Jaguar XJ6, The Complete Buying Guide

Overview

The Jaguar XJ6 is, quite possibly, the finest saloon car of the twentieth century. That’s not hyperbole, it’s the considered opinion of virtually every motoring journalist who drove one in period, and it holds up remarkably well today. When the Series 1 launched in 1968, it set a new standard for ride quality, refinement, and luxury that Mercedes-Benz, BMW, and everyone else spent the next decade trying to match.

The XJ6 spanned three series across 24 years of production (1968-1992), evolving from a groundbreaking new design into a mature, thoroughly developed luxury saloon. Along the way, it was offered with engines ranging from a 2.8-litre six to a 5.3-litre V12, in standard and long wheelbase forms, and under both the Jaguar and Daimler badges.

The good news for buyers is that the XJ6 is one of the most affordable ways into classic Jaguar ownership. A presentable Series 3 can be found for well under $20,000 AUD. The bad news is the same as every Jaguar from this era: rust, Lucas electrics, and the potential for maintenance costs to dwarf the purchase price.

But if you buy well, maintain properly, and accept the car’s foibles, you’ll own a machine that rides like a cloud, looks like a million dollars, and makes every journey feel like an occasion.

The Three Series

Series 1 (1968-1973)

The original and, to many eyes, the most beautiful. Sir William Lyons styled the XJ6 himself, his last major design project, and the proportions are near-perfect. The low roofline, slim pillars, curved glass, and delicate chrome work create a car that looks smaller than it is and more elegant than it has any right to be.

Engines were the 2.8-litre and 4.2-litre versions of the XK inline-six. The 2.8 was a de-stroked economy option that satisfied nobody, it’s slower, less refined, and no more economical in practice. The 4.2 is the one to have. From 1972, the V12 option arrived (badged XJ12 or, in Daimler form, Double Six), offering extraordinary refinement and equally extraordinary fuel consumption.

The Series 1 is the most collectible and, increasingly, the most expensive. Prices have risen sharply as the car’s significance is recognised. A good Series 1 4.2 now commands $25,000-40,000 AUD, with exceptional examples pushing higher.

Series 2 (1973-1979)

US safety regulations forced changes that most enthusiasts consider detrimental. The bumpers grew substantially (raised, heavy rubber-faced units), the front grille was enlarged, and the overall look became heavier. Some interior changes followed, improved heating and ventilation, revised instruments, and various safety modifications.

Under the skin, the Series 2 was progressively improved. Fuel injection replaced carburettors on some markets, the power steering was refined, and build quality gradually improved (from a low base, Series 2 production coincided with some of British Leyland’s worst industrial relations crises).

The Series 2 is the least sought-after XJ6 variant, which makes it the cheapest. A running Series 2 4.2 can be found for $10,000-20,000 AUD. They’re not as pretty as the Series 1, but they’re mechanically similar and thoroughly usable.

Series 3 (1979-1992)

The definitive XJ6 for most people. Pininfarina was engaged to update the styling, a controversial decision at the time but one that produced a handsome, more modern-looking car. The roofline was raised slightly (improving rear headroom), flush-fitting door handles replaced the chrome pull types, and the overall appearance was cleaned up while retaining the essential XJ proportions.

The Series 3 benefited from 13 years of continuous development. Later cars have Bosch ignition (replacing the troublesome Lucas systems), improved build quality, and better corrosion protection. The 4.2-litre XK six continued as the standard engine, with the V12 available as the XJ12/Sovereign/Daimler Double Six.

The Sovereign trim level added luxury equipment, wood, leather, electric everything. The Daimler badge brought the same mechanicals with higher trim and the distinctive fluted grille. Both are built on the same production line as the standard XJ6.

The Series 3 is the most practical choice for regular use. Best parts supply, most refined, easiest to maintain. A decent Series 3 4.2 runs $8,000-20,000 AUD, making it one of the great classic car bargains.

