before the replacement of the front springs, shocks and mounts as someone is going to notice.

 

My understanding is that the whole car is one big semi-integrated set of computers talking to each other. When the Jaguar engine and transmission are swapped (besides the new engine/trans needing their own computer to run), their corresponding control modules disappear, and a number of messages go missing (think engine speed to feed the tach and the like). Therefore, a substitute bridge module has to be introduced to "convert" or "translate" the messages to and from the Jaguar network and the new (GM?) network. I believe Jaguar Specialties developed such a module for the old 4.0 setup, but not for the newer 4.2. The general idea is to keep all the pre-existing Jaguar modules happy enough that they look functional, and avoid the famous messages on the XK8 Jaguar built with a manual gearbox ("Incorrect part fitted").

 

Nick,

Please read all of these messages from the Guys on the forum closely, as you will get a good bit of truth and information about our Cars! My 2nd XK was a 2000 XKR Coupe it came from the Factory with a 4.0 Supercharged Engine and all the Goodies. It was more fun that a box-full of Monkeys and was smooth as glass! The Engine, a 4.0, is what is known as a "square" Engine; which means the Piston and the Stroke dimensions are the same, whereas the 4.2 Engine has the same basic Piston diameter as the 4.0 but the Stroke is longer. The difference is in the smoothness or vibration of the Engine....which is almost undetectable...except at high RPM's. The 2000 also had a 5 Speed Mercedes Tranny, which worked great.....I miss that part of the 2000 very much....Then in 2003 they changed the Tranny and the Engine to the 4.2 with the 6 Speed.....I've forgotten how many new or different parts Jaguar said they changed but it was a bunch!

The 4.2 Engine has more power and of course being an old Hot-Rodder I like that...The Brakes are better...Brembos and the Wheels are larger at 20"'s! Overall a much better Car with some nice improvements....

I now have the 2005 XKR Coupe, which I traded up to as my 2003 Coupe was Totaled! It now has 95,000 miles on it.....So Nick it's a hard decision you will have to make......I think that in England the most important thing to look for would be "RUST" and basic under-carriage....then if the Body is accident free, I wouldn't worry much about the Engine.....If your foundation is good you can build the Mechanics back to new or better, if you want! Then you would have a great Car that will last a long time......That is what you want, as the XKR Coupe will be a Classic soon! The better you treat it the more it will be worth! Today, you need to start a search for the "Best" overall Coupe you can find....It will show-up if you work at it!


Billy Clyde in Houston

 

+1 Nick

 

Thanks for the info folks. I was not considering any sort of engine swap, but was just curious about why it would work in a 4.0 and not a 4.2. Your answers made it quite clear

 

Hi All,

Thanks for your answers - the feedback was great. Sorry for my delay in acknowledging all of them - an avalanche of work and other commitments flew in.

I have taken on-board what has been said.

Do not over analyse, act now life is short (thanks StuG for sharing your personal story) and fear RUST not engines.

DandyAndy thanks for reminding me about the MOT checker web site the advisory and failure history is an amazing resource.

You guys have motivated me to get of my @** and start moving!

Thanks, Nick

 

Of course mechanicals should take priority - especially with the teething problems documented in the 4.0 when new - but one minor element that's often left out of these conversations is the interior differences between early and late XK8s.

Connolly Leather, founded in 1878, had a long history of supplying high quality leather to the Royal Family, Ferrari, Rolls-Royce, etc. but unfortunately went out of business in 2002. Therefore, Jaguars manufactured more than a few months after they shut their doors likely no longer have "Connolly" leather. Certainly the leather supplier which Ford/Jaguar used to replace Connolly is of high quality, but it likely can't claim Connolly's heritage. The Rolls and Bentley folk lament about Connolly in the link bellow:
Is Connolly leather out of business? - Rolls-Royce and Bentley Forums
Connolly England

Lastly, I find that the earlier XK8 dashboards more often have classic - and in my opinion more beautiful - analog gauges (oil, electric, & clock) . Nigel Thorely notes that the alternative GPS dash is also no longer supported.

 

Connolly is apparently back in business. I had heard that so Googled and found this on Wikipedia:

"An attempt to expand into the American market in the 1990s failed badly and Connolly Leather ceased trading in June 2002.[1]
[2] However, in 2003, Jonathan Connolly established C B Leather Ltd and resumed the manufacture and production of high quality leather and now sells under both C B Leather and Connolly."

I wish my '06 XK8 had Connolly leather. My '92 Range Rover had it and it held up amazingly, considering the dirt and other abuse it suffered.

Granville

 

Nigel Thorley needs to come and browse this forum then, because there have been many documented DIY upgrades to the old sat nav. I did what many others have done and replaced it with a modern 5" Garmin touch screen unit with reversing camera. A very cheap upgrade that keeps the car looking original but with a modern sat nav.

 

Thanks for the comments and reminder Granville. I forgot to point out the link to a new "Connolly" earlier; here it is again. Connolly England . It seems like this Connolly is headed in the direction of Modern Creation München https://de.mcmworldwide.com/en/sitemap , who apparently can be commissioned for customized automotive interiors but is predominantly focused on clothing and accessories.

But that may be different from the "Connolly Bros" site: Present - CONNOLLY , found when searching for "C B Leather Ltd." Perhaps during Connolly's restructuring the intellectual property ended up a few different places. But the good news for restorations is ". . . [Connolly Bros] focus is very much on designing the leather for the individual customers' requirements, producing authentic hide for restoration work and, in many cases, developing unique colours and textures for individual projects."

JW

 

Correction - Both Connolly websites above are apparently partners and/or associated with each other since the automotive contact email: sales@connollybros.co.uk is listed on both sites.

 

If it is really "all about the money" than the answer is a 4.0 as they are less money.

If you are asking is it worth it?

My personal opinion (which is of no more value than another) is no. Instead of buying a 4.2 buy a supercharged 4.0 and do the upgrades with the extra cash, or buy a 4.0 and have about half the money you need for a 5.7 install. Either of those options will give you far more performance than the extra 0.2 liters.

 

Hi there. Do you have details of this or a post showing the process? I would be interested in doing the same thing - 2003 XKR.

 

Have a look at this thread:-

https://www.jaguarforums.com/forum/x...armins-181527/

In brief I dismantled the original sat nav, keeping the bezel and the buttons, then glued the Garmin into the original bezel and took the power from the original sat nav wiring harness. The bezel with Garmin attached then screws back into the dashboard, so you get an almost exact OEM finish.