Jaguar X300/X308 (1994-03)

HISTORY
The old joke that you needed to buy two Jaguars, one for driving while the other was being repaired, was all too true during the horror Leyland years. Ford ownership transformed the last XJ40 models, its corporate purchasing power lifting the quality of components almost overnight. The new X300 series launched in November 1994 built on these advances as well as marking a major rethink in driveline refinement and a return to traditional XJ6 styling.

Although the return to Jaguar's original XJ6 look cleverly masked the XJ40 origins of the new model, the first six-cylinder X300 models featured a development of the XJ40 dash which many owners prefer to the later XJ8 style. However, cabin changes were extensive including seats, improved climate control air-conditioning system, a new style of leather trim, heavily revised sound system and many detailed refinements.

Rear cabin space in this Jaguar series is tight for larger passengers. The long wheelbase versions are popular where rear seat space is important while the standard wheelbase is valued by drivers who place a premium on agility, compact size and less weight. In terms of resale, they balance out when buyers usually want one or the other.

The AJ6 engine in the XJ40 despite ongoing improvements was never as smooth as it should have been hence the exhaustive changes for the new AJ16 engine in the X300. From the new block and piston design to the head, fuel injection system and distributorless ignition, the big Jaguar six was transformed. It came in short and long stroke capacities plus a supercharged version. Suspension was also heavily revised for reduced body roll and better handling. The Sport suspension was lowered and firmer while the supercharged XJR's suspension was firmer and lower again commensurate with its big boost in performance.

The V12 engine continued in the X300 in its latest 6.0-litre specification as fitted to the last XJS models but was dropped at the end of 1995 from Jaguars and the end of 1997 from Daimlers. In its last days, this V12 engine was reliable and long lived and despite the extra fuel consumption, it appears that the X300 versions may already be classics when the X300 in Jaguar and Daimler forms was the most competent and advanced setting for this evocative engine.

The X300 underwent another extensive round of changes in October 1997 with the introduction of several all new V8 engines that shared the same capacity as the sixes. These models are often referred to as the X308 series. Jaguar also introduced the latest multi-plexed wiring and electronics system to reduce wiring complexity and weight. Although styling was little changed, the body featured hidden structural upgrades and detailed exterior changes including jeweled headlights, chrome bumper caps and revised indicator light units front and rear. The dash was an all new design with larger glove compartment and new LCD driver displays.

The new AJV8 engines featured variable valve timing, twin cams per bank, four valves per cylinder, all alloy construction, split block cooling system and electronic throttle control and were mated to a new five speed automatic. Power was boosted at all levels with outstanding open road economy on premium unleaded fuel only. Suspension was heavily re-engineered at the front while the rear was retuned.

Jaguar service specialists who once worked around the clock to service the old XJ6 Series I,II and III and the early XJ40 joke that the X300 caused a severe downturn in their businesses. While this is undoubtedly true, the reality is that the growing list of standard equipment will always mean there will be extra niggles as they age. However, once any initial problems are sorted and the kms tick over on these later Jaguars, maintenance appears to be on a par with top shelf European and Japanese rivals. In terms of driving pleasure, styling and cabin ambience, they offer unique and lasting appeal.

KEY CHANGES:

SPECIFIC X300 CHECKPOINTS:

Body
Check the paint finish and gaps on all panels for consistency. Painted bumpers and their chrome highlights need to be perfect for neat appearance but the corners are often crunched. Check for damaged lights especially those mounted in the bumper and gouged alloys.

Check that all instrument panel display functions including clock are operational. Check operation of power windows and sunroof as these could be problem areas in earlier cars. Airbag sensors can also malfunction. Check that all speakers work.

Central locking and courtesy lights can play up. Check that remote locking and interior lights do what they should.

Consider a pre-purchase inspection by a Jaguar specialist who is familiar with how the car should drive and how it left the factory.

Check all wood and leather for sun damage and scratching. Leather is now old enough to warrant regular applications of conditioner.

Drivetrain
Later AJ16 engine was a big improvement but can suffer from glitches in the electronics which may cause the car to shut down or not start. It can be a faulty crank angle or coolant sensor. Water pumps, thermostats and coolant hoses are routine service items to avoid overheating. Check all exhaust fittings. Some may have minor oil leaks.

Radiators can leak at the seal between header tank and core.

Make sure that maintenance records have covered time requirements as well as distance as overdue coolant and hydraulic fluid changes in the various power steering and brake systems can wreak havoc in the aluminium componentry.

The V8 engines once sorted are magnificent but there were early problems. Aluminium block has Nikasil bores which are created by etching the aluminium to expose long-wearing silicone content for the pistons and rings to seal against. The process was not successful in all early examples leading to loss of compression and excessive oil consumption. Most were replaced but check anyway as they can't be repaired.

Some XJ8 examples will have brand new replacement engines after secondary timing chain tensioner fails. Any suspicious timing chain rattle on start-up or at around 2000 rpm needs to be addressed immediately.

Long 15,000km service intervals are too long for the complexity of the engine especially for those owners who run past the due date or distance. They will catch up with the car as it ages. Service centres are reporting worrying sludge build-up in examples where the sump has been removed. This can impact on the operation of the timing chain tensioners which will destroy the engine if it causes the timing chain to fail. Depending on operating conditions, all X300 models need fresh, quality oil every 7500-10,000km.

Annoying engine stalling in the early XJ8 in some markets was traced to throttle body problem. Before undertaking engine miss or stalling repairs on low mileage cars it is worth checking to see if there was a software or componentry update for that year.

The auto transmission can also vary according to how it has been looked after. Check for jerky shifting. Some earlier cars can have more driveline vibration than is desirable.

The battery is in the boot so check for corrosion or acid damage. Battery needs to be healthy and correct specification to push through the wiring and deliver healthy zap in the engine bay.

Suspension and Brakes
Disc rotors are routine replacement items but seem to last better than German rivals.

Sophisticated front and rear suspension depends on many bushes and joints that soften or wear and will need progressive replacement after 100,000 km to maintain quiet, controlled ride.

Check that ABS is working.

Choose tyres according to whether you want low road noise/comfortable ride or roadholding. Bigger rims and low profile tyres may grip better but do reduce the magic carpet effect. Sport and XJR are noticeably firmer in the ride department but body roll is much lower.

Check for underbody damage as chassis competence encourages push-on driving over bad surfaces.

Thanks to Caulfield Jaguar (03) 9578 2500