Read closer sbobev… they don’t have the same sensor. The both have CPS, but not the same sensor. The 4.0 version is ridiculously unreliable (genuine Jaguar, Lucas, beck arnley, SNG Barratt no name… no luck with any of them)
I think the first thing I would do is check on the age of the spark plug wires, several years ago on the old site we had a big discussion on the cause of the Marrelli Meltdowns, all my research I believe came down to degeneration of the carbon core in the wires causing very high impedance and the very high voltage coils shorting out the A bank. Then the cat overheated and melted and your V12 is a I6. That will really slow you down! If the car was regularly driven I think it will be a nice trip. At expressway speeds it should run cool as long as it is not a traffic jam, like Atlanta! Kuhn and Coventry West would be the best in that city. I-10 from Ga to Texas is a thousand mile runway! Flat as a board. Also a Gold AAA card will get your car shipped to the home of record if you need it, great to have.
Dan
Such a road trip could be anywhere between out of this world exhilaration and abject misery.
There are people who sell a V12 XJ-S, or a 4.0 XJ-S, and it really has been well looked after and has no immediate problems.
Then there are the other people, probably in the majority.
The other people might be honest and say what is wrong, but if they want a good price for the car their memory of the car’s troubles can be anything but complete.
Not sure why anybody in Texas would go for an XJ-S in NY. For sure even in the States a 95 V12 convertible is not common, later cars tend to be 4.0 engined. So maybe the magnet was the fact it was a later car with a V-12. Otherwise shop for a V12 close to Texas and if not in a hurry you will get what you want.
The deed is done, so time to evaluate the risk and ways to mitigate it.
The risk is high in the sense a 24 YO XJ-S can have many problems that are not obvious if you just drive it around the block.
If you can make contact with the Jaguar Owners Club in NY see if you can get a knowledgeable person to look at the car or suggest a mechanic who will give it a once over. That can eliminate a number of the obvious problems. You really need the car up on a hoist to check it.
Overheating is a typical problem because the V-12 cooling design has little reserve in hot weather.
The radiator is a weak point, it must be clean inside and have plenty of airflow. You could drive the car for at least half an hour in a situation that will challenge the cooling system and see the result. Do not rely on the car’s temp gauge, buy an infrared beam temp gauge and do a few measurements on the engine and hoses.
If that all stacks up you have a 95% chance of 2,500 miles with no hitch.
I found my receipt Magnecor Wires, all the right length and each one labeled!
My writings are based on the pre-90’s XJ-S; the 5.3 litre Coupe and Cabriolet; I hope I don’t scare you off. A well maintained XJ-S is a dream to own, and can be very trouble free. Maintenance is or can be expensive; but again, it’s the number of parts as well as the amount of liquids you’re dealing with.
Here’s a brain dump, Thought, Experiences, and sheer ramblings not in ay particular order. Just as I think about it. or pops into my head. I may have repeated myself - sorry… I’ve gotten pulled way from this post and am too lazy to re-read it. 
Oil pressure is greatly dependent upon the type of oil. I run Castrol 20-50 in mine and my oil pressure pretty much stays in the “normal” all of the time. But again, my XJ-S’s are pre-90’s and pre-ford. In mine, it’s not uncommon for a warm engine to dip down to 25-30 PSI at an idle, but will pop right up in the top end of the “Normal” range as soon as you set off.
Rumor has it, the sending unit has been updated to keep the “low oil pressure freak out” to a minimum by making more of a light switch either you have oil pressure or you don’t.
The oil you put in your XJ-S will greatly depend on the ambient temperature and the oil viscosity.(according to the manual anything above 70f should be either 20/40 or 20/50. 20/40 is a bit hard to come by. Me? I use Castrol 20/50, Transmission Dextron II D or II E, Prestone phosphate free BS 6580 standard (this will be on the side of the bottle)
Fuel run Premium 90 octane or above. I carry a can of octane boost in the boot just incase I’m somewhere that doesn’t have 90 octane. It has happened to me in the past.
