Executive Summary
The Jaguar AJ126 is a 3.0-litre supercharged V6 petrol engine produced from 2012 to 2019, fitted to performance variants of the Jaguar XF, XJ, F-Type, F-Pace and XE. It is essentially a V8 with two cylinders removed, sharing its architecture with the renowned AJ133 5.0-litre V8.
If you are searching for an AJ126 engine for sale in the UK, expect to pay £2,500 to £6,000+ for a reconditioned unit supply-only, with fitted prices ranging from £4,500 to over £9,000 depending on the vehicle and specification. Used engines are cheaper but carry higher risk, while reconditioned units with warranties offer the best value for most buyers.
The AJ126 is broadly reliable when properly maintained, but known issues include timing chain stretch (typically beyond 100,000 to 150,000 km), supercharger coupler wear, coolant system leaks, and oil leaks from valve covers and seals. Buyers should also be aware of a technical service bulletin regarding misfiring on replacement or remanufactured units.
Engine Finders is a price comparison platform, not a direct engine seller. Final pricing, warranty terms, and availability vary by vetted UK supplier. Professional diagnosis is recommended before purchasing any replacement engine.
AJ126 Engine Specifications at a Glance
| Specification | Detail |
|---|---|
| Engine code | AJ126 (also known as Land Rover 306PS) |
| Production years | 2012–2019 |
| Displacement | 2,995 cc |
| Configuration | V6, 24-valve, DOHC |
| Bore × Stroke | 84.5 mm × 89.0 mm |
| Compression ratio | 10.5:1 |
| Fuel system | Direct injection |
| Forced induction | Eaton M112 Roots-type supercharger with intercooler |
| Power output | 340–380 PS (250–280 kW) |
| Torque output | 450–460 Nm |
| Timing drive | Chain |
| Recommended oil | 5W-20 |
| Oil capacity | 7.25 litres |
| Euro standard | EURO 5 |
| Estimated lifespan | ~300,000 km (with proper maintenance) |
Which Jaguar & Land Rover Models Use the AJ126?
The AJ126 was installed across the Jaguar and Land Rover ranges:
| Model | Generation | Years |
|---|---|---|
| Jaguar XE | X760 | 2015–2019 |
| Jaguar XF | X250 (Mk I), X260 (Mk II) | 2012–2018 |
| Jaguar XJ | X351 | 2012–2019 |
| Jaguar F-Pace | X761 | 2016–2018 |
| Jaguar F-Type | X152 | 2013–2019 |
| Land Rover Discovery | L462 | 2017+ |
| Range Rover | L405 | 2013+ |
| Range Rover Sport | L494 | 2013+ |
| Range Rover Velar | L560 | 2017+ |
Important: The AJ126 was also used in various Land Rover models under the name 306PS. Always confirm your engine code via your VIN or logbook before ordering.
AJ126 Reliability & Common Problems
The AJ126 is a generally robust engine, but like any performance powerplant, it has known failure points. For a wider view of how it compares across the marque, see our guide to Jaguar engine reliability, best and worst engines. Buyers should be aware of the following issues:
1. Timing Chain Stretch
The AJ126 shares timing chain tensioner issues with its V8 sibling, the AJ133. The timing chain has a limited service life, typically 100,000 to 150,000 km (62,000 to 93,000 miles).
Symptoms:
- Rattling noise on cold start-up
- Engine management light illumination
- Reduced performance
- In severe cases, chain skipping teeth causes pistons to hit valves, resulting in engine destruction
The AJ126 is an interference engine. If the timing chain fails, pistons strike valves, ruining the top end. Early V6 engines (pre-2015) used 6.3 mm pitch chains; later revisions used more durable 8.0 mm pitch chains. Our guides to Jaguar XE P250/P300 timing chain stretch and F-Pace timing chain tensioner failure cover the same failure pattern in detail.
2. Supercharger Coupler (Damper Sleeve) Failure
The damper sleeve in the supercharger drive fails relatively quickly.
