cautious about
  • 1.5 dCi Euro 4 (68/70, 85/86 and 105/106 hp, 2005-2010)[1][2][3][11]
  • 1.5 dCi Euro 5 with particulate filter (75, 90, 95 and 110 hp, 2010-2015)[1][3][23]
  • 1.5 Blue dCi with SCR and AdBlue (85, 95, 100 and 115 hp, from 2018)[20][24][25]
  • 1.8 TDCi 75/90/100 (entry-level tunes: Focus I and Transit Connect)[6][7]
  • 1.8 TDCi 110/115/125 (Focus II, C-Max, Mondeo, Galaxy, S-Max and Transit Connect)[6][7][8][26][27][28]
AvoidVersions to avoid
  • 1.5 dCi Euro 3 (65, 80/82 and 100 hp, 2001-2005)[1][4]
None

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

Cars that each one is fitted to

1.5 dCi

See the 46 models with the 1.5 dCi

1.8 TDCi

See the 8 models with the 1.8 TDCi

Other comparisons

With the 1.5 dCi

With the 1.8 TDCi

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. Fiabilité du 1.5 dCiFiches-auto.fr · Motoring press · published 19 April 2024 · consulted 26 September 2026 · in French
  2. Fiabilité Renault Clio 3 : que vaut le modèle en occasion ?Caradisiac · Motoring press · published 26 November 2012 · consulted 26 September 2026 · in French
  3. Maxi-fiche fiabilité : que vaut le Renault Scénic 3 en occasion ?Caradisiac · Motoring press · published 2 February 2016 · consulted 26 September 2026 · in French
  4. Maxi-fiche occasion : que vaut le Renault Scénic 2 en seconde main ?Caradisiac · Motoring press · published 29 October 2014 · consulted 26 September 2026 · in French
  5. Ford Duratorq engineWikipedia · Other source · consulted 27 September 2026
  6. Fiabilité et pannes du Ford Mondeo 3 (1.8 TDCi 125ch)Fiches-auto.fr · Owners' forum · consulted 27 September 2026 · in French
  7. Fiabilité et pannes du Ford Focus 2 (1.8 TDCi 115ch)Fiches-auto.fr · Owners' forum · consulted 27 September 2026 · in French
  8. Fiabilité et pannes du Ford S-MaxFiches-auto.fr · Owners' forum · consulted 27 September 2026 · in French
  9. Renault K-Type engineWikipedia · Other source · consulted 26 September 2026
  10. Moteur K RenaultWikipédia · Other source · consulted 26 September 2026 · in French
  11. Fiabilité Renault Mégane 3 : que vaut le modèle en occasion ?Caradisiac · Motoring press · published 25 November 2015 · consulted 26 September 2026 · in French
  12. Mercedes abandonne le 1.5 dCi Renault pour un moteur maison, qui émet plus de CO2 !Caradisiac · Motoring press · published 26 October 2020 · consulted 26 September 2026 · in French
  13. Nissan : le Qashqai reçoit un nouveau moteur dCiCaradisiac · Motoring press · published 14 September 2018 · consulted 26 September 2026 · in French
  14. Estos son los motores Renault que usa MercedesDiariomotor · Motoring press · published 22 December 2019 · consulted 26 September 2026 · in Spanish
  15. Ford FocusWikipedia · Other source · consulted 27 September 2026 · in Spanish
  16. Ford Transit ConnectWikipedia · Other source · consulted 27 September 2026 · in Spanish
  17. Volante bimasa, averías y precio de sustituciónDiariomotor · Motoring press · published 3 November 2020 · consulted 26 September 2026 · in Spanish
  18. Diesels : volant moteur défectueuxFiches-auto.fr · Owners' forum · published 17 October 2025 · consulted 26 September 2026 · in French
  19. Fiabilité du Renault Kadjar : la maxi-fiche occasion de CaradisiacCaradisiac · Motoring press · published 19 November 2020 · consulted 26 September 2026 · in French
  20. Fiabilité du Dacia Duster 2 : la maxi-fiche occasion de CaradisiacCaradisiac · Motoring press · published 27 April 2022 · consulted 26 September 2026 · in French
  21. Fiabilité du Renault Captur : la maxi-fiche occasion de CaradisiacCaradisiac · Motoring press · published 2 March 2018 · consulted 26 September 2026 · in French
  22. Fiabilité des 180d / 180 CDI MercedesFiches-auto.fr · Motoring press · consulted 26 September 2026 · in French
  23. Fiabilité du Nissan Qashqai 2 : la maxi-fiche occasion de CaradisiacCaradisiac · Motoring press · published 22 December 2017 · consulted 26 September 2026 · in French
  24. Fiabilité du 1.5 Blue dCiFiches-auto.fr · Motoring press · published 18 May 2022 · consulted 26 September 2026 · in French
  25. Maxi-fiche fiabilité - Renault Clio 5 : loin d'être irréprochableCaradisiac · Motoring press · published 19 April 2024 · consulted 26 September 2026 · in French
  26. Ford Focus Mk2: Probleme und SchwachstellenGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German
  27. Ford Mondeo Mk4: Probleme und SchwachstellenGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German
  28. Ford S-Max: Probleme und KrankheitenGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German