2003 Lancia Thesis problems
The 2003 Lancia Thesis was sold with an engine that we have documented: the 2.4 JTD / JTDm Multijet. It has no documented serious faults for the cars of that year. Outside the engine, 6 documented faults affect 2003 cars, such as control unit faults and electronic warnings with no real cause.
2003 Lancia Thesis score: good reliability
Calculated using only 9 documented faults and their sources: the most serious and frequent faults weigh more. How it is calculated
- Engine7.53 faults
- Gearbox9.31 fault
- Suspension10.0No documented faults
- Brakes9.31 fault
- Tyres and wheels10.0No documented faults
- Steering10.0No documented faults
- Electrical system9.61 fault
- Headlights and lights10.0No documented faults
- Electronics and infotainment8.22 faults
- Climate control10.0No documented faults
- Bodywork and interior8.61 fault
- Airbags and safety10.0No documented faults
What changes compared with the 2002 Lancia Thesis
The same engines and the same documented faults as in 2002.
2.4 JTD / JTDm Multijet engine in the 2003 Lancia Thesis
Names: 2.4 JTD 10V 150 CV · 2.4 Multijet 175 CV · 2.4 Multijet 185 CV
- Buy
2.4 JTD 10V (136-150 hp, 1998-2007)
136–150 hp
Auto Świat says the 10V breaks down relatively rarely on its own and that its faults tend to come from lack of maintenance and wear (small oil leaks, air-flow meter, crankshaft sensor and high-pressure pump), with a fairly durable injection system. The 156 page has testimonies of 136 and 150 hp cars with between 219,000 and 394,000 km. These are cars more than 18 years old: demand the invoice for the last belt and water pump change.[2][3][4]
- With caution
2.4 JTDm / Multijet 20V (175-185 hp, 2003-2009)
175–185 hp
Auto Świat describes the 20V as more complex and more failure-prone than the 10V. On the 175 hp 156 page (29 testimonies) the most-cited items are the EGR valve (7), probes and sensors (6) and the turbo (3). We have not found testimony pages for the 166 or the Thesis. Worth buying with the invoice for the belt and water pump and by checking the EGR and the particulate filter (if fitted).[2][3]
Faults that affect 2003 cars
- Medium severityFrequency: OccasionalEmissions controlClogged or faulty EGR valve on the 2.4 JTD and JTDmThe EGR valve is the most-cited fault in the testimonies for the 200 hp 2.4 JTD of the Alfa 159: 24 mentions in 63, plus 8 in 36 for the 210 hp and 12 in 64 for the 156. It gets dirty or fails; RACE puts the cost of replacing an EGR between €130 and €800 on cars in general (not a price specific to this engine).Repair (garage): €130–€800
- Medium severityFrequency: OccasionalInjectionInjector failure and diesel leaks on the 2.4 JTDmThere are injector failures on the 2.4 JTDm: 9 mentions in 163 testimonies for the Alfa 156 and 159. A 2008 210 hp lost five injectors one after another at 93,000 km, with diesel leaks, and Fiat's 2007 action on the 200 hp replaced all the injectors.
- Medium severityFrequency: OccasionalClutchDual-mass flywheel and clutch wear on the 2.4 JTDThe flywheel of the 2.4 JTD appears in 11 mentions out of 163 testimonies (6 on the Alfa 159, 5 on the 156), often together with the clutch and between about 113,000 and 200,000 km. Auto Świat warns that on the 10V replacing the dual-mass flywheel can be expensive and that not all parts are easy to find.
Faults outside the engine in the 2003 Lancia Thesis
- Medium severityFrequency: OccasionalElectronics and infotainmentControl unit faults and electronic warnings with no real causeThesis owners describe sensitive electronics: control units that go haywire, warning lights that flag non-existent faults, and an alarm that goes off for no reason. These are owner testimonies, not statistics.
- Medium severityFrequency: OccasionalBodywork and interiorCorrosion on the bonnet, tailgate, rear pillar and underbodyAUTO BILD, in its review of the Thesis as a modern classic, says rust is a recurring issue: it appears on the bonnet edges, around the tailgate number plate, on the rear pillar and on the edges and floor of the underbody.
- Medium severityFrequency: RareBrakesElectric parking brake that gives problems or locks the gearboxTwo sources link the Thesis's electric parking brake to problems: an Italian comment describes a lot of inconvenience, and a French user reports an automatic with the gearbox and brake locked by an electrical fault.
- Medium severityFrequency: RareElectronics and infotainmentESP and ASR stability control faultsTwo sources from different countries cite ESP/ASR faults on the Thesis: an Italian owner says they often play up, and a French user asks about an intermittent ESP fault.
- Medium severityFrequency: RareGearbox and clutchAutomatic gearbox jerking due to unrenewed transmission oilOn Thesis cars with a five-speed automatic (Aisin), AUTO BILD says the manufacturer does not prescribe changing the gearbox oil, but that it needs doing every 50,000 km: without it, sludge builds up, blocking channels and valves and causing jerks when changing gear.
- Low severityFrequency: RareElectrical systemElectric door and tailgate openers failingAUTO BILD cites the electric opening mechanisms of the doors and rear tailgate as a weak point of the Thesis, which are prone to failure.
Buying a 2003 Lancia Thesis?
We will put you in touch with a partner only if you authorise it in the form.
Frequently asked questions
Is the 2003 Lancia Thesis reliable?
The 2003 Lancia Thesis was sold with an engine that we have documented: the 2.4 JTD / JTDm Multijet. It has no documented serious faults for the cars of that year. Outside the engine, 6 documented faults affect 2003 cars, such as control unit faults and electronic warnings with no real cause.
Is the 2003 Lancia Thesis better than the 2002?
Going by the documented faults, they are the same: the same engines and the same faults affect the 2002 and 2003 cars. Choose on condition, mileage and maintenance history.
What faults does the 2003 Lancia Thesis have?
The most important ones documented for 2003 cars are: clogged or faulty EGR valve on the 2.4 JTD and JTDm (2.4 JTD / JTDm Multijet, medium severity), injector failure and diesel leaks on the 2.4 JTDm (2.4 JTD / JTDm Multijet, medium severity), dual-mass flywheel and clutch wear on the 2.4 JTD (2.4 JTD / JTDm Multijet, medium severity), control unit faults and electronic warnings with no real cause (electronics and infotainment, medium severity) and corrosion on the bonnet, tailgate, rear pillar and underbody (bodywork and interior, medium severity).
Own a 2003 Lancia Thesis? Tell us what faults you have had and at how many kilometres. Report your fault.
Sources
Every fact on this page links to its source. If you find an error, let us know.
- Lancia ThesisWikipedia (español) · Other source · consulted 8 October 2026 · in Spanish
- Silnik 2.4 JTD: mocny i trwały, ale czasem też kapryśnyAuto Świat · Motoring press · published 26 September 2011 · consulted 8 October 2026 · in another language
- Fiabilité Alfa-romeo 156: pannes par motorisation (2.4 JTD)Fiches-auto.fr · Owners' forum · consulted 8 October 2026 · in French
- Alfa Romeo Brera (guía del taller)The Alfa Workshop · Other source · consulted 8 October 2026