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Discussion Starter · #1 ·
Hi all
I am quite new to these engine so please bare with me.

I currently have a 2000 Outback 2.5 SOHC with bad oil consumption. I have replaced all the PCV however still no joy.

I have pinned the issue down to stuck/crusty Oil control rings and/or worn piston rings.

Therefore I have got hold of a OEM ring kit and am going to replace them. However I have a few questions regarding end gaps as I do not really understand.

Being OEM rings do I have to check both the rings and the oil control rings? Also with the oil control rings there are the outer solid rings with the zig zag shapped middle of the sandwich. Do all 3 parts of the oil control rings need gap checking or just the two outers of the sandwich?

Also I get that the compression rings are inserted into the cylinder using the piston to get square however where do you measure? The top, middle or bottom of the cylinder wall?

Any help would be much appreciated
 

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2012 Outback - 2005 Outback XT
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Hi all
I am quite new to these engine so please bare with me.

I currently have a 2000 Outback 2.5 SOHC with bad oil consumption. I have replaced all the PCV however still no joy.

I have pinned the issue down to stuck/crusty Oil control rings and/or worn piston rings.

Therefore I have got hold of a OEM ring kit and am going to replace them. However I have a few questions regarding end gaps as I do not really understand.

Being OEM rings do I have to check both the rings and the oil control rings? Also with the oil control rings there are the outer solid rings with the zig zag shapped middle of the sandwich. Do all 3 parts of the oil control rings need gap checking or just the two outers of the sandwich?

Also I get that the compression rings are inserted into the cylinder using the piston to get square however where do you measure? The top, middle or bottom of the cylinder wall?

Any help would be much appreciated
You don't mention mileage, but given the age and the problem, I assume it's pretty high.
Re-ringing might be fine for lawn mowers and other small displacement engines, but not so much the automotive engines.
The bores need to be checked for wear and taper. Then you can decide where to go from there. Just popping new rings in a old engine is a recipe for failure. They won't seat right.
Assuming bore is good, ring gaps should be checked an inch or so down in the bore.


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On the Super Mod Squad
2002 3.0 VDC Wag + 2018 2.5 Leg Ltd
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somewhere in this thread there would be information about rings in a Ej251/ EJ252 type engine. Rare thread here of a short block rebuild, as most people would not bother to do such work on a subaru short block as they are just laying around before the cars get crushed for rust.

and yes, another example of how much #photobucket sucks donkey balls.

http://www.subaruoutback.org/forums...644-bought-overheated-2001-obw-gonna-fix.html
 

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I should have added that a re-ring simply isn't a cost effective repair given the cost of a used replacement engine or short block.

I've built a few engines over the years, and unless it was for a high performance build, I wouldn't mess with it. Just not worth the hassle.

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Discussion Starter · #5 ·
Thanks for the replies

Yeah I get that a replacement engine would be easier.
However buying another block form an old car is a bit of a risk again and that one might be as bad if not worse. On my current engine the head gaskets have just been replaced along with new valve seat seals and a complete polish up.
It also had new crank, cam seals, water pump and all pump. granted I can swap all that over onto another block but is it not better the devil you know?

btw cheapest decent block I can find id £750 (rebuilt one) vs £75 for a set of new rings and some time??

Help please!!
 

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Thanks for the replies

Yeah I get that a replacement engine would be easier.
However buying another block form an old car is a bit of a risk again and that one might be as bad if not worse. On my current engine the head gaskets have just been replaced along with new valve seat seals and a complete polish up.
It also had new crank, cam seals, water pump and all pump. granted I can swap all that over onto another block but is it not better the devil you know?

btw cheapest decent block I can find id £750 (rebuilt one) vs £75 for a set of new rings and some time??

Help please!!
How have you determined the problem is worn rings and not worn cylinder walls? Sounds like you are guessing.
 

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On the Super Mod Squad
2002 3.0 VDC Wag + 2018 2.5 Leg Ltd
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I see you are in the UK .

typical EJ25 SOHC type short blocks of that era, are pretty trouble free things, ....vs. other makes, so you don't have to find one that is already "rebuilt",

...just any old one that was not abused like being run out of oil. clean it up, ...polish the surfaces,

buy a set of new head gaskets, (old ones get squashed 1 time).
 

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I would take a contrary position. If you are comfortable pulling the engine and have the tools needed to remove the pistons. You will need to remove the oil pan too in order to access the rods to line things up to get the piston pins back in. Not a big deal once you have the engine out on a stand. You will also be able to take a close look at the cylinder walls to see if the cross hatch is missing in any areas (a visual sign that significant wear has occurred in those areas). A machine shop could also measure the bores at that point just to make certain they aren't too far out of spec. Since you already replaced the crank, I assume you have new mains/rod bearings so the cylinder bores is the only question. I just finished doing this on my similar vintage Outback but I did need a rebore and new pistons. Even if you do need a rebore and oversize pistons/rings, you can still do that cheaper (parts-wise) than buying a rebuilt short block. If you aren't in a rush and enjoy doing this kind of work, go for it!
 
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