Has anyone gotten so frustrated with trying to diagnose and repair their XJS's where they have been tempted to lump their jaguars. The XJS is a beautiful automobile and when it runs, it runs like a well oiled machine and the key word is WHEN. I'm specifically talking about the later XJS (94-96) When these cars begin to fail, parts are hard to find, very expensive, difficult to diagnose w/o the now antiquated PDU's WDS, IDS machines, or software etc. Many people denigrate jag owners who have gone this route. But at some point in time if you plan on keeping your XJS, you will have to "lump" IMO because when you add up the costs for parts, vs the cost of lumping the end seems to justify the means. Thoughts, comments are welcome. Good, bad, or indifferent.

 

No, never frustrated with my XJS and/or its problems.

It's rewarding when you fix it.

Thats what I bought it for.

The 94-96 cars (I6) are generally regarded as being the easiest XJS to live with, with all oily parts common to the X300 saloon of the same era, so plenty of technical help available, so I'm not sure why you called out those cars in particular as hard/expensive to maintain

Do you own an XJS ?

 

NO. No and again NO. I own an 86 XJS 5.3 and my daily is a 97 XJ6L 4.0. I have no problems finding affordable parts and both my cars are maintained by me and mostly run like good watches. I bought a Jaguar because I love Jaguars and have ZERO desire to own a lumped version. Am I against lumping? YES but then again it's an open forum and my as well as others opinions were asked. Jaguar made a great, beautiful product that when cared for properly will provide years and miles of faithful service. Don't throw the baby out with the bath water. Lumping a car is no simple picnic and your $ and time to do that would be well spent making your current jaguar reliable.

 

Lump it because you want a lump. More power, better performance, better handling. I see it like this...If you cant get the the car to run right as is, you probably don't have the needed technical skills to do a proper lump. The XJS v12 or I6 is nothing magical, fuel, air and spark makes them run.

 

DUDE...

Is ANYONE HERE, PHYSICALLY or FINANCIALLY helping YOU with YOUR CAR....

NO???

Spend your money as you CHOOSE.

Perhaps you were up all night covering the internet from end to end with stories over most of the 20th and 21st centuries about Jags by the side of the road with the hood up, but I DOUBT IT.

I CHALLENGE you to find better workmanship, attention to detail or more COMMON SENSE with regard to lumping Jags than is located HERE: Jaguar Specialties.

I own a 90 XJS conv, bought it for PEANUTS with not a DENT, PAINT SCRATCH, OR INTERIOR FLAW (GUESS WHAT WAS WRONG WITH IT?), and plan to spare NO EXPENSE doing an LS1/T56 conversion that will leave me smiling, powerful and dependable for YEARS TO COME.

I am SURE I could POSSIBLY locate a v12, replace mine and cross my fingers every time I turned the key like some rat under WITSEC, but I'm going NEW TECHNOLOGY GM.

MY POINT?

It is IMPOSSIBLE to act like Jags are not mechanically PROBLEMATIC without getting the SIDE EYE: EVEN JAG ADMITS IT. Just do what YOU wanna do, with YOUR car and YOUR MONEY. You're a GROWN MAN, who MORE THAN LIKELY isn't planning to cruise around with ANY of us once your Jag is DONE... SO ENJOY IT FOR YOU.

 

this crap has been over and over!

but a V8 or I6 will never sound or drive like a V12 smoothness!

nobody will ever use all the power thats available!

mines been runnin g 21years now, no problems i couldnt fix at home!

and value will drop 50%, a few years back a XJS with a lumped Chevy 454 BBC 7.4L, came up for sale , it took over a year to sell for $1500. USD.

more torque than 99% SBC could ever make!

 

I know I'll get crap for this one. I have a 86 that is lumped. sbc 350 and I love it. It always starts, it always runs and it's inexpensive to repair. Parts are available almost anywhere.
My sbc is adout 400 hp and torque. Sure its not as smooth as a stock V12 but who cares. If I wanted smooth I would have bought an electric car. I want power and performance and I have it to spare.
I prefer it over the V12 hands down. The swap isn't that much work or money.
.

 

I LOVE lumped XJS's with V-12 badging! Yeah, you know who you are! 😂😂😂

 

Yup 96 4.0 convertible. See poor idle thread. A little history on the car


Purchased Aug 2004. Sept 2004 no start, replaced ckps 150.00 sensor still no start. ended up having to replace ecu $2,000 after replacing ecu vehicle started up right away. smooth sailing 2004- Nov 2014. got poor idle no power, engine visibly shaking at idle. Replaced spark plugs. same problem. I know cars break down with age. see poor idle thread update.

