XJ-S V12 maintenance

Engine

Dear Jaguar lovers, many of us love the great XJ-S V12; but this classic Jaguar deserves maintenance, care and love. A V12 can clock up 300,000 miles if we keep it with respect and correctly maintained. Yes, of course I’m talking about regular oil changes, changing all the plugs when needed and making sure the cooling system is up to scratch. It’s famous as the golden rule for the XJ-S V12 ‘Don’t cook it’; yes because if a V12 overheats, the valve seats can loosen when it cools back.

Cooling

V12 is a big engine in a tight engine bay, but if the owner keeps everything in tiptop condition it can work perfectly, but that requires regular inspections, decent antifreeze/corrosion inhibitor, and a through cleanout at least every four or five years. Be cautious of worn viscous fan hubs, debris caught between the radiator/evaporator/oil cooler, sticky thermostats and old perished hoses. When refilling, early systems must be bled using the valve located top left on the radiator.

Steering

Now let’s talk about XJ-S rack and pinion power steering which gradually became less assisted and more responsive with the passage of time. Therefore, you must look out for leaking rack seals; squeeze the gaiters to check if they’re full of escaped oil. The pinion seal can leak due to its close proximity to the exhaust, but can usually be replaced without a complete stripdown. Bushes can also become slack and may feel floating steering problem but you can replace them with sports type bushes.

Ignition System

Dear friends you might think that I missed writing about an important thing regarding XJ-S and that’s ignition system, so let me. Well, buried deep within the V of the engine, the ignition is usually neglected, which is a shame because spot-on ignition is the key to a crisp, responsive engine. Cars with OPUS and Lucas ignition (prior to 1989) have a mechanical advance mechanism within the distributor, which will seize if not lubricated, significantly restricting performance. Likewise a faulty or disconnected vacuum advance/retard system will increase fuel consumption unnecessarily. Timing is set manually prior to 1989 while later cars with Marelli mapped ignition have an octane plug existing the loom on the left side of the engine bulkhead which, when bridged, advances the ignition and allows the use of Shell Optimax or similar. In terms of reliability the original OPUS system is not good, and so conversion to the later Lucas constant energy system is well worthwhile.

Body

In coupe form, the body shell is exceptionally rigid, contributing to the car’s fine handling. Unfortunately, the lack of an open option at the original design stage means that the roof is an integral part of that strength. So, while the cabriolet (1983-1987) is tolerable on smooth roads, the full convertible (1988 on) does suffer noticeable scuttle-shake, which means it’s vital that the under-body bracing (where fitted) is left in place even if it does make some servicing difficult. Rust is an ever-present worry but one that can be minimized by meticulous cleaning and regular topping up of the rust proofing defenses. A common misconception is that facelift cars don’t rust, but seriously they do – it just takes a little longer.  

Transmission

I think we should now talk about the transmission of Jaguar XJ-S V12. The Jaguar four speed manual gearbox is fitted to around 350 early cars is more than capable of handling the power of a standard V12, while the parallel Borg Warner Model 12 automatic was similarly strong. Its successor, the GM 400, though not quite as bulletproof, was much lighter and smoother through the gears, while the 480LE  (6.0-litre) added a much-needed overdrive fourth gear, but unfortunately can’t be fitted to earlier engines as the larger bell housing dictated an enlarged boss on the back of the engine block.

Fuel System

Dear Jaguar lovers let’s move to the fuel system of XJ-S V12. Well, the analogue (3CU) system used prior to 1980 is basically a box of transistors and diodes; it works reliably enough and most problems are traceable to a perforated vacuum sensor or worn tracks in the throttle switch. The digital system (6CU) that followed is far more sophisticated but can fail occasionally in fuel pump switching. Its successor (16CU) introduced the microprocessor and could think for itself, while the final incarnation (26CU) added a diagnostic facility. There you have it – almost the history of fuel injection in one car. Look out for leaking fuel tanks (they crack around the baffle spot welds) and hardened, perished fuel hoses under the bonnet the former is nuisance, the latter can be potentially dangerous.

