Even before I purchased my first XK8, I had loved the XJS. I am now quite seriously contemplating an XJS V-12 convertible. I have been reading the forum trying to educate myself as to what issues I can expect. I think my favorite analogy was its like a horse, not very practical, but if you know what you're in for and love it, then it can be worth it.

My question is with regards to different model years. Does anyone know of a source that has the differences by model year? I am looking at an '89 5.3L right now. I don't know how that compares to a 94-95 6.0L. Is the 5.3 any less reliable as a motor? Any problems in particular to the '89? I know that the 12's are hard to work on either way. Any tips?

Giddyup!

 

In the 'How to' sticky at the top of this forum, you will find an XJS buying guide that has good tips about what to look for.

Also in the downloads link in the sticky, you will find many year by year update documents that show changes introduced in each model year.

Obviously later cars benefitted from some more modern enhancements to the engines and drivetrains, also important things like zinc coated body parts and waterproof connectors and such.

Reliability wise, it really mostly depends on how the car was maintained as even the later cars are now pushing 20 years old.

Cheers,

Allan

 

Some very good questions, and since I recently went through a similar "what year do I want?" search, I might be able to offer a few tidbits. Definitely read through the How To sticky Allan mentioned, though; that's where I got most of my info!

On the V12s, you have 3 more or less "distinct" flavors. Before 1984, you have the non-HE versions, most of which used Opus ignition. They're known for less gas mileage, and fewer "creature comforts". Then you had the HE V12s from 84 on, and from 84-88.5 they used Lucas ignition, which was generally regarded as better than the Opus and not as flakey/dangerous as the 88.5+ Marelli ignition. In 1991 or so you got the "face lift" cars, which changed the front grille/headlights a bit, and more importantly (ruined, in my opinion) the tail lights. You then get the 6.0 V12, which from what I've heard generally was a slightly better engine than the 5.3 HE V12.

For me, I decided that I didn't like the post-facelift styling, and I really didn't want Marelli ignition (How To link should explain most of the differences, and each ignition type has their own "special" needs), so that pretty much meant an 84-88.5. I decided I didn't want ABS brakes, which were introduced in 1987 I think, so that meant 84-86.

Edited to add:
You said you're looking at an 89, which definitely used the Marelli ignition. I'd strongly recommend checking the How To links and the buyer's guide by Doug, as there are some definite things you will want to look for and/or ask about. Main thing, for all XJS really, but the Marelli cars in particular, is fuel lines and distributor/rotor. All the normal used car stuff applies too, of course, but be extremely critical of the fuel injection system, as faults there are both common and can easily result in fires.

 

Hi Guys,

Thanks for the input. I have read the buying guide and have started in on the "book". Unfortunately, they are giving me second thoughts

The car I'm looking at is in great shape and lower miles, but it looks like Valander is right and 94+ or 84-88 would be the way to go.

I still have to find out if the Marelli ignition was maintained, or else try to deduct that from the price if I decide to go ahead. It would be great if somebody came up with a conversion or some other ignition system to replace the Marelli (maybe I'll come across something).

Anyway, thanks for all the advice... especially if you have some first hand knowledge like Valander, let me know your thoughts.

Thanks,
Nick

 

Mind if I clarify a couple things ?



Pre-mid-1981 are the "non-HE" V12s. The HE engine was introduced in calendar year 1981 (July?). For the USA these was "1982 Model Year" cars.

(BTW, Jaguar got really weird on "model year" designations with the USA-market XJSs. But that's another story)





Using USA model-year designations that would be 1982 through 1989½. Marelli cars came out in calendar year 1988, yes, but it was during the 1989 USA model year. So, early (USA) 1989MY cars had Lucas and later (USA) 1989MY cars had Marelli. The VIN break was 156xxx.



ABS was 1989 model year....again, using "USA speak"


Cheers
DD

 

Thanks for the clarifications, Doug. The USA MY and production date thing can easily throw one off; it certainly does me sometimes.

As for my "first hand knowledge," it's really quite limited. As Doug points out, the exact MY thing is less reliable on when a particular change was done than the actual VIN, and I'm pretty sure there's a list somewhere that indicates where those changes happened.

And I definitely didn't mean to (necessarily) scare away from Marelli ignition; if it's maintained, it can be perfectly fine. But it's pretty common that used cars are not maintained that well, so it's something to be very aware of. If the car you're looking at has good service records, etc., then that would be better than an unknown of a more "targeted" year. A lot also comes down to how comfortable you might be doing various jobs on your car.

 

Mareli was introduced somewhere around March 1989 my car is an April build and has Mareli. From what the previous owner told me this was one of the first in Australia, and was used in the 6.0L until replaced by the Ford EDIS in I think about 1995/6. My 1994 6.0L spare engine has Mareli.

The Mareli system is not flaky if its maintained properly. Main problem (Fom my point of view) is lack of maintenance, mostly the failure to replace the front plugs, this causes the spark to find its way to earth via the distributor.

 

Well, I went and did it. I went out to look at an '89 V-12 convertible with 48,000 miles on it and I drove it home. Exterior looks great and interior in good condition. Owner had it serviced when needed, but has not had any preventive maintenance performed. So it looks like after 24 years and piece of mind I am going to need to inspect and possibly change the cap and rotor, replace plugs and wires, and possibly replace cooling hoses. The previous owner just had one blow out a couple of weeks ago, so if one was ready to go...

Boy, what a great ride. It really is something to be behind the wheel of such a unique car with a smooth V-12. I have never driven anything that just feels so good to cruise. My XKR runs great and is tight and fast, but the XJS is just a very nice combo of large luxury, sporty fun, and smooth British power.

Already a few gremlins. Somehow the door locks got out of sync and I couldn't unlock it. Manually setting them both to unlock seems to have solved the problem. With AC on, the condensate was dripping on the exhaust causing steam when I shut it down and I thought it was smoking for a bit. Speedometer is off about 8 mpg and cuts in and cuts out at random.

I have some experience working on vehicles. I do much of the work on my cars, but still have taken them to the shop for some bigger jobs. Just one look under the hood of this beauty and I am smart enough to know that I am in trouble. Hopefully with help from this forum and its great members I will enjoy working on the new Brit, instead of intimidated by it.

 

Congrats! Going through and doing hoses, plug wires, etc. is a good plan, and what I'm in the middle of doing. It might be a good idea for extra peace of mind to have a compression check done, too, just to know where you stand.

Speedo going in and out could likely be earths somewhere, as I believe they're all electric, not cabled. Flaky earth connections are definitely common gremlins on the XJ-S.

And yeah, that ride is something, innit?

 

Welcome to our world, you never own an XJS is it a love affair (as my wife says the other mistress).

Definitely do ALL spark plugs, leads and pull the dissy cap check the rotor and cap, replace if needed. Being an 89 it could be Marelli or Lucas, Marelli cars have 2 ignition modules on the radiator top support.

Mostly the front plugs never got changed in the 5.3 because of the AC compressor. To change them just unbolt the compressor and lift it out of the way, you do not need to disconnect the lines. I used a vacuum to clean the crud from around the plugs before I pulled them out.

Let us know if you need more help. Good luck