I would get a specialist to check the timing chains as this is a weak point on these engines and the chains are prone to snapping and creating huge amounts of damage !

Thanks for your thoughts and suggestion. I have already had it checked by a specialist and his diagnosis was probable v v t unit wear. Indeed Jaguar themselves issued a bulletin highlighting this problem and they quoted two engine numbers between which this problem may occurr. Unfortunately my engine number falls in the middle..... I have been in dicsussion with the factory and they simply do not want to know - almost as if the faulty design (which they have revised twice - so there must have been a problem) is not their responsibility. Regarding your suggestion about these engines having a potential timing chain problem, I am aware of this (and had chains and tensioners expediently replaced in my Daimler Super Eight some years ago) but I understood it applied specifically to the 3.2 and 4.0 litre V8, and that the later 3.5 and 4.2 V8 were free of this. Anyone else out there with experience and advice please?

Grandadbeard, I started mine this morning with the bonnet open and I would say the noise is probably from the top although it is so brief it's a job to tell with certainty, I would describe it as a loud mechanical clatter. I put in my previous post that the noise happened after standing for 3 days but it does seem to vary if according to the length of the journey the last time it was used, it was out yesterday for about 8 miles and it clattered today. Any similarities with yours?

Mine's been sorted out.

I have what sounds like this exact issue, can you please tell me what the problem was and how you got yours sorted out.

Thanks in advance.

Scott