I've been researching the timing chain issue for awhile and there is not a lot of information. There is the lawsuit, but I can't find a resolution although I see Jaguar is trying to nix it.
So, what I've found:
The AJ V8, AJ133 5.0 litre Gen III is not a Ford engine by any stretch. Purely Jaguar. I haven't owned Land Rovers, only Jaguars, but the engine is practically the same.
They require a special CASTROL oil spec and I can't remember which. It is specified by an insert in the owner's manual. In my case the dealer had the wrong version, but I caught it before it was put in my car. They had to find another CASTROL supplier.
The issue is that GDI cars cause sooting from LSPI, low speed pre-ignition -much like diesels. The fine particles of soot contaminate the oil. This is why companies like Amsoil have concentrated their efforts in to reduce the damage from LSPI.
The contaminants plug the small orifices (orifi ?) in the timing chain tensioners causing them to stick and not tension the chains eventually resulting in expensive repairs or replacement of engines.
I've read the tensioners were re-designed 3 times and the affected years are 2012-2014. I had a 2013 XKR and this is one of the reasons I let it go. Since Jaguar has released virtually no information, I do not know if this issue has been resolved. Hence my resolve not to buy any 5.0 GDI engine. The 4.2 liter Supercharged engines appear to be bulletproof. I have over 150k miles on my 04 XJR and it has had no major issues. Doesn't even leak oil! Unlike the Mercedes SL500 R129 which leaks worse than the Exxon Valdez. (I have a small poor man's mini collection of European heartbreakers.)
Don't know if I've added any clarity to the issue, but until I see something definitive on this issue, I'm not buying any Jaguar newer than 2009 with the 4.2 Supercharged.
Cheers,