I own a 2011 Jaguar XJL that I purchased about a year ago from a dealer in Atlanta. During my inspection of the car I failed to check the operation of the sun blind. Something I regretted to do. When I brought the car home I tested the sun blind which was open but did not move forward when I pressed the console button. I could hear the motors working just fine but no movement. I began my research on Jaguar Forums and read about this problem with several suggestions on repair but nothing work manually trying to move the blind forward or tying to re-syching the blind. I decided to get a quote from the local Jaguar Dealer, but much to my dismay, the quote included full replacement of both motors and dropping the headliner for $1,800. Obviously I did not go forward with the repair due to being too cost prohibitive. Instead I found an ex-Jaguar mechanic thru the Jaguar Club that I belonged to. At one meeting in Feb, the mechanic agreed to look at my sun-blind after I sent him a video of the sound that the blind was making. He thought the problem was with the plastic feet that slides on the rail. I have attached a picture of the feet. He ordered two feet and during our Jaguar Club meeting he installed the plastic feet without dropping the headliner. Amazing, he got the sun blind working like a gem. I paid him $100 for the plastic feet and his time. I was thrilled that the sun blind worked and that it only took about 15 minutes of the mechanics time for repair. It goes to show you that if you search for a solution to a problem you are able to find a solution without spending a fortune.
My next goal is to find a touch up painter to come to my home and touch up two scratches on the boot and bonnet. I have seen them at dealership where trade-ins are touched up by an expert painter, but have not located one in my area yet. I will continue to search and if anyone knows of someone that they have used I would appreciate the contact information.
Out of the four Jaguars I own by far the XJL is the best. It has the acceleration of a S/C like I XKR and comfort like my XF. If you buy any used Jaguar remember to do a complete inspection just like the Judges do during a Concours. Test everything no matter how small or insignificant. It will help you when it come time to negotiate the price.

 

I have the same problem, would love to hear more details on how this repair was done.

 

Sadly it is not uncommon for dealers to diagnose the problem as remove/replace and not actually invest the time into checking the basics. Even more frustrating for you in this instance because the blinds failing due to a broken or mislocated foot is widely known and there are service bulletins about it.

Those plastic feet are located on the end of the front tensioner bar on the blind (the bit that moves forward and backward and pulls the blind off the sprung cassette). If the bar is not correctly located into one or both ends it can cause it to bind instead of moving, but the most common cause is the bit with the angled tooth on John's photo either wears and pops out because the blind wasn't tensioned evenly, or just breaks off. That tooth clips into a sliding carrier that moves up and down the channel either side of the car to move the blind, and while the angle is meant to prevent it popping back out it is not that hard to pull it out.

If it has just unclipped you'll normally see the other side of the blind move slightly before the motor starts grinding. You can try popping it back in again, but unfortunately the only real way you can do that is to remove the blind from both feet and then reattach afterwards. It's not hard, but it is hard to explain without looking down on it from above, which you can't do it without removing the roof opening panel glass. It rotates down/forward away from the casette (a bit like changing a florescent lighting tube where it rotates and clicks into position).

If your symptom is just a loud grinding noise with no movement, and the noise carries on for about 15 seconds, you probably have another common-ish problem where the gear driven by the motor that engages with the wire spring that rotates to move the carrier back and forth, is out of alignment. There is a little plastic piece that sits above the gear to prevent it moving away that wears over time. You can replace the plastic piece (it is available to buy for not much money) but really replacing the motor with new is best as it has been revised to omit it entirely. Sadly both of those require the roof lining to be dropped, and you need to remove the roof opening panel glass panel and both blinds. That is why you normally replace both motors at the same time. The new motors come with a service kit that replaces the springs as well.

 

The left corner of the feet appears to have broken off the foot. The mechanic was able to loosen the headliner enough to replace the feet and was able to get the sun blind to begin moving. He did tell me that he thought the motors had been replaced earlier by the PO. Sorry I can’t be more specific as I did not do the repair, but it did not take him long to repair.