Welcome to the joys of FI. ESS will be able to help you more than I/we will. You probably have some kind of issue, incorrect base timing, worn parts, etc. I am very skeptical that a skimmed head is magically the difference between pinging all the time and not. It just doesn't make that much difference. Your setup is not that aggressive. It's also possible that what you are hearing isn't ping, but I don't know.
I wouldn't try "band-aid" fixes.