2009 Subaru Forester Problems: 8 Known Issues

On the 1998-2010 Subaru Forester EJ25, the EJ25 2.5L horizontally-opposed engine in 1998-2010 Foresters is notorious for external head gasket failure. Unlike typical blown head gaskets that cause overheating, the Subaru EJ25 gaskets fail externally, leaking coolant and oil down the sides of the engine. The failure is caused by the gasket material (composite) breaking down over time, combined with the horizontal orientation placing uneven stress on the gaskets. This is widely considered the most common and well-documented Subaru defect.

On the 2009-2013 Subaru Forester EJ255 2.5L Turbo, the turbocharger oil-feed line on the EJ255 uses a banjo (union) bolt containing a fine mesh screen meant to keep debris out of the turbo. As the engine ages or oil-change intervals stretch, sludge and carbon clog the screen and starve the turbo of oil. The turbo bearing then overheats and fails — the shaft can break and the compressor wheel disintegrate, sending metal debris into the oil pan, oil cooler and engine bearings, often destroying the engine. Subaru later deleted the screen on the union bolt because of these clogging-induced failures.

On the 2004-2013 Subaru Forester EJ255 2.5L Turbo, the turbocharged EJ255 has thin, cast-piston ringlands that crack under detonation. The large bore, high cylinder temperatures and a flat oil pan that lets oil slosh away from the pickup under cornering make the engine vulnerable: a single knock event (low-octane fuel, poor tune, hard driving, or oil starvation) can fracture the second ringland. Once cracked, combustion gases blow into the crankcase and oil consumption spikes to roughly a quart every 300-500 miles, with misfires and eventual catastrophic engine failure.

On the 2009-2010 Subaru Forester EJ253 2.5L SOHC, the 2009-2010 SH Forester still used the belt-driven SOHC EJ253, one model generation before the chain-driven FB25 arrived for 2011. Owners of these EJ253 cars report climbing oil consumption at higher mileage, but the mechanism is different from the FB25 story: on the EJ253 it is hardened valve stem seals (and in some engines an improperly machined valve guide bore) letting oil down the guides, plus generalized external seepage from cam and crank seals — not the low-tension piston-ring design that drove the 2011-2015 FB-engine class-action settlement. Getting this distinction right matters because a 2010 Forester is NOT covered by that settlement or its extended warranty, and dealers correctly reject those claims. Symptoms are blue smoke on startup and after long decel, and topping up between changes.

On the 1998-2010 Subaru Forester, the EJ-series front-mounted oil pump has a rotor cover (backing plate) held on by five small screws installed without thread locker at the factory. On high-mileage engines these screws routinely work loose. Pressurized oil then escapes past the rotor cover into the pump body behind the front crankshaft seal, which pushes the seal partly out of its bore and produces what looks like a classic 'front main seal leak' — often re-leaking within months of a seal-only repair. The same internal leak bleeds pump volume and can show up as low oil pressure, a flickering oil light at hot idle, or lifter/HLA tick. Technicians who have opened many EJ pumps report finding loose screws on nearly every one.

On the 2009-2013 Subaru Forester, certain 2009-2013 Foresters are equipped with a Takata-sourced front passenger frontal airbag inflator using non-desiccated phase-stabilized ammonium nitrate (PSAN). Over years of exposure to heat and humidity, moisture intrusion can degrade the propellant so the inflator over-pressurizes and ruptures its metal housing during deployment, spraying shrapnel into the cabin. This is the industry-wide Takata defect that has caused deaths and injuries. Subaru's Forester remedy has been tracked under recall campaigns TKA/TKB/TKC (NHTSA 19V-009 and related), with an interim 'like-for-like' replacement followed by a final non-Takata/desiccated inflator. Only the passenger-side front inflator is affected; the driver front airbag on these Foresters did not use a Takata inflator.

On the 2009-2013 Subaru Forester 2.5L EJ255 Turbo, on turbocharged Forester XT models, the relay controlling the secondary air injection (SAI) pump can fail in the closed position, leaving the air pump running continuously. Sustained operation overheats the pump, which can melt surrounding components and create a fire risk even with the vehicle parked. Subaru recalled about 100,000 turbo vehicles (Forester XT, Impreza WRX/STI, Legacy/Outback turbo) for the defect.

On the 1998-2010 Subaru Forester, on automatic-transmission Foresters with the 4EAT gearbox, all-wheel drive is managed by an electronically controlled multi-plate transfer (MPT) clutch on the tail of the transmission, modulated by the 'Duty C' solenoid. When the solenoid sticks or the clutch pack glazes, the clutch stays fully applied on dry pavement and the car binds, shudders and hops through slow tight turns — parking lots, U-turns, driveways. Mismatched tire circumference (one new tire, or uneven wear) accelerates it by forcing the clutch to slip constantly. The diagnostic that confirms it is inserting the FWD fuse in the underhood holder: if the binding disappears with the transfer clutch de-energized, the fault is in the AWD path, not the front axles or brakes.