What to Look For

Body and Rust

Same story as every Jaguar from this era. The XJ6’s monocoque structure corrodes, and when structural components go, the car’s rigidity is compromised. The good news is that the XJ6 was built in much larger numbers than the E-Type, so parts supply is better and the knowledge base is deeper.

Critical rust areas:

• Sills, inner and outer. The primary structural concern. Check thoroughly from underneath. Push a screwdriver into them. When sills rot, doors sag, the floor flexes, and the car becomes structurally unsound.
• Floor pans, particularly under the front and rear carpets. Lift the carpets and check. Water ingress from windscreen rubbers, door seals, and blocked drains causes hidden rot.
• Rear wheel arches, inner and outer. Stone chips start the process, blocked drainage accelerates it.
• Front wings, around headlights, indicator mounts, and the bottom edges. Replacement wings are available.
• Boot floor and spare wheel well, water pools here from failed seals and blocked drains. Check carefully.
• A-pillars and windscreen surround, failed windscreen rubbers let water track down the pillars. Rust here is expensive to repair.
• Lower rear quarters, the panels between the rear wheels and the boot. These trap mud and moisture.
• Subframe mounting points, front and rear. Corroded mounting points mean the subframes aren’t properly secured. This is a safety issue.

Australian-delivered cars are generally better than imports. No road salt, drier conditions, and less exposure to the British weather that killed so many XJ6s. But neglected Australian cars still rust, blocked drains and failed seals cause the same damage regardless of climate.

Mechanical

XK Engine (4.2-litre): The same legendary twin-cam six that powered the E-Type. In the XJ6, it’s detuned for refinement rather than performance, still 170-180 bhp, but with a focus on smooth power delivery and low-speed torque.

• Oil leaks are standard. The XK engine weeps from every gasket. The rear main seal is the worst, replacement requires gearbox removal.
• Check oil pressure, should be 40+ psi at 3000 rpm when hot.
• SU carburettors (Series 1) need regular balancing. Fuel injection (later Series 2 and all Series 3) is more reliable but has its own issues.
• Listen for timing chain rattle on cold start.
• Blue smoke on overrun means valve guide wear. Blue smoke under load means ring wear.
• Overheating is a concern, ensure the cooling system is in good order.

2.8-litre XK Engine: Avoid. It’s underpowered, unreliable (the de-stroked design causes bearing issues), and there’s no good reason to buy one when 4.2 cars are abundant.

V12 (XJ12/Double Six): Magnificent refinement, catastrophic fuel consumption (20-25 L/100km). The same cooling, head gasket, and maintenance concerns as V12 E-Types and XJ-S models. Only buy a V12 XJ if you genuinely want and can afford the experience. The six-cylinder car is the sensible choice.

Transmission

Automatic (most common): Early cars used the Borg-Warner BW66 three-speed automatic, adequate but not brilliant. Later Series 2 and all Series 3 cars received the GM TH400 (three-speed) or, on the very latest models, the ZF four-speed. The GM TH400 is excellent, strong, smooth, and reliable. The BW66 is acceptable but weaker.

Manual (rare): A four-speed manual with overdrive was offered on some six-cylinder models. It’s uncommon, particularly in Australia, but adds driver engagement. The manual gearbox itself is robust.

Electrical

Lucas. Again. The XJ6’s electrical system is complex, it’s a luxury car with power windows, central locking, climate control, and numerous other electric systems, all running through Lucas components.

• Series 1 and 2 cars have Lucas ignition, replacement with electronic ignition (Pertronix or similar) is strongly recommended.
• Series 3 cars with Bosch ignition are significantly more reliable.
• Check every electrical function: windows, mirrors, locks, lights, wipers, heated rear screen, instruments.
• The A/C system is complex and expensive to overhaul.
• Wiring looms deteriorate. A complete rewire is a major job but transforms reliability.

Interior

The XJ6’s interior is one of its greatest assets, acres of wood and leather, comfortable seats, and a sense of occasion that modern cars struggle to replicate.

