Subaru Forester 2009–2013Common problems, reliability & repair costs

Symptoms: Oil level drops noticeably between changes with no visible leak; low-oil light between services; in neglected cars, engine damage from running low. Subaru's own test threshold was consumption over 1/3 quart per 1,200 miles.

Fix: The real fix is a short block (new pistons and rings) — defective piston rings are the root cause named in the 2014 class action. Subaru settled in 2016 with an 8-year/100,000-mile warranty extension for affected cars; that window has closed on every 2011–2013 Forester, so today it's an out-of-pocket short block or a disciplined check-and-top-off routine. A car that already got its settlement short block is the best version of this generation.

Sources: CarComplaints — Subaru oil consumption class action, CarComplaints — 2011 Forester (worst problem: excessive oil consumption), Subaru Forester Owners Forum — 2011–14 oil consumption class action (merged thread)

Symptoms: Oil weep or coolant crust along the head-to-block seam (visible from under the car), slow coolant loss, sweet smell after driving, and eventually overheating if ignored. Usually starts as an external leak, not the catastrophic internal failure of earlier Subarus.

Fix: Replace both head gaskets with updated multi-layer-steel gaskets. It's roughly a 10-hour job on a boxer engine, so labor dominates the bill. Smart money does the timing belt, water pump, and cam/crank seals at the same time since it's all apart. A documented head-gasket job is a selling point, not a red flag.

Sources: MechanicBase — Subaru head gasket problems, years and models affected, All Wheel Drive Auto — Subaru head gasket problems explained, Samarins — 2009–2013 Subaru Forester review and common problems

Symptoms: No warning. Affected non-desiccated Takata passenger-side inflators can degrade with humidity and heat exposure and rupture in a crash, sending metal fragments into the cabin.

Fix: Free recall repair at any Subaru dealer — the passenger frontal inflator is replaced. Multiple recall waves ran through the late 2010s and early 2020s, so check the specific VIN at nhtsa.gov/recalls before buying and get it done if it's open. Driver-side airbags on these cars were not Takata units.

Sources: NHTSA — Takata recall spotlight, Subaru — Takata airbag recall information

Symptoms: Soft or sinking brake pedal, visible brake-fluid seepage near the rear lines, low fluid level. Applies to cars registered in road-salt states, where the four-wheel-drive brake lines can rust through.

Fix: Subaru's 2014 recall inspects the lines, replaces any that seep, and applies anti-corrosion wax — free at a dealer if the VIN is open. On a rust-belt car that's already had the recall, still get the lines inspected on a lift; out-of-recall line replacement at an independent shop runs a few hundred dollars.

Sources: Subaru Forester Owners Forum — NHTSA recall 14V-311 brake lines (2009–13), NHTSA — 2010 Subaru Forester recalls and complaints

Symptoms: Turbo whine or rattle, blue smoke, loss of boost, oil-pressure or AVCS-related codes. Root cause is a fine mesh screen inside the banjo bolts feeding oil to the turbo and cam-timing solenoids — it clogs with debris and chokes off oil.

Fix: If caught early: clean or remove the banjo-bolt screens (a known Subaru service-bulletin item, TSB 02-103-07R era) and stay strict on oil changes. If the turbo already ran dry: turbo replacement, and inspect for bearing debris downstream. The EJ255's piston ringlands are also less tolerant of heat and low octane than the non-turbo engines — another reason this trim punishes neglect.

Sources: Subaru Forester Owners Forum — SH 2.5XT known issues (2009–2013), Subaru Forester Owners Forum — oil supply screen in the banjo bolt

Symptoms: Check-engine light with front A/F sensor heater or response codes (P0032 and friends), rough idle or surging in some cases, slightly worse fuel economy. The sensor element can crack; Subaru ran a service program (WXW-80) for cracked front sensors on related models.

Fix: Replace the front air-fuel sensor with an OEM-grade unit (Denso/NTK). Cheap aftermarket sensors on these engines have a reputation for failing again within months — this is a part worth buying right the first time. Persistent P0420 codes after a sensor may mean the catalytic converter is on its way out, which is a four-figure job.

Sources: RepairPal — Subaru front O2 sensor service program, Subaru Forester Owners Forum — front A/F ratio sensor continuously failing

Tools: None (hands only; small screwdriver helps on the glovebox)

1. Unclip the airbox lid in the engine bay (driver's side), lift it, and swap in the new panel filter with the seal seated flat.
2. Re-clip the lid and make sure no clip is left hanging — a leaking airbox lets unfiltered air past the MAF sensor.
3. For the cabin filter, open the glovebox, squeeze the sides to drop it past its stops, and remove the filter cover behind it.
4. Slide the old cabin filter out, insert the new one with the airflow arrow pointing down, and reset the glovebox.

Tools: Jack + jack stands, 14/17mm sockets and wrenches, Hex key or Torx to hold the stud (varies by link), Penetrating oil

1. Raise the front of the car, support it on stands, and remove both front wheels.
2. Soak the end-link nuts with penetrating oil — they live in the splash zone and rust.
3. Hold the ball-stud with a hex key while breaking the nuts loose; remove the old link top and bottom.
4. Install the new link, torque both nuts with the suspension loaded (jack under the control arm) so the bushings sit at ride height.
5. Repeat on the other side — replace in pairs — then test-drive and listen for the clunk over bumps to be gone.

Tools: O2 sensor socket (7/8 in / 22mm with cable slot), Breaker bar, Penetrating oil, Anti-seize (usually pre-applied on new sensor threads)

1. Work with the exhaust warm (not hot) — the sensor threads release easier.
2. Locate the front A/F sensor in the exhaust ahead of the catalytic converter and unplug its connector.
3. Soak the base with penetrating oil, then break it loose with the O2 socket and breaker bar.
4. Thread in the new sensor by hand first, snug it to spec, and route the harness away from the hot pipe.
5. Reconnect, clear the code, and confirm the check-engine light stays off over a few drive cycles.