Jaguar XJ X351Saloon2010–2019Every engine fitted to the X351 flagship saloon - from the 3.0-litre V6 diesel and supercharged V6 to the 5.0-litre naturally aspirated and supercharged V8s. Real UK replacement costs and honest reliability data for Jaguar's last traditionally-powered XJ. Backed by 151+ real UK enquiries in 2025 [JAG-VERIFIED].
151+XJ X351 Enquiries (2025)JAG-VERIFIEDSaloon
7Engine Codes
Part ofEngine Finders
Every engine fitted to the X351 specifically - including the 3.0 V6 diesel, the 3.0 supercharged V6 that replaced it, the 2.0 turbo four for the Chinese market, and the full range of 5.0 V8s.
Overview
The X351 is the fourth generation of Jaguar's flagship XJ saloon, launched in 2010 as the first model to feature Ian Callum's new design language.
Built on a revolutionary all‑aluminium architecture - claimed to be the lightest in its class by 150 kg - it introduced a dramatic, coupé‑like silhouette that transformed the XJ's image. The engine line‑up evolved significantly: at launch, the XJ offered a 3.0‑litre V6 diesel, a 385 PS 5.0‑litre naturally aspirated V8, and a 510 PS 5.0‑litre supercharged V8. In 2012, a 3.0‑litre supercharged V6 and a 2.0‑litre turbocharged four‑cylinder were added for the growing Chinese market. The flagship XJR arrived in 2013 with a 550 PS supercharged V8. Production ended in July 2019 after more than 120,000 units.
Key Facts
Platform
Jaguar X351 (all‑aluminium monocoque, front‑engine, rear‑wheel drive)
Predecessor
Jaguar XJ (X350)
Successor
None (XJ was discontinued; no direct successor)
Sibling body styles in this generation
4‑door saloon (standard and long wheelbase)
Market Intelligence
The XJ X351 generated 151 real UK engine enquiries in 2025 [JAG-VERIFIED], with the 3.0 V6 diesel and 5.0 V8 supercharged variants accounting for the majority of demand.
Best Petrol Overall
3.0 Supercharged V6 (306PS)
“The 3.0-litre supercharged V6 offers 340 PS of smooth, responsive power without the V8's running costs or complexity. Cooling system pipework and supercharger insulator springs are the only real watch points. It's the sweet spot in the petrol range.”
Who it's for: buyers who want modern petrol refinement without V8 running costs.
Highest Risk
5.0 Supercharged V8 (508PS, early pre‑2013)
“Timing chain guide wear on early 5.0-litre AJ133 engines is a known issue. PCV diaphragms rip with age, causing oil consumption and lean running codes. Vacuum pump oil leaks are common. Later cars received updated tensioners.”
Who it's for: buyers with documented timing chain work or post‑2013 cars.
Most Expensive Failure
5.0 Supercharged V8 (508PS, XJR/XJR 575)
“Timing chain replacement on the 5.0-litre AJ133 is an engine‑out job requiring specialist tooling - £2,500–£4,500 is typical. A full engine replacement can exceed £9,000. The XJR's 550 PS variant adds parts scarcity and cost.”
Who it's for: buyers with deep pockets who want the ultimate XJ flagship.
Best Value
5.0 Naturally Aspirated V8 (508PN)
“The 385 PS 5.0-litre naturally aspirated V8 delivers V8 grunt without the supercharger's additional complexity. It's cheaper to buy, run, and repair than the XJR. Watch for timing chain guides on early cars, but otherwise robust.”
Who it's for: buyers who want V8 presence without supercharger costs.
Best Petrol Overall
3.0 Supercharged V6 (306PS)
“The 3.0-litre supercharged V6 offers 340 PS of smooth, responsive power without the V8's running costs or complexity. Cooling system pipework and supercharger insulator springs are the only real watch points. It's the sweet spot in the petrol range.”
Who it's for: buyers who want modern petrol refinement without V8 running costs.
Highest Risk
5.0 Supercharged V8 (508PS, early pre‑2013)
“Timing chain guide wear on early 5.0-litre AJ133 engines is a known issue. PCV diaphragms rip with age, causing oil consumption and lean running codes. Vacuum pump oil leaks are common. Later cars received updated tensioners.”
Who it's for: buyers with documented timing chain work or post‑2013 cars.
Most Expensive Failure
5.0 Supercharged V8 (508PS, XJR/XJR 575)
“Timing chain replacement on the 5.0-litre AJ133 is an engine‑out job requiring specialist tooling - £2,500–£4,500 is typical. A full engine replacement can exceed £9,000. The XJR's 550 PS variant adds parts scarcity and cost.”
Who it's for: buyers with deep pockets who want the ultimate XJ flagship.
Best Value
5.0 Naturally Aspirated V8 (508PN)
“The 385 PS 5.0-litre naturally aspirated V8 delivers V8 grunt without the supercharger's additional complexity. It's cheaper to buy, run, and repair than the XJR. Watch for timing chain guides on early cars, but otherwise robust.”
Who it's for: buyers who want V8 presence without supercharger costs.
Most Overlooked
3.0 Naturally Aspirated V6 (AJV6)
“The 238 PS 3.0-litre naturally aspirated V6 was the entry-level petrol before the supercharged V6 arrived in 2012. It's smooth and refined but underpowered for the XJ's size. Rare in the UK, but a good choice for those who prioritise simplicity over pace.”
Who it's for: buyers who want V6 refinement without forced induction.