Symptoms:
- Rattling or grinding noise from the supercharger
- Reduced boost pressure
- Loss of power
3. Cooling System Issues
- Water pump failure is common
- Plastic cooling tee often cracks and bursts
- Coolant leaks can lead to overheating and engine damage
Symptoms:
- Coolant loss without visible external leaks
- Temperature gauge reading high
- Coolant warning light
4. Oil Leaks
Oil leaks through valve covers and seals are reported. A related issue is PCV valve failure, which our guide to Jaguar XF 3.0 V6 supercharged PCV valve failure covers, as it causes blue smoke and oil consumption.
5. Misfire on Replacement Units (Technical Bulletin)
A Land Rover technical service bulletin (SSM75971, March 2023) identified that replacement new or remanufactured AJ126 engines may experience misfiring or rough running for the first few minutes after a cold start. The root cause was identified as improper valve clearances, particularly exhaust valves below specification.
Action: Check valve clearances and correct any discrepancies.
6. Oil Overfill Risk
The AJ126 is sensitive to oil overfilling. A teardown of a failed 2017 Jaguar XE AJ126 with 66,000 miles found it had been overfilled with oil, at 9 quarts when it should hold only 5.7 quarts. Overfilling causes the crankshaft to churn the oil, creating foam and reducing lubrication, leading to bearing failure.
Key takeaway: Always follow the 7.25-litre oil capacity and use 5W-20 specification oil.
AJ126 Engine Replacement Cost UK
Price Ranges by Engine Condition
| Condition | Supply Only | Supply & Fit | Warranty |
|---|---|---|---|
| Used | £2,500–£4,000 | £4,000–£6,000 | 3–6 months |
| Reconditioned | £2,500–£6,000+ | £4,500–£9,000+ | 12–24 months |
| New | £6,000–£10,000+ | £8,000–£12,000+ | 2–3 years |
Note: Prices are indicative UK market ranges. Exact quotes vary by supplier, model, and specification. See our engine replacement cost guide for how these figures compare across the market.
Real-World Examples
- 2017 Range Rover Sport AJ126 (remanufactured, supply & fit): £4,500 engine + £500 recovery = £5,000 total
- 2017 Range Rover Sport AJ126 (used, supply & fit with recovery): £3,995 engine + £1,500 fitting + £300 recovery = £5,795 total
- Jaguar F-Type AJ126 (reconditioned, supply & fit): £5,995
- Jaguar F-Type engine replacement (general range): £4,500 to £9,000+
- Jaguar XF 3.0 V6 replacement: £4,500 to £7,000
Labour Costs
Labour typically adds £1,000 to £1,500 to the supply-only price, depending on:
- Vehicle model (F-Type engine bays are tighter than XF or XJ)
- Garage location (London and South East command premium rates)
- Whether ancillary components require replacement
Additional Costs to Consider
- Delivery: Pallet delivery of an engine typically costs £150 to £200
- Surcharge/deposit: Many suppliers charge a refundable deposit (£200 to £500) until your old engine is returned
- Ancillary parts: If your existing ancillaries (alternator, starter, supercharger, injectors) are damaged, replacement costs are additional
- ECU recalibration: Required for proper operation
- Coolant and oil: New fluids are required with any engine swap
Where to Find an AJ126 Engine for Sale in the UK
When searching for an AJ126 engine for sale, consider these options:
1. Engine Comparison Platforms
Engine Finders connects you with vetted UK suppliers offering used, reconditioned, and new AJ126 engines. Compare quotes, warranty terms, and supplier ratings in one place.
2. Specialist Engine Suppliers
A number of UK specialists offer remanufactured and used AJ126 units with supply and fit services, particularly those focused on Jaguar and Land Rover engine replacements. Always verify credentials, reviews, and warranty terms before committing.
3. Online Marketplaces
Used and reconditioned AJ126 engines are available on general marketplaces, but you should carefully verify seller ratings, warranty terms, and the engine’s history before purchase.
