Hello welcome to Just Answers Heavy Equipment! I will assist you with your question.
I would be willing to bet that the mating surface on the engine block has a flaw that is allowing your leak. I would remove the heads (all 3) and have them measured and tested and have the block surface measured and tested. Even though these engine have separate heads you always want to do all the heads at once.
ok-should we see a pattern on head gasket?
I am sorry what are you referring to as "pattern"?
evidence of water leaking into a specific cylinder
Yes but not always will it be evident during visual inspection as water/coolant is thin liquid and will pass through areas smaller than your eye may see. that is why a precise measurement needs to be taken.
this would do it overnight, but run during day ? Why not leak all the time ?
If you have a good head machine shop in your area these places are usually able to send someone out to do a thorough inspection on both surfaces.
Yes I have seen this happen before. I believe what happens is the water is vaporized while running. but during night just fills the cylinders
since it is entering the cylinders slowly it has little or no effect on running.
By replacing the head we have eliminated a crack in the head and a pin hole from electrolysis in liner as well ?
should or can we shim liners after confirming surface deteriation ?
No. but the surface can be "resurfaced"
That is all of the info I can offer. I believe that disassemble is needs so that a thorough inspection can be performed to determine the exact area.
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Does rocker box have water running through it on top of culinder ?
How can water enter cylinder if liner if mating properly w/head, block surface should not matter because it would leak externally .?
No the rocker bock does not. I am sorry I don't think we are communicating well. In this situation you have an undetermined factor which can only be determined from inspection as far as I am aware. Since I am unable to to this my self I can not give you a exact or specific answer. I will Opt Out so that another expert can give you an answer. Thank you have a great weekend!
Please do not respond or the question will be locked to me and another expert can not answer.
what surface needs to be resurfaced
my mechanic said he measured heighth and found it to be .004