I've just crossed 30K miles and am noticing the same. I only get the lurch when the AC is on and, when I'm doing highway/interstate speeds. Once the AC is turned off, burps go away.

I also hear a clicking noise that seems to come from the engine. Almost sounds like the sparks out of an electric lighter for Gas burners. Don't know if this is related to my engine burp.

98.5, 2.5 Lt Auto.