broken ring?
 

ok i have a 97 12 valve with 269,000 miles and it had a external hg leak so i took the head off and all the cylinders looked great except one had a vertical black line that looked like a sharpie pen line. it wasnt all the way up where the comp rings go and there was no scratch that i could feel so i think its from the oil scraper ring? my buddy is a cummins mech and thought it could be a broken oil scraping ring since it didnt go up as high as the top comp rings do. anyways the hg is fixed and i put over 4 thousand miles on it and the thing doesnt use a drop of oil and no blowby out the oil cap or blowby tube. do you think im ok for a long time or is it going to all of a sudden start sucking oil and get blowby? i know if it was a comp ring that is not good and it would be using oil and have lots of blowby. my mech buddy said just run it and it wont give me any trouble for years but just wondering if anyone had any idea about it. thanks in advance.

My thoughts .... F its eating up the lower cylinder .... Its gonna be a problem later more than sooner .... Meaning if you intend on keeping this engine .... You might wanna think about honing that cylinder and getting some new rings .....

its yours either way ...:c:

Yeah that's what I was thinking but the Cummins mechanic buddy said he motor already has 259,000 miles just run it. It should be good for at least another 50,000 miles before it starts giving me trouble. I only drive it about 8 to 10,000 miles a year so that's a long time. It just seems like it wouldn't last that long with a broken ring after reading all the broken ring stories.

its not now that I would be concerned about .... if you continue to run it the damage could be far worse on the supposedly 50K it my or may not have left ... if its a good engine 500K is not an issue ...

This is my advise - fix it now before it bites you in the ass sooner than you might hope for .... :c:

yea i should have done it when i had the head off, my buddy the cummins mechanic helped me with the head gasket and i asked if it was his truck what would he do. he said lets put it back together with the new head gasket, thats what he would do if it was his. i told him i would pay him to fix the ring or even hone and put new rings in all the cylinders but he said dont waste my money, i was thinking on building up a extra longblock while mine is still going that way when mine starts to go the new longblock will be ready.

Good idea .... I would never allow an engine like that to leave my shop with out a signed waiver releasing me of liability's involved with a dead cylinder or a bad engine .... Just too dang costly:td::nope:

so has anyone else heard of someone with a broken oil scraper ring and how long before they started using oil or blowby to the point of needing a rebuild?or maybe not a problem since the compression rings are still good?

Its going to vary per the driver, stresses put on engine, actual shape that the engine is in to start with..... Could be 10miles could be 10k .... No one could give you an exact answers on that magic number ..... You will either get it done .... Or you will find out when it starts puking oil or blue smoke all the time ....:s:

well im hoping it will go a long time and give me a warning like start to use more and more oil and more blowby little by little when it does get worse. my motor is stock and im keeping it that way and i use it as my daily driver to pick up parts for my business. i was looking for someone that had the same thing happen to them and hoping they will tell me it wont get worse if its a oil scraper ring lol! but i know thats probably not going to happen. i have put over 4,000 miles on it since we put it back together and there is no blowby or oil usage yet so i think the motor is in great shape besides the ring. is there a possibility it could have that thin black line from something else like a piece of debris or something? i have seen lots of pics of cylinders with lines like it on the internet but in more than one cylinder and multiple lines in each cylinder but all of them seem to be all the way up as far as the compression rings go not just partially up like mine.

If you fix it now then it will save u $ in oil due to consumption as well as machine work to cylinders later on