Mercedes CLS 63 AMGEngine Rebuild— From £6,500
Specialist Mercedes CLS 63 AMG engine rebuilds and replacements, with registration-based engine matching, nationwide recovery and a 12-month unlimited-mileage warranty
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 CLS 63 AMG Engine
Vehicle
Mercedes CLS 63 AMG
Model
CLS
Variant
CLS 63 AMG
Fuel
Petrol / Petrol Twin-Turbo
Engine
M156 (C219) · M157 (C218) · M177 (C257)
Capacity
6.2L / 5.5L / 4.0L
Generation
C219 (2004–2010) · C218 (2010–2018) · C257 (2018–2023)
Rebuild From
£6,500
Not sure which engine you have?
The CLS 63 AMG 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
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No obligation quote
Mercedes CLS 63 AMGEngine Rebuild Price
Starting From £6,500
Engine Code
M156Rebuild From
£6,500
Generation
C219 (2004–2010)
Engine Code
M157Rebuild From
£6,500
Generation
C218 (2010–2018)
Engine Code
M177Rebuild From
£6,500
Generation
C257 (2018–2023)
Exact price depends on condition and parts required — submit your reg for a fixed-price quote.
Mercedes CLS 63 AMG Valve Seal & Coolant System Wear (C218/C257, M157/M177)
If your CLS 63 AMG is from the C218 or C257 generation — that's 2010 onwards — the M157 or M177 twin-turbo V8 engines are known for valve seal and coolant system wear over time. This is a well-documented pattern among AMG specialists. We replace valve seals, coolant components, timing chains and bearings as standard on every M157 and M177 rebuild.
The earlier C219 generation uses a different engine, the naturally aspirated M156 6.2-litre V8, which doesn't share this specific twin-turbo issue — it's a separate design with its own known characteristics that we inspect case-by-case rather than as a pattern.
Source: established AMG specialist pattern, per VRF-mercedes-cls.md. C219/M156 explicitly excluded from this claim per VRF, correctly scoped to generation
Mercedes CLS 63 AMGENGINE OPTIONS
Every CLS 63 AMG is different. That's why we offer the right solution for your engine, your car and your budget.
REBUILDING YOUR CLS 63 AMG ENGINE
We rebuild the engine your CLS 63 AMG 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 CLS 63 AMG 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 CLS 63 AMG ENGINES
Restoring your existing engine to full working condition rather than replacing it outright. Our rebuild service covers this.
Learn moreREMANUFACTURED CLS 63 AMG ENGINES
Built to original specification with updated components. That's consistent with what our rebuild service delivers on the M256.
Learn moreREPLACEMENT CLS 63 AMG 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 CLS 63 AMG 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 CLS 63 AMG, 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 CLS 63 AMG rebuild looks like.
Mercedes CLS 63 AMG ENGINE REBUILD PROCESS
WHAT MERCEDES CLS 63 AMG OWNERS SAY
WE COVER YOUREXACT VEHICLE
Enter your registration below and we'll confirm your CLS 63 AMG has the M256, along with an exact rebuild price.
WHY MERCEDES CLS 63 AMG OWNERS CHOOSE US
Engine matched using VIN or registration number — confirms M156 vs M157 vs M177 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 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 CLS 63 AMG
RECOVERY
Mercedes CLS 63
DIAGNOSTICS
Mercedes CLS
STRIPPED ENGINE
Mercedes CLS S
TIMING CHAIN REPLACEMENT
Mercedes CLS 63 AMG
IN FOR REBUILD
Mercedes CLS C
REBUILD IN PROGRESS
HOW IT WORKS
SEND YOURREGISTRATION
RECEIVE YOURFIXED-PRICE QUOTE
WE RECOVERYOUR CAR
REBUILD &REFIT
Most CLS 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 CLS 63 AMG 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 CLS 63 AMG ENGINE
The CLS 63 AMG has been the flagship performance variant of the CLS range since 2004, spanning three generations under one badge. The first-generation C219 car (2004–2010) uses the M156 — a naturally aspirated 6.2-litre V8 that was AMG's first entirely in-house developed engine. From 2010, the C218-generation CLS 63 AMG switched to the M157, a 5.5-litre twin-turbo V8 that delivered significantly more torque. The final C257 generation (2018–2023) uses the M177, a 4.0-litre twin-turbo V8 shared with other contemporary AMG models. Each is a different unit entirely, not an evolution of the previous one — which is why we confirm your exact engine by registration before quoting. The CLS was discontinued entirely after the C257 in 2023, 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 CLS 63 AMG on the road.
