M Class Diesel Engines
from £1,800 to £4,500
Rebuilt units from £1,800 · Common codes: OM642.DE30.LA, OM647, OM648, OM629
Mercedes-Benz ENGINE MARKETPLACE
Mercedes M Class M272/OM642/M276 Engine Solutions - UK Specialists
Get quotes from trusted UK Mercedes M Class engine specialists. Compare reconditioned & used engines for ML 250 to ML 63 AMG - M272/OM642/M276 covered. Get a quote before it's too late.
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12-Month Warranty
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M Class Petrol Engines
from £2,200 to £5,200
Rebuilt units from £2,200 · Common codes: M272.9xx, M273.9xx, M276, M112
M Class AMG Engines
from £4,500 to £12,000
Rebuilt units from £4,500 · Common codes: M156, M157, M113K
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Supply & fit available - parts and labour from vetted specialistsInstant engine replacement quote - 100% free, no obligationEngine replacement near me - UK-wide specialist networkCompare reconditioned, rebuilt & used engine pricesSupply & fit available - parts and labour from vetted specialistsHow It Works
3 Simple Steps3 Simple Stepsto Finding the Best Mercedes Benz M Class Replacement Engineto Finding the Best Mercedes Benz M Class Replacement Engine
12-Month Warranty
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Most replacements completed within 3-5 days.
Live UK Engine Market Data
What Are UK Drivers Paying for Mercedes-Benz M Class Engine Replacement
The table below shows typical UK rebuilt engine costs across Mercedes-Benz M Class variants, covering documented failure causes, chassis generations, engine codes, and fuel types based on current market data.
Average Market Prices
↻ Last updated: 4 Aug 26, 9:26
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Variants We Cover
Mercedes-Benz M Class Engine ReplacementAll Variants Covered
Not sure which variant your Mercedes-Benz M Class is- Enter your registration number above - we'll identify the exact sub-model, engine code and compatible replacement options instantly.
M Class
Engine Codes
Mercedes-Benz M Class Engine CodesFull Technical Specifications & Replacement Guide
Every engine code fitted to the Mercedes-Benz M Class across all generations, with technical specs, compatible variants and trims, known failure points, and average rebuilt prices from UK specialists. Select any engine code to compare quotes.
Diesel Engines
Extracted from detailed diesel engine families across Mercedes Benz M Class variants.
OM647 - 2.7L Diesel
Main replacement triggers are timing chain wear, EGR / cooling faults and turbo-control issues.
Compatible variants
ML 270 CDIML 270 CDI EleganceML 270 CDI Avantgarde
Avg. rebuilt price
£1,800 - £2,600
Supply only
Technical specifications
- Fuel type
- Diesel
- Engine size
- 2.7L
- Power output
- 163 hp
- Years fitted
- 1999-2005
Common failures
- ●Main replacement triggers are timing chain wear, EGR / cooling faults and turbo-control issues.
- ●Confirm exact engine code and fitment before ordering.
- ●Ask for warranty and supply & fit terms.
Not sure which engine code?
Can’t find your engine code- Enter your registration number above - we’ll instantly identify the exact unit, its technical specifications, and live replacement prices from UK Mercedes-Benz M Class engine specialists. Every rebuilt engine comes with a minimum 12-month unlimited mileage warranty.
M Class
Common Problems
Mercedes-Benz M Class Engine Problems - What It Costs to Fix & When Replacement Makes Sense
Mercedes-Benz M Class OM642 Oil Cooler Leak - Why ML 350 CDI Engines Fail Prematurely
Mercedes-Benz M Class OM642 Oil Cooler Leak
Most affected vehicles
Mercedes-Benz M Class ML 280 CDIML 300 CDI
Mercedes-Benz M Class ML 280 CDI, ML 300 CDI, ML 350 CDI (2005-2015, OM642.DE30.LA)
Failure mileage range
60,000 - 90,000 miles
Typical failure window
Root cause
The OM642 oil cooler gaskets and plastic filter housing degrade under prolonged thermal cycling, causing high-pressure oil to seep into the cylinder head valley and eventually contaminate coolant or strip drive belts.
Repair options & estimated costs (UK ranges)
| Repair tier | Dealer price | Specialist price | What it involves | Longevity / suitability |
|---|---|---|---|---|
| Minor - Preventative Seal & Housing Update | £800 - £1,200 | £550 - £850 | Draining coolant/oil, replacing revised Mercedes-spec gasket kit, updated plastic housing, and pressure testing the cooling circuit. | Solves early-stage seepage permanently when caught before cross-contamination. Not viable once oil enters the coolant system. |
| Major - Cooler Assembly & Head Cleanout | £2,800 - £4,200 | £1,900 - £2,800 | Full valley strip-down, chemical degreasing of cylinder head surfaces, cooler core replacement, and updated EGR cooler integration. | Restores factory sealing but carries residual risk if microscopic coolant ingress damaged head gasket surfaces. |
| Full Replacement - Rebuilt / Reconditioned Engine | £7,000 - £9,500 | £3,500 - £5,200 | Supply & fit of a dyno-tested OM642 unit with reinforced cooler seals, upgraded tensioners, and bench-verified EGR calibration. | Eliminates legacy thermal weakness completely. Ideal for vehicles with prior overheating or hydrolock symptoms. |
Our recommendation
Address OM642 seepage at the first sign of dampness in the engine valley. If caught early, a specialist seal update with revised gaskets resolves the issue for under £1,000. Once oil migrates into the cooling system or timing covers, cross-contamination makes partial repair a false economy, and a full Mercedes-Benz M Class engine replacement becomes the only reliable path.
