Subaru bóxer engine: faults and reliability

• 2.0i 150 hp (EJ204, 2007-2014)

  2007–2014 · 150 hp · EJ204

  With caution

  Gebrauchtwagenberater cites damaged cylinder head gaskets, especially on older cars, and high oil consumption on the petrol Impreza III; check the coolant and oil levels and ask for the service history.^[2]

• 2.5i 167-173 hp (EJ253, 2009-2014)

  2009–2014 · 167–173 hp · EJ253

  With caution

  We have not found any European source that rates this particular engine; Gebrauchtwagenberater and Wikipedia cite cylinder head gaskets on the EJ engines and SlashGear says Subaru moved to multi-layer steel gaskets around 2010. Ask for the service history and check the coolant.^[2][5][10]

• 2.0 D 147-150 hp Euro 4 (EE20, 2008-2010)

  2008–2010 · 147–150 hp · EE20

  Avoid

  AUTO BILD records bearing and crankshaft failures in Legacy and Outback models built between autumn 2007 and February 2009 (109 free replacements out of 12,000 engines in Sweden) and Gebrauchtwagenberater speaks of numerous engine failures in 2007-2009 Impreza models; Subaru treated each claim as a goodwill gesture and no source describes a reliable check beforehand.^[2][3]

• 2.0 D 147-150 hp Euro 5 (EE20, 2010-2015)

  2010–2015 · 147–150 hp · EE20

  With caution

  AUTO BILD sees an improvement from 2010, but its 2019 reader survey records engine problems in 32% of owners of the diesel XV I and it only advises the diesel for "true optimists"; insist on a service history, no oil leaks and a particulate filter in good condition.^[1]

• 2.0 D 147-150 hp Euro 6 (EE20, 2015-2018)

  2015–2018 · 147–150 hp · EE20

  With caution

  AUTO BILD says the new 2015 block should bring peace of mind, but it still recommends the petrol engines and no source quantifies the failures of this version; same checks as on the Euro 5.^[1][11]

• 1.6i 114 hp (FB16, 2011-2023)

  2011–2023 · 114 hp · FB16

  Buy

  AUTO BILD recommends the XV I's petrol engines without reservation; the only warning is to use the chassis number to check that the valve spring campaign was carried out on cars built in 2013-2014 (DVSA R/2019/025).^[1][12]

• 2.0i 150 hp (FB20, 2011-2018)

  2011–2018 · 150 hp · FB20

  Buy

  AUTO BILD recommends the XV I's petrol engines without reservation. Two British campaigns need checking: the valve springs on cars built in 2013-2014 and the ignition coils on those built from September 2016 to October 2019.^[1][12]

• 2.0i 156 hp (FB20D direct injection, 2018)

  2018 · 156 hp · FB20D

  Buy

  We have not found any faults specific to this variant; you only need to check the British ignition coil campaign, which covers cars built between September 2016 and October 2019.^[9][12]

• 2.0i e-Boxer 150 hp (FB20 mild hybrid, 2019 onwards)

  since 2019 · 150 hp · FB20

  Buy

  We have not found any documented engine faults in European sources, it is a recent engine and, among the campaigns in the British database, the November 2020 to June 2021 Forester only appears in one concerning the fuel pump (99 cars, R/2022/266).^[12][13]

• 2.5i 175 hp (FB25, 2015-2021)

  2015–2021 · 175 hp · FB25

  With caution

  None of the European sources consulted rates the FB25 or documents faults specific to it, and English Wikipedia does not list specific European models; the oil consumption of the FB engines documented in the US is not confirmed in Europe, so keep an eye on the oil level.^[6][8]

Buy: No known serious faults, or they have already been corrected, in this version. With caution: Worth buying if something specific is verified: history, a replaced part or a completed campaign. Avoid: High risk of a serious fault that is hard to check for or prevent.

1. 1Critical severityFrequency: CommonLubricationBearing wear and crankshaft failure on the EE20 dieselOn the first EE20 boxer diesels (Legacy and Outback built from autumn 2007 to February 2009; Impreza 2007-2009) the crankshaft bearings could fail and break the crankshaft, destroying the engine. AUTO BILD cites two causes: silicone in the sump and bearings with incorrect clearance.Appears at around 65,000 km
2. 2High severityFrequency: OccasionalCylinder head and blockDamaged cylinder head gasket on the EJ petrol enginesDamaged cylinder head gaskets are cited on the EJ petrols (2.0 and 2.5), especially on older cars; Wikipedia records frequent failures of the single-layer gasket on the EJ251, and SlashGear places Subaru's switch to multi-layer steel gaskets around 2010.
3. 3Medium severityFrequency: CommonEmissions controlClogged particulate filter on the EE20 dieselThe particulate filter on the EE20 boxer diesel tends to clog, especially on those built up to the end of 2010 according to Gebrauchtwagenberater; AUTO BILD cites it on the XV I together with a rising oil level, among the diesel's problems.
4. 4Medium severityFrequency: OccasionalInjectionImprecise injectors and sooty EGR valve on the EE20 dieselThe EE20's Denso injectors can work imprecisely and produce a knocking noise, and soot in the injectors and EGR valve can lead to expensive repairs; AUTO BILD cites 500-800 euros per injector in Germany.
5. 5Medium severityFrequency: OccasionalIgnitionShort-circuiting ignition coils on the Forester, XV and Impreza (2016-2019)Two British campaigns (2020 and 2021) affect 2,338 Forester, XV and Impreza cars built from September 2016 to October 2019: one reprograms the control unit because the coil stays powered after the engine is switched off, and the other replaces all the coils, which can short-circuit and leave the car unable to start.
6. 6High severityFrequency: RareCylinder head and blockValve spring breakage on models built in 2013 and 2014In 2019 the DVSA recorded a recall for possible valve spring breakage on the Forester, Impreza, XV, Outback, Legacy and BRZ built in 2013 and 2014 (812 cars in the UK); the fix is to replace all the springs.
7. 7Medium severityFrequency: RareTransmissionLeaking CVT gearbox oil cooler hose on the Legacy and Outback (2010)In 2010 the DVSA recorded a recall of 404 British Legacy and Outback cars for a CVT gearbox oil cooler hose that could break, causing loss of drive and oil on the road; a modified hose is fitted.

