at the risk of covering old ground, I am considering an XJS, and trying to decide between a 6 and a V12. The heart says V12, the head says 6.
I figure that a good AJ16 or AJ6 4 litre will be lighter in the front for handling, yet reasonably easily tuned up to, say 260-280bhp with straight forward mods. That would make for a reasonably quick, nice GT car.
The heart wants a V12, preferably a late 6 litre for the extra power and 4 speed gearbox, then go down the AJ6 Engineering route of bolt-on mods, aiming for about 350-360 bhp. However I haven't seen a 6 litre XJS for sale in NZ despite a year of constantly watching. I don't know how many 6 litres were sold here, although there are a few saloons.

Others of you will have been through this process before. What are the opinions?

some XJSes for sale in NZ at moment - asking prices are rising, but not many selling it seems - http://www.trademe.co.nz/Browse/Cate...ch_suggested=0

 

Al,

The XJ-S is V12 only in my opinion.

I know the +++ for the 6, especially as you said, when maintenance needs doing.

The weight would be so close as to not really have a huge effect on wear and tear items.

The 6ltr is SKINNY on the ground down this way, no matter what others say.

A real late 5.3, with the Marelli etc etc, sorted is a very reliable beast. Of course there will be that loooooooong catch up list to be done, as with any car.

Do the "Ron Moore" manual trans conversion. Wake that beast up, and you will end up on the other island in no time flat.

It is a tough ask, but thats my 2 cents worth at 45c outside, and 46c the next 2 days, bugga.

 

I'd rather have a V12. There's just something about "V12" and "XJS"....they go together like a hand fitting into a glove. Know what I mean?

But a 4.0 six cylinder car with a 5-speed gearbox would be a real treat as well, I'll have to admit.

The youngest XJSs are now, what? 17-18 years old? Unless you find (and pay for) an exceptional example be prepared for rehab work....a "looooong catch up list", as Grant says. Many have not been particularly well cared for. And the 5.3 V12s have some special needs that often go unsatisfied. We can help sort through those; not that big of a deal and, for many, part of the fun.

Since you're agreeable to either I wouldn't rule anything out. Do plenty of searching and shopping. When 'the right car' comes along, you'll know it.

Cheers
DD

 

Grant is 100% correct IMO. As long as you enjoy fettling cars (and do not buy ANY Jaguar if you do not) the V12 is the one. After a V12 the six, although a lovely car, feels somewhat gutless. I have a 5.3 with some of the AJ6 stuff on it, and it is a rocketship. I do not believe the 6 litre V12 is so much better that a good 5.3 HE (Lucas or Marelli ignition) with decent bodywork should be passed up.

The guys on here will give you a pretty comprehensive list of what needs to be done to turn an XJS into a reliable car, and the V12 list of things is not much longer than the 6's. Mainly to do with oil leak prevention and radiator/cooling system maintenance. Apart from the engine/gearbox the cars are identical.

Those of us who let our hearts rule have never regretted it, and neither will you. Once sorted the cars are reliable, it is bodywork condition you need to beware of though. Look for RUST everywhere, never buy one without going underneath (car on ramp so you can really see everything) with a screwdriver. All carpets up, boot carpet up, sills, jacking points, etc etc etc. Poke everything, HARD. It is the bodywork that will soak up the time, money and break your heart, if it is in poor condition.

 

I think it depends on what you are looking for. The silence, smoothness and silkiness of the V12 is definitely alluring but from a performance perspective, I will differ from the others by saying it is a bit slow and ponderous (in 5.3L form with a lazy 3 speed autobox)

My 4.0 with 5 sp manual gearbox will easily out accelerate and out handle any stock 5.3L XJS and is a much sportier ride. If you can find a 6.0L then that would be a touch faster and the 4 speed autobox improves responsiveness but handling would not much better, the nose is too heavy.

Either way late model 94-96 XJS are the best in terms of build quality and reliability in my view.

 

We can probably get the list started for comparison.
I'll start by providing the list for th six:
1. Clean throttle body
2. Replace camcover and spark plug gaskets.

Done.

Who wants to do the list for the twelve?

 

Heh heh.....

For an older 5.3 V12 that'll be a long list! Some items will simply be age related, others more along the lines of 5.3 quirks that must be addressed. A higher amount of dedication and owner involvement required to sort through the list. But, as long as the list is, it's all low-tech DIY stuff. Do it all, do it once, do it right.....and you're good to go for years.

For the 6.0 V12 I thinks it's more along the lines of drive it and fix whatever problem needs fixing as it crops up. The six cylinder (the AJ16 at least) is about the same.

Let's not suggest, though, that choosing a 6-cylinder car positively guarantees a no-hair-pulling-required ownership experience. It doesn't. Not, at least, with the AJ16 version. The engine itself is a gem but the engine management system....not so much. Some of my driveability problems with the AJ16 have left me positively longing for my old 5.3 V12 ! Coil failures, fuel trim problems, check engine lights, phantom trouble codes, crank sensors, misfires...the list goes on.