Rear/front suspension

Here comes the time to talk about rear/front suspension of Jaguar XJ-S.  They key to maintenance here is to regularly check all eight bonded mounts and bushes for deterioration. Grease everything and stick to quality replacement universal joints and bearings. A tendency for the car to steer from the rear will usually be due to worn radius arm bushes, while a clunking when coming on or off power is caused by loose power wishbone brackets at the location where they are shimmed to differential. Worn wishbone bushes can significantly alter the wheel alignment, effecting the steering and increasing tyre degradation. Wear in the upper bushes can only be felt with no load on the bump stops, while the lower bushes will move off centre as they deteriorate. Few greasable ball joints remain now, but they can wear far more than the later (interchangeable) sealed type. Also beware of substantial hidden corrosion beneath the powder coating on later sub-frames.

Brakes

As well maintained XJ-S should never be short of braking ability in general driving. Up front the four-pot calipers should be checked for perished dust boots, while heavily-lipped discs should be replaced rather than machined, otherwise they’ll be undersize and will distort.  At the rear, the inboard discs can suffer from lack of maintenance due to their inaccessibility, particularly the separate handbrake calipers which will drop pads if the car is driven with the applied. The outboard discs fitted from the 1993 model year are easier to service, suffer less from heat and offer vastly improved handbrake efficiency, as the expense of slight increase in the un-sprung weight. 

Electrical System      

A complex car by 1970s standards, the XJ-S rivaled many light aircraft in the wiring department. Fortunately, most of it is old school stuff with not a logic earth or multiplex in sight but, while the color codes are distinctive and follow a sensible formula, the wiring diagram is daunting. The electrical fault diagnostic handbook (part AKM9051), which breaks things down into single circuits, is a great autojumble find. The biggest problem concerns the wiper motor, suspended beneath the scuttle vent, protected by a flimsy piece of biodegradable plastic. Replacements are all but impossible to find so rebuilding the original is often the only option. Less common as a failure but infinitely more of a pain when one does go – is the original type of started motor, as removal of both the steering rack and right hand exhaust is required for full access. Later high-torque starters are easier to reach but perversely give less trouble.

Trim  

The minimalist interior of the pre-HE was not universally loved and the return of wood and leather was warmly welcomed in 1981. Recaro-style seats and an improved timbre-topped console followed in 1987, when many felt XJ-S interior styling reached a peak. By 1990 an airbag steering wheel (without airbag in the UK) and XJ40-style switchgear had diluted things somewhat. The facelift has limited electric seat adjustment, better switches and color coded dash casing. Early trim should be looked after as little is available today, even second hand. An interior’s greatest enemy is damp, so make sure the scuttle drain tubes are clear and all rubber screen seals are in good order. 
For service intervals please check service tips page.

Dressed to impress

“Perfection is attained not when there is no longer anything to add, but when there is no longer anything to take away” this quote might be written for something like XJ220 because perfection of this car is fully fixed. I still remember the days when I started loving this supercar and it was on my mind just like a dream girl. I always observed that people like Jaguar XJ220 because of various reasons and I’m writing this post to share the reason with you guys, for which I still like this car so much. But let me start with the brief background of this marvelous vehicle.

Well, many years ago XJ220 was born from the desire of a group of Jaguar’s engineers to produce a modern day interpretation of XJ13 project; the XJ220 certainly had all the ingredients to be a great car. In 1980 the concept was first exhibited in British Motor Show and created a storm because of its amazing stylish look. Although, today so many great cars are available and can be seen so instantly, but Jaguar XJ220 is still one the most desirable car all over the world. Probably, no car had ever designed to compare the unique look of this stylish chic and that’s why people still love to see it even in present times.

In my life I saw many Jaguar XJ220s but my heart never filled seeing them.

Truly, the harmonious organization of all its components makes it great car of all times. From high fidelity prototype to the actual model for sales, the XJ220 always performed the wonders and received so much love from almost all the car lovers. Wherever it goes, always makes the people desiring for it. Wherever it parked, compels the people stop walking to see it. Although, XJ220 has seen many years of its life but it’s still young, beautiful and capable of attracting the people. Undoubtedly, Jaguar XJ220 is one of the fastest Jaguars ever manufactured and most importantly its not just fastest Jaguar, but also aesthetically pleasing and well performing. Whenever I see fastest cars ranking, XJ220 shocks me by holding its position every year, so with knowing all this how can I stop myself loving the great XJ220.  

