JaguarAJ-V8Petrol4.0–4.2L V81996–2009

Jaguar AJ-V8 4.0/4.2 EngineSpecs, Reliability& Replacement Cost

The Jaguar AJ-V8 is a 4.0–4.2L DOHC V8 family - smooth and characterful, but early plastic timing chain tensioners are its Achilles' heel. Backed by real UK enquiries in 2025.

Jaguar AJ-V8 4.0/4.2 Engine - Specs, Reliability & Replacement Cost

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  • 8 Models Fitted

  • /100 Engine Score

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Jaguar AJ-V8 (Gen I/II)
Engine Overview

All the essential specifications, performance data, and compatibility information at a glance.

Engine Family

Jaguar AJ-V8 (Gen I/II)

Fuel

Petrol

Configuration / Displacement

90° V8, 4.0L (3,996 cc) / 4.2L (4,196 cc)

Power Range

290–420 HP

Years Produced

1996–2009

Models Fitted (Jaguar only)

8 models

Cross-Brand Fitment

Also fitted to Land Rover Range Rover/L322 → landroverengine.uk

Overall Engine Score

-/

★★★★☆

Verdict & Rating

Rating:

3.5

out of 5

90% confidence - based on UK enquiries and cross-referenced specialist rebuild reports.

The AJ-V8 is a smooth, characterful V8 with genuine longevity - but early plastic tensioners can destroy it without warning - buy only with proof of updated metal tensioners fitted.

Engine Score breakdown:

DimensionScore (of 20)

Reliability

3.5★ × 4

14 /20

Repair Cost

Reconditioned supply midpoint £5,500–£7,000 → falls in £5,000–£6,999 band

12 /20

Repairability

Mix of cheap fixes (tensioners, water pump) and a few expensive ones (crankshaft/bottom-end)

12 /20

Parts Supply

Well-supported but some parts (Nikasil-era blocks) now scarce

16 /20

Replacement Economics

Reconditioned cost ~45–59% of lowest host-vehicle value

12 /20

Total Engine Score

66 / 100

Best for:

Enthusiasts who appreciate a refined V8 and maintain it diligently.

Avoid if:

You cannot verify the timing chain tensioners have been updated to the metal-spec units.

Compatible Jaguar Models

Jaguar AJ-V8 (Gen I/II) engines are fitted across 8 models from 1996–2009.

Jaguar Exclusive Engine

This is an exclusive Jaguar engine. No cross-platform sharing.

1996
13 Years of Production
2009

XK8

/ XKR

Generation

X100

Variant/Badge

4.0L / 4.2L (NA & SC)

Years

1996–2006

XJ8

/ XJR

Generation

X308

Variant/Badge

4.0L / 4.2L

Years

1997–2003

XJ8

/ XJR

Generation

X350/X358

Variant/Badge

4.2L

Years

2003–2009

S-Type

Generation

X200

Variant/Badge

4.0L / 4.2L (NA & SC)

Years

1999–2008

S-Type

R

Generation

X200

Variant/Badge

4.2L Supercharged

Years

2002–2007

XF

Generation

X250

Variant/Badge

4.2L

Years

2008–2009

XK

Generation

X150

Variant/Badge

4.2L

Years

2006–2009

Daimler

Super Eight

Generation

X350

Variant/Badge

4.2L Supercharged

Years

2005–2009

+

Other Jaguar Models

AJ-V8 (Gen I/II) also appears in limited variants and markets.

View full details ›

Compatibility Verified

All compatibility data verified from Jaguar parts catalogues and specialist databases. [JAGUAR-VERIFIED]

Also powers the Land Rover Range Rover L322 4.4 → landroverengine.uk

Jaguar AJ-V8 (Gen I/II)Engine Price Guide

All prices are estimates from UK specialists

[JAGUAR-QUOTE]

USED

Supply Only

£2,500–£4,500

Fitted (Indie)

£3,500–£5,500

Warranty

3–6 months
Most Popular

RECONDITIONED

Supply Only

£4,500–£7,500

Fitted (Indie)

£5,500–£8,500

Warranty

12 months

REBUILT

Supply Only

£6,000–£9,500

Fitted (Indie)

£7,000–£11,000

Warranty

12–24 months

Fitting a Jaguar AJ-V8 typically takes 12–16 hours at £65–£95/hr (independent) or £110–£160/hr (London/SE dealer).

Parts cost is similar across Jaguar and Land Rover applications; labour time varies by engine bay access - the XK's tight bay adds time versus the XJ's more generous layout.

Compare Jaguar AJ-V8 (Gen I/II) engine prices from UK specialists

Frequently Asked Questions

Expert answers to the most common Jaguar AJ-V8 (Gen I/II) engine questions.

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