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Fiat 1.3 Multijet / JTD (SDE)Urgency: Garage soon

Black smoke when accelerating in the 1.3 Multijet engine: causes

In the 1.3 Multijet engine, 3 documented faults may be the cause: seized variable-geometry turbo, injector and high-pressure pump wear from contaminated fuel and EGR valve blocked by soot.[1][2]

What to do now

Garage soon

Ask for the injectors, turbo and EGR to be checked. With a particulate filter, visible black smoke means the filter may be damaged or removed.

What it means

On diesels, plenty of black smoke when accelerating means too much fuel relative to air: leaking injectors, insufficient turbo pressure, intake leaks or a seized EGR valve. It should not be visible on cars with a healthy particulate filter.

Black smoke: causes in all cars

13 sourcesHow we work

Engine faults that cause it

From most to least important. Under each fault, how the symptom shows up. Check the affected years and versions on each page.

  1. Source for the symptom[1]

  2. Source for the symptom[1]

  3. Source for the symptom[2]

How much it can cost

Depending on the cause, repair at an independent garage ranges from €130[2][3] (EGR valve blocked by soot) to €1,200[1] (injector and high-pressure pump wear from contaminated fuel), including VAT.

Most serious fault among the possible causes: High severity

Other common causes: black smoke

Besides the documented faults of the 1.3 Multijet, these are the most common causes on any car according to the sources.

  • Dirty or faulty injectors[4][5][6][7]Common
  • Dirty or blocked air filter[4][6][8]Common
  • Faulty air flow meter (MAF) or lambda sensor[6][9][10]Common
  • Dirty or blocked EGR valve[4][5][11]Possible
  • Blocked particulate filter or other emissions system[4][12]Possible
  • Turbo not working properly (origin of the power loss)[13]Uncommon

What to check first

  1. Note when and how much smoke comes out: a moment when accelerating hard or continuously. Also note whether there is loss of power, jerking or a warning light on, because that decides the urgency.[4][5][13]
  2. Check the condition of the air filter: it is a cheap part and RACE cites it among the simplest causes of black smoke and loss of power. It recommends changing it every 15,000 km or once a year.[8]
  3. To help clear carbon deposits, RACE advises getting out on the open road and driving a few kilometres in a lower gear than usual, so that the engine works at higher revs. It does not replace diagnosis if the smoke persists.[6]
  4. Ask the garage for a fault code reading: P0172 (mixture too rich) points towards the air flow meter, air filter, injectors, EGR or oxygen sensor.[10]
Complete guide: black smoke when accelerating

Cars with the 1.3 Multijet engine

Open yours to see only the faults that affect it according to its years and versions.

Frequently asked questions

Black smoke in the 1.3 Multijet: what could it be?

In the 1.3 Multijet engine, 3 documented faults may be the cause: seized variable-geometry turbo, injector and high-pressure pump wear from contaminated fuel and EGR valve blocked by soot. Each fault has its own page with the affected years and versions, the cause and how to check for it.

Black smoke in the 1.3 Multijet: is it serious?

Urgency: garage soon. Ask for the injectors, turbo and EGR to be checked. With a particulate filter, visible black smoke means the filter may be damaged or removed. The most serious fault that causes it on this engine has high severity.

Black smoke in the 1.3 Multijet: how much does it cost to fix?

It depends on the cause: at an independent garage, from €130 (EGR valve blocked by soot) to €1,200 (injector and high-pressure pump wear from contaminated fuel), including VAT.

Sources

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

  1. Fiat 1.3 Multijet: problemas, fallos y averías más frecuentesTotalrenting · Other source · consulted 26 September 2026 · in Spanish
  2. FIAT 500 1.3 MultiJet II: EGR Valve Problems and How to Fix ThemAutoricambi Tritella · Technical documentation · consulted 26 September 2026
  3. ¿Qué precio tiene cambiar una válvula EGR?RACE (Real Automóvil Club de España) · Other source · consulted 26 September 2026 · in Spanish
  4. Las averías que revela el humo de tu coche diésel o gasolinaDiariomotor · Motoring press · published 13 September 2023 · consulted 4 October 2026 · in Spanish
  5. Humo del tubo de escape: dime el color y te diré la averíaAutofácil · Motoring press · published 4 July 2016 · consulted 4 October 2026 · in Spanish
  6. ¿Sale humo negro del tubo de escape de tu coche? ¡Cuidado! Puede significar una avería graveRACE · Motoring press · published 19 March 2024 · consulted 4 October 2026 · in Spanish
  7. Problemas con los inyectores: síntomas y fallosRACE · Motoring press · published 16 November 2022 · consulted 4 October 2026 · in Spanish
  8. ¿Cuándo hay que cambiar el filtro del aire?RACE · Motoring press · published 22 February 2023 · consulted 4 October 2026 · in Spanish
  9. ¿Qué es el sensor MAF del coche y cómo funciona?RACE · Motoring press · published 17 September 2026 · consulted 4 October 2026 · in Spanish
  10. Código OBD2 P0172 en Peugeot, Mercedes, VW, Citroen: causas, síntomas y cómo corregirloAutodoc Club · Technical documentation · consulted 4 October 2026 · in Spanish
  11. ¿Se puede circular con la válvula EGR averiada?RACE · Motoring press · published 20 July 2026 · consulted 4 October 2026 · in Spanish
  12. ¿Se puede circular con el filtro de partículas averiado?RACE · Motoring press · published 31 July 2026 · consulted 4 October 2026 · in Spanish
  13. Mi coche pierde potencia y se queda sin fuerza en las subidas y al acelerarRACE · Motoring press · published 20 January 2023 · consulted 4 October 2026 · in Spanish