Jaguar 4.0 V8 Specialists

Jaguar XJ 4.0 V8 Engine Replacement Compare Prices & Get Quotes

Get quotes today from trusted UK Jaguar XJ 4.0 V8 engine specialists. Compare prices on reconditioned, rebuilt and used engines to find the most cost-effective solution for your classic executive saloon.

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12-Month Warranty

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100+ Suppliers

Jaguar XJ 4.0 V8 Engine

from£2,500 to £4,500

Usedfrom £800
Reconditionedfrom £1,800
Common codesAJ26, AJ27 [ESTIMATED - using AJ41 as proxy]

Jaguar xjUsed Engine — AJ26

Jaguar xj 4.0 V8 Reconditioned Engine — AJ26

Jaguar xjReconditioned Engine — AJ26

Jaguar xjRebuilt Engine — AJ26

Instant QuotesNo Obligation100% FreeReconditionedRebuiltUsedSupply & Fit AvailableUK-Wide NetworkInstant QuotesNo Obligation100% FreeReconditionedRebuiltUsedSupply & Fit AvailableUK-Wide NetworkInstant QuotesNo Obligation100% FreeReconditionedRebuiltUsedSupply & Fit AvailableUK-Wide NetworkInstant QuotesNo Obligation100% FreeReconditionedRebuiltUsedSupply & Fit AvailableUK-Wide Network

How it works

3 Simple Steps to Finding the Right Replacement Engine

Clear information first, then the right engine and specialist for your exact vehicle.

Variant History

Jaguar XJ 4.0 V8 Engine History & Specs at a Glance

When the Jaguar XJ 4.0 V8 launched as part of the X308 generation, it replaced the older 3.2L and 4.0L X300 units, bringing refined aluminium blocks and improved torque delivery to the flagship saloon range. Over its production run, it received a critical revision to address early cylinder lining concerns.

1997
AJ26 4.0L V8 launched (284hp), featuring Nikasil cylinder liners which later proved susceptible to premature wear with certain historical fuel additives.
1999
AJ27 4.0L V8 introduced, featuring revised traditional iron cylinder liners and updated engine management to permanently resolve the Nikasil degradation issue, remaining in production until 2003.

Every engine fitted to the Jaguar XJ 4.0 V8 is covered below, with UK rebuilt pricing and known failure points to help you make an informed replacement decision.

Engine Codes & Pricing

Jaguar XJ 4.0 V8 Engine Codes Specifications & Replacement Cost

Find your exact engine code, specs and UK replacement cost guide.

AJ26 — 4.0L Petrol (1997-1999)

Power Output: 284hp
Years Fitted: 1997-1999

Can’t find your exact engine code?-> Get quotes for AJ26 Jaguar XJ 4.0 V8 engine replacement

-> Get quotes for AJ26 Jaguar XJ 4.0 V8 engine replacement

Common failure points and repair options

Nikasil Cylinder Liner Degradation

Affected: Jaguar XJ 4.0 V8 (AJ26, 1997-1999)
Typical failure mileage: 60,000 - 100,000 miles

Root cause

Historical high-sulphur fuels reacted with the Nikasil coating, causing it to flake and leading to rapid bore wear, loss of compression, and heavy oil consumption.

Repair options

Repair tier	Dealer price	Specialist price
Full Replacement - rebuilt/reconditioned engine	£6,000-£8,500	£2,500-£4,500

Our recommendation

If your XJ 4.0 V8 is an early AJ26 showing signs of bore wear, a full replacement with an AJ27-spec rebuilt unit is the only permanent fix. For lower-value examples, a verified used engine may be the pragmatic choice.

-> Compare rebuilt AJ26 Jaguar XJ 4.0 V8 engine prices

Harmonic Damper & Timing Chain Wear

Affected: Jaguar XJ 4.0 V8 (AJ27, 1999-2003)
Typical failure mileage: 80,000 - 120,000 miles

Root cause

The rubber element in the crankshaft pulley harmonic damper degrades over time, causing wobble and potential accessory belt failure. Concurrently, timing chain tensioner oil feed pipes can become restricted, leading to chain stretch.

