In the end it was she who found me. And I need advice!!
 

Hello all
Not so long ago I wrote the post "is it a wise purchase?" about deciding over straight six or V12, based on future resale value vs. cost of maintenance. You all gave me very useful advice that helped me a lot.
Last Thursday I was having a few beers with the other members of the Jaguar Club of Catalunya, including the head mechanic of Mendieta Sport Cars, those Jaguar experts who take care of the maintenance of our cars. He told me that an unexpected opportunity had come along and he immediately thought of me: a 6.0 V12 convertible unit with just 30.000 miles in my hometown of Barcelona. They have serviced this car since the day it left the factory and they can guarantee that it is in perfect shape, with all maintenance récords available and can also guarantee that the mileage is real. The owner has recently died and his children want to get rid of the car for about €20.000.
I have no reason to doubt the word of my mechanic because as I told you in the last post, they are not just mechanics but probably the best Jaguar experts in all of Spain. But no matter how much I trust them and no matter how well maintained the car has been, I will inspect it in full detail to avoid surprises because the age is there.
I have read that if that 6.0 V12 engine has been properly serviced it is extremely reliable, but I am still scared about it because my mind was set on a less exotic but more simple to maintain straight six 4.0. But this unit with proven full service history seems so good that I need again your kind advice to know what I might get into
1- I have read that the Magneti Marelli distributor may fail in one bank, leading to fire in the cats because of unburned fuel. I do not know if that happens often, but the end result scares me to hell, Should I replace the distributors and sleep well, or disregard such engine because of the possibility of eventual disasters?
2- I have also read that rubber hose quality in Jaguars of that period was pretty poor despite the fact that such 6.0 V12 engine had been already improved by Ford. And no matter how well maintained that car has been, age of components is still there. Do you recommend me to replace ALL the fuel and coolant hoses?
3- The first thing I would do is to replace the thermostats and clean the radiator and cooling circuit to remove even the smallest molecule of eventual sludge. And I would also check the cooling fans to make sure that they work perfectly, but this car would move in the Barcelona weather where temperatures in August may go up to 100 degrees F. Will that V12 engine bear such heat in special situations like bumper to bumper traffic jams?
4- I have also read that many electric wires are located in the V12 engine valley, so they may get destroyed due to heat. Is that a real threat waiting to happen?
When it comes to future value as a classic, I know that a 6.0 V12 convertible XJS will retain a much better value than the 4.0 straight six because Jaguar built many less units, but I am still scared to hell about the potential problems of this engine that may turn a pleasant ownership into a financial nightmare. But I cannot forget the guarantee that this car has been always maintained by Jaguar enthusiats who know it like the back of their hands and who have proven me their expertise and honesty in the maintenance of my current XJ-358.
To make a long story short, I still think that a 4.0 straight six makes more sense, but I need to be convinced that this 6.0 V12 engine is not as scary as it seems as long as it is maintained properly. Can you help me decide?
Once again, I thank you all in advance for your useful and generous advice.

I have a 1994 6.0 convertible, and it now has about 165,000km on it. I have driven it in temperatures up to about 40C, and the cooling was fine.

1. In all the years I have been reading the various Jaguar forums, I think I have only heard of 3 Marelli failures. They seemed to happen in high mileage cars that had not been maintained well. The biggest thing is changing the sparkplugs at the recommended intervals, and having the proper gap. I think if that is done, you can forget about Marelli failures.

2. I would disagree about hose quality, I though it was exceptional in that era. Hose failures of OE hoses are not common. In contrast, I also have a 2007 X Type and it has far fewer KM than my XJS and has had a number of hose failures. I'd inspect the hoses, but if they are soft and pliable with no visible bulges or cracks, keep them.

3. A clean radiator is important on the V12. Just today I have the radiator out on my car for cleaning, as there can be an incredible amount of fluff, leaves and debris between the radiator and condenser. Removal and cleaning is the only way to do it right, so that is worth doing, even at the low KM. If the cooling system is well maintained, eg, a clean radiator and fan clutch operating as intended, it will handle the heat fine. See the discussion about measuring the thermostat extension from yesterday to block off the radiator bypass passage. I would measure the thermostats in a pan of boiling water before installing them, rather than just going with a Jaguar OEM thermostat and assuming it's good. I think the radiator is more likely to be contaminated with airflow blocking debris on the outside, than the inside.

4. The 6.0 has much less wiring in the engine valley than the 5.3. Inspect it, but it also seem to be less affected by heat than the previous generation wiring.

The 4.0 AJ16 engine has chronic problems with ignition coils, it also affects the X300 saloons. I had one of those and finding OEM quality coils is becoming a problem now. It seems like you have come across a good XJS, I would go in with eyes open, but don't be afraid of a good one. I'd take a well maintained 6.0 over a neglected 4.0 any day, and the interior of the 6.0 is nicer I think. Make sure everything is there, like the convertible top cover. They should be padded leather on a 6.0 and match the colour of the seats, including the piping.

I hope this helps, but feel free to ask any more questions. What colour is this 6.0, and do you like it?

This is my radiator after about 20,000km from when I last cleaned it. There is a quite a bit of poplar fluff in the fins that isn't visible. It's important to get all that out to have good airflow.

https://cimg7.ibsrv.net/gimg/www.jag...3a32811ce9.jpg

At 30,000 miles that 6.0L isn't even broken in yet. I wouldn't hesitate to buy a 6.0L, vast quality improvements, better Fordified gaskets, seals etc.

You can buy aftermarket silicone hose kits for the V12 if it's that much of a concern. Personally I wouldn't bother so long as hoses are soft and visibly ok...I've had replacement hoses fail in less than 10,000km so I just buy lengths of green heavy-duty stuff and cut to length as needed since the kits disappointed me so much.


https://cimg3.ibsrv.net/gimg/www.jag...f10a6814a7.png

I mean, you will have issues, but there is a whole community here for assistance. If you can get it, I would go for it. If you really have it on good word that it’s been maintained in this fashion, then there is no question. Go for it. Just know you will have issues at some point, that’s just common sense, she’s an old girl.... Good luck.

DIOS+PATRIA+REY

Thank you very much for your quick answers, that are helping me reduce my fears. Actually, some members of my Jaguar club laughed at my fears of a V12 engine and reminded me that my current car has also a gigantic 4.2 V8 engine that is not precisely simple.
The color of that car is blue. My favorite would have been burgundy, but the blue is also very beautiful.
I understand that age brings eventual problems, but I am familiar with that because I still keep and maintain myself two cars built in 1985. Also I understand that the complexity of that V12 will limit the DIY that I do with my other cars, but it is the price to pay for having such special automovile.
My XJ358 Works perfect and it has never given me any problem because I am very strict with the maintenance. From your words I can see that if such XJS is in good shape and I am equally strict with its maintenance, it should not give me any problem other than the logical replacement of parts due to wear or age.
Spikepaga : In Spain, that sentence you finished your post with implies a political movement. I was surprised to read it from an American who lives in Texas!
Once again, thank you all very much for your advice.

Yes sir, My mom’s dad is from a long line of Carlistas.