4. Jaguar Land Rover Dealers
New OEM engines are available but at significantly higher cost, typically three to four times more than a quality reconditioned alternative.
Used vs Reconditioned vs New: Which AJ126 Should You Buy?
| Option | Pros | Cons | Best For |
|---|---|---|---|
| Used | Lower upfront cost | Unknown history, no warranty, hidden damage risk | Budget-conscious, low-mileage needs |
| Reconditioned | New wearable parts, warranty, tested | Higher cost | Most owners – best value |
| New | Perfect condition, full warranty | Very expensive | Concours restoration, long-term ownership |
Recommendation: For most AJ126 buyers, a reconditioned engine with a 12-month or longer warranty offers the best balance. The additional cost over a used engine is justified by:
- New pistons, rings, bearings, and timing chain
- Professional cleaning and inspection
- Warranty protection against failure
- Peace of mind on a high-performance engine
Our reconditioned versus new engine guide explains the trade-offs in full.
Practical Takeaways
What to Check Before Buying an AJ126 Engine
- Verify the engine code. Confirm AJ126 via your VIN or logbook. The AJ126 is sometimes listed as 306PS in Land Rover applications.
- Check the chassis code. Ensure compatibility with your specific model year and specification using our engine compatibility guide.
- Request warranty terms in writing. Minimum 12 months recommended for reconditioned units.
- Ask about timing chain replacement. Verify the timing chain and tensioners have been replaced or are within service life.
- Inspect the supercharger. Check for coupler wear and smooth operation.
- Confirm oil specification. The AJ126 requires 5W-20 oil and 7.25 litres capacity.
- Verify the supplier. Use vetted suppliers only, and our guide on what to check before buying a reconditioned engine online can help.
Models to Approach with Caution
- Early AJ126 engines (2012 to 2015), which may have the earlier 6.3 mm pitch timing chains that are more prone to stretch
- High-mileage units without documented timing chain replacement, as timing chain failure is catastrophic
- Engines with unknown service history, as oil condition is critical and overfilling or poor oil can destroy this engine
When to Use EngineFinders
If you are facing an AJ126 engine replacement, Engine Finders connects you with vetted UK suppliers for no-obligation quotes. Always:
- Confirm the exact engine code from your VIN
- Request written warranty terms before committing
- Have your vehicle professionally diagnosed to confirm engine replacement is the correct solution. Our engine repair versus replacement guide helps you decide
Enter Your REG to Get a Free Engine Quote
Frequently Asked Questions
How much does an AJ126 engine cost in the UK?
A reconditioned AJ126 engine typically costs £2,500 to £6,000+ supply-only, or £4,500 to £9,000+ supply and fitted. Used engines start from £2,500. Prices vary by supplier, model, and specification. Compare quotes from vetted UK suppliers for the best deal.
What vehicles use the Jaguar AJ126 engine?
The AJ126 was fitted to Jaguar XF, XJ, F-Type, F-Pace and XE models from 2012 to 2019, as well as Land Rover Discovery, Range Rover, Range Rover Sport and Velar models.
Is the AJ126 a reliable engine?
The AJ126 is broadly reliable with proper maintenance, but known issues include timing chain stretch (100,000 to 150,000 km), supercharger coupler wear, coolant system leaks, and oil leaks. Regular servicing with 5W-20 oil is essential.
What causes AJ126 engine failure?
Common causes include timing chain failure (catastrophic in an interference engine), oil overfilling (causes foaming and bearing failure), coolant leaks leading to overheating, and supercharger wear.
Can I fit an AJ126 engine myself?
DIY fitment is not recommended unless you have professional mechanical experience and specialist tools. The job requires engine hoists, timing tools, and diagnostic equipment. Professional fitment also provides warranty cover on both parts and labour.
Should I buy a used or reconditioned AJ126 engine?
Reconditioned engines offer better value for most owners. They cost more but include new wearable components and typically carry 12 to 24 month warranties. Used engines are cheaper but higher risk, with limited warranties and unknown history.
