Re: XF Auto slow to change when cold
Sounds like sticky valves caused by a worn front clutch pack or front band.
But make sure you check the oil level the correct way. Engine warm & running, remove dipstic from trans, wipe, switch engine off & dip the stick within 30 seconds. Checking while running will give a false reading on that model, The oil is splashed onto the stick while running. If you have been driving with a low oil level there will be clutch/band wear.
A worn front clutch can give those symptons, the wear material goes through the shift/governor valves causing late shifts until the vehicle warms up & the valves become free. The clutch can no longer handle the torque load, so gives a slight slip.
If it is the front band, same thing goes as for clutch pack. The band material is burnt/worn and the wear material goes through the system. An adjustment,service and a friction modified additive might give you a little bit of time.
One last thing, they do sometimes have a problem with the throttle pressure cable (kick down) seizing.