Grand-touring V12 classic now within reach
Once dismissed as the E-Type's ungainly successor, the XJS has matured into a respected grand tourer with values that remain accessible compared to other V12 classics. Convertibles and early pre-HE V12 coupes command the strongest premiums, while six-cylinder models offer the cheapest entry point. Values dipped around 34% in real terms over five years to 2025, making now a reasonable time to buy before the market potentially corrects.
We track 8 known issues across the Jaguar XJS range, including 1 rated as safety-critical. Knowing which variants and configurations to approach with caution can save you from expensive surprises after purchase.
Found a Jaguar XJS? Enter the reg to see which of our 8 known issues apply to that exact car, plus full MOT history and mileage checks.
XJS-Early (1975–1991) — Engine options included the 3.6 AJ6, 5.3 V12. Our database flags 8 known issues on this generation, 1 of which are rated as safety-critical. The most significant concern is Structural corrosion around suspension mounting points (£2,000–£4,000 to address).
XJS-Late (1992–1996) — Engine options included the 4.0 AJ6, 5.3 V12, 6.0 V12. Our database flags 8 known issues on this generation, 1 of which are rated as safety-critical. The most significant concern is Structural corrosion around suspension mounting points (£2,000–£4,000 to address).
MOT data shows the XJS fails at 12.1x the fleet average for load-bearing structure corrosion within 30cm of suspension mounting points. This affects the structural integrity around spring mountings, shock absorber towers, and subframe attachment points. The XJS monocoque construction means suspension loads are transmitted through relatively thin steel sections that are prone to corrosion from trapped moisture and road salt. Once structural integrity is compromised around suspension mountings, the car becomes unsafe to drive and requires extensive welding or replacement sections.
Structural failure around suspension mountings can cause suspension components to detach while driving, leading to complete loss of control. Repair requires cutting out corroded sections and welding in new steel, typically costing £2,000-£5,000 depending on extent. In severe cases the car may be beyond economical repair.
Inspect the wheel arches, sills, jacking points and door bottoms carefully. Press gently on sills to check for soft spots. Look underneath for corrosion on structural components. Check the MOT history for corrosion-related advisories or failures.
MOT data shows the XJS fails at 207.3x the fleet average for power steering fluid leaking or system malfunction, the highest failure rate in the entire dataset. The XJS power steering system uses a belt-driven pump feeding a rack-and-pinion system through high-pressure hoses. Common failures include pump seal deterioration, rack seal failure, and high-pressure hose rupture. The system operates at high pressure and the components are now 30+ years old with limited parts availability.
Power steering failure makes the car extremely difficult to manoeuvre, particularly dangerous given the XJS weight of 1,700kg. Complete system failure can occur suddenly through hose rupture. Pump replacement costs £800-£1,500, rack replacement £1,200-£2,500, with labour adding significantly to total cost.
During the test drive, check the steering for excessive play, vibration or pulling to one side. Listen for groaning or whining when turning the wheel at low speed. Power steering fluid level and condition should be checked on hydraulic systems.
The V12 engine uses aluminium cylinder heads that are prone to cracking due to thermal stress from the engine's operating temperature and inadequate cooling system maintenance. The heads can crack between valve seats or around the combustion chamber, leading to coolant loss into the cylinders or external leakage. This is a well-documented issue across all V12 XJS models, with failure typically occurring when the cooling system has not been properly maintained or the engine has overheated.
Cracked cylinder heads require removal and either welding repair or replacement. Head removal on the V12 is complex due to engine bay access. Repair costs typically range £2,000-£5,000 including labour. If coolant enters the oil system, internal engine damage can extend the repair significantly.
Look for oil weeping around gasket surfaces — rocker cover, sump and timing cover are common areas. Check for coolant mixing with oil (creamy residue on the filler cap) which indicates a more serious head gasket issue.
MOT data shows the XJS fails at 71.4x the fleet average for wheel bearings with excessive play. The XJS uses conventional taper roller bearings at all four corners that require periodic adjustment and greasing. The bearings are subjected to high loads due to the car's weight (1,700kg) and wide wheels, while age and lack of maintenance cause seal deterioration and grease breakdown. Failed bearings create dangerous handling characteristics and can seize completely.
Worn bearings create dangerous handling instability and can seize while driving, potentially causing wheel detachment. Bearing replacement requires specialist knowledge of preload adjustment. Individual bearing replacement costs £200-£400 per corner but multiple bearings often need attention simultaneously.
Listen for knocking, clunking or rattling over bumps during the test drive. Inspect the underside for corroded or cracked suspension components. Check the MOT history for suspension-related advisories, which often predict future failures.
The AJ6 straight-six engine is prone to head gasket failure, typically between 60,000-100,000 miles. The gasket fails due to thermal cycling between the aluminium head and iron block, exacerbated by cooling system neglect. Early symptoms include external coolant seepage from the head-to-block joint, progressing to internal failure where coolant enters the combustion chambers or oil system. This is a well-documented issue requiring engine-out repair due to access limitations in the XJS engine bay.
Head gasket failure requires engine removal for access in the XJS. If coolant contaminates the oil system, bearing damage can extend the repair significantly. Typical repair cost including labour is £600-£1,200 for gasket replacement alone, but associated work often increases this substantially.
Look for oil weeping around gasket surfaces — rocker cover, sump and timing cover are common areas. Check for coolant mixing with oil (creamy residue on the filler cap) which indicates a more serious head gasket issue.
For the full breakdown of all 8 tracked issues with repair costs, see the Jaguar XJS common problems page.
Based on 22k real DVSA MOT tests, the Jaguar XJS fails more often than average on several items. The biggest outlier is power steering fault at 207x the fleet average, followed by emissions failure (122x).
When viewing a specific car, check its MOT history for recurring advisories in these categories. See the full Jaguar XJS MOT failure breakdown for data at every mileage point.
Routine servicing (oil and filter change every 6k miles) typically costs £80–£120 at an independent garage.
See the full Jaguar XJS service schedule for every interval and cost breakdown.
The Jaguar XJS has some well-documented weak points, including 1 safety-critical issue that demand careful checking. The right example, properly maintained, can still be a sound purchase — but cutting corners on the pre-purchase inspection is not advisable. 1991-1996 (galvanised body, revised 6.0 V12 or AJ16 six-cylinder, best build quality)
Before committing, check the car's full MOT history, verify the service record is complete, and if possible arrange a specialist inspection. Enter any registration into our free report to see the complete picture.
Get Car Wise maintains a database of known mechanical issues for every popular car on UK roads, tracking the faults that owners, specialists and DVSA data reveal.
When you run a report on a specific Jaguar XJS, we cross-reference the exact variant, engine and age against our database of 8 known issues. Combined with full MOT history analysis, mileage verification and DVLA data, you get a complete picture before viewing.
Enter the registration for MOT history, mileage verification, known faults for that exact variant, and a Get Car Wise Score.
This guide was compiled from independent expert reviews, DVSA MOT data, specialist workshops and our own database of 8 known Jaguar XJS issues. We are not affiliated with any source listed.