Mercedes CLS 500Engine Rebuild— From £3,200
Model: CLS
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 500 Engine
Vehicle
Mercedes CLS 500
Model
CLS
Variant
CLS 500
Fuel
Petrol
Engine
M273 (C219) or M278 (C218)
Capacity
5.5L (M273) / 4.7L (M278)
Generation
C219 (2004–2010) · C218 (2010–2018)
Rebuild From
£4,500
Not sure which engine you have?
The CLS 500 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 CLS 500Engine Rebuild Price
Starting From £4,500
Engine Code
M273Rebuild From
£4,500
Generation
C219 (2004–2010)
Engine Code
M278Rebuild From
£4,500
Generation
C218 (2010–2018)
Exact price depends on condition and parts required — submit your reg for a fixed-price quote.
Mercedes CLS 500 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 CLS 500 uses a completely different engine family from the V8 M178 fitted to the CLS 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 CLS 500ENGINE OPTIONS
Every CLS 500 is different. That's why we offer the right solution for your engine, your car and your budget.
REBUILDING YOUR CLS 500 ENGINE
We rebuild the engine your CLS 500 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 500 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 500 ENGINES
Restoring your existing engine to full working condition rather than replacing it outright. Our rebuild service covers this.
Learn moreREMANUFACTURED CLS 500 ENGINES
Built to original specification with updated components. That's consistent with what our rebuild service delivers on the M256.
Learn moreREPLACEMENT CLS 500 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 500 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 500, 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 500 rebuild looks like.
Mercedes CLS 500 ENGINE REBUILD PROCESS
WHAT MERCEDES CLS 500 OWNERS SAY
WE COVER YOUREXACT VEHICLE
Enter your registration below and we'll confirm your CLS 500 has the M256, along with an exact rebuild price.
WHY MERCEDES CLS 500 OWNERS CHOOSE US
Engine matched using VIN or registration number — confirms M273 vs 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
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 500
RECOVERY
Mercedes CLS 63
DIAGNOSTICS
Mercedes CLS
STRIPPED ENGINE
Mercedes CLS S
TIMING CHAIN REPLACEMENT
Mercedes CLS 500
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 500 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 500 ENGINE
The CLS 500 was a V8-powered mainstay of the original CLS range, spanning two generations from 2004 to 2018. The first-generation C219 (2004–2010) uses the M273 — a 5.5-litre naturally aspirated V8. The second-generation C218 (2010–2018) switched to the M278, a 4.7-litre twin-turbo V8 — a genuinely different engine with a different character and layout. Knowing which one your car has matters, because the components and rebuild specifics differ between them — which is exactly why we confirm your exact engine by registration before quoting.
We continue to rebuild and replace M256 engines for every CLS 500 on the road.
MERCEDES CLS 500 ENGINE CODES
M273 (C219, 2004–2010)
A 5.5-litre naturally aspirated V8 fitted to the first-generation CLS 500. No specific known issue has been independently confirmed for this engine in this application.
Check Your M273 CLS 500M278 (C218, 2010–2018)
A 4.7-litre twin-turbo V8 fitted to the second-generation CLS 500. No specific known issue has been independently confirmed for this engine in this application.
Check Your M278 CLS 500MERCEDES CLS 500 ENGINE COMPATIBILITY
Because the CLS 500 spans two distinct V8 engines across two generations, fitting the wrong replacement — or assuming an M273 part will work on an M278 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 500 ENGINES BY YEAR
From the R190's launch in 2023, the CLS 500 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 500 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 500 MODEL YEAR:
Mercedes CLS 500
2004 Engine Rebuild
Mercedes CLS 500
2005 Engine Rebuild
Mercedes CLS 500
2006 Engine Rebuild
Mercedes CLS 500
2007 Engine Rebuild
Mercedes CLS 500
2008 Engine Rebuild
Mercedes CLS 500
2009 Engine Rebuild
Mercedes CLS 500
2010 Engine Rebuild
Mercedes CLS 500
2011 Engine Rebuild
Mercedes CLS 500
2012 Engine Rebuild
Mercedes CLS 500
2013 Engine Rebuild
Mercedes CLS 500
2014 Engine Rebuild
Mercedes CLS 500
2015 Engine Rebuild
Mercedes CLS 500
2016 Engine Rebuild
Mercedes CLS 500
2017 Engine Rebuild
Mercedes CLS 500
2018 Engine Rebuild
If your registration year isn't listed above, get in touch — we'll confirm availability directly against your reg.
MERCEDES CLS 500 ENGINE COSTS
A Mercedes CLS 500 engine rebuild starts from
£4,500
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 500 ENGINE SIZES
• Mercedes CLS 500 3.0 Litre Engine (M256, I6)
MERCEDES CLS 500 FUEL TYPES
• Mercedes CLS 500 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.