The X351 rule
A £5,500–£9,000 5.0 XJR recon against a £12,000–£25,000 XJR sits at 22–75% of the car's value - at the upper end, that brushes our 60% Jaguar scrap threshold. Against a £20,000+ example, the same recon drops to 28–45% - a repair decision, not a scrap question. For a 3.0 V6 diesel at £10,000–£18,000, a £4,500–£7,000 recon is 25–70% - borderline on lower‑value examples. Value the car first; if it's a pre‑2013 5.0 without timing chain history, walk away or budget for the work immediately.
Key Takeaways
Which X351 Costs Least To Own?
3.0 V6 Diesel (AJV6D) - proven reliability, reasonable economy, no supercharger complexity.
Which X351 Costs Most To Own?
5.0 XJR (550 PS) - timing chain work is engine‑out, parts are scarce, and running costs are eye‑watering.
Which X351 Is Best Value?
5.0 V8 Naturally Aspirated (508PN) - V8 presence without the supercharger's costs or complexity.
5.0
AJ133 Timing Chain Guide Wear
Affected models:
Typical failure mileage:
Root cause:
Our Recommendation
If you're buying a pre‑2013 5.0-litre X351, look for documented timing chain work or budget £2,500–£4,500 immediately. A preventative chain and tensioner replacement is dramatically cheaper than the £5,500+ replacement that follows a failure. On a car worth under £15,000, evaluate carefully before committing.
5.0
AJ133 PCV Diaphragm Failure
Affected models:
Typical failure mileage:
Root cause:
Our Recommendation
If your 5.0 V8 develops oil consumption or lean running codes, have the PCV diaphragms inspected immediately - a £400–£900 repair is far cheaper than the £4,500+ replacement that follows a catastrophic failure. On supercharged cars, it's worth combining this with timing chain work as the supercharger is already off.
3.0
V6 Supercharged (306PS) Cooling System
Affected models:
Typical failure mileage:
Root cause:
Our Recommendation
Have the cooling system inspected at every service - a £400–£800 preventative repair is far cheaper than the £4,500+ replacement that follows an overheat. If you hear a knocking noise from the front of the engine, have the supercharger insulator spring checked immediately.
2.0
i4 Turbo (Chinese Market)
Affected models:
Typical failure mileage:
Root cause:
Our Recommendation
This engine is rare in the UK. If you're considering a 2.0T X351, ensure parts availability and specialist support exist locally. A £500–£1,200 turbo repair is manageable, but a full replacement at £2,500+ may not be justified given the car's value.
Battery
& Electrical Gremlins (All Models)
Affected models:
Typical failure mileage:
Root cause:
Our Recommendation
Before chasing electrical faults on an X351, check the battery voltage first. A weak battery (below 12.4V) can cause a cascade of warning lights that disappear with a new battery. If you're buying an X351, budget for a new battery immediately. For early cars, check the sunroof runners for corrosion.
Scope note: All variants listed are X351 only. The 2.0T was primarily offered in the Chinese market but is also present in limited numbers in the UK. The XJR (550 PS) arrived in 2013, with the XJR 575 and XJ50 special editions launched in 2018.
Most Requested Engines (2025)
Most Requested Variants
Average Replacement Cost
£4,500–£7,500 (reconditioned, supply only)
[JAG-QUOTE]
Most Common Failures
Live FeedJaguar XJ X351
5.0 AJ133
3
enquiries
Jaguar XJ X351
3.0 V6 Diesel
2
enquiries
Jaguar XJR X351
5.0 SC
2
enquiries
Most Requested Engines (2025)
Most Requested Variants
Average Replacement Cost
£4,500–£7,500 (reconditioned, supply only)
[JAG-QUOTE]
Most Common Failures
Most Requested Engines (2025)
Most Requested Variants
Average Replacement Cost
£4,500–£7,500 (reconditioned, supply only)
[JAG-QUOTE]
Most Common Failures
Scope note: All variants listed are X351 only. The 2.0T was primarily offered in the Chinese market but is also present in limited numbers in the UK. The XJR (550 PS) arrived in 2013, with the XJR 575 and XJ50 special editions launched in 2018.
Most Requested Engines (2025)
Most Requested Variants
Average Replacement Cost
£4,500–£7,500 (reconditioned, supply only)
[JAG-QUOTE]
Most Common Failures
Most Requested Engines (2025)
Most Requested Variants
Average Replacement Cost
£4,500–£7,500 (reconditioned, supply only)
[JAG-QUOTE]
Most Common Failures
Most Requested Engines (2025)
Most Requested Variants
Average Replacement Cost
£4,500–£7,500 (reconditioned, supply only)
[JAG-QUOTE]
Most Common Failures
Live FeedJaguar XJ X351
5.0 AJ133
3
enquiries
Jaguar XJ X351
3.0 V6 Diesel
2
enquiries
Jaguar XJR X351
5.0 SC
2
enquiries
Trusted XJ Engine Suppliers
every garage and engine rebuilder in our network is vetted, rated and reviewed by real XJ owners, as part of the Engine Finders network.
Compare XJ Engine Replacement Companies
see prices, warranty terms and supply & fit options side‑by‑side before you commit.
UK Engine Replacement Services for XJ
covering every variant from 3.0 V6 diesel to XJR 575, with supply‑only or full supply & fit available nationwide.
Find the best Jaguar XJ X351 engine replacement UK drivers rely on. Compare real prices from trusted specialists on EnginesMarket today and get back on the road with confidence.
Compare Jaguar XJ X351 Engine Prices on EnginesMarket