Sign up to the FREE Jaguar World e-newsletter


X308 Owner’s Guide
Sunday, 15 May 2011 17:04

Though engine issues blighted the reputation of Jaguar’s first V8-engined XJ, today a well-sorted example makes for a stylish, rapid and reliable car. So what do you need to bear in mind to make sure your car lives up to that standard?

Words: Garreth Coomber & Pictures: Jackie at Sweet Creatives


Perspective can be incredibly important when judging a car, and that’s especially true of the X308 XJ range, current from late 1997 to mid 2003. Often derided since then, and with some justification, for its unreliable engines and ‘sealed-for-life’ gearbox, the X308 still sold in greater numbers and is considered by some more elegant and sporting than its successor, the X350. In fact with the current XJ taking an entirely new styling direction, the X308 may well prove to be the ultimate rendition of the original XJ concept, with the supercharged XJR an almost certain bet for classic status in the future.

The really good news is that with the right care none of the X308’s reliability issues are insurmountable and, in fact, many of those still on the road will have had the big problems such as the timing chain tensioners, Nikasil bores and gearbox sorted by now. Even should the worst happen and an engine or gearbox fail, there are now sufficient numbers of cars leaving the road through accident damage etc to provide an adequate supply of good replacement parts, while even the cost of rebuilding the originals has come down in recent years.

So, perhaps now might well be the ideal time to own one of these cars; with values of good examples unlikely to fall further, hanging on to the right model such as an XJR, Sovereign or Daimler, might even prove to be a good investment long term. And whatever happens value wise, you will still have one of the best driver’s cars of its era to enjoy in the meantime.    

Let’s not beat around the bush, the ‘AJ26’ 3.2- and 4.0-litre V8 engines were problematic with timing chain, water pump and Nikasil (bore coating) failure affecting a huge number of early cars. In fact, were it not for Jaguar’s decision to replace many of the engines afflicted by the Nikasil issue free of charge up to a maximum limit of 100,000 miles, the company’s reputation may well have been damaged.

Thankfully, that was not the case, and it must be made clear that the basic design of the V8 was very good. The later and near bullet-proof 4.2-litre version with relatively minor changes has confirmed that, so with the right care and a few precautionary modifications there is no reason why the engine in an X308 should not last as long as the car.


Nikasil failure – where the special nickel-silicone coating used instead of a conventional steel cylinder liner proved susceptible to the corrosive sulphur found in the petrol of the time, ultimately resulting in loss of compression and the need for a replacement engine – should no longer be an issue as most seriously affected engines should have been replaced by now and the sulphur content in today’s fuel is too low to cause further damage. Jaguar switched back to conventional steel liners from engine number 000818-1043 (18 August 2000), and most factory exchange engines will also be to this specification. Should your car still retain its original Nikasil engine, try to avoid short journeys and switching off/restarting before it has come up to full operating temperature – good advice for any engine when you come to think about it!

Similarly, there should be little reason these days to worry about the reliability of the thermostat and water pump, as both will almost certainly have been replaced by now, the latter ideally with a 3.5/4.2-litre unit which is directly interchangeable and can be identified by its one-piece casing. Cars still retaining the original two-piece pump can be susceptible to localised overheating as the pump impeller wears away, often in conjunction with a faulty thermostat that causes the engine to run slightly warmer than
it should.

Thanks to SSS Jaguars for loaning us the immaculate XJR in the pictures from its sales stock.
Tel: 01622 844608 / web:



To read more about this Jag see the June 2011 issue of Jaguar World. Latest issue available here.