Cheap To Buy, Not To Own: 1986 Jaguar XJS V12

$1,300 with the option to submit a best offer seems downright cheap for the chance to own one of Jaguar’s prettiest coupes. Of course, it was also one of the most expensive cars to maintain, often with little financial reward on the other side for your investments. Still, parts are valuable and a SBC swap is an industry-approved method of keeping these big cats on the road. Find this 1986 V12 coupe here on eBay and located in a garage somewhere in Forest City, Iowa.

And here, we have evidence of the 20 years parked claim! The trouble with buying these Jaguars as projects has always been the high risk / low reward scenario. Owners claim they are phenomenal drivers’ cars, but those are examples running in top condition. To get there, you have to be willing to acknowledge you likely won’t see your investment in repairs returned to you. That V12 may be a honey when it’s running well, but it’s a nightmare when it’s not.

Fortunately, the interior looks quite decent. I tend to see the insides as being a greater indicator as to how the car was maintained while it was running. The exposed wire harness beneath the steering column is of some concern, along with the seller’s lack of detail on why the car doesn’t run currently. Transmissions are fairly durable but worth upgrading if the project demands it; for instance, the V12 Quarterbreed conversion features a bolt-on GM T700 overdrive tranny.

You don’t have to look far to find the (often hilarious) gripes about Jaguar’s V12. Its dark web of Lucas wiring and seemingly endless vacuum lines will make you rip your hair out and the “two of everything” approach to engine building (two radiators, two coolant tanks, two gas tanks, etc.) likely doubles the amount of time basic engine work requires. I don’t even want to fathom attempting a headgasket repair. But to own a V12 this cheaply, the costs have to come from somewhere. Feeling brave, my friends?


  1. wuzjeepnowsaab

    Pull the lump, LS swap and done. Cheap car even with the swap

    • Mark S.


  2. edh

    LS swap and make a coffee table out of the V12.

    • Brakeservo

      There was a Jag V12 powered T Bucket running around Portland – looked super cool and of course offered superb access to that engine.

  3. grant

    My dad’s driving partner had one of these that he bought new in the mid-to-late 80s. He loved it and always stayed up on the maintenance but I haven’t seen him in 15 years so I don’t know if he still has it. He did say that it was nightmarishly expensive to maintain but he wouldn’t have it any other way.

  4. XJSLord

    Expensive parts, tough to fix, parts break frequently, but they drive like a dream. Nothing is better than the sound of a V12 under the hood. I’d keep the 12. My XJS in pic

    Like 1
  5. Solosolo KEN TILLY Member

    I am an absolute purist as far as classic cars and bikes are concerned, however, in this case an SBC sounds like the way to go as having had a couple of them they are horrendously expensive to maintain, even when they are good runners, let alone when they need refurbishing.

  6. UK Paul

    Parts are cheap on a positive. Whats that black box on top of engine?

    • David

      That is the electronic ignition unit. Funny enough, it says Lucas, but the internals are GM.
      You guessed, had to change on mine.

      • UK Paul

        I hadn’t noticed that before. Thanks .. was curious what it was.
        I have nearly bought an XJS so many times in my life and never got around to it.
        They are starting to shoot up in value here now. Too many cars on the drive at the moment sadly.

      • Fiete T.

        My 4L has mainly Bosch, ATE & Hitachi parts…even the AF meter says Lucas on it, but right below is “Made in Japan” and Hitachi. But it runs

  7. Bob

    I have a friend that owned the convertible, and although he loved the car, the maintenance costs finally drove him to dump it for a fully equipped Range Rover.
    The sound of that engine was something to behold!

    • Fiete T.

      Jaguar to a Range Rover..?
      Didn’t learn, lol?

      • UK Paul

        My Range Rovers have never let me down apart from a knocking on the suspension that was a little elusive to track down on my current RR.
        Been excellent as a rule… previous one didn’t even need a bulb over several years ownership.

