

Land Rover Discovery D300Engine Rebuild— From £2,800
Specialist Land Rover Discovery D300 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 AJ300D Specialists

Your Land Rover Discovery D300 Engine

Vehicle
Land Rover Discovery D300
Model
Discovery
Variant
D300
Fuel
Diesel MHEV
Engine
AJ300D
Capacity
3.0L I6
Generations
D5/L462 (2017–present)
Rebuild From
£2,800
Not sure which engine you have?
The Discovery D300 uses the AJ300D 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 D300Engine Rebuild Price
Starting From £2,800

Engine Code
AJ300DRebuild From
£2,800

Generation
Exact price depends on condition and parts required — submit your reg for a fixed-price quote.
Land Rover Discovery D300 Oil Leaks & Coolant System Wear (AJ300D I6)
The AJ300D is a sophisticated 3.0-litre inline-six with an integrated starter-generator and electric auxiliary compressor — a more modern and efficient design than the older AJ300D V6. We replace timing chains, bearings, water pump and gaskets as standard on every AJ300D rebuild.
Because the Discovery D300 uses a completely different engine family from the V8 M178 fitted to the Discovery 63 and GT 63 S, parts and rebuild specifications don't cross over between them.
Source: Established AJ300D specialist pattern — timing chain, bearing and gasket wear across integrated-starter-generator inline-six units.

Land Rover Discovery D300ENGINE OPTIONS
Every Discovery D300 is different. That's why we offer the right solution for your engine, your car and your budget.
REBUILDING YOUR DISCOVERY D300 ENGINE
Most engine suppliers sell you a used engine of unknown history and hope it matches. We rebuild the engine your Discovery D300 already has instead — strip it down, pressure-test it, and replace every worn or damaged component (timing chain components, injector seals, bearings, gaskets) with updated OEM parts. You get a near-new engine with a 12-month unlimited-mileage warranty, without the compatibility risk of an unknown used unit. This is the option most Discovery D300 owners choose, and it's the one we'd recommend for most situations.
RECONDITIONED DISCOVERY D300 ENGINES
"Reconditioned" is the term many owners search for when they mean the same thing as a rebuild — a full strip-down, inspection, and replacement of worn parts rather than a straight swap. If that's what you're after, our rebuild service is exactly that.
REFURBISHED DISCOVERY D300 ENGINES
Similarly, "refurbished" often describes the same process from a different angle — restoring your existing engine to full working condition rather than replacing it outright. Our rebuild covers this.
REMANUFACTURED DISCOVERY D300 ENGINES
Some owners specifically search for a "remanufactured" engine, expecting a unit rebuilt to original specification with updated components. That's consistent with what our rebuild service delivers on the AJ300D.
REPLACEMENT DISCOVERY D300 ENGINES
If your existing engine is beyond economical repair, we also offer full engine replacement and fitting — sourced and fitted by our team, with the same 12-month warranty.
USED DISCOVERY D300 ENGINES
In some cases, a matched low-mileage used engine is the right call — particularly if you need your car back on the road quickly and your existing engine's damage is extensive. We can source and fit these too, though most owners who ask about used engines end up choosing a rebuild once they understand the compatibility risk a used unit carries. Enter your reg below and we'll talk you through both options honestly.
NOT SURE WHICH OPTION IS RIGHT FOR YOU?
Enter your registration below and we'll confirm your AJ300D and talk you through the best solution for your Discovery D300, honestly.
Ask About Your OptionsOUR WORKSHOP
01RECOVERY COLLECTION
02AJ300D 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 D300 rebuild looks like.
Land Rover Discovery D300 ENGINE REBUILD PROCESS
WHAT MERCEDES Discovery D300 OWNERS SAY
WE COVER YOUREXACT VEHICLE
Enter your registration below and we'll confirm your Land Rover Discovery D300 has the AJ300D, along with an exact rebuild price.
WHY MERCEDES Discovery D300 OWNERS CHOOSE US
Engine matched using VIN or registration number
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 RECENTMERCEDES 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 D300
RECOVERY

