The XK 4.2 V8 uses the AJ-V8 Gen III — a 4.2-litre naturally aspirated V8 petrol engine. It was fitted from 2005 to 2014 across the X150 generation of the XK, replacing the earlier X100-era AJ26/AJ27 engines. The AJ-V8 Gen III represents a significant evolution of Jaguar's V8 family, with improved timing chain components and revised cylinder heads compared to earlier iterations. The XK 4.2 V8 is no longer in production, but we continue to rebuild and replace engines for every one still on the road. Jaguar XK 4.2 V8 Engine Compatibility The XK 4.2 V8 uses the AJ-V8 Gen III engine across its entire X150 production run. Unlike some models that switched engines mid-generation, the 4.2-litre V8 remained consistent throughout. Before we quote or supply anything, we confirm: Your exact engine code (AJ-V8 Gen III) via registration or VIN Your generation (X150) Drivetrain and ancillary specification Any electronics or ECU considerations specific to your exact build This is why we always start with your registration rather than a generic XK quote — it protects you from paying for parts that don't fit your actual car. Jaguar XK 4.2 V8 Applications by Generation Generation Chassis Years Engine Code Fuel X150 X150 2005–2014 AJ-V8 Gen III Petrol Jaguar XK 4.2 V8 Engines by Year Year Generation Engine Code Fuel Service 2005 X150 AJ-V8 Gen III Petrol Rebuild / Replacement 2006 X150 AJ-V8 Gen III Petrol Rebuild / Replacement 2007 X150 AJ-V8 Gen III Petrol Rebuild / Replacement 2008 X150 AJ-V8 Gen III Petrol Rebuild / Replacement 2009 X150 AJ-V8 Gen III Petrol Rebuild / Replacement 2010 X150 AJ-V8 Gen III Petrol Rebuild / Replacement 2011 X150 AJ-V8 Gen III Petrol Rebuild / Replacement 2012 X150 AJ-V8 Gen III Petrol Rebuild / Replacement 2013 X150 AJ-V8 Gen III Petrol Rebuild / Replacement 2014 X150 AJ-V8 Gen III Petrol Rebuild / Replacement We Cover Every Jaguar XK 4.2 V8 Model Year: ✓ Jaguar XK 4.2 V8 2005 Engine Rebuild ✓ Jaguar XK 4.2 V8 2008 Engine Rebuild ✓ Jaguar XK 4.2 V8 2012 Engine Rebuild ✓ Jaguar XK 4.2 V8 2014 Engine Rebuild If your registration year isn't listed above, get in touch — we'll confirm availability directly against your reg. Jaguar XK 4.2 V8 Engine Sizes ✓ Jaguar XK 4.2 Litre Engine (AJ-V8 Gen III, V8) Jaguar XK 4.2 V8 Fuel Types ✓ Jaguar XK 4.2 V8 Petrol Engine Rebuilds Jaguar XK 4.2 V8 Engine Costs A Jaguar XK 4.2 V8 engine rebuild starts from £4,500. A full replacement engine and fitting service is also available. Exact pricing depends on the condition of your existing engine and the parts required — submit your registration for a fixed-price quote within 30 minutes. Related Jaguar XK Variants Looking for a different XK engine? We also cover: [Jaguar XK8 Engine →] · [Jaguar XKR (X100) Engine →] · [Jaguar XK 5.0 V8 Engine →] · [Jaguar XKR (X150) Engine →] · [Jaguar XKR-S Engine →] [← View All Jaguar XK Engines] Frequently Asked Questions What engine does the Jaguar XK 4.2 V8 use? The XK 4.2 V8 uses the AJ-V8 Gen III — a 4.2-litre naturally aspirated V8 petrol engine. It was fitted throughout the X150 generation from 2005 to 2014. How much does a Jaguar XK 4.2 V8 engine rebuild cost? Rebuilds start from £4,500. Exact price depends on condition and parts required — submit your reg for a fixed-price quote. Which engine code is fitted to my XK 4.2 V8? Enter your registration on this page and we'll confirm your AJ-V8 Gen III engine spec before you're quoted anything. Do you rebuild AJ-V8 Gen III XK 4.2 V8 engines? Yes. We replace the timing chain, tensioners, guides and water pump as standard on every AJ-V8 Gen III rebuild. Do you supply used XK 4.2 V8 engines? Yes, in some cases a matched low-mileage used engine is the right option. Our team will advise honestly once we've matched your registration and understood your situation. Can you recover my XK 4.2 V8 if the engine has failed? Yes — nationwide recovery is available from £70, and most vehicles are collected within a few hours of booking. How long does an XK 4.2 V8 engine rebuild take? Most rebuilds are completed within 3-5 working days from the time your car arrives at our workshop. Is rebuilding better than fitting a used engine? For most XK owners, yes. A rebuild removes the compatibility risk that comes with an unknown used unit's history, and comes with a 12-month unlimited-mileage warranty — often longer and more comprehensive than what a used engine supplier offers. <a name="quote-form"></a> Get Your Free Jaguar XK 4.2 V8 Fixed-Price Quote [Quote Form: Registration Number | Postcode | Name | Phone | Email | Issue/Enquiry Type (dropdown: Engine Failure / Replacement Needed / General Enquiry) | Submit] Most quotes returned within 30 minutes during working hours. json { "@context": "https://schema.org", "@graph": [ { "@type": "Organization", "@id": "https://jaguargarage.uk#organization", "name": "Jaguar Garage", "url": "https://jaguargarage.uk", "email": "info@jaguargarage.uk", "telephone": "+44 01268 944 234", "sameAs": [ "https://facebook.com/jaguarrebuildgarageuk", "https://twitter.com/jaguarrebuildgarageuk", "https://instagram.com/jaguarrebuildgarageuk", "https://tiktok.com/@jaguarrebuildgarageuk" ] }, { "@type": "AutoRepair", "@id": "https://jaguargarage.uk#autorepair", "name": "Jaguar Garage – XK 4.2 V8 Engine Rebuild Specialists", "url": "https://jaguargarage.uk/jaguar-xk-4-2-v8-engines", "telephone": "+44 01268 944 234", "email": "info@jaguargarage.uk", "priceRange": "£££", "address": { "@type": "PostalAddress", "streetAddress": "Unit A5 Windsor Road, Commercial Estate, Ramsden Heath", "addressLocality": "Billericay", "postalCode": "CM11 1QE", "addressCountry": "GB" }, "openingHours": "Mo-Fr 09:00-18:00, Sa 11:00-14:00", "areaServed": "GB", "parentOrganization": { "@id": "https://jaguargarage.uk#organization" }, "brand": { "@type": "Brand", "name": "Jaguar" } }, { "@type": "Service", "serviceType": "Jaguar XK 4.2 V8 Engine Rebuild & Replacement", "provider": { "@type": "AutoRepair", "name": "Jaguar Garage" }, "areaServed": "GB", "offers": { "@type": "Offer", "priceCurrency": "GBP", "price": "4500", "description": "Jaguar XK 4.2 V8 engine rebuild starting price, AJ-V8 Gen III" } }, { "@type": "FAQPage", "mainEntity": [ { "@type": "Question", "name": "What engine does the Jaguar XK 4.2 V8 use?", "acceptedAnswer": { "@type": "Answer", "text": "The XK 4.2 V8 uses the AJ-V8 Gen III — a 4.2-litre naturally aspirated V8 petrol engine. 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We continue to rebuild and replace AJ-V8 Gen III engines for every XK 4.2 V8 on the road.