 

Lone jag, just a thought....why not post over on the X300 board, I've a 97 X300 with the 4.0 and hang out over there , lots of knowledgeable people over there on the 4.0. Also the CPS (crank position sensor) is very prone to failure due to age (had one crumble in me trying to remove it) also the CTS ( coolant temp sensor) can play fits with the running and is an inexpensive change. The ECU relay can play up and while unsure of its local in the XJS I know it's behind the passenger headlight on the x300 and can be swapped out with a neighboring relay to check it.

 

Hey, it's your car and you can do whatever you want with it.

I've watched the "lump wars" for over 20 years now. Frankly, it's always struck me as beyond silly. The one part of the XJS that is most robust and least prone to failure is the engine itself. Yes, the engine. It doesn't matter if it's the V12, the AJ6, or the AJ16. They are all nearly bulletproof, particularly relative to their production numbers.

If an XJS *needs* to be lumped, some mechanic, PO, or current one, somewhere along the way screwed up.

I don't see how throwing a GM small block in cures dodgy relays, corroded wire contacts, failing solder joints, or any of the other many things that actually cause problems in the XJS.

However, if you want to feel better about your ownership experience, spend some time on other high end/lower production car forums. Do you think keeping a 1995 BMW 850i on the road doesn't involve "hard to find, very expensive, difficult to diagnose"?

I can understand if you're frustrated, keeping complex high-end 20+ year old cars working properly isn't easy. That's why people buy new cars, so they don't have to deal with that. However, it can be really rewarding and interesting if you don't throw in the towel.

You can get a cloned IDS/WDS dealer tool for very little money if that is your worry, but most of what you might need a standard ODBII reader will work. Lots of great folks here willing to help.

 

Am I misunderstanding this? Are you saying you had 10 years of carefree driving, and after hitting a recent snag you want to lump it?

Apologies if I'm misreading.

 

Just to add a data point I had a 1992 Series III V12 sedan. Every GM part in the car failed at least once - ignition amp, transmission, AC compressor, power steering pump. Net total of Lucas parts that failed - 0.

The most frequent failure point on a V12 is the GM ignition amp. Should I cure that by putting in a 350 with the exact same amp? Or replacing the failed TH400 behind the V12 with a TH400 behind a 350? Makes no sense to me. In my experience the road to reliability is get rid of the GM crap!

 

I have a 96. I've been through the wringer on idle issues. I've concluded that taking it to a shop that has the equipment is the easiest option. Should take a $150 hookup to the IDS/WDS.

When the computer was unable to resolve my issue (shudder every 32 seconds) it was a faulty intake manifold gasket.

From my years of reading as many posts in the AJ16 as possible (in both the XJS and X300 forums) I've found that aftermarket coils cause weird problems, as does the TPS in the throttle body.

After that the list of possible items gets significantly more rare.

A cloned copy of the WDS/IDS will set you back $150. (British diagnostics on eBay). Although I own it, I have to admit, other than reading ABS codes, I haven't really needed it. There are only three things it can do: (1) reorient the oxygen sensors and (2) reset the TPS and (3) read Jaguar specific trouble codes like ABS.

I can manually fix the TPS, now that I know what the car is looking for (0.6v at idle), I think playing around with which harness the O2 sensors plug into, resolves the other unique feature. Reading ABS codes is what I bought it for. (It helped find which one of my four sensors were dirty. After taking the wheel off and cleaning the sensor, I haven't had a problem in the last year, so I have basically broken even on it)

Anyways, once resolved, my XJS has been a reliable, quiet daily driver. I drive it on cold days, rainy days, hot days....every day.

I think if you spent a little money with a shop, you would save a ton of money over the long haul compared with lumping it, if you're considering doing this for reliabilities sake.

If you were interested in performance or other reasons, then I would stay out of this discussion.

 

By the way, there are two Jaguar specialty shops in the DC area. I have experience with both and can make recommendations to you if you ever considered driving it up to the DC area.

I think if you called ahead and made a reservation, they could find your problem or completely solve it for you altogether!

Have you taken it to a shop that has Jag specific diagnostic hardware?

 

In 2001, I bought a very decent 83 XJ6. Great, and wifey loved it, "her Jaguar". Although, German born, she was enthralled with all things English. Princess Dianna, her heroine.


Well, one hot day, I went on a business trip to CA's Central Valley.
Smooth running, AC doing great. first call went just fine. Second call, the same. Time to go home. Had watched gauges carefully for OP, volts, Temps, etc. all just fine.


Then, out of the blue, horrible growl, blue smoke and it quit!!! Coasted in to a convenience store with limited facility. No crank, stuck.


Cooled down. Added water. cranked happily, no fire. Too happily.


Flat bed home, the back way.


After a day or so, I started checking it out. Whoah, zero compression in all holes!!!!


More time goes by, Jaguar in the garage, still. I was working long hours. But, after a lot of research, I chose the "Lump" path.


Not cheap and not easy. Many travails to over come. It wasn't til 2006, that it passed it's special SMOG and was road legal.


