Jaguar XJ-S and XJS buyer's guide

The V12 is an unreliable engine to avoid.

The V12 is regarded as durable when it has been serviced properly, with regular oil and coolant changes. The trouble usually comes from neglect, especially of the cooling system, rather than from the design.

A very low mileage car is always the best buy.

Cars that sit unused suffer seized brakes, perished seals and stale fluids. A moderate mileage with a full, continuous service history can be a safer buy.

Facelift cars from 1991 do not rust.

Later cars used more galvanised steel, but they still rust, particularly around the windscreen, wheel arches and jacking points. Check them as thoroughly as an early car.

Every open XJ-S is a convertible.

The 1983 to 1988 XJ-SC is a cabriolet with a fixed frame and removable roof panels, not a full convertible. The factory full convertible arrived in 1988, and some earlier open cars are conversions by outside coachbuilders.

Bodywork and structure

Rust is the main concern on any XJ-S or XJS, and structural repairs are expensive. Take a torch, a magnet and a mat, and spend most of your time underneath and on the lower body.

• Sills, inner and outer: look for rot, plates welded over the originals and cover sills. Check the seam where the sill meets the floorpan along its length.
• Jacking points: holes, crushed metal and fresh underseal that may hide repairs.
• Floorpans and front footwells, including around the seatbelt mountings. Lift the carpets if you can and feel for damp.
• Front wings: the bottom rear edge should sit flush and solid against the sill. Check around the headlamps, the arches and the bonnet's wing mounting flanges.
• Rear wings: check the arches and the lower front edge where the wing joins the sill. There should be a visible seam; if it has gone, expect filler.
• Rear radius arm mountings: these rot and, if they fail, affect how the rear wheels are located.
• Front subframe and crossmember: rot here is common and expensive to put right.
• Windscreen surround and scuttle: corrosion at the bottom of the screen frame is common and costly. On later cars, also check the forward edge of the roof.
• Doors rot from the inside, often where water gets past the window rubbers. Check the bottoms and for sagging at the hinges.
• Pre-facelift cars: check the rear buttresses, bootlid trailing edge, rear window surround and behind the bumpers.
• Front and rear valances and the double-skinned front damper mountings.

Engine

Both engines last well with regular servicing and suffer badly without it. A full history showing oil changes and coolant changes every two years matters more than the mileage.

• Coolant should be clean and the correct colour. Brown or sludgy coolant suggests long neglect and internal corrosion, and many specialists advise walking away.
• Overheating: silted radiators cause it on both engines. Watch the gauge, check the fans work and look for leaking hoses.
• Oil pressure when warm and at speed should typically read around 40 to 50psi. Low readings need explaining.
• V12: ask when the spark plugs were last changed; the rearmost plugs are hard to reach and often neglected.
• V12: listen for timing chain rattle and misfires, which are hard to hear on twelve cylinders. A compression test before purchase is worth considering.
• AJ6 and AJ16: look for signs of head gasket failure, such as white emulsion under the oil filler cap, oil in the coolant or unexplained coolant loss.
• Six-cylinder cars: listen for timing chain and tensioner noise on start-up.
• Oil leaks around the cam covers and at the rear of the engine, more likely on rarely used cars.
• A smell of burning oil, smoke on start-up or clanking are reasons to walk away or get a specialist opinion first.

Gearbox and drivetrain

Most cars are automatics, which suit the car well. Manual cars exist, mainly six-cylinder models, and early manual V12s are rare.

• Automatics: changes should be smooth and prompt, and kickdown should work without hesitation.
• A knock from underneath when pulling away can point to worn or collapsed gearbox mountings.
• Manual six-cylinder cars: check for crunching into first and second and for clutch slip.
• Early V12 manuals: confirm with documents that the gearbox is original, as the option is rare.
• Rear differential: listen for whine at speed and look for oil leaks at the pinion seal.
• On cars with inboard rear brakes (before mid-1993), differential leaks can reach the discs and pads, so look for oil around the rear brakes.

Suspension, steering and brakes

The suspension gives a good ride, but it is complex and wears. Many cars need a full overhaul, so look for evidence it has been done.

