At least when I was shopping an XF (the new XJ had grown too big for my garage), my research indicated that 2012 was the last year for the NA v8 in the XF. It was 2017 and I originally was thinking a 2015 model, but I had previously driven an XK with the NA V8 and I just thought that it felt and sounded better than the supercharged v6. But more than that, I'm a DIYer and I figured that the NA would be easier for me to maintain and repair myself rather than having to R&R a supercharger to get it out of the way for other routine repairs. However, I preferred the newer look and so I decided to seek out only a 2012 model, the last year of the NA v8 and first year of the facelift. Took months to find one with low miles. But the poor XF, was rather indistinguishable from my brother's Lexus ES350 when parked next to one another (I swear there's not 5% difference in the roof line of both cars.) Just so that people wouldn't think I was driving just an ordinary grocery-getter, I purchased a 5.0 trunk badge for the XJ from Jaguar and installed on my XF. I forget what year model they looked up to find it, but I think it was only on one or two eariler year models. I've seen a lot of 3.0 badges on both XFs and XJs but I think most 5.0 cars were de-badged because I've only seen three others besides mine.

 

Getting back to how can you tell the V6 from a V8 when you lift the hood on an XJ. Correct me if you know better, but none of the V6 XJs have the symposer which is visible on the firewall. I don't know if all the V8s have it, but I think they do in order to amplify that throaty growl preferred by those who want the sound to go with the performance.

 

I'm 99% sure all V6s (AJ126 that is) got the symposer up until it was discontinued, XJ included.
I know all V6 F-Types got it until some time around the 2022 models when it was discontinued on both the V8 and V6, but seeing as the XJ had been discontinued by then it didn't make any difference to the XJ.
And many F-Type owners (me included) have disabled it because it sounds crap, which is a 30 second job.
Removing it altogether is a whole 'nother thing though as it's a real PITA to access the various parts and pieces, especially on the V8, and you need a way such as a blanking plate to plug a hole in the rear.

 

I agree,, Chris, 100%, and really miss our 2012 XJ-L............

On a side note, could someone explain what a "symposer" is, and what it does? Thanks!

 

Well I found the sound from the symposer to be weird? If it was a throaty growl I probably would have left it alone. But on my XJ and especially after I put a tune on it the noises the symposer made were just a bunch of odd noises. It was embarrassing to me when I had passengers because it would make a strange noise at an odd time.

Even when stock I always thought what is that noise?? Then I learned about the symposer and how common it is or was to pipe certain engine noises into the passenger cabin. Many cars do this so not uncommon at all.

I have to say just like the soft close doors I wish Jaguar had used that money on something of value instead.
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OzXFR, my 2014 XJ super charged AJ 126 does not have the symposer and I know other 126 owners have indicated they do not have a symposer on their XJs. When was the symposer discontinued on the 126 engine specifically in the XJ. My impression was that the Land Rover V6 and F type V6 had it but not the XJ V6s. No big deal if we really don't know but I thought I'd ask.

 

It's hard to see on the XJ? Way in the back and not easy to get too. When I disconnected mine I had to put a blanket on top of the engine so I could lay on the engine to access the symposer.
I have a 2014 with a V-8 and it did have it.
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I read elsewhere that the six was an eight with two "dead" cyclinders which I didn't believe for a minute... no way they'd have two empty cylinders just chilling there. This I can believe though, and it saves redesigning most of the supporting hardware so it seems like a smart move to me. I also found a thread where a guy found a coffee table made from one and you can see it pretty clearly here too.

I barely slept last night with this question on my mind - does this mean a 5.0 should just bolt into any car that came with a 3.0 without major fabrication?

 

From the AJ133 Technical Training pdf (April 2009):

 

Thanks for clarifying that, I learn something new every day!
I have no idea if or when the symposer was discontinued on the XJ V6, but it seems likely it never got it in the first place.

 

Read on another thread that the trim dictates the engine type, is that correct?

R-sport is always v6
XJ Supercharged and XJR are always v8
Portfolio could be either though?
Were there any other trim levels?

 

No Well, sort of no.

In the UK at least, most trim levels could be selected with a variety of engines (leading to diesel R-Sports!) excepting the Supersport and the R, which were always the relevant 5.0 SC V8. And after 2018, when all the not-R cars were diesel. (... but the diesel is a V6, so R-Sports & Portfolios were always V6, but not always petrol)

Trim levels in the UK were (complicated but the fact that they varied from year to year):

Luxury, Premium Luxury, R-Sport, Portfolio and Supersport. Then Ultimate. After the facelift the Supersport and Ultimate were abandoned to be replaced by R575 and Autobiography.

In the UK Rs were SWB only, Ultimate and Autobiography were LWB only.

I think.

 

V6 LWB supercharged portfolio/autobiography one of 7 made for the UK market

 

Mechanically yes, but electronically there are dirrerences, so it is not a direct swap, nor economically sensible project.

 

Thanks!

 

Absolutely stunning motor.

 

LOL I am not known for choosing "economically sensible" projects 😂 I have an XES, and the news that my engine bay will take a 5 litre is rather interesting to me...

Thanks

 

Just trade it in on a Project 8!
A heavily modified XE with the highest factory output for the AJ133, 600 HP.
But relatively rare and not exactly cheap.
Seriously though, although the V8 will obviously physically fit in the engine bay of an XE the electrical and computer/module modifications alone needed to get it to play nice with the car would be an absolute nightmare and most probably end up costing you more than it would to trade up to a Project 8.

 

A Project 8 is the dream, but according to this article "... only 300 are being built by SVO ... and they are all left-hand drive, so the Project 8’s not road-registerable in Australia." Is that incorrect?

To be honest this idea will probably never happen, but the fact that the engines are physically the same size has got me doing some serious thinking....

 

Yep, all Project 8s are LHD so only a dream in Oz.