Compare rebuilt OM642 engine prices for your Mercedes-Benz M ClassReplacement Engine Options
Mercedes-Benz M Class Engine TypesOptions, Costs & What to Expect
Every engine type is available through the UK network with typical price ranges based on variant, engine code and budget.
Mercedes-Benz M Class Reconditioned Engines (Recon)£2,200 - £4,200((supply only))
Mercedes-Benz M Class Rebuilt Engines£2,400 - £4,800((supply only))
Mercedes-Benz M Class Used Engines£1,200 - £2,800((supply only))
Mercedes-Benz M Class Remanufactured Engines£3,500 - £6,500((supply only))
Mercedes-Benz M Class Refurbished Engines£1,800 - £3,600((supply only))
Compare Mercedes Benz M Class engine prices with vetted UK suppliers
All engine types include a minimum 12-month unlimited mileage warranty when sourced through EngineMarket. Prices are typical UK market ranges based on historical quote data from our network and depend on exact engine code, variant, mileage and supplier. Use our free comparison tool above - enter your registration to get tailored quotes for your specific Mercedes-Benz M Class within hours.
Engine Sizes
Mercedes-Benz M Class Engines by SizeFind the Right Displacement for Your Variant
Every factory-fitted displacement across the Mercedes-Benz M Class range is listed below, complete with compatible engine codes, production years, and documented failure notes to help you identify the correct replacement unit.
The 2.7-litre inline-five established the entry point for the W163 generation, delivering reliable low-end torque for urban driving and light towing throughout its UK production run. Its common-rail architecture offered improved refinement over earlier indirect-injection units while maintaining robust mechanical durability for high-mileage ownership.
⚙
Engine Code(s)
OM647
▣
Compatible Models (UK)
ML 270 CDI
ϟ
Power output
Verified by registration
△
Common Failure Points
Injector copper seal leakage, turbocharger VNT actuator arm wear at higher mileage
Production Years: W163, 1999-2005
Get quotes for Mercedes-Benz M Class 2.7L diesel enginesMercedes-Benz M Class Engines Fuel Type
Mercedes-Benz M Class Engines by Fuel Type
Mercedes-Benz M Class Diesel Engines
DieselDiesel CDI and BlueTEC units power the majority of UK M Class replacements, spanning the OM647 inline-five through to the dominant OM642 V6 across W163, W164 and W166 generations.
Common Mercedes-Benz M Class Diesel Engine Families
- •OM642 - dominant 3.0L V6 (ML 350 CDI), oil cooler seal weakness per TSB LI01.40-P-059842
- •OM647 - reliable 2.7L inline-five (ML 270 CDI W163), injector seal wear at high mileage
- •OM648 - smooth 3.2L inline-six (ML 320 CDI W163), EGR cooler gasket failure common
Found In
- •W163 (1997-2005) - OM647 2.7L, OM648 3.2L
- •W164 (2005-2011) - OM642 3.0L, OM628/OM629 4.0L V8
- •W166 (2011-2019) - OM642 3.0L BlueTEC Euro 5/6
Known For
- •Exceptional motorway fuel economy and towing capability across all generations
- •OM642 oil cooler/filter housing seal degradation at 60k-90k miles (high-volume repair)
- •Strong UK replacement demand on ML 350 CDI due to fleet prevalence and private ownership
Typical Diesel Models
- •ML 270 CDI
- •ML 320 CDI
- •ML 280 CDI
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Mercedes-Benz M Class Diesel Engines
DieselDiesel CDI and BlueTEC units power the majority of UK M Class replacements, spanning the OM647 inline-five through to the dominant OM642 V6 across W163, W164 and W166 generations.
Common Mercedes-Benz M Class Diesel Engine Families
- •OM642 - dominant 3.0L V6 (ML 350 CDI), oil cooler seal weakness per TSB LI01.40-P-059842
- •OM647 - reliable 2.7L inline-five (ML 270 CDI W163), injector seal wear at high mileage
- •OM648 - smooth 3.2L inline-six (ML 320 CDI W163), EGR cooler gasket failure common
Found In
- •W163 (1997-2005) - OM647 2.7L, OM648 3.2L
- •W164 (2005-2011) - OM642 3.0L, OM628/OM629 4.0L V8
- •W166 (2011-2019) - OM642 3.0L BlueTEC Euro 5/6
Known For
- •Exceptional motorway fuel economy and towing capability across all generations
- •OM642 oil cooler/filter housing seal degradation at 60k-90k miles (high-volume repair)
- •Strong UK replacement demand on ML 350 CDI due to fleet prevalence and private ownership
Typical Diesel Models
- •ML 270 CDI
- •ML 320 CDI
- •ML 280 CDI
Mercedes-Benz M Class Petrol Engines
PetrolPetrol V6 and V8 units deliver refined performance across all M Class generations, from the robust M112/M113 classics to the direct-injection M276 and high-output AMG M156/M157 powerplants.