• Check the wood veneer, cracking and lifting is common. Restoration is expensive.
• Leather wears and cracks if not maintained. The Connolly leather used in these cars responds well to proper care.
• Headlining sags, a common problem, especially in the heat.
• Seat mechanisms (especially powered seats) can fail.
• Check the instrument cluster, the Smiths gauges are specific and expensive to repair.

Price Guide (Australia)

Series 1

• Project / non-runner: $5,000-12,000 AUD
• Running driver, cosmetic issues: $15,000-25,000 AUD
• Good condition, well-maintained: $25,000-40,000 AUD
• Excellent / show standard: $40,000-60,000+ AUD
• V12 (XJ12): Add 30-50% to the above ranges

Series 2

• Project / rough: $3,000-8,000 AUD
• Running driver: $8,000-15,000 AUD
• Good condition: $15,000-25,000 AUD
• Excellent: $25,000-35,000 AUD
• V12: Add 30-50%

Series 3

• Project / rough: $3,000-8,000 AUD
• Running driver, presentable: $8,000-15,000 AUD
• Good condition, well-maintained: $15,000-25,000 AUD
• Excellent / Sovereign / Daimler: $25,000-40,000 AUD
• V12 (Sovereign V12 / Double Six): $15,000-35,000 AUD

Daimler-badged versions command a modest premium (10-20%) for their higher trim levels, but the mechanicals are identical to the equivalent Jaguar. The fluted grille and “D” badges add cachet but nothing mechanical.

Running Costs

Parts availability: Excellent for Series 3, good for Series 1 and 2. The XJ6 shares its engine and many components with the E-Type and XJ-S, broadening the parts base. SNG Barratt, David Manners, and Martin Robey all support the XJ range comprehensively.

Servicing: Straightforward for a competent Jaguar specialist. The XK engine is well-understood, and routine maintenance is not complex. Budget $2,000-4,000 AUD per year for regular maintenance on a sorted car. V12 models cost 30-50% more.

Fuel economy: 4.2 six: 14-18 L/100km. V12: 20-25 L/100km. Run 98 RON.

Insurance: Agreed-value classic policies through Shannons or similar. Reasonable premiums for a car in this price range.

Which One Should You Buy?

The smart buy: Series 3 4.2 Sovereign. The most refined, best parts supply, Bosch ignition on later cars, and the Sovereign trim gives you all the luxury equipment. This is the XJ6 that works best as a usable classic.

The purist’s choice: Series 1 4.2. The most beautiful XJ, the most collectible, and increasingly the most expensive. Buy it if aesthetics matter more than practicality.

The bargain: Series 2 4.2. Nobody wants them, which means prices are low and you get all the XJ6 qualities for minimal outlay. The raised bumpers aren’t pretty, but on the road, the experience is fundamentally the same.

The experience: Series 3 V12 (Daimler Double Six). The ultimate refinement, a V12 luxury saloon with ride quality that embarrasses modern cars. But the fuel bills and maintenance costs are serious. Only for enthusiasts who understand and accept the commitment.

Avoid: Any 2.8-litre car. Any XJ6 with no service history and a suspiciously low price. Any car where the sills and floors haven’t been inspected properly.

The Verdict

The XJ6 is one of those cars that makes you wonder why anyone buys anything else. The ride quality is extraordinary, better than most modern luxury cars, certainly more comfortable than any SUV. The cabin is a beautiful place to spend time. The XK engine, for all its oil leaks and age, is a characterful and willing companion. And the way other road users react to a well-presented XJ6, pulling over, waving, giving you space, is a daily reminder that you’re driving something special.

The compromises are real: rust, electrics, fuel consumption, and the need for specialist maintenance. But these are known quantities, well-documented, and well-supported with parts and expertise. A good XJ6 is not expensive to keep on the road, it just needs attention.

Buy the best you can afford, focus on the body condition above all else, and join the JDCA. The club’s XJ register is one of the best resources available, and the collective knowledge of the membership will save you from every mistake they’ve already made.

The XJ6 defined the luxury saloon. Forty-plus years on, it still sets the standard for how a car should ride.