piston wear

[RustyRuu]

So i was about to slap my heads gaskets on and start resembling my 02 legacy and moved the block to a bench in a different part of my garage for better lighting.

 

i as i was prepping the deck i noticed some funny looking lines in the cylinder bore that definitely was not crosshatching .

 

so just to be sure i removed the pistons. and this is what i found, the wear in the picture would be on the top of the cylinder/ piston, so those are the top skirts of the piston.

 

ive researched around and heard it could be bent rods. they are straight up and down and not at and angle though.

 

this is on all 4 piston top skirts, all bottom skirts look good, well at least not like that.

 

the picture is from the drivers side, right piston #2, left #4. my #1 and #3 pictures did not turn out but are alot cleaner looking less wear by a long shot. but they still have it on the top skirts as well.

 

i guess im just looking for feed back or what i should do in this situation?

pistons no good?

obviously hoon the case halves (if i can ever get them apart, im trying)

new connecting rods and probably bearings?

 

like i said im trying to get the case apart to look at the bearing wear and clearances but its sorta fused on a dowel pin i think and is taking quite a bit of work

 

around 195.000 on the clock

[RustyRuu]

was looking at a 944 forum since you know they know the world is flat as well..

 

so i see that this could just be from running the car too rich of fuel this causes the walls to be clean of lubricant/ oil and cause this wearing in the thrusting direction. solution is new injectors.

but in all 4 hmmm?

 

could be a deformed piston from detonation?

again all 4 hmm?

 

or bad oil and combution rings. the oil rings collapse causing oil to burn at a more rapid rate. this would have gone unnoticed.

 

i always checked my oil at all top offs but i only had it for a year (40.000miles thats a rough year) and it ran good just leaked everywhere and need oil constantly the previous owner i cant speak for. all i know is its my problem now.

 

also i heard this was due to clearance being too big from the piston to the cylinder wall. to reassemble it with new piston rings and it will be ok.

 

have also read this is normal since subaru ditched there longskirt pistons from there 2.2 and went with the short skirt/ no skirt design in the 2.5 and the result is more piston wear and piston slap from the motor

[Max Capacity]

Contact Dave at Cryotuning. Ask him if he knows a good machine shop close to you. The machine shop can answer all your questions and rebuild that engine correctly.

 

You should call the local dealer, talk with the parts guys and see who they send there engine too for machine work. May be stopping by the parts guy's would be better, show a little effort.

 

Ask the auto parts stores also, they should know the good shops.

[heiche]

Doesn't really look that abnormal for pistons that have seen 200K miles. With that amount of miles, it's up to you how to proceed. Many would either fit new pistons and have the block bored, or simply swap in a new shortblock. Or you could slap on some new rings and call it a day, but there's a lot of wear in an engine that's seen that many miles (as seen in your posted pic).

 

As far as separating the case halves, please make sure that every bolt has been removed. I know in my 2.5 there were some sneaky little bolts on the back of the engine (in front of where the flywheel would normally reside, and on the bottom where the oil pan would normally be). If you have them all out, one way to start the separation process is to take the scissor jack out of your trunk, place it in that same area normally covered by the flywheel, orient it so will push out sideways (the way you want the halves to separate), and crank it a little. It shouldn't need that much force, and if it does you might be fighting a bolt or 2 that still remain.

[RustyRuu]

If you have them all out, one way to start the separation process is to take the scissor jack out of your trunk, place it in that same area normally covered by the flywheel, orient it so will push out sideways (the way you want the halves to separate), and crank it a little. It shouldn't need that much force, and if it does you might be fighting a bolt or 2 that still remain.

 

I've been trying that technique everything separates but the top front above the oil pump and there is no bolt in site holding it together.i removed 4 from the front face. but haven't spent much more time on it i work late and sleep in later so just have not found the time to play with it again.

thanks for the response

[monkeyposeur]

Are you sure you removed the small 10mm bolt (same size as the oil pump bolts) in the oil pan area inside the block where the bottom of the oil pump is located? Lots of people forget that bolt. I did too. I beat that block like it owed me money for a good 20 minutes, lol. But if it isn't coming apart it's almost always a forgotten bolt.

[RustyRuu]

Are you sure you removed the small 10mm bolt (same size as the oil pump bolts) in the oil pan area inside the block where the bottom of the oil pump is located? Lots of people forget that bolt. I did too. I beat that block like it owed me money for a good 20 minutes, lol. But if it isn't coming apart it's almost always a forgotten bolt.

 

i am sure i have that one i have 3 corners come up but not the front top. only bolts i have in are a couple in the water jacket just in case it pops one wont just fall on my foot or floor. i

 

backed those all the way out and then turned them 2 turns in so its definitely not those.

 

i will post picks since its such a bizarre phenomenon but literally all bolts are out i pretty sure there is a dowel pin in that corner but ill keep trying.

 

i really have only tried to do it for 20 min or so since i thought i removed all the bolts but no luck.

 

it will come with time and patience but right now i have none and and leaving it as is until i do.

[RustyRuu]

here are a couple pictures of my worst looking bearings the first two are the thrust bearing and the next is the number 4 main.

 

all of them have this sort of wear on them but these worst wear were the best pictures i took.

 

the first and third picture are the bearings on cylinder 1 and 3 case half and pictures 2 and 4 are from the cylinder 2 and 4 case half.

[heiche]

those don't look too bad. you going to replace them (and polish the crank)? or just putting everything back together?

[RustyRuu]

i will replace and polish crank and i need advice on what i need to do exactly about my cylinder walls. they so so i cant catch a nail on the marking.

 

i just need to talk to a real trust worthy mechanic to tell me what i should do to just hoon it or bore it and get new pistons. im still stumped and am calling around for shops right now.

 

i dont want to go straight to the machine shop since they will probably tell me its forshitled and bore it and take all my money. i want to take it to someone who will notice its not worth machining and getting a shortblock is cheaper than all the work.

 

machine shop will take my money and ill be stuck trying to deal with all this over bore piston matching.

 

its not a turbo im not looking for it to be maybe a short block is better than all the machine shop labor and parts prices but thats where im at totally stuck and not making a decision anytime soon. i get my licence back in February, i have plenty of time.

[Max Capacity]

I guess you have read my click here link. It's cheaper to get a new ej257 then pay the machine shop to do all the work of boring and matching the bore to the pistons and assembling the short block.

 

I have known my machine shop for a very long time. They charged me $1200 for every thing they did for me.

[RustyRuu]

i am debating just getting new rings and bearings and polished crank and letting it go its only a ej253 NA. can find ej253NA short blocks for cheap but dont know if the sensors will swap over.

 

would doing this just give it bad compression if the scoring is deep?