Jaguar XJ6 and XJ12 Series 1, 2 and 3 buyer's guide

The Jaguar XJ was launched in September 1968 to replace Jaguar's range of older saloons. It was low, wide and quiet, with independent suspension and disc brakes all round, and it stayed in production in three series until the last Series 3 Daimler Double-Six was completed in November 1992. Six-cylinder cars are XJ6s, V12s are XJ12s, and Daimler versions were sold as the Sovereign, Double-Six and Vanden Plas.

People buy them for the ride, the refinement and the looks, and because a good one can still be used regularly. The XK six and the V12 are long-lived engines when looked after, but many XJs were run cheaply in later life, and a neglected car can hide expensive rust and faults behind smart paint and leather.

This guide is for buyers looking at an XJ saloon or Series 2 coupe at a dealer, privately or at an auction such as Mathewsons in North Yorkshire, and for owners preparing to sell. It does not cover repairs: where work is needed, a Jaguar specialist can advise.

By Jon Cosson · Checked 20 October 2026

At a glance

Built	1968 to 1992 (six-cylinder cars to 1986 to 1987, V12 cars to November 1992)
Series	Series 1 (1968 to 1973), Series 2 (1973 to 1979), Series 3 (1979 to 1992)
Body styles	Four-door saloon in standard and long wheelbase; two-door pillarless XJ-C coupe (1975 to 1977)
Six-cylinder engines	XK straight six in 2.8 litre (2792cc), 3.4 litre (3442cc) and 4.2 litre (4235cc) sizes
V12 engine	5.3 litre (5343cc) V12, carburettors at first, fuel injection from 1975, HE version from 1981
Gearboxes	Mostly automatic; four-speed manual with optional overdrive, then a five-speed manual on Series 3 sixes
Fuel tanks	Twin tanks, one each side of the boot, each with its own filler cap and a switch to change between them
Daimler versions	Sovereign (six), Double-Six (V12) and Vanden Plas, plus Daimler XJ-C coupes
Maker	Jaguar Cars, part of British Leyland for much of the run
Design	Sir William Lyons; Series 3 roof and detail changes by Pininfarina
Clubs	Jaguar Enthusiasts' Club, Jaguar Drivers' Club, Daimler and Lanchester Owners' Club

The Jaguar XJ6 and XJ12, Daimler Sovereign, Double-Six and Vanden Plas in brief

The XJ6 was shown in September 1968 with 2.8 or 4.2 litre versions of the XK six, and was named Car of the Year after its launch. The 4.2 was the mainstream engine. The 2.8 was built for markets that taxed engine size and gained a reputation for holed pistons; it was dropped in 1973. Series 1 cars have a tall grille, a low front bumper and twin fuel tanks. A Daimler Sovereign followed in October 1969.

The V12 arrived in summer 1972, creating the XJ12 and the Daimler Double-Six, with four Zenith-Stromberg carburettors and automatic transmission only. Later in 1972 long-wheelbase saloons added four inches between the axles, mostly in rear legroom, and the Daimler Double-Six Vanden Plas, finished by Vanden Plas in London, was the first in the range on the longer shell. Series 1 V12s were built for little more than a year, so they are scarce.

The Series 2 appeared in autumn 1973 with a raised front bumper for US safety rules, a shallower grille and a new dashboard. The short-wheelbase saloon was dropped in late 1974. In 1975 a 3.4 litre six replaced the 2.8 and the V12 gained fuel injection. Built during British Leyland's worst years for quality, the Series 2 has a reputation for poorer build and electrics.

The two-door XJ-C coupe was shown in 1973 but reached customers only in 1975, largely because sealing the frameless side windows proved difficult. It uses the short wheelbase with longer doors, has no central pillar and has a standard vinyl roof. It was offered with the 4.2 six or the V12 as a Jaguar or a Daimler until November 1977. Sources differ on the total, but around 10,000 were made, only 407 of them Daimler Double-Six coupes.

The Series 3 arrived in spring 1979. Pininfarina revised the roof line with a taller, crisper glasshouse and larger windows, and the car gained thicker bumpers and a simpler grille. The 4.2 six now had fuel injection while the 3.4 kept carburettors, and a five-speed manual, the LT77 gearbox shared with Rover, replaced the four-speed and overdrive. The more economical High Efficiency (HE) V12 arrived in 1981. This is generally regarded as the best built of the three series.

