Hello Phil
Your post is certainly there for all to read! We have a 2007 S-type which doesn't have your problem. However, occasionally I did have a "grumbling" noise from somewhere in the dashboard which, to cut a long story short, was diagnosed as the directional motors......still working perfectly, but making a noise about it. Strangely, the problem disappeared recently, although the climate system is working perfectly.
Whilst at the Jaguar Parts Day at Stoneleigh, we spoke with a Jaguar Technical fellow who suggested we should be best living with the grumblies as the particular motors are buried right at the front of the dashboard area; parts are not particularly expensive but the labour bill could be a little frightening. This Jag Tech chap did explain that if the motors fail, then the climate system will not work well. However, all 4 at the same time does seem a little unusual.
We think a call to a Jaguar Independent Specialist would be best.....somebody who knows Jaguars, rather than somebody who needs to call the main dealer to ask the question! You'll also find that Jag Indie labour bills will be considerably less than Main Dealer. Another point the Jag Tech chap made.......unless you are very handy, don't try dismantling the dash yourself!
Good luck, hopefully happy growling!