Severity colours: low, medium, high, critical. How we rate them

Manufacturer

Subaru

Family

Cuatro cilindros bóxer (horizontales opuestos) de Subaru: gasolina EJ204 de 2.0 litros y EJ253 de 2.5 litros (2007-2014), gasolina FB16, FB20 y FB25 (2011 en adelante, incluido el e-Boxer híbrido suave) y turbodiésel EE20 de 2.0 litros (2008-2018). Los EJ llevan correa de distribución; los FB y el EE20, cadena. No incluye el seis cilindros EZ36 del Outback, los turbo de gasolina (EJ255 del Forester XT, EJ257 del WRX STI, FA20 turbo y FB16 turbo del Levorg) ni el BRZ.

Fuel

—

Displacement

—

Cylinders

4

Fuel system

Naturally aspirated

Injection

Indirect injection

Timing

Chain

Power

114–175 hp

Peak torque

350 Nm

Production

since 2007

Makes

Subaru

Technical data^{[4][5][6][7][8][9]}

1. 2007–2014

   2.0i 150 hp (EJ204, 2007-2014)

   Naturally aspirated boxer of 1,994 cc (92 x 75 mm), twin overhead camshafts and AVCS variable valve timing; English Wikipedia describes the EJ engines as having a timing belt. It produces 150 hp in the Impreza III (2.0R), the Forester III (2.0X, with 196 N·m) and the 2009-2014 Legacy V; the EJ204 code is inferred from English Wikipedia, because the German press does not give it.^{[2][5][13][16]}

2. 2008–2010

   2.0 D 147-150 hp Euro 4 (EE20, 2008-2010)

   Boxer turbodiesel of 1,998 cc (86 x 86 mm, 16.3:1), variable-geometry turbo and Denso common-rail injection at 1,800 bar: 150 hp and 350 N·m in the Legacy, Outback and Impreza, and 147 hp in the Forester. It was only offered with a six-speed manual gearbox and a particulate filter; the first Legacy and Outback had an open filter.^[2][4][11]

3. 2009–2014

   2.5i 167-173 hp (EJ253, 2009-2014)

   Naturally aspirated boxer of 2,457 cc with a single camshaft per cylinder head: 123 kW (167 hp) in the Legacy V and Outback IV before the facelift and 127 kW (173 hp) after it, with the Lineartronic gearbox (CVT) according to German Wikipedia from May 2013 in the Outback. English Wikipedia identifies it as the EJ253 and places the Legacy with this engine in 2009-2012.^[5][8][16]

4. 2010–2015

   2.0 D 147-150 hp Euro 5 (EE20, 2010-2015)

   Euro 5 evolution with a 16.0:1 compression ratio according to the Polish article; AUTO BILD places an improvement in bearing failures from 2010 and English Wikipedia's Forester page speaks of an engine reworked for Euro 5 in 2011. The Outback IV received the Lineartronic gearbox in May 2013.^{[1][8][11][13]}

5. 2011–2023

   1.6i 114 hp (FB16, 2011-2023)

   Four-cylinder of 1,600 cc, 84 kW (114 hp) and 150 N·m with a timing chain, fitted in Europe to the XV I (from December 2011) and the XV II (2018-2023), with a five-speed manual gearbox or CVT in the former and a CVT as standard in the latter.^[6][9]

6. 2011–2018

   2.0i 150 hp (FB20, 2011-2018)

   Four-cylinder of 1,995 cc, 110 kW (150 hp) and 196-198 N·m with a timing chain, with a six-speed manual gearbox or CVT. It is fitted to the Forester IV (2.0X) and the XV I (2.0i).^[6][7][9]

7. 2015–2018

   2.0 D 147-150 hp Euro 6 (EE20, 2015-2018)

   2015 Euro 6 version: 15.2:1 compression, 2,000 bar injection pressure and a third chain for the fuel pump, according to the Polish article; AUTO BILD mentions a new engine block in 2015. The Forester has had a CVT with the diesel since 28 March 2015, and diesel production ends in 2018.^[1][7][11]

8. 2015–2021

   2.5i 175 hp (FB25, 2015-2021)

   Four-cylinder of 2,498 cc, 129 kW (175 hp) and 235 N·m with a timing chain, only with the Lineartronic gearbox, in the Outback V. German Wikipedia gives the Outback V's 2.5i as running from 2015 to 2018; the years after the 2018 update are not stated in the source.^[6][8]

9. 2018

   2.0i 156 hp (FB20D direct injection, 2018)

   Direct-injection variant of the FB20 with 115 kW (156 hp) that German Wikipedia gives for the XV II in Europe between January and August 2018; the English page identifies it as the FB20D (115 kW in Europe).^[6][9]

10. since 2019

    2.0i e-Boxer 150 hp (FB20 mild hybrid, 2019 onwards)

    Modified FB20 of 110 kW (150 hp) and 194 N·m with a 12.3 kW (16.7 hp) electric motor built into the Lineartronic gearbox; Subaru presented it for the European Forester at the Geneva Motor Show in March 2019. The XV II also has it. It does not include the 2024 Forester (SL) e-Boxer, which according to German Wikipedia has different specifications.^[7][9][13]