So I needed to open my miata to replace the head but I found some lines in cylinder 3 (see picture) they don't seem to be scratches because I can't feel them when running my nail over them and I can barely see them so they just seem like dirty marks.

The rings have been replaced before so I am guessing improper install but my question is, do I need to worry about it or not?

 

Is that a hole in the piston? If so, you have bigger problems than a dirty cylinder...

 

That looks like a little carbon on top of the valve relief, Roger. Or a couple of drops of coolant from the removal of the head.

Those discolorations on the cylinder wall are completely inconsequential. Rest well. Nothing to worry about.

 

Oh. Duh. Guess I should have my coffee before replying,

 

hahaha that would be pretty funny though "nah don't mind the hole in my piston, is that line bad?" 😉 thank you for replying though!!!

 

thanks a lot for the fast response, yes it is a bit of coolant. So luckily not a hole.
but now I can put my mind to rest knowing that I wont have to do the bottom end as well 😂 thank you again for replying

 

what makes you think you won't have to do the bottom end.....

 

well nothing was wrong with it before, I would reckon that they aren't suddenly broken 😂

 

my point is, you are here already.
maybe refresh some stuff?
new rings, leave the bearings if they are good, you can reuse them.
hone the cylinders.

 

that has already been done around 6000 miles ago

 

okay,
ive seen engined with much higher mileage where you cans till see the hone....but you do you.

 

yeah that is why I was asking for tips, I am definately not the most experienced guy. I am learning as I go. I appreciate your tip!
are there any thing I can look for just to check if something might be wrong?

 

until you assemble the whole engine and do a leak down test, nope.


and it would suck to do all that and still have bad comp.
ijs, bite the bullet and get intimate with your car.