Mercedes GLS500Engine Rebuild— From £3,200
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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 GLS500 Engine
Vehicle
Mercedes GLS500
Model
GLS
Variant
GLS500
Fuel
Petrol Twin‑Turbo V8
Engine
M278
Capacity
4.7L
Generation
X166 (2015–2019)
Rebuild From
£6,500
Not sure which engine you have?
The GLS500 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 GLS500Engine Rebuild Price
Starting From £6,500
Engine Code
M256Rebuild From
£3,200
Generation
R190 (2023–present)
Exact price depends on condition and parts required — submit your reg for a fixed-price quote.
Mercedes GLS500 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 GLS500 uses a completely different engine family from the V8 M178 fitted to the GLS 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 GLS500ENGINE OPTIONS
Every GLS500 is different. That's why we offer the right solution for your engine, your car and your budget.
REBUILDING YOUR GLS500 ENGINE
We rebuild the engine your GLS500 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 GLS500 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 GLS500 ENGINES
Restoring your existing engine to full working condition rather than replacing it outright. Our rebuild service covers this.
Learn moreREMANUFACTURED GLS500 ENGINES
Built to original specification with updated components. That's consistent with what our rebuild service delivers on the M256.
Learn moreREPLACEMENT GLS500 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 GLS500 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 GLS500, 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 GLS500 rebuild looks like.
Mercedes GLS500 ENGINE REBUILD PROCESS
WHAT MERCEDES GLS500 OWNERS SAY
WE COVER YOUREXACT VEHICLE
Enter your registration below and we'll confirm your GLS500 has the M256, along with an exact rebuild price.
WHY MERCEDES GLS500 OWNERS CHOOSE US
Engine matched using VIN or registration number — confirms M278 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 *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 GLS500
RECOVERY
Mercedes GLS 63
DIAGNOSTICS
Mercedes GLS
STRIPPED ENGINE
Mercedes GLS S
TIMING CHAIN REPLACEMENT
Mercedes GLS500
IN FOR REBUILD
Mercedes GLS C
REBUILD IN PROGRESS
HOW IT WORKS
SEND YOURREGISTRATION
RECEIVE YOURFIXED-PRICE QUOTE
WE RECOVERYOUR CAR
REBUILD &REFIT
Most GLS 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 GLS500 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 GLS500 ENGINE
The GLS500 uses the M278 — a 4.7‑litre V8 twin‑turbo petrol engine. It was fitted from 2015 to 2019 across the X166 generation, serving as the flagship non‑AMG V8 option in the GLS range at that time. The GLS500 is no longer in production, but we continue to rebuild and replace engines for every one still on the road.
We continue to rebuild and replace M256 engines for every GLS500 on the road.
MERCEDES GLS500 ENGINE CODES
M256 (R190, 2023–present)
A 3.0-litre inline-six petrol mild-hybrid engine fitted to the GLS500 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 GLS500MERCEDES GLS500 ENGINE COMPATIBILITY
Because the GLS500 uses a single engine family across its entire production run — the M278 V8 — there is no confusion about which engine code applies. All X166‑generation GLS500 models share the same 4.7‑litre twin‑turbo unit, so compatibility is straightforward. We still confirm your registration before quoting, mainly to verify ancillary specifications and ensure we match the correct parts for your exact build.
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 GLS quote — it protects you from paying for parts that don't fit your actual car.
MERCEDES GLS500 APPLICATIONS BY GENERATION
Generation
Chassis
Years
Engine Code
Fuel
MERCEDES GLS500 ENGINES BY YEAR
From the R190's launch in 2023, the GLS500 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 GLS500 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 GLS500 MODEL YEAR:
Mercedes GLS500
2015 Engine Rebuild
Mercedes GLS500
2016 Engine Rebuild
Mercedes GLS500
2017 Engine Rebuild
Mercedes GLS500
2018 Engine Rebuild
Mercedes GLS500
2019 Engine Rebuild
If your registration year isn't listed above, get in touch — we'll confirm availability directly against your reg.
MERCEDES GLS500 ENGINE COSTS
A Mercedes GLS500 engine rebuild starts from
£6,500
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 GLS500 ENGINE SIZES
• Mercedes GLS500 3.0 Litre Engine (M256, I6)
MERCEDES GLS500 FUEL TYPES
• Mercedes GLS500 Petrol Mild Hybrid Engine Rebuilds
RELATED MERCEDES GLS VARIANTS
Most Mercedes GLS engine rebuilds are completed within 3-5 working days.
Nationwide recovery and collection available for all GLS models.