Jaguar XK8/R

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Do you drive this great classic or are thinking of buying one? Here’s how to ensure that you get the best out of your car for years to come

How time flies! Jaguar’s XK8 is now an amazing 20 years old and now represents one of the best modern classic bargains you can find with prices starting from a few thousand pounds. For the DIY enthusiast it’s not too difficult to maintain at home, thanks to the basic hardware being XJ-S derived. However, as with any modern, the Jag is pretty high tech so certain jobs need expert help. Here’s how to do your bit at home to make this cat purr!

1. BOTTOM END

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According to specialists Elite and Performance Jags (01332 265826), fitting the later 4.2-litre engine, which gives 300bhp even in standard tune, is not as simple as it initially sounds because, although the inferior 4-litre ECU suffices and can be used, it ideally requires the 4.2’s ECU system plus needs the later six-speed transmission to suit. The American Kenny Dell supercharger has seen a whopping 650bhp achieved from up to 4.8-litres.

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Aston, using the same basic block, albeit dry-sumped, achieved 4.3 and 4.7-litres but can’t be utilised without a lot of mods so not worth considering. The 4-litre engine (pre year 2000) was well known for excessive bore wear due to the Nikasil bore coating breaking down. However, this was pretty much eradicated some years ago and, besides, good second-hand engines can be picked up very cheaply – from under £500 on eBay.

2. TRANSMISSION

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XK8s are always autos and you’re likely to be stuck with it. Elite and Performance Jags made the manual an Aston Vanquish, ’box work but the sheer cost – now at over £10,000 – negates it for most. What you can have instead (from Racing Green Cars) is a sequential ‘Speedshift’, which operates the J-gate selector via steering wheel paddles, albeit only for XKR models. At £1554 fitted it’s a much more viable proposition although still quite pricey.

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When new, the auto box was filled and sealed for life but according to Jag experts Racing Green Cars of Hants (http://www.racinggreencars.com), experience has proven that many transmissions have failed in service due to oil degradation so it’s wise to have the old lube syphoned out and replaced periodically. Other ills are usually electronic. If earlier recalls have been done all should be fine; run car in ‘manual’ mode to check all is ok.

3. ENGINE OUTPUT

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Interest in the original 4-litre has mostly petered out as their values slumped. Better induction filters (K&N) and a sports exhaust give useful performance increases for minimal outlay. David Manners, for example, sells a sports stainless system for under £1250 while XK8 experts Paramount Performance (http://www.paramountperformancetuning. co.uk) quotes around a 10bhp increase with a sports air filter box from K&N adding another six horses. Other easy tweaks include a rechip and remap or upgraded ECU and Paramount markets such a set up for a little over £700.

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XK8Rs possess more performance potential, simply by making the supercharger spin faster. Paramount Performance sells a £3000 upgrade that promises over 400bhp, Racing Green Cars says an additional 130bhp can be coaxed if the ECU is altered to suit. It sells a sports supercharger pulley (£425) but warns against cheap alternatives that don’t fit properly or may require modification to the engine block. Faulty timing gear is well known but this problem is mostly cleared up now. A £1000 fix, use better 4.2-litre items. Just frequently moving car around can mess up ECU’s brain.

4. BRAKES

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XK8 benefits from second-hand XKR (and XJR) anchors otherwise it can get expensive. First budget mod are fitting EBC pads and uprated Discs. Paramount provides a full kit comprising Alcon callipers and discs at £4500 all in while David Manners offers Brembo components for the front at under £1000 per side. Racing Green Cars markets kits from Brembo and Arden plus has developed a specific upgrade for XK8s already fitted with Brembo bits.

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Don’t be surprised to find that the brakes have taken a pounding or already been uprated with aftermarket pads or the sexier Brembos as fitted to the XKR. Roughness and vibrations through the steering and brake pedal point to new discs and pads being needed. Racing Green Cars makes uprated Steelflex brake hoses which give a better, firmer feel and worth fitting if the originals need replacing anyway.