Cheers
DD

 

Doug,

I completely agree with you. I'm often baffled that people believe the AJ16 is superior to the AJ6 in terms of reliability. In my experience it is the opposite. The AJ16 is, as you say, let down by it's quirky engine management. The old school AJ6, although having it's own quirks, is by and large a workhorse and easy to work on and understand

 

I've had none those issues crop up in my 40,000 mile history over two AJ16 engine cars.

I do admit that when I first bought the second car (first one was rear ended, thus totaled), it did have a high idle that seemed to be resolved only with the Jaguar PDU. All other attempts at a reset using the manual, did not stick. Ever since that reset a year and 10,000 miles ago, the car has been solid. The previous one, was just as consistent.

I think the previous comment was dead on. Look around and buy the best XJS you can find. That could end up being the 5.3, could be the AJ6 or 16.... I think when you find the right one, that's the one you buy. Perhaps you don't go in there with a preconceived notion.

Ultimately either 6 should be less work. If you don't mind the extra work, and find a well sorted v12, that could be a better deal.

 

Just wait


XJSs nowadays are often just pleasure cars and they don't rack up high miles and, as results, seem to suffer less.

A higher mileage/higher use XJS with the AJ16 would probably be a different story. Scan the X300 list for a taste of what can happen . The X300s generally get quite a bit more use.

Cheers
DD

 

I love my V12 and would buy the V12 again. I use my XJS as daily transport to and from work.

I have a late pre-facelift 1989 build sold in Aus 1990. Marelli and lip seal rear main. It has been fantastically reliable even when I bought it from a barn unused for 9 years. I did basic maintenance and then drove it 7000km across Australia. Even did the last 1000km on 11 cylinders due to a faulty ignition lead ( I didn't replace these) and it was hardly noticed.

The ONLY times it has let me down was when someone had done something (like leave the thermo fan fuse out or nick a radiator hose with a screwdriver)

 

After initial sorting-out (all the usual stuff) I had great luck with my '88 V12 as well. I used the car for many 500-600 mile weekend jaunts. Never skipped a beat !

The ONE time it conked out it was due to an error on my part. I had left the distributor wiring connector only partially seated. Over a period of time it worked itself loose. Gah!


Cheers
DD

 

has to be a V12. There is nothing better than the joy of opening the bonnet and seeing a real engine.


As for "lazy" I would seriously dispute that. There is a big difference between a small engine revving its guts out and a V12 putting its power to use without fuss. There are not too many 30-year plus cars that will comfortably move at over 240kph (yes I admit to having done that on Australian roads) in total safety. Try that in any other car other than serious exotics at much higher prices.


the XJS in V12 format has lost none of the base criteria against which it was designed, e.g. high speed, long distance cruising in absolute comfort. The 6 cylinder version simply cannot match that.


enjoy
BernardS

 

Yup! The 5.3 XJS will reach and hold high cruising speeds with great ease.

But the same long-leggedness that makes high speed cruising so easy also....well....blunts the thrill of acceleration at legal speeds


Cheers
DD

 

V12. End of message.

Its worth it alone just for that alien starter cranking noise that sounds more like a jet engine cranking. And if you actually get one that starts and continues to run, thats just icing on the cake!

 

just as sarc says. I'm v12 all the way. I had a 95' six for 4 months and it was great.
but my 12 is the 1st love.

 

I would say they are totally different cars. You could drive an AJ16 car as it is a light weight sports car. The V12 engine is heavy, but thanks to the weight on the front, it runs really straightforward on the highway, from which you feel less stress.
About the sound, the V12 is far better when you fabricate the exhaust! It is fun to drive in a highway tunnel lol
Some say V12 are just a GT, but you can drive it like a sports car with a little bit fat tires if you want to.

6.0 produces more power and 4AT is nicer when considering transmitting engine torque to the axle, but I prefer 5.3 + 3AT, it is much smoother. Plus I hear some cases where 6.0s are broken, because of the poor gas flow in the head. My friend had his cars piston melted during a highway use.

Referring the seats, the latest integral headrest seat looks better than older ones, but when you sit on it the older ones are much better.

Mine is a facelift 5.3 '92, I use it as my daily driver(I drive it more than 10K miles per year!) and haven't have any problems. I think it is even more reliable than X300s.
I replaced all the ignition parts and cooling hoses, f/r subframe bushes, fixed oil leakage from the front crankshaft seal, and that makes my car a reliable one. Actually I replaced Ac hoses too, I can't survive the summer in Japan without AC!

No other V12 can be affordable and reliable like this.
I also recommend a V12 car.
I don't think it is such a terrifying car.

 

Japthug,

I like the comment, ",,,,, not terrifying at all".

I reckon that is created by us to keep the prices down so we can afford em.

Looking at the world market, just for giggles, ours are seriously high $$ in my opinion.

 

My AJ16 XJS is my daily driver, driven in rush hour Tampa traffic and it hasn'y failed me once in 6 years.
Having said that my AJ16 '96 Vanden Plas has faults with the idle and stalling and throws no codes. After screwing around with these problems for two years I've thrown in the towel. I'm parting out the '96 and bought a '90 XJ40 Majestic as its replacement.

As a daily driver and with sportier handling a 6 cylinder XJS can't be beaten, but then there's that V-12...

 

Face it. You can either follow your heart, or you can spend the rest of your life kicking yourself because you didn't get an XJS with "the REAL motor".