Mercedes G300Engine Rebuild— From £3,200
Mercedes G300 Turbodiesel Engine Rebuild — From £1,900
Rated Mercedes 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
M256 Specialists
Your Mercedes G300 Engine
Vehicle
Mercedes G300
Model
G-Class
Variant
G300
Fuel
Diesel
Engine
OM606
Capacity
3.0L I6
Generation
W463 (pre-2018)
Rebuild From
£1,900
Not sure which engine you have?
The G300 uses the M256 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
Mercedes G300Engine Rebuild Price
Starting From £1,900
Engine Code
OM606Rebuild From
£1,900
Generation
W463 (pre-2018)
Exact price depends on condition and parts required — submit your reg for a fixed-price quote.
Mercedes G300 Oil Leaks & Coolant System Wear (M256 I6)
The M256 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 M276 V6. We replace timing chains, bearings, water pump and gaskets as standard on every M256 rebuild.
Because the G300 uses a completely different engine family from the V8 M178 fitted to the G-Class 63 and GT 63 S, parts and rebuild specifications don't cross over between them.
Source: Established M256 specialist pattern — timing chain, bearing and gasket wear across integrated-starter-generator inline-six units.
Mercedes G300ENGINE OPTIONS
Every G300 is different. That's why we offer the right solution for your engine, your car and your budget.
REBUILDING YOUR G300 ENGINE
We rebuild the engine your G300 already has instead of selling you a used engine of unknown history — strip it down, pressure-test it, and replace every worn or damaged component (timing chains, bearings, water pump, gaskets) with updated OEM parts. Near-new performance with a 12-month unlimited-mileage warranty.
From £3,200RECONDITIONED G300 ENGINES
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 moreREFURBISHED G300 ENGINES
Restoring your existing engine to full working condition rather than replacing it outright. Our rebuild service covers this.
Learn moreREMANUFACTURED G300 ENGINES
Built to original specification with updated components. That's consistent with what our rebuild service delivers on the M256.
Learn moreREPLACEMENT G300 ENGINES
If your existing engine is beyond economical repair, we offer complete engine replacement and fitting – sourced and fitted by our team, with the same 12-month warranty.
Learn moreUSED G300 ENGINES
Matched low-mileage used engines for when time is critical. We source and fit these too, but most owners choose a rebuild once they understand the compatibility risks.
Learn moreNOT SURE WHICH OPTION IS RIGHT FOR YOU?
Enter your registration below and we'll confirm your M256 and talk you through the best solution for your G300, honestly.
Ask About Your Options
OUR WORKSHOP
01RECOVERY COLLECTION
02M256 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 Mercedes G300 rebuild looks like.
Mercedes G300 ENGINE REBUILD PROCESS
WHAT MERCEDES G300 OWNERS SAY
WE COVER YOUREXACT VEHICLE
Enter your registration below and we'll confirm your G300 has the M256, along with an exact rebuild price.
WHY MERCEDES G300 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 No widely-reported engine issue for this variant — we still recommend a full inspection before any long journey.
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.
Mercedes G300
RECOVERY
Mercedes G-Class 63
DIAGNOSTICS
Mercedes G-Class
STRIPPED ENGINE
Mercedes G-Class S
TIMING CHAIN REPLACEMENT
Mercedes G300
IN FOR REBUILD
Mercedes G-Class C
REBUILD IN PROGRESS
HOW IT WORKS
SEND YOURREGISTRATION
RECEIVE YOURFIXED-PRICE QUOTE
WE RECOVERYOUR CAR
REBUILD &REFIT
Most G-Class 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 G300 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 MERCEDES G300 ENGINE
The G300 Turbodiesel uses the OM606 — a 3.0-litre inline-six diesel that was fitted to the W463-generation G-Class from the 1990s through to the 2000s. It's a well-known engine among G-Class enthusiasts and restoration specialists, valued for its durability and mechanical simplicity compared to later, more complex diesel units. The OM606 is a pre-common-rail design that many owners specifically seek out for its reliability and relative ease of maintenance.
We continue to rebuild and replace M256 engines for every G300 on the road.
MERCEDES G300 ENGINE CODES
M256 (R190, 2023–present)
A 3.0-litre inline-six petrol mild-hybrid engine fitted to the G300 from 2023 to present. The M256 features an integrated starter-generator (ISG) and electric auxiliary compressor, making it a more modern and efficient design than the older M276 V6. We replace timing chains, bearings, water pump and gaskets as standard on every M256 rebuild.
Check Your M256 G300MERCEDES G300 ENGINE COMPATIBILITY
The G300 Turbodiesel uses the OM606 diesel engine exclusively. Before we quote or supply anything, we confirm:
Your exact engine code (M256) via registration or VIN
Your generation (R190)
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 G-Class quote — it protects you from paying for parts that don't fit your actual car.
MERCEDES G300 APPLICATIONS BY GENERATION
Generation
Chassis
Years
Engine Code
Fuel
MERCEDES G300 ENGINES BY YEAR
From the R190's launch in 2023, the G300 has used the M256 3.0-litre inline-six mild hybrid throughout. If you're unsure of your exact spec, we'll confirm it before you book.
The M256 has been fitted to every G300 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 MERCEDES G300 MODEL YEAR:
Mercedes G300
2023 Engine Rebuild
Mercedes G300
2024 Engine Rebuild
Mercedes G300
2025 Engine Rebuild
Mercedes G300
2026 Engine Rebuild
If your registration year isn't listed above, get in touch — we'll confirm availability directly against your reg.
MERCEDES G300 ENGINE COSTS
A Mercedes G300 engine rebuild starts from
£1,900
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 G300 ENGINE SIZES
• Mercedes G300 3.0 Litre Engine (M256, I6)
MERCEDES G300 FUEL TYPES
• Mercedes G300 Petrol Mild Hybrid Engine Rebuilds
RELATED MERCEDES G-CLASS VARIANTS
Most Mercedes G-Class engine rebuilds are completed within 3-5 working days.
Nationwide recovery and collection available for all G-Class models.