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Jaguar Xj40

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Jaguar XJ40: A Comprehensive Guide

The Jaguar XJ40, produced from 1986 to 1994, represents a pivotal moment in Jaguar's history. It was the successor to the legendary XJ Series III and a significant departure in terms of styling and engineering. Classified as a full-size luxury sedan, the XJ40 aimed to modernize the Jaguar brand while retaining the qualities of luxury, refinement, and performance expected by its discerning clientele. Although initially met with mixed reactions due to its less curvaceous design compared to its predecessors, the XJ40 has since become a highly sought-after classic, offering a unique blend of old-world charm and modern technology.

Generations

  • 1986-1989 (Pre-facelift): Introduced with the AJ6 inline-six engine. Key features include rectangular headlights, a more angular body design, and a computerized engine management system. Early models are known for some teething issues.
  • 1990-1994 (Post-facelift): Major improvements were made, addressing many of the reliability concerns of the early models. The interior received a significant upgrade, with revised switchgear and improved trim. The front end was restyled, with round headlights becoming an option.

Reliability & Common Issues

While the XJ40 is a desirable classic, prospective buyers should be aware of several potential reliability issues. Thorough inspection and diligent maintenance are crucial for owning a trouble-free example.

Engine (AJ6 Inline-Six):

  • Cooling System: Overheating is a common issue. Regular coolant changes and inspection of the radiator, hoses, and thermostat are essential. Pay close attention to the viscous fan coupling.
  • Head Gasket: Prone to failure, especially on early models. Look for signs of coolant leaks or oil in the coolant.
  • Engine Management System: Early systems can be complex and prone to sensor failures. The Lucas system used in early models can be difficult to diagnose and repair.
  • Oil Leaks: The AJ6 engine is notorious for oil leaks, particularly from the valve cover gasket and rear main seal.
  • Timing Chain Tensioner: Listen for rattling noises on start-up, which may indicate a worn timing chain tensioner.

Transmission:

  • ZF 4HP22 Automatic: Generally reliable if properly maintained. Regular fluid changes are crucial. Slipping or harsh shifting indicates potential problems.
  • GM 4L80E Automatic (Later Models): Found in some later models, particularly those exported to North America. Also generally reliable.

Suspension & Steering:

  • Self-Leveling Suspension (SLS): Fitted to some models. Can be expensive to repair. Consider converting to conventional dampers if SLS fails.
  • Rear Subframe Mounts: Prone to corrosion and cracking. Inspect carefully.
  • Power Steering Rack: Leaks are common.

Electrical System:

  • Wiring Harness: Age-related degradation of wiring insulation can lead to electrical gremlins.
  • Instrument Cluster: Can suffer from flickering or non-functional gauges.
  • Central Locking System: Can be unreliable.
  • ABS System: Check for proper functionality. Sensor failures are common.

Body & Interior:

  • Rust: Especially around the sills, wheel arches, and floor pans. Check carefully.
  • Interior Trim: Wood veneer can crack or delaminate. Leather upholstery can wear and crack.
  • Headliner: Prone to sagging.

Driving Experience

The Jaguar XJ40 offers a distinctive driving experience characterized by a smooth ride, refined engine, and comfortable interior. However, potential buyers should consider both the pros and cons.

Pros:

  • Smooth and Comfortable Ride: The XJ40's suspension provides a luxurious and comfortable ride, ideal for long journeys.
  • Refined Engine: The AJ6 engine is smooth and powerful, offering ample performance for everyday driving.
  • Elegant Interior: The interior is well-appointed with high-quality materials, creating a luxurious and comfortable environment.
  • Classic Jaguar Styling: The XJ40 retains many of the classic Jaguar styling cues, making it a visually appealing car.
  • Relatively Affordable: Compared to newer Jaguars, the XJ40 offers a relatively affordable entry point into the world of classic Jaguar ownership.

Cons:

  • Reliability Concerns: As detailed above, the XJ40 is prone to several reliability issues.
  • Running Costs: Maintenance and repair costs can be high, especially for older models.
  • Fuel Economy: Fuel economy is not a strong point, especially for models with the automatic transmission.
  • Dated Technology: The XJ40's technology is dated compared to modern cars.
  • Parts Availability: While many parts are still available, some specific components can be difficult to source.

Buying Advice

When buying a Jaguar XJ40, careful inspection and due diligence are essential. Here's some advice to help you find the best example:

Years to Look For:

  • 1990-1994 (Post-facelift): These models benefit from numerous improvements and are generally more reliable than earlier versions. The facelift also brought round headlights as an option, which many find more appealing.
  • Later Production Years Within the Post-Facelift Period: Models produced closer to 1994 are likely to have benefited from even more refinements and improvements.

Years to Avoid (or Exercise Extreme Caution With):

  • 1986-1989 (Pre-facelift): These models are more prone to reliability issues and may require more maintenance. However, a well-maintained example can still be a rewarding ownership experience.

Key Inspection Points:

  • Rust: Check the sills, wheel arches, floor pans, and around the windscreen.
  • Engine: Listen for unusual noises, check for leaks, and ensure the engine runs smoothly. Perform a compression test if possible.
  • Transmission: Check for smooth and timely gear changes.
  • Suspension: Inspect the suspension components for wear and tear. If equipped with SLS, check for proper functionality.
  • Electrical System: Test all electrical components, including lights, gauges, and central locking.
  • Interior: Check the condition of the interior trim and upholstery.
  • Service History: Look for evidence of regular maintenance. A well-documented service history is a good sign.

General Advice:

  • Hire a Professional: Consider having a pre-purchase inspection performed by a qualified mechanic with experience working on Jaguar vehicles.
  • Be Prepared for Maintenance: Budget for potential repairs and maintenance costs.
  • Join a Jaguar Club: Joining a Jaguar club can provide valuable resources and support.
  • Don't Be Afraid to Walk Away: If you are not comfortable with the condition of a particular car, don't be afraid to walk away. There are plenty of other XJ40s out there.

By following this guide, you can increase your chances of finding a well-maintained and reliable Jaguar XJ40 that will provide years of enjoyment.

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