Everything we learned after tearing apart our Subaru WRX engine | Redline Updates - Hagerty Media

Last week Davin was able to disassemble our 300,000-mile 2002 Subaru EJ205 engine. Did he do it the right way? Maybe not. Did it come apart? Yes, it did. However, after going through all the work and talking to some local Subaru guys, we learned a few things worth sharing.

First major Subaru engine-disassembly lesson learned: There are plugs in the block that, once removed, allow the wrist pins to slide out. That means the pistons can stay in the bores while the connecting rods and crank come out together. Subaru aficionados know this one already, but Davin dives headlong into the disassembly and manages to get the job done regardless. Next up, an inspection of the bores and pistons shows that a bit of honing should clean everything up and the piston’s skirts look only slightly burnished, so they could be fine to reuse once they get a new ring pack.

While inspecting the bottom end of the high-mileage mill, Davin finds bearings that are on their last legs. It turns out that the disassembly and rebuild may have come at just the right time before any catastrophic damage was done to the crank’s bearing surfaces. To make sure that the future bearings lead a long, happy life, Davin plans to install an STI oil pump. That means more volume gets pumped out of the sump and up to the heads—but making sure that oil gets back to the sump is important as well.

After a quick look at the heads and valvetrain, Davin is ready to get started on the clean-up process, so it’s time for the parts washer and vapor hone. Before long, things will be coming back together and we’ll have another update coming your way soon!

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