[BURN-BROS]

Glenn, I do not know enough about them to tell you with absolution. My gut says not to worry about very small RMS leaks. I do believe that if the leak was a significant one I would want to do something about it. I would monitor it.

The coolant going in the combustion should not be ruled out as it might be weeping in during the periods of sitting or temp transition. The test for gasses is not always definitive. Certain conditions may have to be met before the leak is apparent( this part I know from experience). Maybe a scope though the spark plug hole to verify? Coolant does not just disappear, if it isnt on the ground it is going somewhere.