There's a few things to watch out for on early XJ8s (i.e. pre-2000).
Poor cold starting could be a Nikasil problem (google for this) - that
means a replacement engine. Having said that, by now I'd expect most
cars with that issue to be dead or have a replacement engine as we now
have lower sulphur petrol so less erosion of the linings takes place.
The only real check for this is a blow-by compression test.
Listen for timing chain rattles - replacement of the plastic tensioners
and chains will cost you a couple of thousand.
In many ways the last of the XJ6s are better than the first of the XJ8s,
but I prefer the XJ8 (I've had a couple of them, one of the first from
1998, and currently a very late 2002 model - they are daily drivers for
me, not weekend cars).

Make sure there is a full, up to date, verifiable service history -
preferably with invoices showing what has been done. These cars are
great when looked after, but can be extremely expensive if neglected.
Check all of the electrics; this isn't an XJ specific issue, but as with
any modern car, apparently minor issues (e.g. the seat memory not
working) can need replacement of expensive computer units.

Take a look at a few, don't jump on the first you see. Quality can be
very variable, especially at the price point you are looking at; cars
that age may well have had several owners, and later ones may have
skimped on the upkeep leaving potentially expensive jobs for you to pick
up. Even "minor" issues like it needing a set of tyres will take a chunk
out of your budget; a set of good quality ones will cost you £500+.

Also, be aware of trim level differences; some can be surprisingly basic
for such upmarket cars (items such as cruise control, electric seats on
both sides and even CD players weren't fitted to all models).

Owning an XJ isn't an inexpensive experience, but I can't imagine
driving anything else now.

Matt

If you find an XJ8/XJR prior to 2003, be aware that if the timing chain
tensioners and water pump haven't been replaced, you will have to do so.
Jaguar used plastic parts and they will fail at some point. With the
tensioners, results of failure are catastrophic --the engine will be
wrecked. My mechanic says the earliest he has seen tensioners fail is 40,000
miles, although the norm seems to be a lot higher than that. Warning sign:
you will hear a rattling noise from the front of the engine upon cold start
up. Another issue with XJ8/XJR prior to 2001 -- Nicosil cylinder liners.
These were used by both Jaguar and BMW in that era, and both discovered to
their horror that the liners eventually disintegrate, probably due to high
sulphur content in gasoline used. This is not so much an issue anymore, as
fuels are much improved these days. Fixes for this include relining the
cylinders or replacing the engine block with a short block.

I have a 2001 XJ8 Vanden Plas, and I am going to replace the tensioners,
tensioner guides, and chains  -- upper and lower --  and the water pump this
spring. I have been quoted a cost of $2200 Canadian for this (it is better
to do the pump and tensioners etc at the same time, as they are both at the
front of the engine, and you will save labour costs. Somebody from your neck
of the woods (UK) told me the going rate he was quoted was about 1200
pounds.

When I purchased the car, I negotiated $3000 off the asking price to cover
these repairs.

Hope this helps, and doesn't in any way detract from your enthusiasm for
Jaguars. The XJ8 is a beautiful car and the engine is superb. There is
nothing quite like a Jaguar, and the XJR will be particularly exhilarating.

Alan Strickland
Victoria, BC Canada