Good evening,
At the risk of resurrecting an old thread, I came here from a Google search.
I have posted similar over on jaguarforums.co.uk, but I believe the problems you describe also describe exactly the problem I am having with my 18 plate XJ.
It doesn't always like to downshift readily, and there is quite a booming vibration below 1500rpm or so on a light throttle, as if everything is labouring somewhat. Very unrefined. My previous 2015 XF-S (275bhp) and 2013 XF (240bhp) were far smoother.
Upon being persuaded to kickdown, everything is as smooth as silk at higher revs. And indeed, sometimes it does this itself. But for the most part, the car seems to want to drag itself up from low revs. 70mph in 8th seems to be right in this range, and a gentle acceleration from here (where the law allows, of course) is rather unrefined.
Did you get a fix for your issues, and if so, do you know what was done?
Many thanks!
Mark