In 1983 to 1984 the Sovereign name moved to the top Jaguar models and the Vanden Plas name was dropped in the UK, so the top Daimlers became the Daimler 4.2 and the Double-Six. The XJ40 replaced the six-cylinder Series 3 in 1986, although six-cylinder production ended in early 1987. The V12 continued, the Jaguar-badged car being dropped shortly before the Daimler, and the last Series 3 Double-Six was completed in November 1992.

Versions to know

Version	Years	What to know
Series 1 XJ6 2.8 and 4.2	1968 to 1973	The original shape, with a tall grille and low bumpers. The 4.2 is the one to look for; the 2.8 is less powerful and its engine is known for piston failures, so many have had replacement engines. Short wheelbase except for the late XJ6L.
Daimler Sovereign Series 1	October 1969 to 1973	Daimler-badged XJ6 with the 2.8 or 4.2 engine and higher standard specification. Mechanically the same as the Jaguar.
Series 1 XJ12 and Daimler Double-Six	1972 to 1973	The first V12 saloons, on four carburettors and automatic only. Built in small numbers in both wheelbases, which makes them the rarest XJ saloons. Fuel consumption is heavy.
Daimler Double-Six Vanden Plas	1972 onwards	The most expensive version when new, finished by Vanden Plas with extra trim and equipment, and the first XJ on the long wheelbase. A six-cylinder Vanden Plas 4.2 joined during the Series 2 run.
Series 2 saloons	1973 to 1979	Raised bumper and new dashboard. Short wheelbase to late 1974, long wheelbase after that. 2.8 and 4.2 sixes, then 3.4 and 4.2 from 1975; V12 fuel injected from 1975.
XJ-C coupe (XJ6C, XJ12C, Daimler Sovereign and Double-Six coupes)	1975 to 1977	Two-door pillarless coupe on the short wheelbase, with a standard vinyl roof. Wind noise and window sealing are known issues, and many coupe-specific parts are hard to find.
Series 3 XJ6 3.4 and 4.2	1979 to 1987	Pininfarina roof, larger glass and new bumpers. The 4.2 is fuel injected, the 3.4 uses carburettors. Most are automatic. Sovereign became the top Jaguar from 1983.
Series 3 XJ12 and HE V12	1979 to 1992	Fuel-injected V12 with the GM automatic. HE engines from 1981 are more economical. Later V12s were sold as the Jaguar Sovereign V12 and the Daimler Double-Six.
Series 3 Daimler Sovereign, Vanden Plas, 4.2 and Double-Six	1979 to 1992	Daimler versions with higher-specification interiors, badged Daimler 4.2 and Double-Six with Vanden Plas-level trim after 1983 to 1984.

Pros and cons

Pros	Cons
Ride comfort and refinement that still compare well with much later saloons. The 4.2 XK six and the V12 are durable engines when the cooling system and servicing have been kept up. The long-wheelbase saloons have generous rear legroom and a large boot, so they are usable family classics. Mechanical parts and service items are widely available, and there is a large specialist network in the UK. Daimler versions are mechanically identical, which widens the search for a good car. Active clubs offer model knowledge and technical help.	The steel monocoque rusts in many places, and structural repairs can be extensive and expensive. Some outer panels, including rear wings, doors and coupe-specific parts, are scarce, so repairs often use let-in sections. Trim restoration is costly: leather, wood veneer, carpets and headlining add up quickly. Inboard rear brakes and handbrake calipers are awkward to reach, so they are often neglected. Series 2 cars have a reputation for poorer build quality and more electrical faults. The V12 is unforgiving of overheating and poor maintenance, and engine work on it is a specialist job.

Pros

Cons

Ride comfort and refinement that still compare well with much later saloons.
The 4.2 XK six and the V12 are durable engines when the cooling system and servicing have been kept up.
The long-wheelbase saloons have generous rear legroom and a large boot, so they are usable family classics.
Mechanical parts and service items are widely available, and there is a large specialist network in the UK.
Daimler versions are mechanically identical, which widens the search for a good car.
Active clubs offer model knowledge and technical help.

The steel monocoque rusts in many places, and structural repairs can be extensive and expensive.
Some outer panels, including rear wings, doors and coupe-specific parts, are scarce, so repairs often use let-in sections.
Trim restoration is costly: leather, wood veneer, carpets and headlining add up quickly.
Inboard rear brakes and handbrake calipers are awkward to reach, so they are often neglected.
Series 2 cars have a reputation for poorer build quality and more electrical faults.
The V12 is unforgiving of overheating and poor maintenance, and engine work on it is a specialist job.

Myths and realities

A Daimler is just a Jaguar with a different grille, so it is worth less as a car.

