</font><font color="blue" class="small">( This is how it is with trucks anyway. If you have ever seen the liners that come out of engines that have had the coolant neglected you would know what i mean )</font>
I have seen it. Pin holes in the liner from the outside inward.
These were on wet sleeved engines (the coolant runs directly around the cylinder liner).
My Kioti tractor does not have wet sleeve type cylinders.
I do my truck and wife's car every 3 years, @ 30k miles. My previous truck, bought new, was 16 years old with about 150k miles. I never had a problem with the radiator. Distilled water is nice because all the minerals should be gone. I never knew it was a ph of 7.