I just picked up a longblock from a maxima and when i got it on a stand and spun the crank to inspect it i saw some markings in one of the cylinder bores. It doesnt feel rough or as though there is any unusual wear. Does any one have an idea what this could be a result of? Is it potentially hazardous to the reliability of the engine?

Here are some pics:

 

That looks like corrosion.

 

Looks like where some moisture was trapped between the piston and cylinder...No big worry if your fingernails don't feel it....

 

thats what i was initially thinking, (or oil blow by-but i dont know if that would even leave marks). im just surprised at the lack of any surface damage or roughness. it's as smooth over the marking as the rest of the bore.

 

Well that's good news, i cant tell any difference in the coating on the bore or any roughness whatsoever. ty for the reply

 

That dark "tinting" is the indication of minor/early corrosion in steel/cast iron. You probably won't feel it......it doesn't appear to have even caused any minor pitting yet.

 

so just how bad is it? will it continue to worsen? if i were to put it back together is engine failure bc of the corrosion inevitable?

sorry for all the questions

 

It won't cause a "failure" and it appears to be so minor that it shouldn't cause any issues. A few "wipes" of the piston rings on the next startup should remove it, is my guess.

 

Engine was setting for awhile it was wasn't running if it got those marks...no biggie, scotch brite will remove, it but it'll be gone with a few rotations of the crank, possible be hand....

 

ty for all of the prompt replies, i really appreciate it. I have been stressin since i saw it.

 

Yeah I wouldn't stress that at all either, otherwise looks great.