MERCEDES CLS 63 AMG ENGINE CODES
M156 (C219)
A 6.2-litre naturally aspirated V8 fitted to the CLS 63 AMG from 2004 to 2010 (C219 generation). This was AMG's first entirely in-house developed engine. While the M156 has known characteristics on other AMG models, we haven't independently confirmed a specific pattern for this CLS application — every rebuild is assessed on its own condition rather than assuming a model-wide issue.
Check Your M156 CLS 63 AMGM157 (C218)
A 5.5-litre twin-turbo V8 fitted from 2010 to 2018 (C218 generation). Known for valve seal and coolant system wear over time — see the callout above. We replace valve seals, coolant components, timing chains and bearings as standard on every M157 rebuild.
Check Your M157 CLS 63 AMGM177 (C257)
A 4.0-litre twin-turbo V8 fitted from 2018 to 2023 (C257 generation). The final engine used in the CLS 63 AMG before the model was discontinued. Shares the valve seal and coolant system wear pattern of the M157 — see the callout above. We service it to the same standard as the M157.
Check Your M177 CLS 63 AMGMERCEDES CLS 63 AMG ENGINE COMPATIBILITY
Because the CLS 63 AMG spans three distinct engines across three generations, fitting the wrong replacement — or assuming an M157 part will work on an M177 car — risks a compatibility problem that's expensive to unpick. 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 CLS quote — it protects you from paying for parts that don't fit your actual car.
MERCEDES CLS 63 AMG ENGINES BY YEAR
From the R190's launch in 2023, the CLS 63 AMG 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 CLS 63 AMG 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 CLS 63 AMG MODEL YEAR:
Mercedes CLS 63 AMG
2004 Engine Rebuild
Mercedes CLS 63 AMG
2005 Engine Rebuild
Mercedes CLS 63 AMG
2006 Engine Rebuild
Mercedes CLS 63 AMG
2007 Engine Rebuild
Mercedes CLS 63 AMG
2008 Engine Rebuild
Mercedes CLS 63 AMG
2009 Engine Rebuild
Mercedes CLS 63 AMG
2010 Engine Rebuild
Mercedes CLS 63 AMG
2011 Engine Rebuild
Mercedes CLS 63 AMG
2012 Engine Rebuild
Mercedes CLS 63 AMG
2013 Engine Rebuild
Mercedes CLS 63 AMG
2014 Engine Rebuild
Mercedes CLS 63 AMG
2015 Engine Rebuild
Mercedes CLS 63 AMG
2016 Engine Rebuild
Mercedes CLS 63 AMG
2017 Engine Rebuild
Mercedes CLS 63 AMG
2018 Engine Rebuild
Mercedes CLS 63 AMG
2019 Engine Rebuild
Mercedes CLS 63 AMG
2020 Engine Rebuild
Mercedes CLS 63 AMG
2021 Engine Rebuild
Mercedes CLS 63 AMG
2022 Engine Rebuild
Mercedes CLS 63 AMG
2023 Engine Rebuild
If your registration year isn't listed above, get in touch — we'll confirm availability directly against your reg.
MERCEDES CLS 63 AMG ENGINE COSTS
A Mercedes CLS 63 AMG 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 CLS 63 AMG ENGINE SIZES
• Mercedes CLS 63 AMG 3.0 Litre Engine (M256, I6)
MERCEDES CLS 63 AMG FUEL TYPES
• Mercedes CLS 63 AMG Petrol Mild Hybrid Engine Rebuilds
RELATED MERCEDES CLS VARIANTS
Most Mercedes CLS engine rebuilds are completed within 3-5 working days.
Nationwide recovery and collection available for all CLS models.