Mercedes Garage
Mercedes-AMG Performance Engine Rebuild
Precision rebuilds for AMG engines – M156, M157, M177, M178, M139, and more. Tighter tolerances, performance-grade parts, and full dyno validation to restore or enhance factory power.
15+ yrs
Mercedes specialists
1,800+
engines rebuilt
12 mo
unlimited-mileage warranty
What Sets AMG Engine Rebuilds Apart
- 01
AMG engines are assembled to finer clearances than standard Mercedes units. From crank journals to cylinder bores, every dimension must be measured and machined to AMG OE specifications.
- 02
Unique valvetrain (e.g., M156's bucket tappets, M178's twin-scroll turbos), high-pressure fuel systems, and performance cooling and lubrication systems require specific expertise.
- 03
Cylinder bores, deck surfaces, and crank journals must be finished to tighter roughness and roundness specs. We use CNC-controlled machining and AMG-specified tooling.
- 04
Every AMG rebuild is run on an engine dynamometer under load, including break-in cycles and high-RPM verification. We check oil pressure, fuel delivery, and power output against factory baselines.
AMG Rebuild Pricing
AMG engines require higher-grade parts and more labour – our rebuilds start at: £6,500 for AMG V8 (M156/M157/M177/M178) AMG 4-cylinder (M139) from £3,600
Pricing includes full disassembly, machining, replacement of all wear parts with genuine or OE-spec components, assembly, and dynamometer testing.
Inside our workshop
Mercedes-AMG Performance Engine Rebuild
AMG Models & Engines We Rebuild
We cover the full range of Mercedes-AMG performance engines – from the M139 4-cylinder to the M178 V8 and everything in between.
AMG model families
- A-Class (A35, A45)
- AMG GT (GT, GT S, GT R, GT 63)
- C-Class (C43, C63)
- E-Class (E43, E53, E63)
- S-Class (S63, S65)
- G-Class (G63)
- GLE (GLE53, GLE63)
- GLC (GLC43, GLC63)
- CLS (CLS63)
- SL (SL55, SL63)
AMG engine families
- M139 (4-cyl turbo, A45/CLA45)
- M156 (6.2L V8, pre-2012)
- M157 (5.5L V8 biturbo)
- M177 (4.0L V8 biturbo, current)
- M178 (4.0L V8, AMG GT)
- M159 (6.2L V8, SLS AMG)
Key AMG variants
Our AMG Performance Rebuild Process
- 01
We disassemble the engine to the bare block. Every component is labelled, inspected, and measured against AMG OE tolerances.
- 02
Cylinder bores are honed to the correct cross-hatch pattern, crankshaft journals are polished, and deck surfaces are checked for flatness. All machining is done to AMG-specified tolerances.
- 03
We use genuine or OE-spec performance parts: timing chains, tensioners, guides, bearings, piston rings, valve stem seals, and gaskets. For AMG engines, we also replace turbocharger seals and coolant components where needed.
- 04
Each bolt is torqued to AMG's specific values, using angle-tightening where required. We use AMG-specified sealants and assembly lubricants.
- 05
The rebuilt engine is run on a dyno under load. We perform break-in cycles, check oil pressure, fuel delivery, ignition timing, and verify power output against baseline data.
- 06
After dyno approval, the engine is installed in the vehicle, road-tested, and subjected to a final diagnostic check with Mercedes-Star Diagnostic (Xentry).
Why Choose Mercedes Garage for AMG Rebuilds?
- AMG-trained technicians – our team has extensive experience with AMG engines, including M156, M157, and M177 families.
- In-house machining – we perform all cylinder boring, honing, and crank work to AMG specifications.
- Genuine & OE performance parts – we use only parts that meet AMG's quality standards.
- Dynamometer testing – every rebuild is validated on our engine dyno to confirm power and reliability.
- 12-month unlimited-mileage warranty – see warranty details.
- Learn more about our workshop →
Is an AMG Performance Rebuild Right for You?
- 01
We inspect your AMG engine – compression, leak-down, oil analysis – to determine the scope of work needed. Many AMG engines benefit from a full rebuild after 80,000-100,000 miles.
- 02
We create a tailored rebuild plan covering all wear items, machining, and any upgrades you may want (e.g., stronger head studs, upgraded turbocharger components).
- 03
We carry out the rebuild with our in-house machining and dyno testing, ensuring the engine performs to AMG standards.
- 04
We install the engine, road-test the vehicle, and provide a 12-month unlimited-mileage warranty for your peace of mind.
Frequently Asked Questions
What AMG engines do you rebuild?+
We rebuild all AMG engines: M156 (6.2L V8), M157 (5.5L V8 twin-turbo), M177/M178 (4.0L V8 twin-turbo), M159 (6.2L V8, SLS), and M139 (4-cylinder turbo). We also rebuild older AMG V12 engines (M275) on request.
How is an AMG rebuild different from a standard Mercedes rebuild?+
AMG engines require tighter tolerances, higher-grade materials, and more precise machining. The assembly process is more labour-intensive, and we use AMG-specific torque sequences and sealants. Post-rebuild testing is performed on a dynamometer under high load to validate performance.
Do you address known AMG-specific issues during the rebuild?+
Yes. For M156 engines (pre-2012), we replace camshaft adjusters and upgrade head bolts. For M157/M177 engines, we replace valve stem seals and coolant system components as part of our standard rebuild procedure, addressing known wear patterns.
What parts are replaced during an AMG rebuild?+
We replace timing chains, tensioners, guides, bearings, piston rings, valve stem seals, gaskets, oil pump components, and any worn turbocharger or ancillary parts. We use genuine Mercedes-AMG or OE-spec performance parts exclusively.
How long does an AMG rebuild take?+
Typically 3-5 working days for disassembly, machining, parts procurement, assembly, and dyno testing. Complex builds with custom parts may take longer – we'll give you a precise timeline when you enquire.
What warranty do you offer on AMG rebuilds?+
Our AMG rebuilds come with a 12-month unlimited-mileage warranty covering parts and labour for any workmanship or component defects.