I caught this one earlier enough, I think the block is probably reuseable. Wasnt bad, decided to pull it before it got worse. No metal in the pan or on the screen. I did notice 2 of the 5 oil pump bolts on the back side of the pump were loose. I'm assuming this caused low oil pressure and caused one of the main bearings to go?

 

I've never bothered tearing a EJ25D block all the way down to look at the designs in the case to see how the oil system functions. I'm about to split the case when I get back to work from lunch but i wanted to find out what were the common points of failure on this style of block? MY1998 block w/135k miles. Oil was clean, hardly any sludge anywhere in the engine.

 

I'm thinking about rebuilding the block this winter as a living room project, mainly to teach myself how to rebuild the bottom end. And it would be nice to have a spare EJ25D for my Outback.

 

Thoughts? Advice?

 

Thanks

You lost rod bearings most likely. The 25D eats rod bearings. If you're lucky, you can get the crank and rods polished and miked, and slap a new set of bearings in. If not, you'll be replacing the crank and rods. I built my hybrid off of a 25D and the only thing usable was the case.

The only time the block is totally unusable is if a rod goes through it. Or it overheats to the beyond extreme and cracks. Minor rod knock is a perfect rebuild candidate.

 

Main bearing knock is almost unheard of. You need a LOT of wear on the mains before the crank gets enough room to get enough momentum to make an audible sound when/if it hits the bearings. Rod bearings almost always go first since they see the most dynamic changes in load.

I've asked several of the technicians I used to work with about signs to look for to determine Rod or Main bearing damage. Rod bearing damage causes knocking, and sometimes low oil pressure, but usually the knock turns into a hole in the block (rod heat seizes to the crank and breaks) before there is a very noticeable change in oil pressure. Main bearing damage almost always starts out as noticeably low oil pressure. Noise then develops as the rod bearings wear due to lack of lubrication at low RPMs.

 

A bad thrust bearing can make some noise when changing from on/off throttle if the crank moves quickly enough. Known as "crank walk". Ask any early Mitsubishi Eclipse/ Eagle Talon turbo owner about Crank walk (or google it, it's fun).

Got it tore down, #3 rod bearing... I guess I shoulda known that from all the EJ25D stuff I've come across. 1, 2 and 4 started to score a little, but on #3 you could see copper/brass or w/e sits behind the silver polishing on the bearings. Mains looked ok.

 

Only Fubar part I came across was one of the sealing bolts grabbed some threads and stripped on the last 5/8" of the threads. I think it can be tapped, there is still a lot of good thread left below it.

 

I guess its time to research rods/bearings/pistons/rings. I'm half tempted to build this engine to supercharge. Either way, I'm dumping the block/crank etc off @ the machine shop, let them look at it and tell me what they think.

i have a good used crank for the early 25d out of a 96 outback