COAL: 1996 Jaguar XJ12 – This Kitty’s Got Claws

The 1994-1997 "X300" XJ

Welcome to Jaguar number 3. My prior two Jaguars (here and here) were X350-generation cars, which were the 2004-2009 ones. I found them to be delightful, characterful machines, when they worked (which was fairly infrequently or never for the 2004). When I wrote about the X350 XJ, I mentioned that it was the first XJ with modern proportions, and the first clean-sheet redesign in almost twenty years.

Well, this car happens to be an X300, which is a couple of generations earlier than X350. The X300 lasted from 1994-1997. It was an improvement upon the XJ40, but was superseded by the X308. All three used the same underpinnings and basic bodyshell (meaning that Jaguar had itself a car with 1970s ergonomics as late as MY2003).

Furthermore, this one was a one-year-only special. 1996 was, of course, the year in which all US-market cars needed to support the full OBD2 standard…and Jaguar’s V12 didn’t quite do that. It used a Nippon Denso ECU that couldn’t do continuous emissions monitoring. Since Jaguar was soon to ax the V12 engine and didn’t want to do expensive re-engineering work, it applied for (and received) an exemption from the EPA for MY1996. When that expired, the V12 stopped being sold in the US. The other thing was that 1996 was the first year in which Jaguar sold a factory LWB body. At that point, all Vanden Plas and XJ12 models became LWB, and there was also an XJ6 L model.

In short, 1996 was the only year in which you could ever get a LWB XJ with a V12.

My interest was piqued the moment I saw it. And, as ever, I wasn’t specifically looking for it. But when it popped up on Facebook Marketplace in early August, I had to at least take a look. The car was in Dallas, which was 3 hours away. The seller had stated that it had received a bunch of work done by the previous owner, and indeed it had. The previous owner had rebuilt the steering rack, rebuilt the ABS sensor, fixed the LCD clock, replaced the spark plugs, redone the brakes, and various other things. It presented well. There was actually a YouTube link for the then-prior owner and all the work he’d done.

After getting in touch with the seller —who had been busy— I booked a one-way rental from Hertz and went down to see the car. The cheapest thing, by a substantial margin, turned out to be a hard-worn 2021 Tesla Model 3, so that’s what I got. To say that car was a massive disappointment would be an understatement. I’d driven one before, but not on the interstate. The seat made my back hurt within about 30 minutes and the sheer amount of noise that came into the cabin would’ve put a 90s Saturn to shame. But, after a stop-off at the Tesla Supercharger in Ardmore, OK, the car got me there.

The Tesla charging. The Supercharger network was about the only positive thing I had to say about this Model 3.


My friend Austin (a different Austin than the one mentioned in prior stories) was local to Dallas, and was supposed to be meeting me there to help me look over the car. He’s pretty mechanically inclined and drives a 1996 Rolls-Royce Silver Spur on which he does much of the work himself. But he ended up getting blocked in his employer’s parking garage by a stuck train and couldn’t make it, so I was on my own. The seller was a mid-20s gentleman who’d bought the car for his father, but his father had lost interest in it. They wanted $8,000 for it, and that was lowered from $9,000. It’d been for sale for a while.

When I got to their house and saw the car’s British Racing Green paint gleaming, I admit I fell in love right then and there. I asked them to make sure I got a good cold start, and—true to form—the engine was cold when I started it up. But it whirred to life without incident. While it was still cold, I went ahead and checked the coolant level (fine), and once it warmed up, the engine oil level (also fine). Despite spending the majority of its life in Connecticut until the prior owner had bought it and had it shipped to Texas, it had only surface rust on the bottom. The paint had one or two small patches where the clear coat was failing, and there were a series of tiny, almost-imperceptible dents along the right side. The rear CHMSL assembly, which should have been bonded to the rear glass, was just sitting on the parcel shelf, tethered by its electrical connector. And the coolant overflow tank had a loose sensor, which could trigger a false coolant warning (a common issue on these X300 Jaguars, it turned out). These had already been disclosed by the seller and would be easily remedied. There was also a fat ream of documentation going back to 2002.

Just look at that gorgeous car.


And that interior! (It’d be cool to get the car phone working).


Most curiously, this car had a different grille and rear plinth on it than would have been installed from the factory. The US-market XJ12 was roughly equivalent to the Daimler Double-Six that was sold in the rest of the world. The Double-Six had the fluted silver grille and rear plinth with a gold Daimler “D”, but our US XJ12 had a smooth chrome grille with black vanes and a gold Jaguar “growler.” It was our Vanden Plas model that got the fluted grille, which this one inexplicably had, along with the Vanden Plas’ silver growler. To this day, I’ve not been able to figure out who did this, and it’s not impossible that the original owner had it done upon purchase or even custom-ordered it that way.

