
Land Rover Discovery P400 Engine Rebuild - From £2,800
Specialist Land Rover Discovery P400 engine rebuilds and replacements, with registration-based engine matching, nationwide recovery and a 12-month unlimited-mileage warranty
Rated Land Rover Engine Specialists - 1,800+ Engines Rebuilt
Specialist technicians with 10-15 years of experience
12 Month Unlimited-Mileage Warranty
Nationwide Recovery
Free Engine Matching by Registration
Ingenium AJ300P (Ingenium 3.0L I6) Specialists
Your Land Rover Discovery P400 Engine

Vehicle
Land Rover Discovery P400
Model
Discovery
Variant
Discovery P400
Fuel
Petrol MHEV
Engine
AJ300P (Ingenium 3.0L I6)
Capacity
3.0L I6
Generations
D5/L462 (2017-present)
Rebuild From
£2,800
Not sure which engine you have?
The Discovery P400 uses the AJ300P (Ingenium 3.0L I6) 3.0-litre inline-six mild-hybrid engine - enter your registration below and we'll confirm your exact spec before you get a quote.
DVLA & VIN verified
100% secure & private
No obligation quote
Land Rover Discovery P400 Engine Rebuild Price
Starting From £2,800

Engine Code
AJ300P (Ingenium 3.0L I6)Rebuild From
£2,800

Generation
D5/L462 (2017-present)
Exact price depends on condition and parts required - submit your reg for a fixed-price quote.
Land Rover Discovery P400 Known Issues by Engine
If your Discovery P400 has the AJ300P (Ingenium 3.0L I6) (L663 generation):
Timing chain wear - Ingenium diesel engines share a well-documented timing chain pattern. We replace timing chains, guides and tensioners as standard on every AJ300P (Ingenium 3.0L I6) rebuild.
Source: established specialist consensus, l663.guide specialist buying guide, what-breaks.com. This applies to L663 Defenders only - not to classic Defender models

Land Rover Discovery P400 ENGINE OPTIONS
Every Discovery P400 is different. That's why we offer the right solution for your engine, your car and your budget.
NOT SURE WHICH OPTION IS RIGHT FOR YOU?
Enter your registration below and we'll confirm your AJ300P (Ingenium 3.0L I6) and talk you through the best solution for your Discovery P400, honestly.
Ask About Your OptionsOUR WORKSHOP
01RECOVERY COLLECTION

02AJ300P (Ingenium 3.0L I6) ENGINE STRIPPED FOR REBUILD INSPECTION

03VALVE COVERS & COOLANT COMPONENT WORK
04TECHNICIANS AT WORK
05ENGINE TESTING (RIG)
06COMPLETED & READY FOR REFIT
Real photos from our workshop - not stock imagery. This is what a genuine Land Rover Discovery P400 rebuild looks like.
Land Rover Discovery P400 ENGINE REBUILD PROCESS
WE COVER YOUR EXACT VEHICLE
Enter your registration below and we'll confirm your Land Rover Discovery P400 has the AJ300P (Ingenium 3.0L I6), along with an exact rebuild price.
WHY LAND ROVER Discovery P400 OWNERS CHOOSE US
Engine matched using VIN or registration number - confirms your exact AJ300P spec before you're quoted
Genuine specialist workshop - not a broker
Specialist technicians with 10-15 years of experience
We don't swap your engine for an unknown used unit
Nationwide recovery, workshop rebuild
12 month unlimited-mileage warranty
All engine ancillaries serviced as part of the rebuild
Trade & public enquiries welcome
Dedicated advisor from quote to fit
OUR MOST RECENT LAND ROVER RECOVERIES & REBUILDS
Real vehicles brought into our workshop. Open bonnets, stripped blocks, and cars ready for collection - this is what genuine engine work looks like.

