Carbon deposits embedded in cylinder wall

[Stewardmf]

Hello,
I picked up a LQ9 with 140k miles on it from the junk yard and while I was cleaning carbon I noticed these spots on the #7 cyl wall.
I cant scrub it off with sea foam and a green kitchen sponge, carb cleaner didnt work either.
It looks like carbon embedded in the wall and it is so smooth that I cant really feel it, the bigger mark deeper in looks like wear or discoloration to me.
I am looking for opinions on what this is and weather or not I can fix it without boring or honing.
Thanks

[David Pozzi]

It looks like slight corrosion from moisture, but very minor. I'd leave it alone & run it.

[Ron Sutton]

It looks like slight corrosion from moisture, but very minor. I'd leave it alone & run it.

I agree. Notice how the bottom of it is a smooth line? That's where the ring was setting for "awhile" ... and a small amount of moisture (water) accumulated there.

Since you're planning to run an engine with 140,000 miles without freshening it ... I am assuming budget is an issue. I agree with David ... run it.

.

[SShep71]

It def looks like mild corrosion, it could have been sitting at the yard for quite some time. Were you able to turn the motor over without problems? IIt wouldnt hurt to take teh motor down to bare block and run a ball hone through those cylinders. You should inspect the other cylinders as well. Inspecting the entire cylinder not just the bore visable at the bottom of the stroke.

[srh3trinity]

I would ball hone,new rings, ARP bolts for the rods, and new bearings if you are going to worry about it. Otherwise, just run it.

[Stewardmf]

Thanks for the reply's guys, the motor turned over real easy and all the bearings "feel" ok fwiw and all the other cylinders look great. I think I'm going to go ahead and freshen it up a bit at least for piece of mind.