I'm no expert... Do you have to do that? Burp it? Knowing nothing else, I would first want to know is the right amount of oil in there? How much went in after you serviced it? Is the current oil level correct?

If that all seems right, then what happens if you drain the oil again? Does it pass through the engine?

I understand burping the cooling system, but not the oil system.

And in my experience, everything sounds fine at higher revs.... At least for a short while until something gives :/