XJS Buyers Guide
This advice is designed as a guide to help you choose the right Jaguar XJS, but it is not intended as an exhaustive evaluation of the car. It assumes some prior knowledge of the models available. It particularly relates to the V12 engine Convertible. Please feel free to email us with any specific questions to graham@greatescapecars.co.uk or call us on 01527 893733. If you have any advice that you think we should add, please also let us know.
General
The XJS was launched in 1975 and continued in production until 1996. 115,413 were built, 29,935 with 6-cylinder engines, 85,478 with V12 engines. The car was facelifted in 1991. The 3.6 engine was launched in 1983, the 4.0 litre in 1991 and a 6.0 litre version of the V12 in 1993. Originally launched as a couple only – due to fears of an American ban on convertibles – the XJS evolved a Cabriolet version in 1983 and a full Convertible in 1988 (when the Cabriolet was discontinued). XJS’ are complex cars both in terms of engine and bodywork. They have also been under-valued for many years, their low prices resulting in many being poorly maintained. This explains why there are a lot of cheap, poor quality cars for sale. Finding a good XJS takes time but due to high production volumes, there are a lot available. Your choice of V6 or V12 power is down to personal taste because performance is similar.
Engine & Transmission
V12
The 5.3 litre V12 engine in the XJS is a classic Jaguar unit – very refined and ultra-smooth (apparently you can balance a £1 coin on it while it’s running). A good V12 is lazy and effortless, winding itself silently into life. These are generally very reliable engines but their main shortcoming is complexity- they can be difficult and expensive to work on. So we recommend that if you’re not too fussed about V12 power then 6-cylinder. Watch out for:
- A deep rumble on start up indicates worn main bearings (walk away)
- Any lumpiness could indicate a fouled plug (some of which are quite hard to reach) or a burned value or leaking head gasket
6 Cylinder
Jaguar put its 3.6 engine AJ6 in the XJS from 1983, replacing it in 1991 with the 4.0 litre version. Both engines are excellent, particularly the 4.0 litre, and offer performance that is virtually identical to the V12. The 6-cylinder engine is easier to work on but has a few more problems than the V12.
- Piston rings, pistons and exhaust valves can be difficult to source for early engines – later pistons can be used but means you need to switch all of them
- Head gaskets tend to go after 50,000 miles
- Valves burn out due to hot spots caused by bad thermostats, poor quality radiators or incorrectly set up timing
- The radiator cooling fins corrode, leading to cooling problems
- Coolant hoses are plentiful and tend to fail
- Check the condition of the virtually concealed water rail hose that runs from the water pump to the water rail that feeds the engine
- Lumpy idling indicates compression problems caused by a weak valve or gasket
- Poor acceleration may be due to worn timing chains or poor valve timing
- Cars with digitally controlled ignition should have the cap and rotor arm checked for corrosion
- If the transmission fluid is brown or black, walk away
- Excess play in the manual gearbox indicates worn gear lever bush
- Manual cars can suffer flywheel distortion and cracking, indicated by clutch judder
Bodywork & Mechanical
XJS’ rust. Most of the mechanical problems on the car are generally caused by corrosion and neglect.
- Check panel gaps and alignment – they won’t be perfect but should be even
- Check for signs of a respray on the coupe buttresses – this is where the paint is usually blended in
- Check bumper alignment on 1981-1993 cars because they are difficult to align well and could indicate a bump
- Check the rear arches for any signs of filler – the arch lip should be no more than two layers of metal thick
- Check for signs of plating or rust around the radius arm forward mount (just inboard of the back end of the sill)
- Feel for wear on the inside front tyres, which can indicate poor alignment or worn suspension bushes
- Check for rust in the door bases and bottom of the front wings, all of which rot inside out
- The rear wings on pre-1991 cars use five different pressings and corrosion can result – check behind the rear bumper and below the windows
- The floorpan is prone to rot - the boot floor, which can rust through, particularly around the battery tray, and under the rear seat. Also check the seatbelt mounts
- Rectangular headlamps tend to rot out and are often replaced with American-spec round ones
- The rear edge of the bootlid is a major rust trap and usually rusted out. Also check around the back window and bases of the C-pillar buttresses (on coupes)
- Cowl areas ahead of the windscreen also rust – repair means removing the windscreen
- Front cross-members can rot through quickly so buy on the condition of the subframe. Cross-members cost £1400 to replace
- Rear suspension mounts are prone to rust, particularly the radius arm mountings
- The front suspension mounts can rot through
- Check the inner wing below the damper mount – it’s a classic rust spot
- When opening the boot, check for a smell of dampness or stale fuel, which can indicate leaking rear screen or blocked drainage channels or fuel tank leak (common on mid-80s cars)
Interior
XJS interiors are hard-wearing with the exception of the walnut veneer, which can tend to delaminate. Although only a cosmetic issue, repair can be expensive.
- If the heavy doors drop as they open then the hinge pins are worn (check for evidence of scrapes on the tread plate)
- A damp or musty smell indicates that moisture is getting in, probably through the heater if the scuttle vent drains are blocked or via the door seals if the roof drains have been blocked with sealant
- Check for damage to the leather seats – piping is easy to repair but damaged panels are difficult to colour match
- Lift the carpets and check the floor for signs of water leaks, particularly the double-skinned area around the accelerator pedal mounts (on both sides) – corrosion here will be expensive