Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2009 Subaru Outback F4-2.5L SOHCFACTORY OEM SERVICE PROCEDURE
Piston, Engine
Piston
Outer diameter
Standard
A 99.505 - 99.515 mm (3.9175 - 3.9179 in)
B 99.495 - 99.505 mm (3.9171 - 3.9175 in)
0.25 mm (0.0098 in) OS 99.745 - 99.765 mm (3.9270 - 3.9277 in)
0.50 mm (0.0197 in) OS 99.995 - 100.015 mm (3.9368 - 3.9376 in)
Outer diameter
Standard
A 99.505 - 99.515 mm (3.9175 - 3.9179 in)
B 99.495 - 99.505 mm (3.9171 - 3.9175 in)
0.25 mm (0.0098 in) OS 99.745 - 99.765 mm (3.9270 - 3.9277 in)
0.50 mm (0.0197 in) OS 99.995 - 100.015 mm (3.9368 - 3.9376 in)
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.