Or it has had a valve crash or a Nikasil failure!

 

That's Mercedes-Benz, not Mercury. (Ford did own Jag at the time...)

 

Let me see if I can summarize what I have gathered here between the 308 XJ8 & XJR. I am commenting only on the mechanical or electrical trouble/service items. I still have questions.
#1) Both have the niksil cylinder coatings. When did this practice stop and it is really anything to worry about?
#2) XJ8 has ZF vs XJR Mercedes. I hear the forward "drum?" was made stronger in the 2000XJ8 ZF. My 98 ZF failed and I replaced the drum with a 2000 and runs fine. Any thing to watch for on the 308 XJR tranny?
#3) I hear some electrical contacts on the 308 XJR ABS speed senor can corrode, but sounds like an easy enough repair.
#4) I assume that the 98 being a new M-year had issues and they were corrected by 2000. Can the same be said of the 2000 XJR? Is my assumption correct?
Thanks to all you gentlemen and scholars out there helping our collective interest.

 

2000 brought about a 'facelift' of sorts, there were quite a few electrical updates, especially in the engine bay around the throttle and cruise control system.
The throttle position sensor is another common fault, but post 2000 is a much more expensive proposition to fix, however on average they also had more premium features, like parking sensors and auto everything

 

Will I be missed if go Mercedes?

 

For real quality the nearest you want to get to a Merc is the tranny in an XJR !!

 

If you have to ask... then you already know the answer

I'm not sure I've ever met anyone who's 'accidentally' bought a Jag. People walk into Merc/BMW/Audi dealerships, see something that takes their fancy and make an impulse decision. Or they're looking for a used car and do the same thing.
Almost everyone I know that has a Jag has had more than one. They're an addiction. Noboby needs a Jag, you WANT a Jag.

And because of that, they're willing to forgive it's flaws. It will have common failure points. It will have idiosyncrasies. But so does your partner, or your children, or your pet. It gives it character, and personality. You get attached to it. And it makes you smile.
That glance back towards the parking lot. The reflection after a polish. Carving a line through a corner, or beating someone unsuspecting off the line. The feel of the wooden wheel in your hand and your **** in the finest leather.

If you want something that will get you reliably from A to B without causing a fuss, then you don't want a Jag. You want an appliance. Maybe you should be looking at Toyotas.

But for me? I love my Jag

 

grandell - you are right. My XJ8 has given me XJR fever. My XJ8 has just about everything new on it with 97k miles. So it can be my Toyota. However, I'm just concerned that the issues with my 98XJ8 tranny and chain tensioners lay dormant in the 2000 XJR. I can handle anything but a major component problem. (SC, Tranny, Engine). I just don't want to. I have hear a rumor the 2000XJR can have the ZF tranny but the forward drum was fixed from the 1998 ZF, I used a 2000 ZF drum to repair my 98 drum. How about the tensioners? I'm waiting for my XJ8's to fail My XJ8 has cost me $5/mile so far excluding gas and oil. Help push me over the edge

 

Grandell - If you want to see a good movie and a great argument between British and German cars, check out "Into the White" you will have to wait for the discussion but it it priceless as is the movie. Its about the only good movie on Netflix (until the word gets out)

 

Here is more research for consideration. Nikasil engines should be avoided if possible but they can be just fine if high grade gas was used. VIN numbers before F00103 are suspect due to high sulfer in gas at the time. After F00103 to F20644 gas was deemed to be of sufficient quality that the lining should be fine. After F20645 liners were steel. No sure guarantee with the VIN. The engine number is the real determinate of the liner material. 08 14 2000 is the 'cut off period' after which steel was used, but that's within a margin of error. Also, 3rd generation tensioners were not used until after '04 (I think). Improvements were made up until this this time, so the later the engine, likely the better the tensioners - but all are suspect until this 04 (I think) date unless they were changed under warranty or for precaution. I have gathered tensioner do not just let go but give a rattling noise indication on cold starts. Failure to heed this warning and their failure is very likely to ruin the engine that cost-wise you may as well look for another one that runs as and scrap what left. XJ8 transmission A-baskets were beefed up circa 2000 but I don't know the specfic's. A trusted mechanic replaced my 98 with a 2000 and showed me the beefed up part. It was almost silly to see the slight increase in metal thickness that made the difference in the two components. 308 XJR's have Mercedes transmissions not the also german ZF type. I have not heard of any concerns with the 308 XJR tranny. So with all this I am close to getting a 2000 XJR VIN ending F08243 - that put me about a thousand units on the safe side of nikasil - right?? but still with tensioner issues - right?? The R is out of my state so I am having to go look at it. If it passes the smell test, car fax and some other pointers everyone has shared I will get it and share what I learn. From my experience with my low mile 98 XJ8 it is possible to easily put 4k into it. My cost of ownership is $5 per mile but I think I am out of the woods. So why would I go for the XJR?