Repair options

Repair tier	Dealer price	Specialist price
Minor/Preventative	£1,500-£2,200	£800-£1,400
Full Replacement - rebuilt/reconditioned engine	£6,000-£8,500	£2,500-£4,500

Our recommendation

Proactively replacing the harmonic damper and timing chain kit on an AJ27 is far more cost-effective than waiting for catastrophic failure. If the engine has already suffered internal damage, carefully weigh the rebuilt engine cost against the car's current market value.

-> Compare rebuilt AJ27 Jaguar XJ 4.0 V8 engine prices

Don't Let Engine Failure Write Off Your Jaguar XJ 4.0 V8

The Jaguar XJ 4.0 V8 is a classic executive saloon, but vulnerabilities in early cylinder linings and aging timing components can quickly escalate into expensive breakdowns. Rather than accepting main dealer premiums or risking unguaranteed used units, EngineMarket connects you directly with vetted UK specialists. Every rebuilt replacement engine we list features upgraded components targeting these exact failure points, is dyno-tested before dispatch, and arrives with nationwide delivery and a minimum 12-month warranty.

Compare Jaguar XJ 4.0 V8 Engine Replacement Prices Now ->

FAQ

Jaguar XJ 4.0 V8 Engine ReplacementFrequently Asked Questions

Everything Jaguar XJ 4.0 V8 owners usually ask before choosing a rebuilt, reconditioned or used replacement engine.

Jaguar XJ 4.0 V8 engine replacement costs typically range from £800 for a used unit to £4,500 for a fully rebuilt engine. Supply-only rebuilt engines average £2,500-£4,500, with supply-and-fit adding £800-£1,200 in labour.

Used AJ27 engines start around £800 supply-only.
Rebuilt units with upgraded liners average £2,500-£4,500.
Supply-and-fit labour typically adds £800-£1,200 to the total.

-> Compare Jaguar XJ 4.0 V8 engine replacement prices from UK specialists today

The AJ26 (1997-1999) used Nikasil cylinder liners, which were prone to degradation from high-sulphur fuels. The AJ27 (1999-2003) replaced this with traditional iron liners, making it significantly more robust and the preferred choice for replacements.

AJ26 is susceptible to Nikasil bore wear and compression loss.
AJ27 features durable iron cylinder liners and updated engine management.
Most specialists recommend upgrading an AJ26 vehicle to an AJ27-spec rebuilt unit.

-> Get quotes for AJ27 Jaguar XJ 4.0 V8 engine replacement

Replacing the engine is worthwhile if the chassis, interior, and electronics remain in excellent condition. However, with typical market values between £2,000 and £6,000, a full rebuilt engine can represent a large percentage of the car's value.

Evaluate the vehicle's overall condition beyond the engine.
A used engine may be more financially viable for lower-value examples.
Rebuilt units offer the best long-term reliability and warranty protection.

-> Find out if your Jaguar XJ 4.0 V8 is worth engine replacement

The most frequent issues include Nikasil liner degradation on early AJ26 models, crankshaft pulley harmonic damper separation, and timing chain tensioner oil feed restrictions on AJ27 models.

Heavy oil consumption and blue smoke indicate bore wear.
A wobbly crankshaft pulley or squealing belts signal damper failure.
Cold-start rattling suggests timing chain stretch requiring immediate attention.

-> Get diagnostic quotes for your Jaguar XJ 4.0 V8 engine problem today

A professional supply-and-fit Jaguar XJ 4.0 V8 engine replacement typically takes 2 to 4 working days, depending on the specialist's workload and whether any ancillary components also require replacement.

Engine removal and installation takes 1-2 days.
Ancillary replacements and fluid flushing add 1 day.
Final ECU adaptation, road testing, and handover complete the process.

-> Book Jaguar XJ 4.0 V8 engine supply and fit appointment

Why Choose Us

Compare Jaguar XJ 4.0 V8 Engine Prices Today

Comparing quotes is completely free and carries no obligation. By entering your registration, you ensure that every quote you receive is precisely matched to your exact Jaguar XJ 4.0 V8 and its specific engine code, connecting you directly with vetted UK specialists who can get your classic saloon back on the road reliably.

50+50+ Jaguar XJ 4.0 V8 engines supplied through our network

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