I have 92,000 mile on my xf and it ticks for a few seconds at start and then goes away almost like low oil or no lubricate was present at start. It doesnt tick after a few seconds of running. I also have a little shake at lights but it doesnt stumble or hesitate. its seem this is happening on cars with as little as 250 miles on them and still happening on a car like mine with hight miles so maybe its just how the cars are and that could be a good thing.