      • Bob

        Don’t think he didn’t get teased for that.

  8. AF

    This cat is about 1k overpriced. $300 is about right Guv! Stick out ya ‘and!

  9. James P Bandy

    Have two V12 Jaguar’ XJ-S and XJ 12…both fantastic..smooth operator’s Mechanical not problem…..Most don’t understand them and therefore “trash” was mentioned GM Trubo 400 Transmission…The rest same as XJ6 suspension/steering/rear end….and nice interior…a Class act. Am glad that there are the nay, nay, nay soothsayers…hence one can have a subtle great car…(Note the Silver Shadow RR I have, has the same transmission)

    Like 1
    • John Taylor

      I used to work for a Jag dealer out here in Australia and you are so right they are very underestimated, the main problem is people don’t drive them enough, would I own one, yep for sure.

  10. Larry Q

    Sooo…this v12 is basically two inline 6s sharing the same crank..sooo twice the cost of repairs. It’s like that with any v engine

  11. HeadMaster1

    I’ve owned a later 6.0l XJ12 and it was an awesome car, never had any trouble other than normal maintained items. Lose the mufflers, leave the resonators and they sound like a Ferrari…….300hp in the mid 90’s was still a great ride

  12. Ben T. Spanner

    I had a 1990 Rouge edition coupe. (Same color as the submitted photo.) I have had six old Jags, and many British cars, so the maintenance problems don’t scare me. Mine had Marelli ignition compnents to go with the Lucas.

    I have been looking at 1993 up convertibles and coupes. Most are 6 cylinder, but there is an occasional 6.0 L V12.

  13. Cap10

    After back-to-back tranny issues in two of my former DD’s, a friend offered to give me a car he’d had in storage for a number of years. He said he’d have his mechanic bring it up to snuff to pass inspection first. I thanked him and asked what it was. He replied, “An ’86 Jaguar XJ-S”! I chuckled and asked, “Riiiight. Really, what is it?” Then, I remember HIS DD was a Jag XJ-6!

    I’ve had many “hot” cars in my lifetime and remember what it was like to ride in my uncle’s ’70 Ford Torino with a 429 Cobra, but I was not prepared for the smooth torque and never-ending acceleration of that Cat!

    At the time, I lived at the bottom of what the locals called, “Mile Hill”. One day on my way to work, I decided to see what my new Cat would do, so I pulled out of my side road and floored it. Let’s just say I ran out of road before she topped out. She was still pulling—up that steep hill—as I passed 120mph and had to start braking for the light at the top!

    The next day—again on my way to work—I decided to take the twisty back roads. I was having so much fun, I forgot about the sharp left I had to make at a T, just around a corner, until it roared up on me!

    I downshifted the slushbox, gave the stoppers a fast/hard jab, and turned hard left into the turn, followed immediately by a judicious amount of fuel. I needn’t have worried. That suspension and those Pirelli’s dug in and she slipped around the turn with no lean, no sliding, no noise, no problem and the V12’s torque pulled me through! None of the cars in my road-rally days served me as well or were so much fun to throw around a curve in such style!

    As I arrived at work, my cheeks hurt from grinning so much!

    Everything I had ever heard about Jaguar was true: beautiful, powerful, and great road manners… however everything else I had ever heard about Jaguar was also true: if it was cold, the heater didn’t work. If it was raining, the wipers didn’t work. If it was dark, the headlights didn’t work. In short, if it was attached to a wire, IT DIDN’T WORK! USUALLY!

    In my eight days of ownership, my friend’s mechanic had it in his shop on three separate days. I usually do my own auto maintenance, but this thing was beyond me. I had even downloaded AND READ an online book, entitled, “Serious Help for the XJ-S Owner”.

    When I picked it up the third time from my friend’s mechanic (the Senior Service Technician at our local Jaguar/Range Rover dealer) he said, “I know a little about your financial situation from the man who gave you this car. You can’t afford this free car.” (Back in the mid-1990’s, his labor rate STARTED at $120/hr!)