Common Mercedes-Benz M Class Petrol Engine Families
- •M272 - 3.5L V6 (ML 350 W164), balance shaft idler gear failure on early pre-2008 units
- •M276 - 3.5L direct-injection V6 (ML 350 W166), improved efficiency with intake carbon buildup risk
- •M273 - 5.5L V8 (ML 500 W164), timing chain guide wear and cam adjuster magnet degradation
Found In
- •W163 (1997-2005) - M112 3.2L/3.7L, M113 5.0L/5.4L, M113K 5.4L supercharged (ML 55 AMG)
- •W164 (2005-2011) - M272 3.5L, M273 5.5L, M156 6.2L (ML 63 AMG)
- •W166 (2011-2019) - M276 3.5L, M278 4.6L biturbo, M157 5.5L biturbo (ML 63 AMG)
Known For
- •Smooth, refined power delivery with strong mid-range torque across V6 and V8 configurations
- •M272 balance shaft catastrophic failure risk on early W164 ML 350 petrol (TSB LI01.20-P-058990)
- •M273/M113 timing chain guide plastic degradation requiring preventative inspection at 80k+ miles
Typical Petrol Models
- •ML 320 / ML 350 Petrol
- •ML 370 (US-spec, limited UK)
- •ML 500
Mercedes-Benz M Class Hybrid / Electrified Engines
MHEVThe Mercedes-Benz M Class was not offered with hybrid, plug-in hybrid, mild-hybrid or electric powertrains in the UK market during its 1997-2019 production run.
Mercedes-Benz M Class Electrified Engine Codes
- •None - no factory-fitted hybrid or electric variants were sold in the UK for this model
- •All UK M Class models use conventional combustion engines with automatic transmission and 4MATIC AWD option
- •No battery-electric drive units, starter-generators or plug-in charging systems to maintain or replace
Found In
- •Not applicable - no electrified M Class variants in UK specification
Important Notes
- •If your M Class has a 48-volt or hybrid badge, verify via registration - it may be a later GLE rebrand (post-2019)
- •Standard diesel/petrol engine replacement procedures apply to all UK M Class models
- •Specialist suppliers focus on OM642, M272, M276, M156 and M157 codes for this generation
Not sure which fuel type your Mercedes-Benz M Class has- Enter your registration number above to instantly identify your engine code, fuel system and compatible replacement options - all backed by a minimum 12-month unlimited mileage warranty from UK Mercedes-Benz M Class specialists.
Engine YearsGet quotes for 1997-2001 Mercedes-Benz M Class replacement engines →
Mercedes-Benz M Class Engines by YearWhat Was Fitted & WhenMercedes-Benz M Class Engines by Year - What Was Fitted & When
This technical timeline covers every major engine change across the Mercedes-Benz M Class production run (1997-2019), organised so owners can quickly identify their engine code, generation and compare rebuilt engine prices from UK specialists.
⚙Key Changes
- ✓Launch of Mercedes-Benz first dedicated SUV platform with permanent 4MATIC all-wheel drive option
- ✓Introduction of OM647 2.7L inline-five diesel and M112 3.2L V6 petrol as core powertrains
- ✓ML 55 AMG variant launched with supercharged M113K 5.4L V8 for performance flagship positioning
▣Main Engines
OM647- 2.7L diesel (ML 270 CDI)
M112.E32- 3.2L petrol (ML 320)
M113.E50- 5.0L petrol (ML 500)
M113K.E54- 5.4L supercharged petrol (ML 55 AMG)
▰Popular Models
- •Mercedes-Benz ML 270 CDI
- •Mercedes-Benz ML 320
- •Mercedes-Benz ML 430
- •Mercedes-Benz ML 500
- •Mercedes-Benz ML 55 AMG
🔧Known For
- ✓Robust mechanical architecture with straightforward servicing requirements for classic SUV restoration
- ✓OM647 injector copper seal degradation at 70k+ miles requiring specialist copper washer replacement
- ✓M113 timing chain guide plastic becoming brittle with age - inspect before high-mileage purchase
- ✓Strong enthusiast community support for W163 parts availability and technical documentation
Engine Codes Covered:
OM647M112.E32M113.E50M113K.E54Not sure which year your Mercedes-Benz M Class was built- Enter your registration number and we'll identify the exact engine, model year, and compatible replacement options instantly - all backed by a minimum 12-month warranty from UK Mercedes-Benz M Class specialists.
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