I have read a number of posts dealing with engine issues of the AJ16, especially related to trouble shooting of bad idle, ignition or fuelling.
I understand that the latest version of the iL6 engine was conceived to be the best of all, with all possible mechanical/ignition/fuelling issues of the AJ6 satisfactorily addressed.
Mechanically speaking this seems all good, but in terms of ECM and because of the electronic control of functions, it seems that when issues arise, they are much more difficult to solve.
In particular, the "adaptative fuelling" of the AJ16 can become a nightmare because the PDU that is required e.g. to make "resets" is no more available while fuelling issues can be easily addressed with the simpler AJ6 engine.
Why did Jaguar and dealers not maintain tools to correctly solve such engine issues and can we expect that appropriate tools be made available in the future?
If not, does this mean that an AJ6 would be a safer/better choice than an AJ16 (all other things being equal) when looking for the long term use of an il6 XJS with peace of mind?
Incidentally I bought my AJ6 XJS without being aware of that...

 

I'll wager that *some* dealers still have the older diagnostic equipment and tools in good working order to the extent that corporate Jaguar can/will provide support and/or suitable substitutes...which appears to have dwindled to virtually non-existent levels. I'm sure some of the dealer tech who post can elaborate. Plus I think there are some aftermarket offerings that do most of what the official Jaguar equipment will do.

I reckon, more than anything else, it comes done to consumer demand. As cars age they are increasingly less like to see dealership service departments .....so there's increasingly little need or incentive to support/purchase/maintain specialty tools and diagnostic equipment


Hard to say. When I sold my X300/XJR there was a slight relief knowing that I wouldn't have to face the problem of re-orienting oxygen sensors or any other operation requiring special equipment. Not that I was being kept awake at night with worry, mind you . I stepped back into older Jags that are 100% DIY.

I think it's a legitimate concern looking forward, though. The AJ16-powered cars are known to be quite reliable....but age will inevitably start taking the gloss of that reputation and the need for PDU-type equipment could end up being a more serious issue than we've experienced thus far.

Let's hear what others have to say.

Cheers
DD

 

Yes it does, the smallest amount of electronic stuff on any car, let alone a 25 year old one, the better! The dealers cannot even fix mystery electronic faults on the most modern of jaguar and all other makes of car. The true horror stories abound, even the JEC magazine prints a few of them each month.
Greg

 

Totally agree, Greg and Doug. Electronics and age do not mix well, as the electronics that may offer advantages in the early days will certainly come back to hurt you with age. My '02 XJR is seriously more electronically complex than my AJ6 XJS and in the early days everything was just fine with it, but as the car aged, things changed and fixing them (i.e. finding intermittent problems) has become very different from fixing my XJS. I remember about three years ago, when this tech at the shop was trying to find my XJR's intermittent running problems, the cockpit looked down right scary, as he had I don't remember how many laptops going in the cockpit with the whole dash completely disintegrated apart and scratching his head for days...and that was three years ago and guess what... by coincidence just today I have taken it back in for the same reasons, intermittently going on limp-home mode. Well, this is when I count my blessings with my AJ6 XJS that I can trust going anywhere without stranding me. Can an AJ16 XJS necessarily be trusted equally, although honestly, I hardly ever hear of face lift cars with engine running problems, probably because the leap from the AJ6 engine did not imply the degree of electronic design changes that the AJV8 engines brought about.

Cheers,

 

Well said Reinaldo-

No doubt that as each year went by with Jaguar the potential for more electronic issues has increased. Any one doubts this just spend some time on the XK8 forums and you will quickly see how many modules etc. can leave you stranded or put you into limp modes.

Heck even the no touch power top on the XK8 can present all types of issues that we with the XJS convertibles will not run into like " green showers " and auto latch problems.

What I am seeing with the XJS is every year can have it's unique set of issues and this can even be an issue within the same year based on date of production. For example I have two '95 XJS' and one is a early production '95 and the other is a late. The late '95 has the better ABS system and I can also communicate with my late '95 OBD2 system with my cheaper scanner but I cannot with my early '95.

Another issue I have seen come up many times in the last 5 years is the issue of the '96 XJS with the AJ16 having a high idle. I even ran into this myself on a potential '96 I was considering to purchase. I have not run into this issue on either of my '95 XJS' so my guess is Jaguar changed something on the '96 which is making the high idle issue more common on the '96 then any year before that.

I am not saying this cannot happen on the '95 but sure appears to be a bigger issue on the '96.

We are all VERY, VERY lucky to be living in a time where we can access information on the internet like we can now on forums, you tube etc. This has allowed the average guy a fighting chance to be able to work on much of this stuff themselves and will allow many of these cars to be driven well into the future.

I chuckle when I hear someone new to XJS' say " take it to the dealer to get it checked out cause they are the experts ". There is more knowledge on this forum about the XJS then you will ever find at a Jag dealer as they have been working on the V8 for so long they would not even know where to get started on the V12 or 6.