Project XJ16

There was a time when Sir William Lyons was much interested to get XJ6 into production, but the program was still behind the schedule, like the S-Type before it. Meanwhile, the need for another Jaguar was becoming increasingly urgent to meet the market demands and to compete with the other cars manufacturers. Therefore, the Jaguar 420 came into existence, in order to to stop the gap in saloon range. The idea of Jaguar 420 was better than expected; nobody knew that this new Jaguar is going to achieve highest standards in the motoring values. Jaguar 420 was judged from every conceivable standpoint and proved to be a great Jaguar from every aspect; like luxury, prestige, outstanding road holding and the advanced engineering. 

Development of the new model started by giving it the Jaguar project code XJ16, work commenced on updating the S-Type and giving it the 4.2 litre engine. Sir William Lyons had no interest to invest too much in new tools for the venture. As I stated earlier, the Jaguar 420 was going to be a stop-gap until the XJ6 was ready, therefore the production was entirely on the urgent basis. Having made a very rough sketch of what was required; Lyons had the panels hand made by Gardner’s department. Sir William Lyons wanted this new model to be ready for production by July 1966; but no detailed engineering drawing had been made till November 1965 so everyone was anxious to get the new model into production. Project XJ16 was given to Bob Knight, who managed the initial work by ordering the body panels to the suppliers (Pressed Steel Fisher). Suppliers agreed to meet the deadline but this interruption meant further delay to the XJ6 program, as the Pressed Steel Fisher was already working for XJ6.

To make the 4.2 litre engine model different from the S-Type, the entire front was remodeled to add more refinement in it. Lyons devised a stylized version of the Mark X front end. Superficially it looked just like a Mark X, but apart from being much smaller and all the details were different. Unlike the Mark X, where the bonnet follows is hinged at the front, the bonnet of Jaguar 420 followed a more normal pattern and is hinged at the rear, as it was on the Mark II and S-Type. Getting the style of the forward-sloping nose was not easy and it did give Lyons some trouble, but he preserved and the result was very pleasing. The Jaguar 420 was fitted with two-carburetor (SU HD8s) version of the Mark X 4.2 litre engine with slight modifications to made it compatible to get desired performance. Jaguar equipped the 420 with three-speed Borg Warner model 8 automatic transmission; this was not manufactured in UK but imported from the North America. Inside the Jaguar 420 wood and leather was used, but in difference to the US safety requirements, the solid wood dashboard and lower screen rail was replaced with the padded vinyl surround. 

Finally, the new Jaguar was announced in 1966 and impressed the people who were informed about a new Jaguar’s arrival in a very short period of time. The motoring journals were also praised the Jaguar 420 so much for its wonderful handling on and off the tarmac. Jaguar produced 420s until the Daimler XJ6 Sovereign arrived. By the time production ended some 16,060 examples had been built, 10,236 Jaguar 420s and 5,824 Daimler Sovereigns.

Beauty needs care and love ...

This is a story about an old 1950 Jaguar MK V which is dying a horrific death, found in backyard of an old man’s house in Pakistan. I was shocked to see this masterpiece in this condition and to listen that the owner is still not willing to sale it. The distinctive styling of Jaguar MK V followed prewar SS-Jaguar lines with upright chrome grille, but the grille of this abandoned MK V has become faded because of having no cover to protect it from moisture, dirt and heat. 

16-inch (410 mm) steel-disc type wheels of this MK V can easily be observed in these pictures, they did not touch road way from many decades. The story becomes sadder when we see its missing eyes. Obviously, I’m talking about the headlamps which can be available and replaced with some other car's because of their common round shape and specific size, but the owner seems not interested in giving this cat its eyes back and I think this car probably wouldn't be able to see again it's past glory days, when it was in running condition with having all of its jewels.

Inside the car you can see so many components are missing in dashboard and look even seats are not there inside the body shell. Steering wheel is also in very poor condition and covered with spider web. Well, I have no idea about the actual reason why he’s not selling his MK V, I thought that he might be a great Jaguar Lover, but if he is then why not even thinking about its restoration. Truly, this car can be back on road again with its prestigious look and can enchant may Jaguar car lovers like us. 

Finally I would like to request its owner (in case he reads my blog’s post) that please if you can’t restore this Jaguar MK V then please at least release its front grille nose from that blue rope piece because otherwise someday someone will try to pull it and the grille which is one of its last remaining jewels will also be broken.