The seller, his father and I all took the car for a very lengthy drive, and it behaved absolutely perfectly. Everything worked. The power-everything (including a power tilt-telescoping steering column) did what it was supposed to, the engine and transmission had nary a stumble, the suspension felt smooth, and even the radio was fine. All in all, it was shaping up to be the best test-drive I’d ever done on an older car. The only issues I found were minor: one of the button packs in the center stack was a bit loose, the car needed an alignment, and the position sensor for the gear selector needed adjusting. The latter meant that you had to often pull the J-gate shifter back and hold it there until the “P” indicator lit up, before starting the car. If you didn’t, the shift interlock would think the car was in gear and not allow it to start.

And that glorious 6.0-liter V12 with 316 hp and 353 lb-ft. With a 3.54 in stroke and a 2.76 stroke, this engine is undersquare… designed for high RPM and high power output.


We got back to their house, and I offered them $7,500, which they accepted.

After that, I dealt with the logistics of turning the Tesla back into Hertz and then catching an Uber back to the seller’s house. While I was there, I opened a classic-car policy with full coverage and a guaranteed value. By the time I got back, it was quite dark. I’d gotten both sets of keys from the sellers and parked the car around the block, just to be safe. I got in, put in my tape-deck-to-Bluetooth receiver, entered my destination home into my phone and set off.

I should have known it was too good to be true.

No sooner than I’d gotten onto the highway, the car began acting funny. I got a light on the instrument panel depicting a transmission with an X over it, which I later learned indicated that the transmission had put itself into failsafe mode, which meant you only had access to second gear. And, indeed, the engine was at 4,000 RPMs, not at all normal for a 6.0-liter V12 on the highway. I pulled over and restarted the car, then set off again. It behaved for another 800 feet and then went back into failsafe mode with a CEL to accompany it. At that point, and right as I was pulling into a gas station, Austin called me and asked how my trip was going.

“Uh, not so good,” I told him.

The classic Jaguar transmission failsafe mode light.


Austin told me to check the transmission dipstick, which was something I was ashamed to admit I hadn’t done prior to purchase. The transmission was basically a 4L80E in a Jaguar-specific bell housing. In fact, Austin’s Rolls-Royce also had a 4L80E in a different bellhousing. And just like his Rolls-Royce and just like any other vehicle with that transmission, the dipstick was on the right side of the engine bay, more or less against the firewall. Austin told me I’d better get it to his house so that we could look at it. Problem was, it was on the south side of Dallas, and I was near Richardson.

I got back on the road, sticking to the side streets, when I accidentally found myself back on the highway. At the same time, I got the failsafe light again and saw the temperature needle creeping toward the red. That could well have been because the engine wasn’t designed to run at such high RPM at that speed but could have also been a coolant problem… like a head gasket leak or a bad water pump. I pulled off of the highway and into a church parking lot, but left the car on and the heat on high. Slowly, the needle crept back down to a normal temperature. I was able to restart it and drive it like that, with the temperature on high and all the vents open, and it drove fine. The transmission shifted into all gears and the coolant temperature stayed at normal.

Austin was waiting for me when I pulled into his driveway. He did a double-check of everything he could, and said it looked fine. The only trouble code was for shift solenoid B. And then we went for a drive. The car drove fine, then, even with the air conditioning on blast. We couldn’t get it to act up… not until I looked over and saw the voltage meter, which should have read 14 volts, maxed out. And the battery indicator was lit up. At that point, we decided to park it and I resolved to spend the night at Austin’s house. That said, I hadn’t eaten, so we made a Taco Bell run in the Rolls-Royce, which I got to drive.

His resplendent 1996 Rolls-Royce Silver Spur IV. He calls it “Peppermint Patty,” because it’s white with a red interior.


The next day, we started the car up and noticed that the voltage meter was now reading 9 volts, the minimum, and the battery light was still lit up. There was no way I was driving this car home. I called AAA and arranged to use my one long-distance tow for the year, and booked a different car with Hertz to get me back home. While I was waiting for the tow truck and for Austin to be able to take me to the rental car agency, I pored over the car’s documentation and texted the prior-prior owner, John, who’d left his information. John said he’d only sold the car because he moved to Thailand and expressed dismay that the previous owners hadn’t fixed the few things that were wrong with it. He said he wasn’t sure why it had acted up.