Definitely check the fluids. XJ-S are (well at least mine are) notorious for heating or rather cooling issues - especially if it’s been sitting for any length of time. If it were me before I made the drive I would:
- be suspect if the engine bay is spotless. Look at the underside of the bonnet - look for tears, water marks in the insulation, it should just be black fiberglass.
- I’d be suspect, and wouldn’t start off on a long trip on freshly changed oil. Look at the inside of the oil filler cap, if it’s spotless, then take your finger and wipe it along the inside of the cam cover. It shouldn’t be gooey, or lumpy. brown discoulation is normal unless using a synthetic like Amsoil.
- squeeze the hoses, look at the ends for cracking or over tightening hose clamps. Could be a sign of leaks or pending leaks
- If the car has been sitting for a while, count on oil leaks. though this is more the norm than not.
Ask for a service history
- Checking the A/C requires special tools; stuff that won’t fit in the boot. Sorry
- Cruise control - out of my 8 Jag’s only one has a functioning cruise control (the 2002 XJR). Hopefully yours works.
- Hoses… there’s a bunch on the V12 it’s been my experience usually it’s the hose on the back of the engine that services the heater control valve and the cross over pipe that services the heads that gives way. The V12 isn’t an engine that takes kindly to be overheated. These engines prefer to run cool. If the engine gets hot, then crank the heater to syphon off some of the heat. Oh, bring a pair of shorts. just in case.
Keep the oil levels where they should be, I carry 3 quarts in the boot (just to be safe). the fill line on the XJ-S dipstick means it’s down a couple quarts. This engine holds 12 quarts of oil.
At 70k if the water pump hasn’t been replaced it’s been my experience that it’s probably due. There’s a weep hole at the bottom of the water pump that will drip when the car is turned off after it’s up to temp.
One thing these engines don’t leak is coolant. Oil - yes. typically it’s the cam cover “D” plug on the back.
When you take it for a drive, listen for wheel bearing noise. If the hubs haven’t been serviced, there will be a bit of bearing noise, it’s really hard to distinguish from tire / road noise. The way to tell is when the tarmac surface changes, the noise won’t. These are pretty durable unless their howling, so in 2,500 miles your wheels aren’t going to fall off.
The brake pedal should be firm if it’s squishy, then more often than not it’s the master cylinder that will need a freshening up. These cars will stop on a dime.
Rust
around the windscreen, make sure the rubber is still pliable
check the exhaust holes in the body - this is a sign of an exhaust leak which will rust out the holes
behind the front wheels (arch)
floorboard next to the transmission tunnel pull up the carpets - yes they pull up without damaging anything. if theirs moisture the condensation tube for the air-con condenser has come loose or the drains for the vent(s) are plugged. There’s two duck bill looking things that coming out of the bulkhead on each side - there are two heater fans one behind the instrument cluster and the other behind the glove box.
Open the boot, and check the inside of the boot lid edges, especially the one when shut is against or close to the bumper (corners especially) that is a common place for rust. there’s an e-book around here someplace (on this website) it’s lengthy but a great source to get up to speed on being an XJ-S owner. Kirby Palm XJ-S - found it.
The V-12
The V-12 is a wonderful engine and if well maintained is good for 250k miles. buttery smooth, legendary power delivery (not neck snapping - but very smooth). This isn’t an engine that just anybody can work on, and unfortunately when it’s time for a service; that sucking sound you here? is the money being sucked out of your pockets. There’s a lot going on under the bonnet, and is twice as many as the 6 cyl sibling. just in the sheer numbers. 12 spark plugs instead of 6, two air cleaners instead of one…
There’s a lot up top top that is in the way for just a simple maintenance item such as a spark plug change.
If the car is as good as it sounds, then that will be a wonderful trip - I envy you! Just keep a hawk eye on the fluids.
Been off the computer for some shut-eye so I’ll try to catch up; don’t be offended if I leave you out or attribute your comment to someone else - I’m old, for goodness’ sake!