 

Honestly after this long I wouldn't worry about nikasil. If an engine was going to fail because of that, it would have done it a long time ago.
Regarding the gearbox, the Merc unit in the XJR's is indestructible. Brabus have tuned mercs to ~700hp and they don't touch the gearbox. The XJ8's are completely different, and you can't compare the two.
Tensioners is a simple case of preventative maintenance. If you can't afford to get them put in then you really shouldn't be spending so much on a car in the first place. And waiting until they fail and then blaming the car is just ignorant.

The only two issues you realistically might face are the ABS computer fault, and the TPS. Both have very clearly documented fixes, and can be done very cheaply with a bit of research here, rather than just giving it to the local dealer.

But really, if you're still on the fence, go and drive an R. You'll know what you want to do either way within a couple of minutes

 

Metal tensioners came in in August 2001, so all 2002 models should theoretically have them

 

I have found an 03' XJR. Has O2 sensor to be replaced? I assume this could be the cat. Any advice?

 

Your car will have 4 O2 sensors, one before and one after the cat on each side. Doesn't mean there's anything wrong with the cats though.

Two are cheap and easy to replace, two are expensive and one is a real PITA to get to. Make sure you know exactly which ones, and what you're getting yourself into, it won't be thousands, but it might get close. Either way it will be a good negotiating point

 

Actually, beginning with the 1999 year model, the factory began installing upgraded plastic tensioners, not metal. The 2004 model year brought metal tensioners, along with a new dual-chain design, in the 4.2L engine. In 2005, Jaguar offered metal tensioners as replacements for the plastic tensioners in our 1997-2003 models.

 

Jeff:
What is the source of your information? In fact, the MY 2002 NA 4.0 liter cars came with metal tensioners and Morse style primary chains. I am pretty sure the SC models did too, but I do not have personal knowledge of that, like I do for the NA.

Do you have reason to believe your car did not come with metal tensioners?

Or are you relaying the erroneous information from the "Jag expert" guy in San Fransisco with the wrong info on his website?

 

PEOPLES: 8am EST 2-11-15 I am looking to buy a 03 XJR. I asked to have it ready for a cold start so the current owner left it in a secured area. I drove by to see it tonight, it needs brakes & rotors all around. It is rainy and got some finger paint from the soot in the tail pipe. I don't think it is any worse than my 98XJ8. Has the moisture in the air turned what may be normal powder soot to a paint? No oil in the pipe. The finish looks good all around but it was dark and rainy. Good coat of wax on it. Very little car fax maintenance indicated. Looks like it was passed around by multiple dealers and was a corporate car. Current 3rd owner has had it for 2.5 years. Driver seat shows the normal wear, all around the car looks excellent. Even wear on tires (I forgot to bounce it for worn struts). Will drive in the am. Current owner is no mechanic so I assume he has taken it in as appropriate for oil. Intake man cleaned, a leaky gasket replace is all he says has been needed. Will ask for oil records. O2 sensor bad so I will run by auto store to confirm code. Can the cat be bad? - I think there is a risk. There is dearth of check points for me to consider since I cant open up to see if chains are metal. Mercedes tranny supposed to be solid. Will look for engine/tranny replacement and leaks at rear differential. What am I missing mechanically?

 

Attention!

"..I have gathered tensioner do not just let go but give a rattling noise indication on cold starts."

Jag Newby here with 0% J. Forum cred, begging all other Jag newbies with early 4.0 V8's to PLEASE
GET. THE.
TENSIONERS. CHECKED.

There are a number of well-meaning shade-tree external checks intended to determine tensioner health. I personally know the engine can pass all that, idle perfectly, silently, cold start clean, and contain replacement plastic tensioners half-gone, vertically cracked, which disintegrate when unbolted.

With the staggering wealth of great information and support on this Forum, there's no reason for the loss of one more 4.0 due to failed tensioner chain loss.


(.. embarrassed, he steps down from the pulpit... )

 

Ross, I'm not sure which web site you're referring to. But I have seen my tensioners up close and personal... They're plastic, 2nd gen, and the timing chain is single, not double like the 4.2L. Three separate mechanics have told me that metal started in '04 with the 4.2L. (Land Rover Redwood City, Redwood City, CA; KATS Britsh Car, Englewood, CO, and The Garage, San Jose, CA.) I'd be interested to know if anyone has different information.

 

Well, my MY 02, Sept 2001 build, NA XJ8 came with metal tensioners and double row primary silent chains. I have owned it since new, and no one snuck in and changed the primary chain while I was not watching. (Just like I assume no one went backwards with yours! )
There have been numerous "discussions" of this point on here and other forums, and the consensus is that the chains changed for engine build date August 2001. Now, as to why your car had the old design, I guess that it might be that SC models did not change until later. Do you know what build date your engine has?

***I found this, although I cannot find the source:"
The first engine to receive metal tensioners (street named the 3rd gen tensioners) was the first 4.0L AJV8, AJ27 built on August 13, 2001; engine S/N 0108130000. All AJV8s built then on had the metal tensioners. These engines made it into about 2/3rds of the entire 2002 production using V8s and all factory models and MYS thereafter."

Also, check you EPC- the new chains are listed after engine code 0108130000

Also, notice the pdf upgrade kit only goes through MY 2002.