Market Position:
Luxury Sedan segment
Competitors 1979:
Mercedes-Benz S-Class, BMW 7 Series, Rolls-Royce Silver Shadow/Spirit, Bentley T-Series
Key Features Vehicle:
Renowned for its ride comfort, refined handling, and distinctive styling; A flagship luxury model for Jaguar.
Key Features Manual:
Comprehensive, vehicle-specific, factory-level detail for technicians and DIY enthusiasts; Digital format for ease of use and portability.
Engine Systems:
Engine (general), Fuel Service Specifications, Emission Control, Intake, Exhaust, Cooling, Lube, Ignition, Starting, Charging
Drivetrain Systems:
Auto Transmission, Clutch, Manual Transmission, Transfer Propeller Shaft, Drive Shaft, Differential, Axle
Suspension Steering Brakes:
Suspension, Tire & Wheel, Brake Control, Brake, Parking Brake, Steering Column, Power Steering
Electrical Systems:
Electrical, Wiring Schematics, Multiplex/CAN Communication (if applicable to 1979 XJ40 architecture, though limited), Horn
Comfort Convenience:
Air Conditioning, Supplemental Restraint System (Airbags - unlikely for 1979, likely covering seat belts), Seat Belt, Engine Immobilizer (unlikely for 1979), Cruise Control, Wiper & Washer, Door Lock, Meter, Audio/Visual, Instrument Panel
Body Interior:
Windshield/Glass Mirror, Seat, Engine Hood/Door, Exterior & Interior
Procedures Included:
Maintenance, Service, Diagnosis, Repair, Step-by-step instructions, Troubleshooting, Component replacement, Adjustments, System checks
Technical Depth:
Factory High Detail; Complete Repair; Advanced Diagnostics
Print Quality:
Printable pages; Enlargement of images possible
Binding Type:
Digital (PDF) - no physical binding
Paper Type:
N/A (Digital format)
Operating Systems:
Windows Vista (32/64), XP, ME, 98, NT, 2000, Mac
Software Requirements:
Adobe PDF Reader, Winzip
Engine Type:
Jaguar V12 (typically)
Engine Displacement:
5.3 Liters (5345 cc)
Engine Configuration:
V12
Horsepower Estimate:
Approx. 244 hp @ 5500 rpm (SAE Gross - may vary by market)
Torque Estimate:
Approx. 280 lb-ft @ 3500 rpm (SAE Gross - may vary by market)
Fuel Delivery:
Fuel Injection (Lucas-Girling or Bosch L-Jetronic typically)
Fuel Type:
Unleaded Gasoline (Premium)
Cooling System Type:
Pressurized Water Cooling System
Oil Capacity Estimate:
Approx. 10 US Quarts (9.5 Liters) with filter
Recommended Oil Viscosity:
Refer to manual for specific viscosity grades (e.g., SAE 20W-50 for ambient temperatures)
Transmission Type:
3-Speed Automatic (e.g., BorgWarner Model 12, ZF 3HP22)
Optional Transmission:
Manual transmission options were rare or non-existent for the V12 XJ in this era, but the manual covers it if available.
Automatic Transmission Features:
Lock-up torque converter (on some later versions), Selectable drive modes (e.g., D, 2, 1)
Automatic Transmission Fluid:
Refer to manual for specific fluid type (e.g., Dexron III or equivalent)
Wheelbase:
Approx. 114.7 inches (2913 mm) for standard wheelbase, 119.7 inches (3040 mm) for long wheelbase
Overall Length:
Approx. 197.0 inches (5004 mm) standard, 202.0 inches (5130 mm) long
Curb Weight Estimate:
Approx. 4200 - 4500 lbs (1905 - 2041 kg)
Gross Vehicle Weight Rating:
Refer to vehicle data plate or manual
Standard Wheel Size:
15-inch alloy wheels
Standard Tire Size:
205/70VR15 or 215/70VR15
Bolt Pattern:
5x120.65 mm (5x4.75 inches)
Safety Ratings:
NHTSA and IIHS ratings from 1979 are not directly comparable to modern standards. Focus on specific system functionality.
Active Safety Features:
Four-wheel disc brakes, Power-assisted steering, Anti-lock Braking System (ABS) was not standard on most 1979 models, but may be present on later XJ40 variants or as an option.
Passive Safety Features:
Seat belts (three-point front, lap rear), Padded interior surfaces, Energy-absorbing steering column, Side-impact beams (structural)
Infotainment Features:
Original analog radio/cassette player, manual climate control, analog gauges.
Driver Assistance Features:
Cruise control (mechanical).
Connectivity Features:
None in the modern sense.
Oil Change Interval:
Refer to manual; typically 3,000-5,000 miles or 6-12 months
Major Service Intervals:
Refer to manual; typically 30,000-60,000 miles for tune-ups, fluid flushes, etc.
Coolant Type:
Ethylene Glycol based coolant (specific mixture ratio)
Brake Fluid Type:
DOT 3 or DOT 4 recommended
Common Issues V12:
Carburetor tuning (Stromberg or SU), ignition system (Lucas electrics), potential for overheating if cooling system maintenance is neglected, oil leaks, transmission issues.
Common Issues Body Suspension:
Rust (particularly around wheel arches, sills, and boot floor), worn suspension bushings, aging rubber hoses and seals, hydraulic self-leveling rear suspension (on some models) can require maintenance.
Oil Filter Part Number:
Refer to manual for specific part number (e.g., Fram PH43, Wix 51515, Mann W112/1)
Air Filter Part Number:
Refer to manual for specific part number (e.g., Fram CA551PL, Mann C34114)
Brand Heritage:
Jaguar has a long-standing reputation for producing luxurious, powerful, and stylish sports sedans and GT cars, emphasizing performance and comfort.
Model Evolution:
The XJ40, launched in 1986, replaced the Series III XJ. However, this manual specifies a 1979 XJ. The 1979 XJ is part of the Series III generation of the XJ, which itself evolved from the original XJ6 introduced in 1968. It featured significant updates over its predecessors.
Production Years Series Iii:
1979-1987 (Series III XJ)
Manufacturing Location:
Coventry, England