Generally speaking, even though I haven’t seen the car, I believe I vetted the seller well and he’s got a good reputation (dealer with lots of recent sales and a shop with good reviews as well as personal atta-boys) Even though the car is in NY it’s actually a California car via NC and VA, apparently protected from salt and other nasties. The mileage is a bit higher than I might like, but the average is less than 3,000/yr, which would be minimum for me if it was evenly distributed (which I’m sure it was not - still had to have been driven at least some each year) - the end of run V-12 is what made me pull the trigger; a '96 might have been a more reliable choice, but I couldn’t get past the lure of the V-12.
To summarize, it sounds like making sure the ignition is sound and doesn’t turn my V-12 into an I-6 which would certainly be a disappointment since a better one of those is readily available in a '96, and making sure the cooling system is up to the task are the two primary areas to verify are sound.
Ron McLeod: Thanks so much for the list of shops - not all on my route, but some are; that was a lot of trouble and I really appreciate it, especially your noting the ones you can endorse.
dhs: Thanks for the heads up on the plug wires; I’ll find out how hard (expensive) changing them would be and see about getting that done locally before I head out. Thanks for looking up your receipt for the wires; again, a lot of trouble and much appreciated.
Mark Lee: So grateful for your comments; that took a lot of time and effort and I appreciate it; the car’s bought so I can’t reject it if it fails something important. And, some don’t have to fixed before the trip but it would obviously be a good idea to check them out when I get the car home.
dhs: I am a AAA member and I think I have a gold card but it doesn’t provide the “get towed home” option. That sounds like the best “repair tool” I could take along on the trip. Do you remember the specifics of that membership option - AAA offices are franchises or at least differ somewhat locally so maybe Texas’ offices don’t offer that - I checked their website and that option is not offered regardless of membership plan. Any thoughts? If anyone else knows of a source for such towing coverage, maybe from someone other than AAA, I’d appreciate the info.
Thanks, everyone. I’m off to catch a plane (not to collect the Jag; that’s at month end) so I’ll be off the air for a few hours but will check as soon as I can. Keep the cards and letters coming, as they (used to) say, as your thoughts occur - I am excited about this as is probably obvious.
Bruce
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Bruce . . .
When I bought my '90 V12 convertible about 7 years ago, I went through Kirby’s book from front to back, and one thing that was very clear to me was that I needed to modify the Marelli distributor by removing the metal nubbin. So I took the car to my mechanic, pointed him at the book, and said “do what Kirby says”. I then jumped in the car and drove to Florida - 1500 miles - trouble-free. My friends, whose experiences were with lesser (and older) British marques, thought I was crazy, or at least risking heartbreak and disappointment, but as it turned out they were wrong.
Lots of valuable experience and advice in this email thread, and every day on this XJ-S forum. It sounds like you have found a pretty good car (as I did). If it were me, I’d make sure I had AAA Premier membership, do a quick check of the obvious, and hit the road. When you get to Texas, use the advice here to make a list of things to check for your mechanic, or pin it up in your shop if you do your own wrenching.
Enjoy the drive. I hope you have a huge grin on your face the whole time. It’s that kind of car.
You will be fine. Just drive her home. Those cars love long journeys. 
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That could be better than buying from a private seller. If his workshop takes a good look at the car and sees anything that might be a problem before buying it, hopefully that modifies the seller’s asking price so there is cash to fix it. Not all dealers are rogues, but it is a profession which has been tainted over the years.
I would still be wary of the cooling system. It is not easy for a mechanic to judge how effective the system is with the car sitting in the workshop. Running the engine at idle for about 30 minutes will get it up to around maximum temperature, but not easy to tell if it is right on its cooling capacity limit or if it has 20% reserve. Of course if it obviously overheats in that test you do know it is defective.
Generally the cooling system works best in moderate cruise on flat roads. Long uphill driving and battling through traffic jams on hot days puts it to the test. If the system is in good shape it works well up to 45deg C ambient.
Mileage of 70k is nothing if the car is well maintained. The Marelli problem has struck a number of owners and any suggestions made to check and/or improve it are worth taking seriously.
Otherwise the XJ-S is as good as any other car for its age. My 1988 5.3L Lucas convertible has given relatively little trouble for its age. The car has done 80k and the engine is still good with one very small oil drip.
