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Recommendations for replacement pistons - EJ25 2003 Baja


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I discovered some scuffing in one of the cylinders of my son's Baja, enough to just barely feel with a fingernail. No wear ridge on top of the cylinder at all, and can still see the crosshatch in the cylinders, except where the scuffing is. So I've decided to bite the bullet and have it bored, and would like to get recommendations for replacement pistons and rings. Some of the sets on eBay are so cheap it scares me. I can't imagine that a complete set of pistons and rings selling for $99 can be very high quality, but maybe I'm wrong, as this is my first EJ25 rebuild. Any recommendations of brand, and vendors to buy from are appreciated.

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Lot of those phase2 EJ25's have scuffing on the top side of the cylinders due to leaking headgaskets and the coolant level in the block dropping below the top of the cylinders. If you can still see the crosshatching and the scoring isn't too deep, I'd run it as is rather than boring it. It will probably use some oil, but not enough to cause problems.

 

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That was a 200k+ mile 2004 EJ25 with blown headgaskets that was run that way for a while. I put it together as you see it in the pictures and it ran fine, quiet, and burns 1qt in 1500 miles on the highway, none around town. I honed one cyl a bit just to crosshatch the polished area of it, and I cutout a cardboard plug to hold the rod centered in the bottom of the cyl while I 3 stone hone'd it. 3 years later it's still running well.

 

Main thing is how it sounded before you took it apart. If it had audible piston slap, it's worth putting new pistons in (but I still wouldn't bother paying for boring and honing). If not, take the oil rings off the pistons and clean out the groove and all the drain holes as there's usually a bunch of carbon baked on and clogging that up.

 

Most of these cars rust out before fatal engine problems kill them around here. So it's not really worth rebuilding them to perfect when good enough will do fine for the rest of the cars life. Add to that a lot of machine shops inexperience with subaru engines will either make the cost of work high or the quality low, and sometimes it's better to just toss it together and call it a day as is.

 

I do regret not putting pistons in a 98 EJ25d that had been badly and repeatedly overheated with massively blown headgaskets. It had bad piston slap when I got it but the gaskets were so blown that it was puffing exhaust out the radiator so I didn't run it long enough to see if the piston slap would get less when it warmed up. I gambled that it would, and it didn't. I had to listen to them slap for the next 80k miles but it ran great so I wasn't going to take it apart again.

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Lot of those phase2 EJ25's have scuffing on the top side of the cylinders due to leaking headgaskets and the coolant level in the block dropping below the top of the cylinders. If you can still see the crosshatching and the scoring isn't too deep, I'd run it as is rather than boring it. It will probably use some oil, but not enough to cause problems.............

 

............I do regret not putting pistons in a 98 EJ25d that had been badly and repeatedly overheated with massively blown headgaskets. It had bad piston slap when I got it but the gaskets were so blown that it was puffing exhaust out the radiator so I didn't run it long enough to see if the piston slap would get less when it warmed up. I gambled that it would, and it didn't. I had to listen to them slap for the next 80k miles but it ran great so I wasn't going to take it apart again.

 

 

WoodsWagon, thanks for that reply. Makes me feel a lot better about not spending a bunch of money. Did you re-ring that cylinder or just put it back together with the used ones?

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Ebay you can get new shortblocks for the range of $1,500 shipped. It's not even worth bothering with unless you get a piston or rod that wants out.

 

My 2001 Forester 2.5 has piston slap for the first 3 mins on a cold start. it has 222k miles, runs great otherwise

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