Parts for your 2020 Subaru Legacy-Oil pump

2020 Subaru Legacy oil pump — what it does, when to worry, and how it’s serviced

Yes, an oil pump is absolutely fitted to the 2020 Subaru Legacy. Both engines offered that year—the 2.5‑litre FB25 and the 2.4‑litre turbo FA24—use a crankshaft‑driven, gerotor (trochoid) oil pump integrated into the front timing cover. This is documented in Subaru’s Factory Service Manual for the 2020 Legacy/Outback (Engine Lubrication section) and confirmed by Subaru’s OEM parts catalog, which lists the complete Oil Pump Assembly and related seals as service parts.

The oil pump’s whole job is to pull oil from the sump and push it under pressure through the galleries to bearings, camshafts and the timing hardware, keeping friction down and heat under control. On these FA/FB engines, the pump also houses a pressure relief valve that regulates system pressure, so it’s central to engine health.

As far as servicing goes, the oil pump isn’t a routine replacement item. What is routine is looking after the oil that it moves. Subaru specifies full‑synthetic oil of the correct grade (typically 0W‑20, check the owner’s manual for your exact trim), and sticking to the service schedule—commonly every 12 months or around 12,500 km in Australia and New Zealand—keeps the pump happy. Clean oil, a fresh filter, and the correct level go a long way.

If an oil pump ever needs attention, it’s usually because of low oil pressure or internal wear following contamination. Replacement is a front‑of‑engine job: the crank pulley and front cover come off, the pump clearances are checked, sealant and O‑rings are renewed, and the pump is primed with fresh oil before first start. It’s specialist work best left to a workshop with Subaru experience, as sealant application, torque specs and cleanliness really matter.

Drivers should keep an eye (and ear) out for:

• Oil pressure warning lamp illuminating or flickering
• Tappet/chain rattle at start‑up that doesn’t quickly quieten
• Knock or rumble that changes with engine speed
• Metallic glitter in drained oil or the filter

If the oil light comes on, stop the car promptly—continuing to drive can damage bearings within seconds. When replacing a pump, good practice is to inspect and clean the pickup and sump, replace related seals, use quality OEM‑spec parts, and verify hot oil pressure after the job. Treated well, the 2020 Legacy’s oil pump is a fit‑and‑forget component for many years of motoring.

Popular questions

Does the 2020 Subaru Legacy definitely have an oil pump?
Yes. Subaru’s Factory Service Manual and OEM parts listings show a gerotor oil pump integrated into the front cover on both the 2.5L FB25 and 2.4L FA24 turbo. It’s crank‑driven and controls oil pressure for the whole engine.

How often should the oil pump be replaced?
There’s no fixed interval. It’s replaced only if pressure is out of spec or there’s damage or wear, often due to contamination or severe overheating. Regular oil changes with the specified grade help the pump last the life of the engine.

What are common signs of oil pump trouble on a 2020 Legacy?
Low oil pressure warnings, persistent top‑end rattle after start, engine knocking, or sparkly metal in the oil. If any of these show up, don’t keep driving—get it inspected straight away.