Sorry the short block didn't solve this issue. I still have the noise, at around 9k now and will do the second oil change shortly will try a different brand synthetic this time around. The noise doesn't happen all the time and is still very inconsistent but when it occurs, it is noticeable and definitely can feel a vibration. Definitely not getting worse so far. I just don't think it's an engine issue it's a software or trans issue that occurs when a certain set of conditions have been met. If I had to guess, I think its a byproduct of the ECU and a cylinder or two is slightly out of whack (leaning out) in a certain set of conditions, not enough to throw a code. Hot or cold engine, winter or summer do not matter. There are not a bunch of low speed hills around here but the easiest way to duplicate is on an inclined driveway in reverse and keep the rpm's around 1100-1200. All of our Hondas have their quirks, the Accord has VCM vibrations in the winter, 15 CRV has exhaust rattles at certain rpm's 09 CRV is a buzzy shaky workhorse and the RL has this. All minor, IMO so far.