uhmm, that's actually the definition of hearsay.

Funny that you seem to think that either Doug or I have an issue with, or are against, the AJ6 or AJ16 engined XJSs, yet we didn't say anything on the subject.

 

I (actually my husband) has a 94 XJS 6.0. We bought it with 78,000 miles on it, and to say the maintenance had been neglected would be an understatement. It was the car of a doctor's mistress and I think she just put gas in it and drove it. At least the oil was changed semi regularly. However, it had the original spark plugs in it for example.

I did a major service: changed plugs, coils, wires, O2 sensors, air injection check valves, all the fluids and brakes. Also took out the PO's electric fans and put the OE mechanical fan and shroud back in.

We've put 25,000 miles on it, and in the summer it's his daily driver. Nothing V12 related has gone wrong with it, the main thing is relays for the convertible top have failed. I put in heavy duty ones from an electronics supplier and had no trouble since.

One very hot day on holidays when climbing a mountain grade the temperature gauge went quite high and wouldn't come back down. Fortunately, it was home the next day and cooler, so the car ran ok. Pulled the radiator and the fins were plugged with sand. The car was originally sold in Florida, perhaps the owner liked going to the beach? I knocked about 2 lbs of sand out of the rad and cleaned it up. Ran cooler after that and the needle doesn't budge in traffic with the AC on, and it used to climb. However, that's not a V12 related failing.

After initially bringing it up to standard and fixing things that I knew were wrong when I bought the car (AC didn't work) it has cost virtually nothing for unscheduled repairs; only scheduled maintenance (oil changes). Considering it's a 22 year old car, it has been very economical to run.

Would I prefer an AJ16 engined XJS over a 6.0? No, I like the extra power of the V12, and the interiors of the late V12 cars are much nicer than the 6 cylinder versions. I have had several V12's and AJ16'ed Jaguars over the years and don't find one or the other particularly more reliable than the other. When buying a used car the treatment by the PO is more important. Given the coil supply problems and sticking throttles of the AJ16's I think I'd rather have a V12.

 

That's great.

I have actual, real world, honest-to-god, did-it-myself, hands-on experience ** actually owning and repairing ** Jags with ** both ** V12 and AJ16 engines. That should count for at least as much as your *observation* of other peoples' ownership experiences, wouldn't you say?

It appears...to me, at least.... that when others report a happy V12 ownership (from their own, real world, hands-on experience) you don't really seem to acknowledge it.




The AJ16 is essentially the same in all applications.

Anyhow, the point is this: having the AJ16 doesn't ensure a happier Jaguar ownership experience. Even AJ16s can have problems. And, as often as not, the woes of Jaguar ownership don't have anything whatsoever to do with the engine.

Cheers
DD

 

Very well put Doug. There seems to me to be a great deal of confused claims being attributed to the V12 owners. AFAIK, none of us have claimed the car will be reliable without a proper maintenance and replacement schedule of the required parts. It is also true in the UK, and from what I read on the forum in the USA, that most garages have no idea how to properly maintain the XJS. What I have found is that with such a regime and with proper knowledge of the car, the V12 XJS is extremely reliable.


None of us has claimed that the cars are often as not sorely neglected when bought second hand and need the backlog of un-performed maintenance to be sorted out before the car becomes reliable. None of us has claimed that access to certain parts in the engine bay is easy.


Context is also important. Critics of the V12 car cannot reasonably expect a car designed in the late 1960s and launched in 1975, which was faster than almost all its supercar rivals and considerably cheaper, not to require regular maintenance and planned replacement of parts. To hold that a 150 MPH supercar designed 55 years ago is not reliable because it will become unreliable if not serviced properly is obviously unreasonable.


In my own case I have driven over 100,000 miles in my car and it has only let me down once, because I had no idea at the time that the injector loom might need changing after 15 hard hot years. The car's fault? hardly. Of course it is mightily frustrating for an owner to be endlessly paying garages who are, in fact, ignorant of the car, to not find a problem; but that is not the car's fault either and does not make the car unreliable either.


The point of a forum like this great place is to help people who are up against it with problems they or their garages cannot solve. As far as I can remember just about all posters who had a problem and stuck with the advice and help offered, have solved it. And I am very hard put to think of any solution that was anything other than requiring a simple fix - once the problem had been identified. And equally hard put to think of a problem that was NOT caused by the lack of a regular maintenance and planned replacement regime.
Greg

 

It's actually pretty good. The car was obviously designed by people who have worked on cars. I had to replace a heater hose and there is just enough space to get in the necessary tools to do the work, and things were placed at an angle to allow for access.

Contrast that to my Saab, where the entire injectior rail and intake manifold has to come off to change a thermostat. It's still difficult, the easiest way to do it is to remove the cylinder head too. Or changing a coolant temp sender, where if they moved the mounting point about 3/8" it could be unscrewed without having to remove the throttle body.

The advantage of the V12 is just about everything is on top. There is virtually nothing under the intake manifolds that needs to be accessed. On the newer engines with the Sanden AC compressors the front spark plugs are accessible too. Compared to the Saab, the V12 is a joy to work on. The V12 is a simple engine, just lots of it.

 

And the initial V12 intimidation disappears rapidly once you've been elbow deep into one.