The XJ12 on a rollback, not 24 hours after I’d bought it. This was a new record for me, really.


My rental car home turned out to be a 2021 Chevrolet Equinox LT, which was more comfortable than the Tesla costing twice as much. It took three hours to get home, and the car actually beat me there. Well…it didn’t go home; it went to the local Jaguar specialists I always use, nearby. They called and said they’d received it and that they’d get around to looking at it the next week.

The Equinox. It was either that or the EcoSport next to it. I think I made the right choice.


As for the XJ12, the shop confirmed that it needed a new or rebuilt alternator. This shop never likes to use aftermarket parts, so it was either a new OEM one for $2,200 or a rebuild for $400. Obviously, I opted for the later route and got the car back a week later.

This was my first time filling up the XJ12, and I thought the filler location was cool. Earlier XJs had two fillers (one on each side) and two tanks; you hit a switch on the dashboard to swap between them.


I had a lovely afternoon with the XJ12, driving 40 miles around town to run various errands. Just as I was almost home and coming to a traffic light after exiting the highway, I heard a nasty grinding noise. It sounded like something was dragging along the road. Hee-hee, someone’s hooptie is making all that racket! I thought smugly.

After proceeding through the intersection and 800 feet, my second thought was Oh, my gosh; that’s my hooptie! Fortunately, the Jaguar shop was a quarter of a mile away, so I limped it there in second. It just so happened that the owner (it’s just him and his wife) was available, and he went for a ride with me in it. At that point, it gave one great lurch and then refused to proceed in any gear other than second. It slipped in all the other gears. He told me to take it to the nearby AAMCO and see what they said, as that’s who he used for transmission work.

The XJ12 looking sorry for itself at AAMCO.


AAMCO called me the following Monday and confirmed—rather stupidly, I thought—that the transmission was slipping. I authorized them doing a teardown, when I really should have just sourced a new transmission. At the time, there was only one used transmission on eBay and I was worried I wouldn’t be able to find one. But then, that same week, a reputable reseller began offering a used OEM XJ12 transmission for the car for just $1,800, with a 5-year warranty. I could have had that shipped straight to the Jaguar shop and they could have installed it. Alas.

By that point, AAMCO claimed to be $2,000 into the teardown. And they had me come in and showed me what was the worst-case scenario: the planetary gearset had more or less come apart in chunks, wreaking havoc on the transmission. The cost to rebuild the transmission started out at $3,900, but then ballooned to $6,500. And, on top of that, they were concerned about the rusty header bolts and so cut my exhaust off.

The XJ12 up in the air at AAMCO, sans transmission.


The cut exhaust.


It took them over a month to rebuild the transmission. The day I picked it up was the same day my current partner flew into town. He lives on the East Coast, so we’re doing a long-distance thing. I picked him up from the airport, then had him go with me to pick up the Jaguar from the shop. It sounded absolutely glorious with no exhaust on it, but I had no intention of leaving it like that. I had an appointment to get it welded back up the next day.

In the meantime, while it was in the driveway, I could tackle a couple of repairs. I had ordered a used coolant tank with a good sensor, and it was a cinch to swap that in, then top the coolant back up and make sure no air was in the system. At that time, I also went ahead and swapped the silver growler on the front grille for the proper XJ12 gold one.

The replacement coolant overflow tank.


The second repair was more involved. I’d noticed that the warning chimes didn’t work. That was a problem for two reasons: One, I’m a chime nerd and actually enjoy warning/seatbelt chimes when a car starts up. And, two, I’m a bimbo who will absolutely leave the lights on and run down the battery; this car didn’t have automatic headlights. The chimes were actually generated by a tiny 66mm, 0.5W, 64-ohm speaker on the right side of the steering column. I couldn’t find an off-the-shelf speaker like it anywhere in the country and ended up ordering an entire new steering column harness, which came with the left and right turn signal indicators. To do this repair, I had to take off the steering wheel, airbag and clock spring, then swap over the innards. But I did get working chimes at the end of it.

The replacement assembly.


Me installing the replacement assembly, part 1.


Me installing the replacement assembly, part 2.


The next morning, I took the XJ12 to my exhaust guy, the same one I’d used when someone stole the cat off of the 2006 Range Rover. The exhaust was there, but hanging with wire, so I had to be careful. He let me know he wasn’t quite sure if he could weld it in-situ because there wasn’t a whole lot of clearance, but he’d sure try. Sure enough, thirty minutes later, he came back into the lobby and said he’d managed to do it. $100 was all I paid. My first break!

