Mercedes-BenzMERCEDES GARAGEMERCEDES ENGINE SPECIALISTS
Mercedes-AMG technician rebuilding an M139 engine block
AMG

OM668 ENGINEREBUILD & REPLACEMENT

Specialist Mercedes-Benz OM668 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 Mercedes-Benz 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

£2,200

Get a Fixed-Price Quote →Call Our Specialists: 0203 488 4649
Mercedes-AMG M139 engine

Mercedes-AMG M139Engine Specifications

Engine Code

OM668

Manufacturer

Mercedes-Benz

Configuration

Inline-4 (I4)

Capacity

2.0L (1,991 cc)

Fuel

Petrol

Production Years

2019–present

Used In

6 Mercedes-Benz models

Not sure if your Mercedes has this engine?

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Mercedes-AMG M139Engine Rebuild Price

Mercedes-AMG M139 engine components

Starting From

£2,200

All OM668 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-Benz OM668 Applications Every Model & Variant

Model

Variant

Generation

Chassis

Years

Powertrain Sub-type

Mercedes-BenzA-Class

A 45 AMG

W177

W177

2019–present

Petrol

Mercedes-BenzA-Class

A 45 S AMG

W177

W177

2019–present

Petrol

Mercedes-BenzC-Class

C 43 AMG

W206

W206

2023–present

Petrol

Mercedes-BenzCLA

CLA 45 AMG

C118

C118

2019–present

Petrol

Mercedes-BenzCLA

CLA 45 S AMG

C118

C118

2019–present

Petrol

Mercedes-BenzGLA-Class

GLA 45 AMG

H247

H247

2020–present

Petrol

Mercedes-BenzGLA-Class

GLA 45 S AMG

H247

H247

2020–present

Petrol

Mercedes-BenzGLC-Class

GLC 43 AMG

X254

X254

2023–present

Petrol

Mercedes-BenzSL

SL 43

R232

R232

2023–present

Petrol

Not seeing your exact model?

Send us your registration and we'll confirm.

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Mercedes-Benz OM668 Rebuild Components

Timing Chain

Timing Chain

We inspect and replace timing chain components as standard during a rebuild.

Bearings

Bearings

We replace main bearings and connecting rod bearings as standard during a rebuild.

Gaskets & Seals

Gaskets & Seals

We replace all gaskets and seals as standard during a rebuild.

Twin-Scroll Turbocharger

Twin-Scroll Turbocharger

The OM668's twin-scroll turbocharger is a key component that is removed, inspected, and refurbished or replaced as part of the rebuild.

Additional Inspected Components

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 OM668's exact ancillary set isn't covered above, we confirm the full scope once your engine is inspected — not guessed in advance.

OUR WORKSHOP

RECOVERY COLLECTION01

RECOVERY COLLECTION

STRIPPED ENGINE BLOCK02

STRIPPED ENGINE BLOCK

TIMING CHAIN REPLACEMENT03

TIMING CHAIN REPLACEMENT

TECHNICIANS AT WORK04

TECHNICIANS AT WORK

ENGINE TESTING (RIG)05

ENGINE TESTING (RIG)

COMPLETED & READY FOR REFIT06

COMPLETED & READY FOR REFIT

Real photos from our workshop — not stock imagery.

WHAT MERCEDES-BENZ OWNERS SAY

Daniel R.

Brilliant service from start to finish. My A 45 AMG runs better than it ever has. Honest advice, clear pricing and the team know their stuff.

A 45 AMG – OM668 Rebuild

Mark T.

They rebuilt my CLA 45 AMG engine with all the updated parts. No more rattling chains. Smooth process and great communication.

CLA 45 AMG – OM668 Rebuild

Ryan P.

Top lads, top job. Picked up and dropped off, engine rebuilt to an extremely high standard. 100% recommend.

A 45 S AMG – OM668 Rebuild

Steve B.

Saved me thousands compared to a main dealer quote. Fantastic workmanship and my GLA 45 AMG is running perfectly.

GLA 45 AMG – OM668 Rebuild

Tom H.

From quote to collection couldn't fault them. Engine looks brand new inside. Warranty gives great peace of mind.

C 43 AMG – OM668 Rebuild

WE COVER YOUREXACT VEHICLE

Enter your registration below and we'll confirm whether your Mercedes has the OM668 before you're quoted anything.

