Nasty - unfortunately bills like this can happen with high powered, high end older cars.
A friend bought a M5 with 89k on the clock (8 years old, one lady owner from new) - within 12 months the gearbox was needing a full replacement at a costs of £6k. Nothing he could do but pay up to get it fixed.
I'm puzzled as to why a fault like "stretched" cam chains, which is actually a wear problem & therefore happens gradually over a prolonged period, should cause a sudden failure.
I always thought the use of cam chains as opposed to rubber belts was for that exact reason - they don’t stretch (I’m not a mechanic though).
Info here might be of use to you:
Jaguar V8 engine questions/concerns - Page 1 - Jaguar - PistonHeads
Might pay you to login (register) with Pistonheads and make contact with the member “Jaguar Steve”, he may be able to advise you.
You've got nothing to lose by trying to get the supplying garage to help cover the cost but I wouldn't rely on it. I also wouldn't repair the car until you either have agreement or otherwise - they may want to look at the car as-is rather than rely on another garage's (somewhat vague) diagnosis. If you go legal you might have to get it inspected by a neutral.
What exactly are they going to do for £5k ? even if they had to remove the engine it sounds expensive to me - if you said £500 in bits (new cam chain, coolant) and £75 an hour labour, thats 60 hours or 8 days... and we're being generous with prices there.
If you said a day to pull the engine, half a day to put a new chain on, then 1.5 days to put it back and get it running again what are the other 5 days for ?
If the chain is replaceable in situ it surely can't be any more than a couple of days.
For reference, a friend currently has a Bentley Continental in bits - someone had the engine out has has set the phasing of cam sensors incorrectly, so he's pulling the engine, correcting the error and putting it back together in a similar time to what I've suggested above.
To make sure the price I was quoted was accurate, I phoned the main jaguar dealership near me for a quote. It was within £100 To the independent garage quote. Parts alone is over £2k. It is engine out, strip down and replace all chains, pulleys and tensioner's. 22 hours Labour.
If the car has done 94K, doubt you can claim off the garage that sold it if you have no warranty.
I bought it with 94k and currently on around 95.5k so not even done 2k miles yet which to me would suggest the fault was on the car when I bought it. Maybe?
Almost certainly underlying wear and tear that has been developing for many years.Is it the fault of the seller if it didn't manifest itself for 6 months?
That is the question I suppose. Just disappointing that I have spent so much money on a car that I have not used that much and now have to spend a third of the original purchase price to be able to use it again.