M139 ENGINEREBUILD & REPLACEMENT
Specialist Mercedes-AMG M139 engine rebuilds and replacements, fitted across the A 45 AMG, CLA 45 AMG, GLA 45 AMG, C 43 AMG, GLC 43 AMG and SL 43. Nationwide recovery, registration-based engine matching, 12-month unlimited-mileage warranty.
Rated AMG 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
Fitted Across 6 AMG Models
Starting from
£3,600
Mercedes-AMG M139Engine Specifications
Engine Code
M139
Manufacturer
Mercedes-AMG
Configuration
Inline-4 (I4)
Capacity
2.0L (1,991 cc)
Fuel
Petrol
Production Years
2019–present
Used In
6 Mercedes-AMG models
Not sure if your Mercedes has this engine?
Enter your registration and we'll confirm.
Mercedes-AMG M139Engine Rebuild Price
Starting From
£3,600
All M139 applications use the same 2.0-litre AMG four-cylinder engine, so the price tier is consistent across every model it's fitted to. Exact price depends on condition and parts required — submit your reg for a fixed-price quote.
Get Your Fixed-Price Quote →
Mercedes-AMG M139 Applications — Every Model & Variant
Model
Variant
Generation
Chassis
Years
Powertrain Sub-type
Not seeing your exact model?
Send us your registration and we'll confirm.
Mercedes-AMG M139 Rebuild Components
Timing Chain
We inspect and replace timing chain components as standard during a rebuild.
Bearings
We replace main bearings and connecting rod bearings as standard during a rebuild.
Gaskets & Seals
We replace all gaskets and seals as standard during a rebuild.
Twin-Scroll Turbocharger
The M139's twin-scroll turbocharger is a key component that is removed, inspected, and refurbished or replaced as part of the rebuild.
Additional Inspected Components
Fuel injectors, high-pressure fuel pump, PCV system, timing chain tensioners and guides, and cooling system components are all measured and inspected.
Components drawn directly from VRF Key Components data. If your M139's exact ancillary set isn't covered above, we confirm the full scope once your engine is inspected — not guessed in advance.
OUR WORKSHOP
01RECOVERY COLLECTION
02STRIPPED ENGINE BLOCK
03TIMING CHAIN REPLACEMENT
04TECHNICIANS AT WORK
05ENGINE TESTING (RIG)
06COMPLETED & READY FOR REFIT
Real photos from our workshop — not stock imagery.
WHAT MERCEDES-AMG OWNERS SAY
WE COVER YOUREXACT VEHICLE
Enter your registration below and we'll confirm whether your Mercedes has the M139 before you're quoted anything.
WHY CHOOSE US FOR MERCEDES-AMG M139 REBUILDS
Engine matched using VIN or registration number
Confirms M139 before you're quoted
We don't swap your engine for an unknown used unit
Every engine is rebuilt properly
All engine ancillaries serviced as part of the rebuild
Everything inspected and renewed
Genuine specialist workshop — not a broker
We rebuild engines in-house
Nationwide recovery, workshop rebuild
From collection to road-ready
Trade & public enquiries welcome
We work with everyone
Specialist technicians with 10-15 years of experience
Skilled, trained and experienced
12 month unlimited-mileage warranty
For complete peace of mind
Dedicated advisor from quote to fit
One point of contact, always
No widely-reported pattern is confirmed for the M139 — we still recommend a full inspection before any long journey.
AMGMERCEDES-AMG M139 ENGINE REBUILD PROCESS
OUR MOST RECENTMERCEDES-AMG 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.
AMG A45 (M139)
RECOVERY
AMG A35 (M260)
DIAGNOSTICS
AMG A45 (M139)
STRIPPED ENGINE
AMG E63 (M177)
TIMING CHAIN REPLACEMENT
AMG C63 (M177)
IN FOR REBUILD
AMG A45 (M139)
REBUILD IN PROGRESS
HOW IT WORKS
SEND YOURREGISTRATION
RECEIVE YOURFIXED-PRICE QUOTE
WE RECOVERYOUR CAR
REBUILD &REFIT
Most cars 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.
AMGABOUT THE
MERCEDES-AMGM139 ENGINE
The M139 is the most powerful four-cylinder engine ever offered from the factory, developed by Mercedes-AMG. In S guise, it produces 421 hp from just 2.0 litres. It's the heart of the current-generation 45-series AMG models (A 45, CLA 45, GLA 45) and has more recently been adopted for the 43-series models (C 43, GLC 43) and the entry-level SL 43.
MERCEDES-AMG M139
APPLICATIONS BY MODEL
The M139 is deployed across the A-Class (A 45 AMG / A 45 S AMG, W177), the CLA (CLA 45 AMG / CLA 45 S AMG, C118), and the GLA-Class (GLA 45 AMG / GLA 45 S AMG, H247). These form the core of the high-performance M139 range. More recently, the engine has been adopted for the C-Class (C 43 AMG, W206), the GLC-Class (GLC 43 AMG, X254), and the SL roadster (SL 43, R232), proving the M139's versatility across different vehicle types.
MERCEDES-AMG M139
ENGINE COMPATIBILITY
Because the M139 is fitted to six different models — from the compact A-Class to the grand-touring SL roadster — compatibility comes down to confirming your exact model, generation, and specific AMG variant (e.g., "45" vs "45 S" vs "43"). A M139 from an A 45 AMG isn't a drop-in match for a M139 from an SL 43 — ancillaries and mounting differ.