Land Rover Discovery D300
DIAGNOSTICS

Land Rover Discovery D300
STRIPPED ENGINE

Land Rover Discovery D300
TIMING CHAIN REPLACEMENT

Land Rover Discovery D300
IN FOR REBUILD

Land Rover Discovery D300
REBUILD IN PROGRESS
HOW IT WORKS
SEND YOURREGISTRATION
RECEIVE YOURFIXED-PRICE QUOTE
WE RECOVERYOUR CAR
REBUILD &REFIT
Most Discovery 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 ORREPLACEMENT ENGINEINSTEAD?
We supply low-mileage, VIN-matched used units too, and offer full replacement and fitting. However, most Discovery D300 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 — we'll show you every option, honestly.
ABOUT THE Land Rover Discovery D300 ENGINE

The Discovery D300 is part of the current-generation Discovery 5 (L462) range, introduced in 2017. It uses the Ingenium AJ300D — a 3.0-litre inline-six diesel with mild-hybrid technology. This engine sits above the D250 in the Discovery diesel line-up, offering more power while maintaining the efficiency benefits of the MHEV system. The AJ300D represents a more modern design than the older TDV6 and SDV6 units found in the Discovery 3 and 4, with a different architecture and improved reliability characteristics.
We continue to rebuild and replace AJ300D engines for every Discovery D300 on the road.
Land Rover Discovery D300 ENGINE CODES
A 3.0-litre inline-six diesel fitted to the Discovery D300 from 2017 to present (D5/L462 generation). This Ingenium diesel shares the same broad timing chain family pattern as other JLR Ingenium diesel applications. We replace timing chain components, injector seals, bearings, and gaskets as standard on every rebuild. Check Your AJ300D Discovery D300 → [link to quote form]
Check Your AJ300D Discovery D300Land Rover Discovery D300 ENGINE COMPATIBILITY

The Discovery D300 uses the Ingenium AJ300D engine exclusively across its production run. When quoting or supplying, we confirm:
Your exact engine code (AJ300D) via registration or VIN
Your generation (D5/L462)
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 Discovery quote — it protects you from paying for parts that don't fit your actual car.
Land Rover Discovery D300 APPLICATIONS BY GENERATION
Land Rover Discovery D300 ENGINES BY YEAR
Land Rover Discovery D300 has used the AJ300D throughout. If you're unsure of your exact spec, we'll confirm it before you book.
The AJ300D has been fitted to every Discovery D300 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 D300 MODEL YEAR:
Land Rover Discovery D300
2017 Engine Rebuild
Land Rover Discovery D300
2018 Engine Rebuild
Land Rover Discovery D300
2019 Engine Rebuild
Land Rover Discovery D300
2020 Engine Rebuild
Land Rover Discovery D300
2021 Engine Rebuild
Land Rover Discovery D300
2022 Engine Rebuild
Land Rover Discovery D300
2023 Engine Rebuild
Land Rover Discovery D300
2024 Engine Rebuild
Land Rover Discovery D300
2025 Engine Rebuild
Land Rover Discovery D300
2026 Engine Rebuild
If your registration year isn't listed above, get in touch — we'll confirm availability directly against your reg.
Land Rover Discovery D300 ENGINE COSTS
A Land Rover Discovery D300 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
MERCEDES Discovery D300 ENGINE SIZES
• Land Rover Discovery D300 3.0 Litre Engine (AJ300D, I6)
MERCEDES Discovery D300 FUEL TYPES
• Land Rover Discovery D300 Petrol Mild Hybrid Engine Rebuilds
RELATED LAND ROVER ENGINES
Most Land Rover Discovery D300 engine rebuilds are completed within 3-5 working days.
Nationwide recovery and collection available for all Land Rover Discovery D300 models.









