Oil level rising: which faults cause it?

The most important among the documented faults: oil cooler seal leak (between the cylinder heads), in the OM642; incomplete particulate filter regenerations and oil dilution, in the 1.3 Multijet; fuel dilution of the oil linked to particulate filter regenerations, in the 2.0 Ingenium diésel; oil dilution from leaking injector seals and DPF regenerations, in the MZR-CD; oil dilution with diesel during DPF regenerations, in the Skyactiv-D; clogged particulate filter and oil dilution, in the 1.8/2.2 DI-D; particulate filter (DPF) clogging in urban use, in the BMW B47; clogged particulate filter (DPF) and oil dilution on short journeys, in the 2.0 CDTI.

Consumption and fluid levelsUrgency: Garage soon

Oil level rising: causes and the faults that trigger it

11 documented faults cause it in 11 engines. The most important:

High severity: Oil cooler seal leak (between the cylinder heads) · OM642
High severity: Incomplete particulate filter regenerations and oil dilution · 1.3 Multijet
High severity: Fuel dilution of the oil linked to particulate filter regenerations · 2.0 Ingenium diésel

What it means

If the oil level goes up between services, something is mixing with it: fuel getting in during failed particulate filter regenerations, or coolant. Diluted oil lubricates worse and can damage the engine.

General explanation from MotorFiable. How it shows up in each engine, with sources, is in the list of faults.

What to do now

Garage soon

Do not add more oil. Ask for the oil to be analysed and for the particulate filter regenerations or possible coolant leaks to be checked.

Reviewed on 9 October 202612 sources How we work

Faults that cause it

Specific engine and gearbox faults, from most to least important (severity × frequency). Below each title, how the symptom shows up in that fault.

- High severityVery frequentFrequency: Very frequentOM642Oil cooler seal leak (between the cylinder heads)The oil level may rise abnormally if coolant enters the oil circuit through the damaged seal, according to one specialist source.Repair (garage): €1,500–€2,200Appears at around 120,000 km
Source for the symptom in the OM642^[1]
- High severityCommonFrequency: Common1.3 MultijetIncomplete particulate filter regenerations and oil dilutionThe oil level on the dipstick rises instead of falling, a sign that it is mixing with unburnt diesel.
Source for the symptom in the 1.3 Multijet^[2][3]
- High severityCommonFrequency: Common2.0 Ingenium diéselFuel dilution of the oil linked to particulate filter regenerationsThe oil level rises between services because the fuel injected during particulate filter regenerations leaks into the sump instead of burning off completely.
Source for the symptom in the 2.0 Ingenium diésel^[4]
- High severityCommonFrequency: CommonMZR-CDOil dilution from leaking injector seals and DPF regenerationsThe dipstick level rises between oil changes and it may smell of diesel if the dilution is high.
Source for the symptom in the MZR-CD^[5]
- High severityCommonFrequency: CommonSkyactiv-DOil dilution with diesel during DPF regenerationsThe level shown on the dipstick rises above normal between oil changes; on the first CX-5 units the warning light did not alert you even when the dilution was excessive.
Source for the symptom in the Skyactiv-D^[6]
- High severityCommonFrequency: Common1.8/2.2 DI-DClogged particulate filter and oil dilutionThe oil level rises above the maximum on the dipstick or the on-board computer when fuel from regeneration seeps into the sump.
Source for the symptom in the 1.8/2.2 DI-D^[7]
- Medium severityCommonFrequency: CommonBMW B47Particulate filter (DPF) clogging in urban useThe oil level may rise if failed regenerations dilute the oil with fuel, according to a specialist workshop.Repair (garage): €500–€1,800
Source for the symptom in the BMW B47^[8]
- Medium severityCommonFrequency: Common2.0 CDTIClogged particulate filter (DPF) and oil dilution on short journeysThe oil level may rise because of diesel fuel getting in during DPF regenerations that are never completed.
Source for the symptom in the 2.0 CDTI^[9]
- Medium severityCommonFrequency: CommonSubaru bóxerClogged particulate filter on the EE20 dieselAUTO BILD lists a rising engine oil level alongside clogged particulate filters; it also records owners without that problem.
Source for the symptom in the Subaru bóxer^[10]
- Medium severityCommonFrequency: Common2.5 TDI R5Leaks and play in the unit injectorsIf diesel gets into the oil, the level rises.
Source for the symptom in the 2.5 TDI R5^[11]
- Medium severityOccasionalFrequency: Occasional1.4 16v and 1.6 MPI/FSIOil consumption, especially on the older 1.4 16vYou have to top up the oil between changes more often than you would expect.
Source for the symptom in the 1.4 16v and 1.6 MPI/FSI^[12]

Which cars it appears in

These faults affect 11 engines. We have documented 89 models from 18 makes with some of the affected versions: open yours to see all its faults.

Engines

Cars with the affected versions

Fiat

Ford

Ford Ka IIEngine: 1.3 MultijetYears: 2008–2016

Jaguar

Jeep

Jeep Grand Cherokee WKEngine: OM642Years: 2005–2010

Lancia

Lancia Ypsilon IIIEngine: 1.3 MultijetYears: 2011–2024

Mazda

See all Mazda models

Mercedes-Benz

See all Mercedes-Benz models

MINI

Mitsubishi

Opel

Seat

Škoda

Subaru

Suzuki

Volkswagen

Oil level rises: causes in your car

1 car has several documented faults that cause this symptom. Choose yours to see only those that affect it, by engine and by year.

Opel 1

Opel Astra J

Other symptoms: consumption and fluid levels

All symptoms

Has this happened to you? Tell us which fault it was, at how many kilometres and how much you paid: it helps other owners know what to expect. Report your fault.

Sources

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

1.Motor diésel Mercedes V6 OM642Motordinámico · Motoring press · published December 2024 · consulted 26 September 2026 · in Spanish
2.1.3 CDTi Opel (Z13DT) Multijet: ficha técnica, problemas y tuningMotordinámico · Other source · consulted 26 September 2026 · in Spanish
3.Fiat 1.3 Multijet: ficha técnica, problemas y tuningMotordinámico · Other source · consulted 26 September 2026 · in Spanish
4.Jaguar Land Rover's Four-Cylinder Ingenium Engine Is Still Giving Its Maker HeadachesAOL · Motoring press · published 10 August 2026 · consulted 27 September 2026
5.Mazda 6 I: Bekannte Probleme und Schwachstellengebrauchtwagenberater.de · Motoring press · consulted 27 September 2026 · in German
6.Aviso a todos los propietarios de Mazda CX-5 Dieselkm77 · Motoring press · published 22 May 2013 · consulted 27 September 2026 · in Spanish
7.Mitsubishi ASX – Typische Probleme & KrankheitenGebrauchtwagenberater.de · Motoring press · consulted 27 September 2026 · in German
8.Motor BMW B47 - Reparación EspecializadaDasercars · Technical documentation · consulted 26 September 2026 · in Spanish
9.Opel Astra J – Typische Probleme & SchwachstellenGebrauchtwagenberater.de · Other source · consulted 27 September 2026 · in German
10.Subaru XV I im Gebrauchtwagen-Test: «Vorsicht vor dem Boxer-Diesel!»AUTO BILD · Motoring press · published 17 December 2019 · consulted 9 October 2026 · in German
11.Kaufberatung gebrauchter VW T5 (2003-2015)Promobil · Motoring press · consulted 5 October 2026 · in German
12.Fiabilité Volkswagen Golf IV - pannes moteur, boîte, électronique...Fiches-auto.fr · Owners' forum · consulted 27 September 2026 · in French