We confirm by registration/VIN before quoting or supplying anything.
MODEL
Confirm your exact model and AMG variant.
GENERATION
Identify the correct generation (W177, C118, H247, W206, X254, R232).
DRIVETRAIN
Specify the variant (45, 45 S, 43).
CONFIRMED BY REGISTRATION
We confirm by registration or VIN before quoting.
AMGMERCEDES-AMG M139
APPLICATIONSWE WORK ON
The M139 is at the heart of some of Mercedes-AMG's most exciting models. From the compact A-Class hot hatch to the refined SL roadster, we work on every M139 application with precision and care.
M139 in the A-Class (W177)
The M139 in the A-Class is one of the most common applications we see — the A 45 AMG and the A 45 S AMG (W177, 2019–present).
Starting from
£3,600
M139 in the CLA (C118)
The M139 in the CLA is one of the applications we work on regularly — the CLA 45 AMG and the CLA 45 S AMG (C118, 2019–present).
Starting from
£3,600
M139 in the GLA-Class (H247)
The M139 in the GLA-Class is one of the applications we work on — the GLA 45 AMG and the GLA 45 S AMG (H247, 2020–present).
Starting from
£3,600
M139 in the C-Class, GLC-Class & SL (W206, X254, R232)
The M139 is the performance engine of choice in the current C 43 AMG (W206), the GLC 43 AMG (X254), and the entry-level SL 43 (R232) — applications we work on regularly.
Starting from
£3,600
Not seeing your exact model above?
Send us your registration and we'll confirm your exact spec.
MERCEDES-AMG M139
BY POWERTRAIN VARIANT
The M139 is available in two power variants. Choose the specification that matches your vehicle to ensure correct compatibility and performance.
STANDARD M139
382 HPApplications: A 45 AMG, C 43 AMG, CLA 45 AMG, GLA 45 AMG, GLC 43 AMG, SL 43.
This is the 382 hp version of the engine.
M139 S
421 HPApplications: A 45 S AMG, CLA 45 S AMG, GLA 45 S AMG.
The 'S' designation denotes the more powerful 421 hp variant.
Not seeing your exact model above?
Send us your registration and we'll confirm your exact spec.
AMGOUR WORKSHOP VIEW OF
THE MERCEDES-AMG M139
Built, rebuilt and tested by engineers who work on Mercedes-AMG engines every day.
Here's our practical view of the M139 across all six model applications.
Note: engine-specific case studies with real job details are not yet included on this page — they'll be added once a documented set of completed M139 rebuilds is available to draw from, rather than filled with placeholder examples now.
A TYPICAL
MERCEDES-AMG M139 REBUILD
The following describes a typical rebuild scope for this engine — illustrative of the work involved, not a specific customer job. Real case studies from our own completed work will replace this section once available.
The M139 is a highly-strung, high-performance engine, and its twin-scroll turbocharger is a central component in its design. A full rebuild involves removing and inspecting the turbocharger, replacing timing chain components, bearings, gaskets, and calibrating the two-stage fuel injection system (direct and port injection). Given its 421 hp output in S guise, the engine's components are stressed to a high degree, and we pay particular attention to the crankshaft and cylinder head during inspection.
Typical Scope:
Timing chain, bearings, gaskets, twin-scroll turbocharger inspection/refurbishment, calibration of fuel injection system
Starting From:
£3,600
AMGMERCEDES-AMG M139
ENGINE REBUILD COST
A Mercedes-AMG M139 engine rebuild starts from £3,600, regardless of which of the six models it's fitted to — the price tier is set by the engine, not the badge on the boot. 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.
Starting From
£3,600
MERCEDES-AMG M139
REBUILD VS REPLACEMENT VS USED
Rebuilding Your M139 Engine
Most engine suppliers sell you a used engine of unknown history and hope it matches. We rebuild the engine your Mercedes already has instead — strip it down, pressure-test it, and replace every worn or damaged component with updated OEM parts. You get a near-new engine with a 12-month unlimited-mileage warranty, without the compatibility risk of an unknown used unit. This is the option most M139 owners choose.
Replacement M139 Engines
If your existing engine is beyond economical repair, we also offer full engine replacement and fitting — sourced and fitted by our team, with the same 12-month unlimited-mileage warranty.
Used M139 Engines
In some cases, a matched low-mileage used engine is the right call — particularly if you need your car back on the road quickly and your existing engine's damage is extensive. We can source and fit these too, though most owners who ask about used engines end up choosing a rebuild once they understand the compatibility risk a used unit carries.
MERCEDES-AMG M139
RECONDITIONED ENGINES
"Reconditioned" is the term many owners search for when they mean the same thing as a rebuild — 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.
MERCEDES-AMG M139
REFURBISHED ENGINES
"Refurbished" often describes the same process from a different angle — restoring your existing engine to full working condition rather than replacing it outright. Our rebuild covers this.
MERCEDES-AMG M139
REMANUFACTURED ENGINES
Some owners specifically search for a "remanufactured" engine, expecting a unit rebuilt to original specification with updated components. That's consistent with what our rebuild service delivers, regardless of which of the six M139-equipped models you drive.
FREQUENTLY ASKED QUESTIONS
GET YOUR FREEMERCEDES-AMG M139FIXED-PRICE QUOTE
Most quotes returned within 30 minutes during working hours.