5. SUSPENSION

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XK8s handle well but ride surprisingly high for a sports car. A quick fix is a set of sportier, stiffer springs, say 25-30mm lower, at around £300 from various sources such as Racing Green Cars, then better damping. Perhaps poly bushing too, although the company adds that unless you’re envisaging track work, stock Jag specification dampers and bushes are difficult to improve upon unless refinement and comfort aren’t a priority anymore.

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Running gear is XJ-S and so well proven. The main wear points are the wheel bearings, compounded by wider wheels and tyres – plus faster cornering. Suspension and steering bushes are prone to quick deterioration and the dampers can lose their edge at higher mileages. The specialist CATS is reliable although the ride at low speed suffers. If you think that all is not well here then have the system checked out professionally.

6. REAR END

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With any new found power you’ll probably welcome a limited slip differential to complement the standard traction control system. Produced by Quaife to Racing Green Cars specification, the ATB (Automatic Torque Biasing) differential is one answer at £895 plus £500 fitting charge. It’s superior to the standard type fitted by Jaguar and worth considering if the standard one is playing

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IRS set up needs its bushes to be A1 – and there’s plenty of them – otherwise handling will be wayward. It’s worth stomaching the expense and renewing them as it will transform the drive, as does having the suspension geometry set up properly and thoroughly by a Jaguar expert. Diffs can leak (at flange and spew oil over rear axle) as well as wear their bearings and even the bearing carriers if bad.

7. STEERING & TYRES

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Early XKs ran 17inch rims but most like to see the fatter 18inch rims. A choice of 30mm or 50mm wheel spacers are popular fitments (try Racing Green Cars) albeit for looks and are not recommended for track use. It also markets a nifty kit (£245 fitted) which converts the standard power steering into a switchable two-tier system, providing lightness for town work.

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There’s a host of tyre and rim combinations – it’s up to you to decide on the merits of their added looks. Spacers demand that the wheel bearings are tip top and will wear out quicker. There’s a shed load of compliance bushes which deteriorate and spoil car’s dynamics – some experts say that Aston DB7 ones fit and are also of better quality. Front wishbones are common wear items.

8. BODY & CHASSIS

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Customising XK8s is a popular pastime with owners and there’s quite a lot of gear available from wheels, grilles and so on right up to full body kits – try Paragon Design and Grantley Design, the latter which gives this 20 year old a modern Jag look. Some like to lower their cars to reduce gap to the wheel arches, a requirement in some markets for snow chains

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Even accepting the earliest cars are 20 years old, XK8s can rust badly, especially sills and floors so check underneath regularly not leaving it to the MoT examiner. The bumper region is pretty susceptible, especially at the rear where they have been known to fall off if really bad although car was always rustproofed – unlike the DB7. The paintwork was always considered a tad ‘soft’ however and this can result in excessive damage on the ‘snout’ caused by stone chips thrown up.

9. TRIM

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Like the exterior, there’s a lot you can do to alter the appearance and comfort of an XK8 – XKRs always had a less traditional wood and leather look and can be substituted with second-hand parts. Mina Gallery has a website worth looking at, for example, that exhibits detail trim and dial upgrades. Paragon Design offers a stereo upgrade encompassing steering wheel controls and custom J gate selector styling mods

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Jaguar trim has always lacked stamina and shows it in fading, worn trim although most seats can be refurbished with an aftermarket kit. The electrical system has been known to play up, especially the central locking and alarm systems. Regularly check that all the toys (including the power seats) work properly. Switchgear is known to fail, but thankfully most of it is Ford-sourced so buy from a blue ova dealer or specialist.

AND ANOTHER THING…

Complementing this service guide nicely is a new book from Veloce called ‘You and Your Jaguar XK8/R’ and is written by a known expert on the model that leaves few stones unturned. Along with the numerous owners’ clubs and forums, this new tome has to be an essential read for any XK8 owner. It’s well worth the £30 asked as it will save you possibly thousands in return. ISBN: 978-1-845848-15-6. Go to http://www.veloce.co.uk for more details.