They are mechanically the same, with higher standard trim on the Daimler. A well-kept Daimler can be a better buy than a tired Jaguar.

Low oil pressure at idle means the engine is worn out.

Very low readings at a warm idle are common, and the factory gauges are not reliable. What matters is a healthy reading at speed, around 40psi on a six, ideally confirmed with a test gauge.

Avoid the V12, it is always unreliable.

The V12 is robust when its cooling system is sound and it has been serviced properly. Neglect and overheating are the risks, so history matters more than engine type.

Rust round the windscreen is just cosmetic.

Bubbling there usually means corrosion under the glass seal, and repair involves removing the screen and often much of the dashboard. Perforation that lets water in is serious.

What to check

Bodywork and structure

Rust is the biggest risk on any XJ, and a car can look smart while the structure is poor. Take a torch, a magnet and a mat, and spend most of your time here.

Front and rear screen surrounds: bubbling under the trim, or water stains on the headlining and in the footwells, point to corrosion under the glass, especially on the Series 3.
Sills, inner sills and jacking points. Check where the sills meet the wings, and look for new outer sills welded over old metal.
Floor pans and the underfloor chassis box sections, including from inside under the carpets and around the seatbelt mountings.
Rear radius arm mounting points in the floor, ahead of the rear wheels. They are a structural item and a common area of rot and poor repair.
Front subframe and front crossmember, which carry the engine and front suspension. Check for flaking, rust under cracked coating and signs of patching.
Front wings around the headlamps, at the bottom rear corners and along the arch lips, plus the front valance and lower bonnet edge.
Rear wheel arches, rear wing bottoms, the rear valance and the wells behind the rear wheels around the fuel tanks.
Boot lid, boot floor and spare wheel well. Lift the boot floor covering and check for water from a leaking rear screen seal.
Coupes: check door fit, window frames and rear quarters carefully, as coupe panels are harder to replace.
Door bottoms, where blocked drains trap water, and panel gaps, overspray and hidden joins that reveal past repairs.

Engine

Both engine families last well with care. Look at the fluids before the engine is started and ask for a cold start if you can.

Dipstick oil: thick black oil suggests infrequent changes, a milky residue suggests coolant in the oil.
Coolant should be clean and of the right antifreeze strength, as weak coolant corrodes the alloy heads and blocks radiators. Look for staining along the head gasket line.
Overheating: watch the temperature gauge on a long run and in traffic, especially on the V12, which does not tolerate it.
Timing chain rattle from the front of the engine at idle or under acceleration. The chains are long, and a worn or broken chain means a major job on either engine.
Oil pressure: on a six, around 40psi at speed is healthy. Very low readings at a warm idle are common and the gauge may be inaccurate.
Oil leaks underneath, often from the rear crankshaft seal, and fuel leaks or smells in the engine bay, which must be taken seriously.
V12: a slight misfire can mean a dead cylinder, so listen for uneven running. Check for oil leaks and ask for records of plug changes and cooling system work.
2.8 litre cars: ask whether the original engine is still fitted, given its history of piston failures.

Gearbox and drivetrain

Most XJs are automatics, and the automatic gearboxes are durable if the fluid has been looked after.

Automatic fluid: check the level and look for clean, red fluid without a burnt smell. Changes should be prompt with no slipping; Series 1 Borg-Warner boxes can feel jerky.
Later V12s use a GM automatic, which should change smoothly. Check for delays when selecting Drive or Reverse.
Manual cars: listen for bearing noise and feel for weak synchromesh. On four-speed cars, overdrive should engage and release promptly; a slow response can mean low or old oil.
Differential: oil leaks from the differential seals can soak the inboard rear brakes. Look at the back of the axle with a torch for wet oil.
Clonks when pulling away or changing direction can come from worn universal joints, propshaft or driveshaft joints, or a collapsed propshaft centre mount.

Suspension, steering and brakes

The XJ rides well only when its many bushes and mounts are in good order. Worn suspension creeps up slowly, and owners often do not notice.

Rear suspension: a soft, wallowing feel or clonking over bumps suggests worn radius arm bushes, subframe mounts or dampers.
Front suspension clonks are often worn damper or wishbone bushes, and vague steering can come from worn upper wishbone bushes.
Tyres: a matching set of a known brand is a good sign. Uneven wear points to worn suspension or poor alignment.
Power steering is standard. Check the fluid level, look for leaks at the rack, and feel for notchiness or heavy spots.
Inboard rear brakes: look for oil contamination and ask when the rear discs, pads and seals were last done, as they are labour intensive to reach.
Handbrake: test it on a slope. The separate handbrake calipers can seize, especially on little-used cars.
Brakes should pull up straight without juddering, and the pedal should be firm.