• Front top inner wishbone bushes wear, often around 50,000 miles, causing wandering and uneven tyre wear.
• Rear subframe: check the mountings for perished rubber, which causes vague handling, and look for cracks around the differential mounting points.
• Radius arm bushes: knocks from underneath often come from here.
• Hub bearings: rock each wheel top and bottom to check for play.
• Steering: turn lock to lock and listen for groans or knocks. Look for fluid leaks at the rack and pump.
• Brakes: the car should stop straight. Pulling suggests a sticking caliper, vibration warped discs. Ask when the fluid was last changed.
• Inboard rear brakes on earlier cars are hard to reach and sometimes neglected; ask when they were last inspected.
• ABS on later cars: the warning light should come on with the ignition and then go out.
• Wheels: check for kerb damage, corrosion and that they are the correct type for the model.

Electrics and instruments

The XJ-S has a lot of electrical equipment for its age, and faults are common on neglected cars. Test everything.

• Work all the electric windows, mirrors, central locking, aerial, lights, wipers and horn.
• Check every gauge and that the warning lights come on at start-up and then go out; test the trip computer where fitted.
• Run the air conditioning and check it blows cold; repairs can be expensive.
• Blocked air-conditioning drains can leak water into the cabin, soaking carpets or reaching control modules.
• Look for amateur wiring, scorched connectors and non-standard additions.
• Convertibles: operate the electric hood fully, up and down.

Interior and trim

The cabin is well built, but full restoration of leather, wood and carpets is costly, so condition here matters.

• Leather seats: the outer bolster of the driver's seat wears first. Look at the piping and stitching.
• Wood veneer on the dashboard, console and door cappings can crack, fade or lift; proper restoration is specialist work.
• Damp carpets point to leaks from the windscreen, scuttle, door seals, sunroof drains, hood or air-conditioning drains.
• Headlining: check for sagging and staining.
• Cabriolets: check the removable roof panels, their seals and the folding rear section for leaks and tears.
• Convertibles: check the hood fabric, rear window, frame and seals.
• Door trims, plastic fittings and some brightwork can be hard to find, so check pieces are present and undamaged.
• Make sure the interior suits the year: the 1991 facelift brought a new dashboard and seats.

Paperwork and originality

Because so many cars were neglected when cheap, the history file is one of the most important things to examine.

• Check the VIN on the car against the V5C, and the engine number against any records.
• A Heritage Certificate from the Jaguar Heritage Trust, based on original production records, can confirm the car's original specification.
• Look for continuous servicing, especially oil and coolant changes. A history that stops is a warning.
• Ask for receipts for structural, suspension, brake and cooling work, with photographs if possible.
• For an XJR-S, Celebration, manual V12 or other rare version, check the paperwork supports the claim and ask the clubs for help.
• Open cars: confirm whether it is a factory XJ-SC, a factory convertible or a coachbuilder conversion.
• Note modifications such as body kits, non-standard wheels, headlamp conversions or polyurethane bushes. They should be declared.
• Check for an import history; left-hand-drive cars and imports are common.

Where do Jaguar XJ-S and XJS models rust?

The sills and sill-to-floor seam, jacking points, floorpans, front wing bottoms, rear arches and rear wing fronts, the windscreen surround, door bottoms, the front subframe and the rear radius arm mountings. Earlier cars also rust at the rear buttresses and bootlid edge.

Should I buy a V12 or a six-cylinder XJS?

The V12 is smoother and has a character many buyers want, but uses more fuel and costs more to maintain. The six-cylinder cars are cheaper to run, easier to work on and the only ones commonly found with a manual gearbox. Condition and history matter more than engine choice.

Is the Jaguar XJS reliable?

A well-maintained XJS can be dependable. Most problems come from neglect of the cooling system, suspension and electrics, so look for a full history of oil and coolant changes.

What is the difference between the XJ-SC cabriolet and the convertible?

The XJ-SC of 1983 to 1988 keeps a fixed frame over the cabin with removable roof panels. The convertible, from 1988, has a full electric hood. Some earlier open cars are coachbuilder conversions.

Is a facelift XJS better than an earlier XJ-S?

Cars from May 1991 have a revised interior, new rear styling, larger side windows and the 4.0 six or later V12s, and the later ones have outboard rear brakes. Many buyers prefer them, but they still rust, especially around the windscreen.

What does HE mean on an XJ-S?

HE stands for High Efficiency. From 1981 the V12 gained new cylinder heads designed by Michael May, which improved fuel economy noticeably. Cars before this are usually called pre-HE.

Is an XJS a good first classic car?

It can be, for someone who wants a touring car and will keep up the maintenance. Buy the best documented example you can, consider a six-cylinder car if running costs matter, and have a specialist inspect the structure first.

Why does coolant colour matter so much?

Radiators silt up and internal corrosion leads to overheating and, on six-cylinder cars, head gasket failure. Brown or sludgy coolant is a sign of long neglect.