GB
FastAccurateNo Guesswork

WHY CHOOSE US FOR MERCEDES-BENZ OM668 REBUILDS

Engine matched using VIN or registration number

Confirms OM668 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 OM668 — we still recommend a full inspection before any long journey.

Mercedes-BenzAMG

MERCEDES-BENZ OM668 ENGINE REBUILD PROCESS

1Diagnosis

We confirm your exact model, generation and assess the damage.

2Removal

Your engine is removed and brought into our workshop.

3Strip-Down

Every component is removed for individual inspection.

4Inspection

Crankshaft, cylinder head, timing chain, twin-scroll turbo, and bearings are all checked.

5Machine Work

Any machining required is carried out to OEM tolerances.

6Component Replacement

Worn or damaged parts are replaced with updated OEM components.

7Reassembly

Your engine is rebuilt to original specification.

8Testing

Every rebuild is pressure-tested before refit.

9Refit

Your engine goes back into your Mercedes-Benz.

10Road Test

A full road test confirms everything's right before we hand your car back.

OUR MOST RECENTMERCEDES-BENZ 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 (OM668)

AMG A45 (OM668)

RECOVERY

AMG A35 (M260)

AMG A35 (M260)

DIAGNOSTICS

AMG A45 (OM668)

AMG A45 (OM668)

STRIPPED ENGINE

AMG E63 (M177)

AMG E63 (M177)

TIMING CHAIN REPLACEMENT

AMG C63 (M177)

AMG C63 (M177)

IN FOR REBUILD

AMG A45 (OM668)

AMG A45 (OM668)

REBUILD IN PROGRESS

HOW IT WORKS

1

SEND YOURREGISTRATION

2

RECEIVE YOURFIXED-PRICE QUOTE

3

WE RECOVERYOUR CAR

4

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.

Mercedes-BenzAMG

ABOUT THE

MERCEDES-BENZOM668 ENGINE

Mercedes-AMG M139 engine on workshop stand

The OM668 is the most powerful four-cylinder engine ever offered from the factory, developed by Mercedes-Benz. 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-BENZ OM668

APPLICATIONS BY MODEL

Mercedes-AMG lineup in showroom

The OM668 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 OM668 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 OM668's versatility across different vehicle types.

MERCEDES-BENZ OM668

ENGINE COMPATIBILITY

Because the OM668 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 OM668 from an A 45 AMG isn't a drop-in match for a OM668 from an SL 43 — ancillaries and mounting differ.

We confirm by registration/VIN before quoting or supplying anything.

Mercedes-AMG M139 engine compatibility scan

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.

Mercedes-BenzAMG

OUR WORKSHOP VIEW OF

THE MERCEDES-BENZ OM668

Built, rebuilt and tested by engineers who work on Mercedes-Benz engines every day.

Here's our practical view of the OM668 across all six model applications.

APPLICATIONS WE SEE:

The OM668 is a relatively new engine, and we see it across the entire range of its applications — from the compact 45-series AMGs to the more recent 43-series models and the SL 43.

WHAT WE REPLACE:

Bearings, timing chain components, gaskets, and twin-scroll turbocharger components as standard. We also inspect and measure the cylinder head, crankshaft, and other critical components.

KNOWN ISSUES:

No widely-reported pattern is confirmed for the OM668 across any of its six applications. We don't treat this engine as having one universal failure mode; diagnosis is required to establish whether an engine needs repair, rebuild, or replacement.

i

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 OM668 rebuilds is available to draw from, rather than filled with placeholder examples now.

A TYPICAL

MERCEDES-BENZ OM668 REBUILD

Mercedes-AMG M139 exploded engine components

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 OM668 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:

£2,200

Check OM668 Rebuild Options →
Mercedes-BenzAMG

MERCEDES-BENZ OM668

ENGINE REBUILD COST

Mercedes-AMG M139 engine

A Mercedes-Benz OM668 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

£2,200

MERCEDES-BENZ OM668

REBUILD VS REPLACEMENT VS USED

Rebuilding Your OM668 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 OM668 owners choose.

Replacement OM668 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 OM668 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.

Ask About Your Options →

MERCEDES-BENZ OM668

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-BENZ OM668

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-BENZ OM668

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 OM668-equipped models you drive.

FREQUENTLY ASKED QUESTIONS

GET YOUR FREEMERCEDES-BENZ OM668FIXED-PRICE QUOTE

Most quotes returned within 30 minutes during working hours.