Yup. In my experience the important thing to learn and remember is that slower is faster. That is, work methodically and avoid attempts at shortcuts....and the job will actually go faster.


Cheers
DD

 

This has been interesting to read. I had a 90 XJS V12. I bought it for a bargain price and though it ran well, I spent a lot of time trying to catch up on neglected maintenance. I did most of the work myself. I learned way more than I ever thought from the experience and even though the engine bay is a tight fit with the V12, a majority of the issues weren't related to the engine, but the perishable (hoses, wiring, belts, etc). The 90 is NOT a complicated car and I really enjoyed my experience with it. I got the bright idea to trade it for a 2012 Lincoln MKZ. While that's a nice car, I really miss my XJS.

I've been looking for another and found a 6cyl that looked good, but from reading this I'm leaning back toward a V12 again. I've located one that has been very well taken care of and loved. I thought it'd be interesting to try that and see how it stacks up against my previous XJS.

Tony

 

Sounds like you found a really good example, if you love the car then go for it!


I've owned my XJS Celebration for nearly 12 years (I tend to keep my cars for a while...)


Reliability wise it's been pretty good, only the high idle and the occasional A/C top up required.


The only things against the car are...
1. Getting parts for the facelift cars are becoming more and more difficult and in some cases more expensive.
2. Bodywork, bodywork...make sure you look over the car very closely.
3. The bushes are not the best I've ever come across...haha.
4. Although I'm 41 I still have problems with insurance, although I've never had an accident or made a claim.


Make sure you find a really good Jaguar garage or enthusiast in your area to help you with any issues.


Mine is a daily driver and because I have no garage at my property the weather has taken it's toll on the bodywork in the last four years. So planning to get the car properly sorted next year, but subframes and underneath are pretty good for a car that's 20 years old.


My Father has one of the Daimler Centuries with the 6.0l V12. Amazing engine and really smooth to drive.

 

I love my 1996 XJS, the mileage is very low,under 10.764 miles .
They are several cars that I would love to purchase...I would love to buy a 1995 XJS V12 almost did a week ago but the seller was asking too much money for it.
I will continue looking but I'm also open to acquiring a 1986-87 XJ6 with very low miles or a 1996 XJ12 also with very low miles or even a Canadian 1992 XJ12, almost did but it had rust.
A little while ago I almost purchased a 2002 XJR-100 off CL out of Florida with 10.000 miles on it but I was too slow to respond to the seller and it did not happen.
Best time to buy a car is between Fall and Winter as sellers do not want to store their cars , so I'm hopeful Anyone? aha aha !

 

Since I don't have a solid Jaguar mechanic in my area who will touch that engine...I would not buy it.

 

YUP, the snooze and lose dilemma.


Way back when, dear departed wifey decided to hang up her keys.
Driving never her strong point. At the time her car was a nice fixed by son and I 66 Mustang 289 powered fast back.


Got two prospects to look. Why at the same time, I've forgotten. good thing or not so good, not sure.


Two brothers interested as it was almost the car their dad had. Including the in dash factory 8 track!!!


The other a dad and young son. Youngster's first car. Lottsa hemming and hawing here.


I saw brother pair a bit agitated. so, I looked to them. One said, "we will take it". Full asking price. Done, was my response.


Dad and son not pleased. I told 'em, you had the chance. Dad reluctantly, but unhappily agreed.


A teaching/learning opportunity, I think so.


I liked that car, but, it was truly surplus. And a relief to me and the kids.


After all, wifey had a driver, me!!!


Carl

 

From my limited experience of 3 years with my 1990 XJS, I love her.

The "problems" are mostly finding parts. A lot of what I've had to do is honestly just maintenance issues from a 26 year old car. IF you can do the work yourself or you have a specialist mechanic that likes you, you can certainly enjoy the car. But as others have said, maintenance is key, and that's where it gets you.

For example - my car was starting to run hot. Not "it's gonna seize don't drive it" but hot, with the auxiliary fan coming on a lot, etc. Radiator needed to be removed, cleaned and re-bored. And while it's out, let's replace these hoses. Oh and both thermostats. And you know you really should do the water pump with all that...$1800 later that's done. Yeah, it was a lot, but then a lot of work was done, some of it preventive.

That said, I love the car. You do need to be patient with them and they are more of a relationship than a driving machine ime but when they run, there's nothing like a V12.

 

I agree with gkazimir. These cars are more than just a machine. They take on the Child status. My next door neighbor (a lady) used to ask to take my 90 xjs v12 out for a date. I was very apprehensive about that fearing the car would have something go wrong and end up sitting on the side of the road. I could likely find the issue and get rolling again in no time.

It doesn't take long for you to just know what's up with the old girl. I traded that one in last summer for a newer Lincoln (big mistake), but have since acquired a 94 AJI6. It's a great car, but it has its own set of issues to work through. I think that is part of the overall charm of Jaguars.

Tony

 

An original v12 pre he head flow 153cfm at 28"
If you take Stan Weiis calculator it will support about 475 hp if everything i stuned and VE is good.
I have ported Pre He head with +1mm valves up to 185 CFM
This supports 570 hp. but this is not tested on the dyno yet.

The Stan Weiss link
Flow-HP

 

Hi

Do anybody actually have dynopapers from their engine? Shassis dyno or engine dyno..