Electrics and instruments

Series 1 and Series 3 electrics are generally reliable; the Series 2 has more trouble. Most faults are switches, connections and earths.

Try every electric window. Failed windows can indicate neglect, although rear windows that do not work may simply be unused.
Test the central locking, lights, indicators, hazards, wipers on all speeds, horn and any electric seats or mirrors.
Heater and air flow: check every setting directs air to the right place and that both blowers work. Faults inside the dashboard are labour intensive.
Air conditioning: if fitted, check it blows cold. Be cautious of a claim that it only needs a recharge.
Fuel tank change-over switch: check both tanks are used and both gauges read, and look and smell for fuel leaks around the tanks.

Interior and trim

Interiors are part of the appeal, and they are among the most expensive things to put right.

Leather: cracks, splits and a sagging driver's seat. Cloth seats are hard to restore.
Wood veneer: lifting, cracking or cloudy lacquer on the dashboard and door cappings. Damp makes it worse.
Headlining: sagging is common, and holes suggest hard use.
Carpets: lift them and check for damp from leaking screens, door seals or the bulkhead. A persistent damp smell is hard to remove.
Coupes: check the vinyl roof for lifting, splits and bubbling underneath, and the side window seals for gaps and tears.

Paperwork and originality

With so many versions and changes over 24 years, the paperwork tells you what the car really is.

Check the chassis or VIN number on the car against the V5C, and the engine number against any records.
Confirm the series, wheelbase, engine and badge match the paperwork, especially for Series 1 V12s, coupes and Daimlers.
A Jaguar Daimler Heritage Trust certificate records the original colour, trim, build and dispatch dates and destination from factory records. It is a reference, not proof of condition or originality.
Ask for receipts and photographs of structural repairs, especially sills, screen surrounds, radius arm mounts and the front subframe.
Note modifications such as engine swaps on 2.8 cars, manual conversions, modern wheels or upgraded cooling. Some are sensible, but they should be declared.

On the test drive

Start from cold if possible, watching for smoke and listening for timing chain rattle.
Watch the temperature gauge throughout, and let the car idle afterwards to check the fans cope.
Check oil pressure on the move once warm.
On an automatic, check it pulls away cleanly and changes smoothly, including kickdown; on a manual, try every gear and any overdrive.
Drive over rough surfaces and listen for clonks; the car should feel settled, not floaty.
Brake firmly on a clear straight road; the car should stop straight with a firm pedal.
Feel for vague or notchy steering, and check the car tracks straight.
Test the handbrake on a slope and try the heater on every setting.
Afterwards, look underneath for fresh oil, coolant, fuel or power steering fluid drips.

Buying at auction

XJ saloons and Daimlers are regular entries at UK classic auctions, including regional sales such as Mathewsons in North Yorkshire. You get less time with the car than in a private sale, so use the viewing days well.

What you can check in viewing week

Use a torch underneath, ideally lying on a mat, to check the sills, floors, radius arm mounts, front subframe, jacking points and the back of the differential for oil.
Use a magnet on the lower wings, sills, arches, valances and around the screen surrounds for filler.
Check the chassis or VIN and engine numbers against the V5C and the catalogue description.
Lift the bonnet and check the oil, coolant and any accessible automatic fluid, and look for fuel and oil leaks.
Lift the boot floor covering and check the spare wheel well and boot floor for water and rust.
Read the history file in full, including old MOTs, receipts and any Heritage Trust certificate.
If start-ups are allowed, listen for timing chain rattle and uneven running, look for smoke, and see whether the oil pressure gauge responds.

What you usually cannot do

You usually cannot drive the car, so the gearbox, suspension, steering and brakes cannot be judged on the road.
You usually cannot put it on a lift, so a full view of the underside is not possible.
You cannot see inside the sills, box sections or behind the screen seals.
You cannot run the engine long enough to see how the cooling system copes when hot, which matters most on a V12.

Tips

Read the catalogue critically. Words such as restored or recommissioned mean little without receipts and dates. Notice what is not mentioned, such as the structure or cooling system.
Check claims about rare versions, such as a Series 1 V12, a coupe or a Vanden Plas, against the paperwork.
Remember the buyer's premium and any other fees on top of the hammer price, and read the terms and conditions before bidding.
Set your limit before the sale, including likely work on brakes, bushes, trim and cooling, and stick to it.
Arrange transport home before you bid. Do not assume a car bought without a test drive is roadworthy, and have insurance in place if you plan to drive it.

