Hello I'm Neal and I am here to help resolve your issue. If I cannot help I will opt out and refer your question to another expert.
I hate to be the one to give bad news, and am sorry you are having these issues.-
Unfortunately that is a sign of coolant in the oil. The reason the noise quit for a short time is that there was no water in the oil right after the oil change, and then as more coolant got into the new oil it would start again.
Have you been noticing a small coolant loss or has it overheated in the past?
I haven't noticed ANY coolant loss. It overheated a year ago, August, while driving from Utah to Idaho.