Should i replace these pistons and rings (with pics)

[blakester]

I kinda agree that if you're already in there that far, with 3000 hours on them, you might as well replace them. About how many hours do you put on it in a year? Just curious.

Yeah i'm definitely contemplating that. I put about 100 hours a year on it, really not all that much. Pistons, rings, head and oil pan gasket are 1100$ for this guy.

 

[RickB]

Your dime. But I would be measuring those pistons AND BORES then deciding. You could probably save $350 - $500 on pistons and it would run just as good for just as long. Putting new pistons in sloppy bores doesn’t accomplish anything worthwhile.

 

[blakester]

Now that i am remembering. Once upon a time there were 2 fuel filters. One near the radiator, and one near the injector pump. I believe one was metal, 30 micron maybe. It broke and I am now down to one filter. Would that mess with the fueling ratio at all, or am I just filtering less large particles out before the small one. (which is very new)

 

[Tractor Seabee]

A quick to get a cylinder/ring wear is to insert the rings in the cylinder and mic between the ring ends and compare with factory spec. 3000 hrs is not that much on a diesel unless there is a contributing factor creating excess wear. Many go much longer w/o an overhaul. Do you stop and start a lot. Just startup can add hours of wear.

As you did not mention your brand and model; why not post a question here on TBN to survey owners of the same tractor you have, on what their experience has been on wear/hours? That might help making a decision. If you continue I would sure mic everything first and compare with factory +/- specs. If in tolerance I would get new rings and a gasket set, de-glaze the cylinder walls, remove any detectable ridge, and put it back together and find the smoking problem elsewhere, its not there unless the rings don't seat right due to glazing.

If your engine is one noted for early wear; then I would be-build from the bottom up s other things are just down the road. Last thought; replace the missing fuel filter. The one ahead of the booster pump is the most critical. The one after, is double insurance or catch booster pump wear particles before the ruin your expensive injector pump.

Ron

 

[blakester]

A quick to get a cylinder/ring wear is to insert the rings in the cylinder and mic between the ring ends and compare with factory spec. 3000 hrs is not that much on a diesel unless there is a contributing factor creating excess wear. Many go much longer w/o an overhaul. Do you stop and start a lot. Just startup can add hours of wear.

As you did not mention your brand and model; why not post a question here on TBN to survey owners of the same tractor you have, on what their experience has been on wear/hours? That might help making a decision. If you continue I would sure mic everything first and compare with factory +/- specs. If in tolerance I would get new rings and a gasket set, de-glaze the cylinder walls, remove any detectable ridge, and put it back together and find the smoking problem elsewhere, its not there unless the rings don't seat right due to glazing.

If your engine is one noted for early wear; then I would be-build from the bottom up s other things are just down the road. Last thought; replace the missing fuel filter. The one ahead of the booster pump is the most critical. The one after, is double insurance or catch booster pump wear particles before the ruin your expensive injector pump.

Ron

I will give that a run with the rings. My make is a CAT me20 with a mitsubishi engine in it. I took a good look at the cylinder walls and there is no ridge at all, but i definitely cant see much of the crosshatch marks in the wall anymore, feels like maybe that means its time to de-glaze. I also don't stop and start the machine unless i have to, and i typically run it at 90% throttle or higher. i have the workshop manual for the machine but i don't see much about the specs in there for tolerance. I guess ill have to look up part numbers?

 

[TimberHole]

An overhaul manual will have dimensions. Maybe you have a service manual?

 

[radios1]

you don't want to deglaze the cylinders with the crank in place, and get grinding grit on the crank..

 

[RickB]

you don't want to deglaze the cylinders with the crank in place, and get grinding grit on the crank..

Only if you are careless. I could tell you how many times I have done it and seen it done but sadly I have lost count.

 

[blakester]

ok, no overhaul manual or service manual i can find anywhere for this baby. Just the parts manual. I went ahead and ordered and installed new rings, I re-honed the cylinders, new gaskets all around, checked the thermostat (works great), Flushed everything out gave it a good clean and re-assembled everything. Two things at this point left. I couldn't crack the injectors from the tubed, they are fully bound up in there so I'm not sure if there is anything to do there. I also couldn't take the injectors apart, so I just did a light surface cleaning. The major thing for me is the rocker adjustment. the clearance is banana's, it's got to be 2mm at Top dead center. However with no information on what the valve clearance SHOULD be I'm not sure where to adjust to. Is there a rough ammount for old engines like this i could just adjust to the middle of normal clearances? This one has me stopped for sure.

 

[MossRoad]

I will give that a run with the rings. My make is a CAT me20 with a mitsubishi engine in it. I took a good look at the cylinder walls and there is no ridge at all, but i definitely cant see much of the crosshatch marks in the wall anymore, feels like maybe that means its time to de-glaze. I also don't stop and start the machine unless i have to, and i typically run it at 90% throttle or higher. i have the workshop manual for the machine but i don't see much about the specs in there for tolerance. I guess ill have to look up part numbers?

When I google a CAT me20 all I get is rubber tracks. Are you sure the machine is a CAT me20? Maybe it's a Mitsubishi me20?

If we narrow down exactly what machine you have first, then maybe we can help you find the engine model, and then a manual to find the engine info.

mitsubishi me20 excavator - Google Search