    The next day, I saw my friend who asked me the loaded question, “How’s it going?” When I told him of my plight, he sighed, hung his head, and said, “I was afraid of that. I feel responsible. Let me see what I can do.” Through his business contacts, he was able to work with a dealer on my behalf to arrange a trade for my Jag and both former DD’s with iffy trannys for a more practical, MORE RELIABLE, family hauler.

    So ended my eight-day love affair with the most beautiful car I have ever owned.

    Be careful what you ask for… you just might get it!

    Like 1
  14. Matt

    I think this might be my XJS I sold online 20 years ago. It was great while it ran, but when the computer went I put it online and sold it to someone in Iowa.

  15. Daniel McCoy

    I bought a 1975 xjs some years ago for $400. This car had been sitting outside in all kinds of weather, the body had been sanded , prepping for paint so after over 10 years of sitting exposed, it had lots of surface rust. The floor pans had rusted out as well as the trunk pan…not a pretty sight…bumpers were missing and tail lights broken out by was a major challenge so I got started on it right away…starting with the engine. There had been an engine fire…it was a Jaguar after all, and the wiring on top of the engine had melted…all needed replacement…then the distributer was all frozen up..had to be reworked, cap replaced, new wires….then I got to the spark plugs…one of the rear plugs broke off in the head…so..I put that piston at the top and drilled it out..this required sitting on the windshield and assuming odd angles to maintain the proper angle, but I got it done without damage to the head, cleaned out the mess with a magnet and oil soaked swab, replaced the plug and off we went…ran like a champ. This car looked horrible when I got it…but after buying parts cars, sanding, filling, replacing panels and was a blast to drive. I guess my point is, these cars are a labour of love…you either love them or hate them…and it requires tender loving care and appreciation to own one. I have never considered installing a SBC ..if I wanted a chevy I would buy one…that being said, the V12 is a great engine worth holding onto….unless you are a lightweight and can’t handle the stress….anyone can work on a takes a good mechanic dedicated to the cause to maintain a Jag. You know who you are. I currently own two of these cars, a 1989 coupe with 53000 miles on it and a 1988 convertible with just over 70000 miles…restoration is underway.

    Like 2
  16. Stephen Coulter

    I just bought a Blue 1986 XJS a month ago sight unseen,classic jag wire rims, the pictures my Friend took and sent. (when i brought up i was looking for an older JAG….he said “My Grandmother has one shes getting ready to list”….) The Pictures were enough for me. Paint needed and minor rust but awesome and complete! it had been in family for many years but they weren’t the first owners appears just as she bought it there was a LOT of updated maintenance done @70,000. Now 106,000 Prev folk took care of it- Grandmothers Passed Husband owned a trucking company and besides Factory- his mechanics did some of the maintenance It was COVID-19 lockdown but we went and got it 20 miles away.i called the same VW tech who pulled in my 62 Karmin Bug convertable 20 years ago- i had done a LOT of research, missed several type S 1960’s that just came and went too fast- i was looking only for a Jag 6 cylinder, older and classic is what i wanted.
    My young Daughters New husband is a Kiwi- His Father owns a 61-62 Jag type X racing original and took me for a ride (::::::::). Gone was my Bug project mentality. So i switched to looking for the Jag. the V12 doesn’t scare me a friend had one 37 yrs ago and always wondered about it. But after i saw how to work on the V12 the first thing i did was buy the Books from Ebay- scored the three most important. HE V12 with Lucas all- wasn’t running but had only been 2.5 years since they started it- found a mouse had chewed the Dist point sending wires and it needed all fluids- but oil was pristine. ordered new dist, rotor, and rebuilt the sending wires. bzzzzzt eh eh eh – VROOM! My plan in starting is to replace all hoses, Ign wires, Do all vacuum hoses as well as do a lot of cleaning- i think every system needs to have something or other done but will be fun and looking forward to driving soon.

    Like 1

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