Land Rover Discovery P400
RECOVERY

Land Rover Discovery P400
DIAGNOSTICS

Land Rover Discovery P400
STRIPPED ENGINE

Land Rover Discovery P400
TIMING CHAIN REPLACEMENT

Land Rover Discovery P400
IN FOR REBUILD

Land Rover Discovery P400
REBUILD IN PROGRESS
HOW IT WORKS
SEND YOURREGISTRATION
RECEIVE YOURFIXED-PRICE QUOTE
WE RECOVERYOUR CAR
REBUILD &REFIT
Most Defender models are recovered within a few hours of booking. Most rebuilds are completed within 3-5 working days.
Workshop slots fill up fast - book your recovery today.
LOOKING FOR A USED OR REPLACEMENT ENGINE INSTEAD?
We supply low-mileage, VIN-matched used units too, and offer full replacement and fitting. However, most Discovery P400 owners choose a rebuild once they realise it removes compatibility risk and works out more cost-effective over the life of the car. Enter your reg below and we'll show you every option, honestly.
ABOUT THE Land Rover Discovery P400 ENGINE

The Discovery P400 is part of the fifth-generation Discovery range (D5, codename L462), introduced in 2017 and continuing through to the present day. The P400 uses the Ingenium AJ300P - a 3.0-litre inline-six petrol engine with mild-hybrid technology. It sits above the P360 in the Discovery petrol range, offering higher output while sharing the same basic Ingenium architecture. As with all modern Ingenium petrol engines, the AJ300P is generally regarded as more reliable than its diesel counterparts, though cooling system maintenance remains important.
We continue to rebuild and replace AJ300P (Ingenium 3.0L I6) engines for every Discovery P400 on the road.
Land Rover Discovery P400 ENGINE CODES

AJ300P (Ingenium 3.0L I6)
A 3.0-litre inline-six petrol engine fitted to the Discovery P400 from 2017 to present (D5/L462 generation). The AJ300P is part of JLR's Ingenium engine family and features mild-hybrid (MHEV) technology. We replace timing chains, bearings, water pump and gaskets as standard on every rebuild.
Check Your AJ300P Discovery P400Land Rover Discovery P400 ENGINE COMPATIBILITY

The Discovery P400 uses the Ingenium AJ300P 3.0-litre inline-six petrol engine across its entire D5 production run. Unlike some Discovery variants that have seen engine changes mid-generation, the P400 has remained consistent on the AJ300P throughout. Before we quote or supply anything, we confirm:
Your exact engine code (AJ300P (Ingenium 3.0L I6)) via registration or VIN
Your generation (L663)
Drivetrain and ancillary specification
Whether your build falls in the early production period (2019-2020) for injector fault coverage
This is why we always start with your registration rather than a generic Defender quote - it protects you from paying for parts that don't fit your actual car.
Land Rover Discovery P400 APPLICATIONS BY GENERATION
Land Rover Discovery P400 ENGINES BY YEAR
Land Rover Discovery P400 has used the AJ300P (Ingenium 3.0L I6) throughout. If you're unsure of your exact spec, we'll confirm it before you book.
The AJ300P (Ingenium 3.0L I6) has been fitted to every Discovery P400 since launch - if your registration year isn't listed above, get in touch and we'll confirm availability directly against your reg.
WE COVER EVERY Land Rover Discovery P400 MODEL YEAR:
Land Rover Discovery P400
2017 Engine Rebuild
Land Rover Discovery P400
2018 Engine Rebuild
Land Rover Discovery P400
2019 Engine Rebuild
Land Rover Discovery P400
2020 Engine Rebuild
Land Rover Discovery P400
2021 Engine Rebuild
Land Rover Discovery P400
2022 Engine Rebuild
Land Rover Discovery P400
2023 Engine Rebuild
Land Rover Discovery P400
2024 Engine Rebuild
Land Rover Discovery P400
2025 Engine Rebuild
Land Rover Discovery P400
2026 Engine Rebuild
If your registration year or model isn't listed above, get in touch - we'll confirm availability directly against your reg.
Land Rover Discovery P400 ENGINE COSTS
A Land Rover Discovery P400 engine rebuild starts from
£2,800
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.

12 MONTH
UNLIMITED-MILEAGE
WARRANTY
LAND ROVER Discovery P400 ENGINE SIZES
• Land Rover Discovery P400 3.0 Litre Engine (AJ300P (Ingenium 3.0L I6), I6)
LAND ROVER Discovery P400 FUEL TYPES
• Land Rover Discovery P400 Petrol Mild Hybrid Engine Rebuilds
Related Land Rover Discovery Variants
Most Land Rover Discovery P400 engine rebuilds are completed within 3-5 working days.
Nationwide recovery and collection available for all Land Rover Discovery P400 models.