All three of my then-current older cars, sitting next to each other. Of course, as of last week, the Audi is gone.


When Eric’s flight home got canceled and I had to pick him up from the airport, this is how I decorated the XJ12. He was highly amused.


The XJ12 was finally in what I hoped was working order. There were only a few more things to fix. The steering needed an alignment, and something screeched when you had the wheel turned at full lock. Unfortunately, when I took it to the tire shop, they said it wouldn’t take an alignment because the bearings were worn. These could be re-shimmed, but I didn’t have the tools to do that, so back to the Euro shop it went. They re-shimmed it, and also adjusted the power-steering belt to fix the screeching. I’d noticed some residue on the rear differential when the car was up in the air at AAMCO; that turned out to likely be fluid that had seeped out of the fill hole when it was serviced previously, because the diff gasket was new and not leaking whatsoever. And they adjusted the gear selector indication switch, which I’d tried and failed to do successfully. They had the car for another week.  After that, I was able to get it aligned without issue.

The XJ12 in the rain, its natural habitat. It’s one of a handful of cars that, comically, just has one windshield wiper that goes across the whole windshield.


That weekend, October 21, I was going to a meet-up in Tulsa (1.5 hours away) hosted by one of my favorite car journalists and with about fifteen other people there. I thought I’d take the XJ12 and see how it did. After all, I had AAA and various other ways to get a tow if it turned out badly. I went the night before, just in case, and was pleased to see the XJ12 acquitted itself without incident. And instead of its usual 12 MPG, it managed 15! Not bad! The same was true on the way home, with nary an issue.

The XJ12. sitting safe and sound in the hotel’s parking garage. Everyone, including my journalist friend, was super impressed with it.


One thing that was starting to get annoying was the cassette-tape-to-Bluetooth adapter I’d been using. Not only did the Jaguar’s tape deck often spit it out because it had a cable that stuck out and kept the deck door from closing… it didn’t actually draw power from the tape deck. It lasted a few hours on a charge and then you had to take it out of the deck and charge it. Fortunately, a really clever fellow in England started a company for retrofitting these older Jag radios with modern technology. His main thing is JagDroid, which gets the touchscreen-era Jaguars Apple CarPlay and Android Auto functionality. I actually had this done to my 2006 XJ. But for the X300, which didn’t have a touchscreen, Ben could only add Bluetooth streaming. I thought that was better than the tape deck, and so ordered a second OEM radio from eBay and then sent it straight to Ben, in the UK. I did that only recently, so I’m still waiting for it back.

The XJ12 came with all the original manuals and even the window sticker. Look at these hand-drawn illustrations. Now that’s what you call detail.


And then, a couple of weeks ago, I had another issue. I’d been lulled into a false sense of security with this XJ12. When I was almost home, I noticed the voltage meter creeping back down below its usual 14 volts, until it finally read 9 volts and then the familiar transmission failsafe mode appeared. I managed to get it home and it had killed the battery enough that it wouldn’t restart. Back to the Jaguar specialists. Earlier this week, they finally called me and said the culprit was the rebuilt alternator. This time, it couldn’t be rebuilt, so they are installing a replacement at no cost to me. They’re out of town on vacation, though, so I won’t get the car back until next week.

The voltage reading much lower than it ought to be.


Back on the rollback. Here, the X5 makes a cameo, as I’d moved it out of the garage in case I was blocked in by the rollback.


In the meantime, I did get my vanity plate for the car. Once I get it back, I’ll slap it on.

“V12PURR.” I like the sound of that. If you’re ever in the OKC area and you see me around, give me a wave!


So that’s where we’re at. The XJ12 has spent more time outside of my custody than in it, but there’s little else major to go wrong. I’m not sure whether the prior sellers knew there was an issue and were trying to get rid of it in a hurry, or it was just my misfortune that it broke two miles from where it was purchased…but I want to think it’s the latter. That’s just how these esoteric, high-end older cars are. A lot of the parts are no longer available (NLA) new and it’s rather specialized, but I think it’s still my favorite car, for sheer presence and character. It certainly gets a lot of attention and compliments. I’ve also found quite a few people willing to help me out with knowledge and experience. John, the prior owner who did much of the work on it, has let me know he’ll want to buy it back if ever he returns to the US from Thailand, but I’m not sure I’ll let him. At this point, I’m in it for way more than the purchase price, and it’s a rare collectible. Unlike other problematic cars I’ve had in this series, it’s actually worth keeping.