Enjoy the drive. With good preparation you should get back to Texas without a hitch and with a smile on your face. If bad luck strikes, post an accurate description of symptoms and there will be plenty of advice.
I downloaded the “book” (but didn’t print it - 780 pages after all). Almost more there than I can handle as one new to the XJS (I’m a long time XK guy - have a 140 restoration under way presently). I think I’ll check to see if the Marelli issue has been addressed, check into the cooling system, including obviously failing hoses, and go for it with a list of shops along the way. I have a friend with a shop in Tampa that is good with the V-12’s but that’s halfway home.
Everyone has gone completely overboard with help for me and I sincerely appreciate it. Nevertheless, if anyone thinks of anything, don’t stop now.
Bruce
Hate to ask, but it would be nice if you started a new thread of your trip. Like a daily blog. Would be fun to follow you.
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I’ll tell you about my first XJ-SC purchase. I’m just South of Pittsburgh. The car was in Jacksonville Florida. Supposedly ran fine. This is Dec. 22nd. My wife insists on accompanying me to get the car and drive home by Christmas. We get there to get the car. The guy is working to get it running perfect. The first sign of Armageddon. We finally get the title transferred and get on the road. About 200 miles into the trip the temp starts to go up. I’ll make the story short. The engine temp. would be okay as long as we stayed below 40 MPH. We had to limp to a motel and stay over night. My wife didn’t find it amusing because she expected to be home for her family’s traditional Christmas celebration. I tried to get the issue resolved. No success. We limped to the Charleston airport. Parked the XJ-SC in long term parking. Rented the last car available and drove home. I drove back down after Christmas with my son and limped the car to a shippers yard. Had it shipped home. I left out a lot of detail out but must include that a number of locals were of extreme help and showered us with kind treatment. I would never drive a newly purchased XJ-S home from any considerable distance . There are just too many things on these cars that get neglected that are not able to be diagnosed in a short period of time.
The old guy opines. Go for it!!! I did that trip in 55. A much simpler car. A 50 Chevrolet for door. NY to El Paso, Texas. Three days. Stopped , in the car, rests. A bite to eat and coffee. fuel. I knew better than to push the babbit pounder past 60MPH. but if steady, it ate the miles.
Ditto on the Blue Ridge. Fabulous.
In to Texas and the Chev was running hot. convenient place to get a “reverse flush”. It worked. cool after that.
Damage. Busted a rear leaf spring. near the forward eye. So the axle remained in place and I kept going. Burnt exalt valve on one hole . Shaky ide but ran OK at speed.
Each fixed, one at a time, once home
Caveat on the road service. Base cover not adequate. Tow mieage limited. I chose not to use the cover on my auto policy. better cover from Allstate. Reasonable price after promotion discount. Beware of the tow outfit if needed. I sent one packing. Tried to rip. daughter off. Using my Jeep and it quit on her. another story for another day.
Today, each of my cars has a tool kit. but the complexities of the cars makes them almost useless for a roadside fix.
Cell and good insurance are the best tools/
But, basics are good. Water, oil ATRF. duct tape, wire…
Oh, I did my trip in July !! No AC in the Chev. I grew up sans AC so. no new to me.
…
Enjoy the adventure… . ,
Before setting off I’d check all the fluid levels and the tire pressures. Need to check transmission fluid with engine running. Got a decent tire pressure gauge? I’d stop at a store and buy a couple of litres of oil, ATF, and some coolant, or distilled water.
A log would be great for me, if boring for all y’all. If I hit a snag, it’s hard to believe the forum would not be there for me. Current plan is to fly to La Guardia late on May 29th (Wednesday); might stay over until Monday and catch a play or other NYC stuff - not often I get a “free” trip there. Then off to Florida via back roads.
Bruce
Transport companies usually have a space open. …probably woul cost less than 1200…check around
The book, and a tablet or laptop, and a voltmeter and some basic tools would be worth having on the trip.
If you proceed with that long drive in spite of all this conversation…please report about the ordeal…
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Follow that up with the Natchez Trace. The Trace is not hilly at all, but otherwise the same style of travel, more about enjoying the drive than getting somewhere quick.
