Probably exists on these forums somewhere but if someone could direct me where or simply opine on this thread it would be much appreciated. I am looking for a laundry list of things that are trouble spots with the 6.0 litre V12 that should be replaced or upgraded to increase reliability, and lifespan of my XJS. Thank in advance for any help in locating a similar thread or suggestions anyone may have.

 

Hello Texknight

The best opinion I can give to new owners on the XJS is to start reading this forum from page 220 through to page 1. A lot of question regarding reliability and life span has been addressed. You will read the stories of cats blocking up and causing fires - of fuel lines cracking and spurting fuel on hot things as well as the joys of overheating engines. Fuel smells in the cabin area due to the fuel tank being in the boot, rust prevention, suspension rubbers wearing out and the list goes on.

In saying that - there is a lot of posts and it took me about 6 months to get through all the ones that I thought was "relevant" to mine. But I sure learnt a lot.

Also learn to use the Threads search forum function at the top right of the screen, it works really well

The points I mentioned above are pretty standard to any older vehicle - low or high mileage, you just need to learn where everything is

Any chance of posting photo's

Cheers
Steve

 

Tex, I suspect many have read your question and silently thought "Geez, where do I begin?". The question is too big too answer !

Anyhow, to start the ball rolling, two things stand out for me:

- The cooling system must be kept 100% up-to-snuff
- The Marelli ignition system must be kept 100% up-to-snuff

Bad things happen if you don't do this!

How much detail are you after? Volumes have been written on both

Others will chime in with more thoughts

Cheers
DD

 

Carefully disconnect every plug and ground and clean with a toothbrush and a can of electrical contact cleaner. Add more ground wires to engine, dash, etc.

Don't make my mistake and try 20 different ways to sort the cooling system. Have the rad professionally serviced. Ensure thermostats are correct type amd work. Suggest a IR handheld temp gauge to verify sensor readings vs gauges.

Ensure throttle assy, rods, etc are set properly

Check or replace O2 sensors (often a forgotten service item)

I frequently run fuel and oil cleaners. A few liters of trans fluid for 100km in the engine will clear alot of crap out. Simply dumping oil doesnt get the sludge out.

If intending to keep and use the car for awhile I would do the entire ignition system once at a set point, like when you reach an easy to remember milage point. Keep all old parts to just incase, and if you need alternative part numbers for Marelli systems I can find them as the OEM items are way over priced or NLA. Ignition amps for example are intetchangable with other brands no need to spend $400usd/each.

And finally it is always recommended to do an Italian tune-up. These cars absolutely run better when pushed you need to red line it on highway for a good 20mins a few times if necessary the car will thank you afterward.

 

Wow!!! Thank you all for the sound advice!! It is a work in progress already have acted on many of the suggestions. I cannot thank you all enough!!

 

Tex
Welcome to the Forum. I would add that the rear axle has 10 grease nipples, plus a plug into the hub for grease to be shoved in. All of the nipples need greasing every 5000 thousand MAX, or once a year. This will have been ignored by the car's previous owners. If this is done the axle will last for ever. Change the diff oil (must use LSD diff oil) as this will also not have been done.
On the suspension and subframe cage mounts, carefully check all rubber components, these may also need changing, maybe, maybe not, but they usually do!
Dowmload Kirbert Palm's book from Jaglovers and read it; it is not so good on the facelift cars, but is VERY important to read. For useful diagrams of parts and part numbers, use this Jaguar Classic Site:
https://www.jaguarclassicparts.com/u...-v179736-parts
Yours is the later series from

• XJS from (V)179737 to (V)226645

 

Greetings Texknight and welcome to the wonderful world of XJS V-12 ownership.

As you can tell Doug is a cornucopia of Jag knowledge and very well respected both here and on "other" Jag boards (Good to see you Doug ).

"- The cooling system must be kept 100% up-to-snuff" Truly the Achilles heel of U.S. V-12 Jaguars, though your 6.0 cooling system is much improved over the 5.3 cars.

"- The Marelli ignition system must be kept 100% up-to-snuff" Your XJS should have the Nippondenso EDIS ignition system.. and it's pretty much trouble free.. I personally liked the Marelli ignition used on later 5.3 cars over the Lucas system used on mid-80's XJS'.

Per my sig; I've had a couple of XJS' (and know my way around them.. "The good, the bad, and the ugly").

We should meet up sometime, I just relocated to San Antonio from San Diego with my wife and our 2 X-Types (Alamo Ranch, off the 1604 and Culebra), I'll warn you; I'm not a Grey Poupon, biscuit munching, teetotaling kind of owner, I do all the work on my cars myself.

Chad & Janet

 

I could have sworn several people have told me that the Japanese system was only used on the saloons, and the XJS remained Italian to the end of its run.

 

You are correct. Just on the same way as the XJS switched to Marelli in 1989, and the V12 saloons kept the Lucas ignition to the end in 1992.

 

I agree we need to meet up. Been on a bit of a XJS slowdown since it has been in shop getting every single component of AC system replaced... OUCH!! In the mean time I bought a 2014 XJR-XJL to drive around. Shhot me a time and spot and we would be glad to meet.

 

The XJS never came with Nippondenso system it was Marelli only the Nipp was in the later saloons. If an XJS has Nipp it is modified.

Marelli ignition maintenance consists of initially checking condition of rotor and replacing ALL 12 spark plugs and testing/replacing ignition leads, if these 2 things are in good condition you will good to go. Marelli cars with the old A6 AC compressor have most likely never had the front spark plugs replaced as yours id a later L it will have the smaller compressor so plug replacement is much easier.

All other maintenance is stock XJS V12 stuff.

 

I have the 4.0, but the rear suspension/axle should be the same.

I have 10 grease nipples back there?

 

Four on the inner fulcrums under the diff, 2 each side.
Four on the drive shaft universal joints (one per joint). You just might have UJs with no grease fittings.
Two on the outer lower wishbone fulcrums: one on each outer hub carrier, underneath on the bottom, greasing the lower outer fulcrum.