What makes one more desirable

Structural condition comes first: documented repairs to the sills, screen surrounds and subframes count for more than fresh paint.
Series 1 cars, especially the 4.2, are generally the most sought after for their original shape and details.
The XJ-C coupe is the most sought after body style, with V12 and Daimler coupes rarest of all.
Series 1 XJ12 and Double-Six saloons are rare and attract specialist interest when their identity is confirmed.
Late Series 3 Sovereigns and Daimlers appeal to buyers who want a car to use regularly.
Manual gearboxes are uncommon and can add interest if they suit the car's paperwork.
Original colour and trim, matching numbers and a Heritage Trust certificate add confidence.
Long ownership and specialist receipts are valued, especially evidence of cooling system care on V12s.

This guide does not give values or predict prices.

Selling a Jaguar XJ6 and XJ12, Daimler Sovereign, Double-Six and Vanden Plas

Buyers know XJs can hide rust and neglect, so a well prepared, honestly described car with good paperwork stands out.

Preparing the car

Clean the underside as well as the bodywork; buyers will look at the sills, floors and subframes.
Fix small faults that put buyers off, such as electric windows, gauges, lights or heater controls, using a specialist where needed.
Have the car serviced so it starts easily, idles evenly and holds its temperature.
Dry out any damp interior and deal with water leaks before showing the car.

Paperwork

V5C in your name with the correct chassis and engine details.
Receipts for structural and major mechanical work, ideally with photographs.
Old MOT certificates and service records in date order.
A Jaguar Daimler Heritage Trust certificate, if you have one, or consider ordering one.
Details of any engine changes, gearbox conversions or modifications, with dates and who did the work.

Where to sell

Owners' club magazines and classified adverts, where buyers know the model.
Jaguar specialist dealers, by outright sale or part exchange.
Classic car auctions, including regional sales such as Mathewsons, after checking the seller's commission and entry terms.

Writing the description

State the series, wheelbase, engine, gearbox, badge and trim level.
Be honest about structural work: say what was done, when and by whom.
Declare non-original engines, conversions and modifications.
Photograph the sills, floors, screen surrounds, engine bay and interior as well as the outside.

Living with one

Mechanical parts and service items are easy to find and many UK specialists know these cars well, though some panels and trim parts are scarce.
Regular servicing matters, particularly oil changes, correct antifreeze and cooling system checks.
Fuel consumption is the main running cost, especially for a V12, so consider how far you will drive each year.
Cars that sit for long periods suffer seized brakes, leaking seals and damp interiors, so regular use helps.
Cars built more than 40 years ago can be eligible for historic vehicle tax and may be exempt from the MOT if not substantially changed. Later Series 3 cars from 1986 onwards reach that age year by year. An annual check is still wise.
Classic insurance with an agreed value and limited mileage is widely available; tell the insurer about any modifications.

Clubs and registers

Questions people ask

Where do Jaguar XJ6s rust?

The screen surrounds, sills and jacking points, floor pans, rear radius arm mounts, front subframe, front wings around the headlamps, wheel arches, door bottoms, valances and the boot floor and spare wheel well.

Which XJ series is best to buy?

Series 1 cars are the most sought after for their looks, while the Series 3 is generally the best built and easiest to use. The Series 2 can be good if well looked after. Condition matters more than series.

Is the Jaguar XJ12 reliable?

The V12 is robust when it has been maintained, with a healthy cooling system and regular servicing. Overheating and neglect cause most problems, and engine work is a specialist job, so history is essential.

Should I avoid the 2.8 litre XJ6?

The 2.8 was less powerful and its engine had a known problem with holed pistons, so many have been changed. A 4.2 is the usual choice, and the 3.4 that replaced the 2.8 is a sound alternative.

What is the difference between a Jaguar and a Daimler XJ?

Daimlers have their own badges and grille and higher standard trim, but they are mechanically the same. The Sovereign is a six, the Double-Six is a V12 and Vanden Plas versions have the most luxurious interiors.

What is the XJ-C coupe?

A two-door pillarless Series 2 built from 1975 to 1977 on the short wheelbase, with a vinyl roof and a 4.2 six or V12, as a Jaguar or Daimler. Around 10,000 were made.

Is a Jaguar XJ6 a good first classic?

It can be, if you buy a car with a solid structure and good history and budget for ongoing maintenance. Have a Jaguar specialist inspect it before you buy if you are unsure.

Sources

Checked 20 October 2026.

An independent guide. Not a valuation and not financial advice. Always inspect a car in person or have it inspected before you buy.