Land Rover Garage - LAND ROVER ENGINE SPECIALISTS
Land Rover technician rebuilding an engine block

Land Rover Discovery D300 Engine 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

GB

Your Land Rover Discovery D300 Engine

Land Rover turbocharged engine

Vehicle

Land Rover Discovery D300

Model

Discovery

Variant

Discovery 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.

GB

DVLA & VIN verified

100% secure & private

No obligation quote

Land Rover Discovery D300 Engine Rebuild Price

Starting From £2,800

AJ300D engine

Engine Code

AJ300D

Rebuild From

£2,800

D5/L462 (2017-present)

Generation

D5/L462 (2017-present)

Exact price depends on condition and parts required - submit your reg for a fixed-price quote.

Get Your Fixed-Price Quote

Land Rover Discovery D300 Known Issues by Engine

If your Discovery D300 has the AJ300D (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 AJ300D 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 engine block

Land Rover Discovery D300 ENGINE OPTIONS

Every Discovery D300 is different. That's why we offer the right solution for your engine, your car and your budget.

01MOST POPULAR

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, injector seals, bearings, gaskets, DC-DC converter) 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.

From £2,800
02

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.

Learn more
03

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.

Learn more
04

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.

Learn more
05

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.

Learn more
06

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.

Learn more

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 Options

OUR WORKSHOP

RECOVERY COLLECTION01

RECOVERY COLLECTION

AJ300D ENGINE STRIPPED FOR REBUILD INSPECTION02

AJ300D ENGINE STRIPPED FOR REBUILD INSPECTION

VALVE COVERS & COOLANT COMPONENT WORK03

VALVE COVERS & COOLANT COMPONENT WORK

TECHNICIANS AT WORK04

TECHNICIANS AT WORK

ENGINE TESTING (RIG)05

ENGINE TESTING (RIG)

COMPLETED & READY FOR REFIT06

COMPLETED & 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

1Diagnosis

We confirm your exact engine code and assess the damage.

2Removal

Your engine is removed and brought into our workshop.

3Strip-Down

Every component is removed for individual inspection.

4Inspection

Crankshaft, cylinder head, timing chain, bearings, water pump and gaskets are all checked.

5Machine Work

Any machining required is carried out to OEM tolerances.

6Component Replacement

Worn or damaged parts are replaced with updated OEM components.

7Reassembly

Your engine is rebuilt to original specification.

8Testing

Every rebuild is pressure-tested before refit.

9Refit

Your engine goes back into your Discovery D300.

10Road Test

A full road test confirms everything's right before we hand your car back.

WHAT LAND ROVER Discovery D300 OWNERS SAY

Daniel R.

“Brilliant service from start to finish. My Discovery D300 runs smoother than ever. Honest advice, clear pricing and the team know their stuff.”

Land Rover Discovery D300 Engine Rebuild

Mark T.

“They rebuilt my AJ300D with all the updated parts. Smooth process and great communication throughout.”

Land Rover Discovery D300 Engine Rebuild

Ryan P.

“Top lads, top job. Picked up and dropped off, engine rebuilt to an extremely high standard. 100% recommend.”

Land Rover Discovery D300 Engine Rebuild

Steve B.

“Saved me thousands compared to a dealer quote. Fantastic workmanship and my Discovery D300 is running perfectly.”

Land Rover Discovery D300 Engine Rebuild

Tom H.

“From quote to collection couldn't fault them. Engine looks brand new inside. Warranty gives great peace of mind.”

Land Rover Discovery D300 Engine Rebuild

James K.

“Professional, reliable and fairly priced. Sorted properly and kept me updated throughout.”

Land Rover Discovery D300 Engine Rebuild

WE COVER YOUR EXACT VEHICLE

Enter your registration below and we'll confirm your Land Rover Discovery D300 has the AJ300D, along with an exact rebuild price.

GB
FastAccurateNo Guesswork

WHY LAND ROVER Discovery D300 OWNERS CHOOSE US

Engine matched using VIN or registration number - confirms AJ300D 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 D300

Land Rover Discovery D300

RECOVERY

Land Rover Discovery D300

Land Rover Discovery D300

DIAGNOSTICS

Land Rover Discovery D300

Land Rover Discovery D300

STRIPPED ENGINE

Land Rover Discovery D300

Land Rover Discovery D300

TIMING CHAIN REPLACEMENT

Land Rover Discovery D300

Land Rover Discovery D300

IN FOR REBUILD

Land Rover Discovery D300

Land Rover Discovery D300

REBUILD IN PROGRESS

HOW IT WORKS

1

SEND YOURREGISTRATION

2

RECEIVE YOURFIXED-PRICE QUOTE

3

WE RECOVERYOUR CAR

4

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 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 and we'll show you every option, honestly.

Ask About Used Engine Options

ABOUT THE Land Rover Discovery D300 ENGINE

Land Rover engine and vehicle

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

AJ300D

AJ300D (D5/L462)

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

Land Rover Discovery D300 ENGINE COMPATIBILITY

Land Rover Land Rover vehicle in workshop

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 (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 D300 APPLICATIONS BY GENERATION

Generation

Chassis

Years

Engine Code

Fuel

D5

D5

L462

2017-present

AJ300D

Diesel MHEV

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.

Year

Generation

Engine Code

Fuel

Service

2017

D5/L462

AJ300D

Diesel MHEV

Rebuild / Replacement

2018

D5/L462

AJ300D

Diesel MHEV

Rebuild / Replacement

2019

D5/L462

AJ300D

Diesel MHEV

Rebuild / Replacement

2020

D5/L462

AJ300D

Diesel MHEV

Rebuild / Replacement

2021

D5/L462

AJ300D

Diesel MHEV

Rebuild / Replacement

2022

D5/L462

AJ300D

Diesel MHEV

Rebuild / Replacement

2023

D5/L462

AJ300D

Diesel MHEV

Rebuild / Replacement

2024

D5/L462

AJ300D

Diesel MHEV

Rebuild / Replacement

2025

D5/L462

AJ300D

Diesel MHEV

Rebuild / Replacement

2026

D5/L462

AJ300D

Diesel MHEV

Rebuild / Replacement

i

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 or model 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.

Land Rover engine

12 MONTH

UNLIMITED-MILEAGE

WARRANTY

LAND ROVER Discovery D300 ENGINE SIZES

• Land Rover Discovery D300 3.0 Litre Engine (AJ300D, I6)

LAND ROVER Discovery D300 FUEL TYPES

• Land Rover Discovery D300 Petrol Mild Hybrid Engine Rebuilds

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.

Land Rover vehicle recovery and collection

FREQUENTLY ASKED QUESTIONS

Land Rover vehicle in a dark showroom

GET YOUR FREE LAND ROVER Discovery D300 FIXED-PRICE QUOTE

Most quotes returned within 30 minutes during working hours.