Bruce - - among your basic tools you plan on taking, you may want to ensure you have a PoziDrive #2 screwdriver in addition to the normal Phillips and flat tip blade tips. As Andrew points out, having laptop or notebook with Kirby’s book downloaded and saved as a PDF will enable searches for info. I fully concur with other recommendations about carrying a few quarts of oil and a gallon of pre-mixed coolant.
As far as the cooling system reliability goes, I might opt for a half-hour idle as Richard mentioned followed by hour or so of driving around in the city where you pick up the car and see how the cooling system does in traffic. And gets you accustomed to gauge changes stuck in traffic and how temp drops back down when some forward speed is present a couple of minutes. And if you have problems in any regard you aren’t far away from the dealer/shop seller agent. I know the deal is done at that point, but if you have good reviews about the shop, then if needed you can have him do some work before you strike out on your odyssey and “get what you get wherever you get to”.
Your new–new to you – Jag (congratulations BTW) is a post-facelift model year, so oftentimes the specifics about your car don’t fit within the experiences of all the community. Your car is of a population of three years out twenty. So please remember that. All the advice and knowledge on this forum is a wonderful tool - - as with all tools, used correctly is best. You have to be the filter that sorts it out. I highly recommend building a library of references - - among them I frequently refer to the Tech Updates to see how my 95 changed from the previous year(s).
The trip computer will display some fault codes if encountered. Having knowledge of the codes meanings/implications will be of use - -so you know whether to NOT DRIVE ANY FARTHER versus limp to a better stopping place. I don’t know if your car includes owner manual or not - -but somewhere on the forums the fault codes have been listed. If you get an CHECK ENGINE on the trip computer, then after you shut the car off, turn the key back on the ACC position within 5 sec and the trip display will show you the code that caused the CHECK ENGINE light. I pulled this from 1994 XJS Range Model Year update
On-board diagnostics (OBD)
The OBD system has been expanded to include two new diagnostic trouble codes (DTCs): 67 and 77. In order to prevent the erroneous flagging of codes. a fuel level input (voltage) to the fuel injection ECM is supplied. The ECM will not flag DTCs 13. 18. 19. 23. 34. 36. 44 and 45 when the fuel tank level falls below approximately 1 gallon.
Diagnostic trouble code summary
The available OTCs are listed in order of priority on the following table. Limp home mode is available as indicated by X. When multiple faults occur, only the highest priority code will be displayed.
CODE – LIMP HOME MODE – ITEM or COMPONENT
29 ECM Self-test
44 X Oxygen sensor circuit - A bank
45 X Oxygen sensor circuit - B bank
13 X Manifold pressure transducer and sensing hose
34 Injector electrical circuits - A bank
36 Injector electrical circuits - B bank
14 X Coolant temperature sensor circuit
17 X Throttle position sensor circuit
18 X Manifold pressure transducer / throttle position sensor
circuit (high throttle voltage / high MAP)
19 X Manifold pressure transducer / throttle position sensor
circuit (high throttle voltage / high MAp)
23 Fuel metering at idle - A and B banks combined
49 X Power resistors electrical circuits
11 X Pressure transducer / throttle position sensor circuit
16 X Intake air temperature sensor circuit
67 Air injection operation (oxygen sensor response)
77 Engine speed (loss of input from ignition ECM)
Clearing diagnostic trouble codes
All DTCs are held in the ECM memory until cleared using serial communication. If the vehicle battery is disconnected the DTC(s) will be cleared.
If your car has AUTO xmsn, the parking brake is an item that I recommend you forget you have - - other than to ensure it is off. In a left hand drive XJS the handle is down whether the PB is ON or OFF - - so you can get in and out. The V12 will pull away in drive with the brake engaged (ask me how I know) and just wear the pads. The caution lights are pretty dim. So now, after having new pads installed, I sometimes check the parking brake holding in neutral on a hill and ensure the warning light comes on - - but then I disengage and leave the handle down all the time. Fortunately my kitty has a flat garage and parking situations I encounter here in south Alabama are generally on a flat piece of ground. Put 'er in Park and turn 'er off.
Hope you have a great trip, but uneventful with regards to XJS issues