Since, then, the GM stuff works great most of the time. Same for the Jaguar stuff..... As to GM,the starter, as to jaguar, the ignition switch!!!


So, if for reasons other than more HP, I'd choose lumping if the engine was seriously hurt.


Not so, if just auxialry stuff, injection, ignition cranking, etc.


I wrote a white paper. Not sure where it is. "Lump Thoughts".


For me, it was the correct course,


the alternative was Jaguar heaven. Oddly, there is such a place, Jaguar heaven, and oddly not far from where mine had it's hzzzy!!!




Off to the yard work....


Carl

 

Took vehicle to Abacus Racing in VA Beach. They work on jags, Ferrari's , rolls, Mercedes, classic corvettes. when I took my vehicle there like I said it was barely running, no power what so ever. There most of the cars they had in their storage area were jags (with a few xjs there too). cost $100 to "diagnose". The shop stated that I needed to replace the ignition coils ($100.00 each) the shop stated that they were firing intermittently and that two were good. I went to get the car and it would not start so I spent an additional 65 to have it towed home. My thoughts were why spend $600.00 for coils to see what happens when I can buy some cheapies to see how the vehicle will behave. I bought cheapies and the results I got you have read in my poor idle thread. The battery I have in the vehicle does not have enough juice to start the vehicle. ( will buy a new battery Wendsday) to see what happens. I will buy new coils (the so called "good ones") individually. And will keep the forum posted.


I lived in Northern, VA from 1999-2004. I worked as a auto technician for Rosenthal Jaguar/ Land Rover. (worked on the Land Rovers) When I moved to Norfolk, I worked at Checkered Flag Jaguar Porsche, Audi for a short time. (only worked on XJ8's and S and X-type jaguars) The only XJS I worked on was mine (just replacing an ecu which today only used ones exist and are probably dodgy in reliability and no refurbishing companies exixt to my knowledge exist and the ones that do only do the XK8 and up) and a 95 convertible V12 ( switched air filters and clean out door lock mechanisms to the key can be use to open/kock doors.


I know that Top Line Jaguar is in Springfield. Cannot drive the car up there because it will stall (I Did mention that in the poor idle thread)


I will work at this problem but when the next major problem occurs should parts be hard to find or expensive. and lumping wont be a suitable option: I will trash the car with a sledgehammer and have it crushed.

 

The face lift XJS should have it's own section on the forum. You are right about the x300 section. More info on the AJ 16 engine.

 

I took my car to Top Line Jaguar when I finally gave up on my idle dip every 32 seconds. They recommended all new coils, a new EGR and some other part. I ended up supplying all the parts and they installed it and reset my adaptations, which I suspect masked the still unresolved problem.

Anyways, several months later, the problem slowly returned. Bottom line is that they never found the problem. I lost a lot of faith in that shop. They kept my car for weeks and ended up throwing parts at it.

I took it to another shop in Rockville, MD that also specializes in Jags. Master Auto Services. He had it for a day and told me that my intake manifold was leaking. Couple days later I had the car back and I never had another problem with my idle.

Two previous shops, one being Top Line, were not able to find that leak. (I took it to my local independent shop first).

Not sure where I'm going with this story, but I will tell you that you can logically think this through assuming the ECU isn't bad...which I've had experience with as well. (I have a spare ECU that doesn't let the oxygen sensors swing. I would love to get that fixed if there ever was a place that could do it).

My previous posts on my 32 second idle problem had a lot of good info. Once you rule out the ECU, the next culprit is vacuum leaks and then sensors. I know throwing parts ATW problem is a bad idea, so I would try desperately to find someone that could really check for vacuum leaks...again. It might be worth your while to do that yourself if you can rent a smoke machine.

Once you cross that off the list, for sure, there are service manuals on jagrepair.com that can help you diagnose the sensors by telling you what the acceptable ranges for sensors are.

I would start by:
1. Check oxygen sensor readings while driving to make sure they are swinging properly
2. Coolant temp sensor
3. MAF
4. TPS

 

Not at all, I have been driving my XJS reliably as a daily for 6 years. There are lots of things that can bust, but I love going down the road knowing I don't have to worry about the engine, because the V12 is bulletproof.

So, maybe dropping in an engine from some other car would get around an ancillary wearing out, but so would simply replacing said part, since whatever it is is simply 20-30 years old now.

What exactly is it that is so problematic on your car that you want to put some other engine in it as a "fix?"

Putting another engine would literally fix none of the problems I have with my car. Trunk paint is starting to fade, window channels need replacing and mess with the window motor, ski slope is toast, need new tires and adjust toe. Steering rack is starting to leak. Blah.

All the issues I have with my car are just because it is old, not because it is a Jag, and the V12 has nothing to do with any of them (okay maybe that one oil leak is hard to reach).

The unavailable tech to diagnose a later car doesn't really matter, it just puts you in the same boat as the rest of us that never had that option to start with.