GLS 3.0 V6 Diesel Engines
from £3,400 to £5,500
Rebuilt units from £3,400 · Common codes: OM642, 642.826, 642.850, OM642.826 BlueTEC
Mercedes-Benz ENGINE MARKETPLACE
Mercedes GLS M176/OM654/M256 Engine Solutions - UK Specialists
Get quotes from trusted UK Mercedes GLS engine specialists. Compare reconditioned & used engines for GLS 350 to GLS 63 AMG - M176/OM654/M256 covered. Get a quote before it's too late.
Supply & Fit Available
12-Month Warranty
Nationwide Delivery
100+ Suppliers
GLS 3.0-4.0 Petrol Engines
from £4,200 to £7,800
Rebuilt units from £4,200 · Common codes: M256, M276, M278, M272
GLS 63 AMG Performance Engines
from £6,000 to £12,500
Rebuilt units from £6,000 · Common codes: M177, M176, M157, 177.980
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Compare reconditioned, rebuilt & used engine prices
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 GLS Replacement Engineto Finding the Best Mercedes Benz GLS Replacement Engine
12-Month Warranty
Supply & Fit Available
Nationwide Delivery
Trusted UK Suppliers
Most replacements completed within 3-5 days.
Live UK Engine Market Data
What Are UK Drivers Paying for Mercedes-Benz GLS Engine Replacement
Shows typical UK rebuilt engine costs for Mercedes-Benz GLS variants with documented failures, engine codes, fuel types and sizes from market data.
Average Market Prices
↻ Last updated: 4 Aug 26, 9:26
Customer Reviews
Trusted by Mercedes Benz GLS Owners Across the UK
Rated 4.8 out of 5 by 1,081 verified customers who sourced reconditioned and used Mercedes Benz GLS engines through EngineMarket.
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Variants We Cover
Mercedes-Benz GLS Engine ReplacementAll Variants Covered
Mercedes-Benz GLS GLS 250d
OM651 2.1L Diesel
Rebuilt Engines: £2,900-£4,400
Mercedes-Benz GLS GLS 350d
OM642/OM656 3.0L Diesel
Rebuilt Engines: £3,400-£5,500
Mercedes-Benz GLS GLS 400
M276 3.0L Petrol
Rebuilt Engines: £4,500-£7,200
Mercedes-Benz GLS GLS 500
M278 4.7L Petrol
Rebuilt Engines: £5,500-£9,200
Mercedes-Benz GLS GL 500
M273 5.5L Petrol
Rebuilt Engines: £4,200-£7,000
Mercedes-Benz GLS GLS 63 AMG
M157/M177 5.5L Petrol
Rebuilt Engines: £6,200-£12,500
Mercedes-Benz GLS AMG GLS 63
M177 4.0L Petrol
Rebuilt Engines: £7,500-£13,500
Not sure which variant your Mercedes-Benz GLS is- Enter your registration number above - we'll identify the exact sub-model, engine code and compatible replacement options instantly.
GLS
Engine Codes
Mercedes-Benz GLS Engine CodesFull Technical Specifications & Replacement Guide
Every engine code fitted to the Mercedes-Benz GLS 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 GLS variants.
OM642 - 3.0L Diesel
Main replacement triggers are timing chain wear, EGR / cooling faults and turbo-control issues.
Compatible variants
GL 320 CDIGL 350 CDIGL 350 BlueTECGLS 350dGLS 350d 4MATIC
Avg. rebuilt price
£3,200 - £5,500
Supply only
Technical specifications
- Fuel type
- Diesel
- Engine size
- 2.987L
- Power output
- 249-265 hp
- Years fitted
- 2006-2019
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 GLS engine specialists. Every rebuilt engine comes with a minimum 12-month unlimited mileage warranty.
GLS
Common Problems
Mercedes-Benz GLS Engine Problems - What It Costs to Fix & When Replacement Makes Sense
The Mercedes-Benz GLS delivers premium refinement and heavy-duty towing capability, but its complex engine families are not immune to high-mileage wear. Replacement demand is heavily driven by the OM642 V6 diesel timing chain system, M276/M278 petrol VANOS solenoid degradation, and AdBlue emission faults in modern straight-six diesels. Every rebuilt...
Mercedes-Benz GLS Timing Chain Failure - Why OM642 V6 Diesel Engines Suffer Premature Wear
Mercedes-Benz GLS Timing Chain Failure
Most affected vehicles
Mercedes-Benz GLS 350dGL 350 CDI
Mercedes-Benz GLS 350d, GL 350 CDI, GLS 350 BlueTEC (2006-2019, OM642)
Failure mileage range
60,000-90,000 miles
Typical failure window
Root cause
The rear-mounted timing chain tensioner relies on consistent oil pressure and precise tolerances. Over time, chain stretch and plastic guide wear cause slack, leading to cold-start rattling and eventual timing misalignment if maintenance intervals are extended or sub-standard filters are used.
Repair options & estimated costs (UK ranges)
| Repair tier | Dealer price | Specialist price | What it involves | Longevity / suitability |
|---|---|---|---|---|
| Minor - Preventative Timing Chain & Guide Replacement | £1,800 - £2,600 | £1,100 - £1,800 | Full chain kit swap with upgraded tensioner, guide rails and oil pump chain inspection | Extends life by 40,000-60,000 miles if caught before severe rattling occurs |
| Full Replacement - Rebuilt / Reconditioned OM642 Engine | £7,500 - £11,000 | £4,200 - £6,800 | Complete engine swap with reinforced timing assembly, new ancillaries and bench-tested calibration | Permanent solution with 12-month warranty; eliminates cumulative internal wear |
Our recommendation
On a Mercedes-Benz GLS worth £12,000-£25,000, early chain replacement is only cost-effective if the block is otherwise pristine. Once cold-start rattle exceeds 65,000 miles, chain slack has usually damaged tensioners and guides internally. We typically recommend a rebuilt unit, as it resolves timing issues while simultaneously refreshing the oil cooler and turbo seals.
Compare rebuilt OM642 engine prices for your Mercedes-Benz GLSReplacement Engine Options
Mercedes-Benz GLS 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 GLS Reconditioned Engines (Recon)£3,500 - £7,200((supply only))
Mercedes-Benz GLS Rebuilt Engines£4,200 - £8,500((supply only))
Mercedes-Benz GLS Used Engines£1,800 - £4,000((supply only))
Mercedes-Benz GLS Remanufactured Engines£5,500 - £11,000((supply only))
Mercedes-Benz GLS Refurbished Engines£2,500 - £5,500((supply only))
Compare Mercedes Benz GLS 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 GLS within hours.
Engine Sizes
Mercedes-Benz GLS Engines by SizeFind the Right Displacement for Your Variant
Every displacement fitted to the Mercedes-Benz GLS is listed below with compatible engine codes, production years and documented failure notes to help you identify the correct replacement unit.
The 2.1L OM651 four-cylinder diesel served as the entry-level powerplant for the X166 GLS 250d, delivering respectable torque for a large SUV while prioritising fuel economy and lower tax bands. Its compact twin-turbo design made it popular with fleet and private owners seeking reduced running costs without sacrificing the GLS's commanding presence.
⚙
Engine Code(s)
OM651
▣
Compatible Models (UK)
GLS 250d, GLS 250d 4MATIC
ϟ
Power output
Verified by registration
△
Common Failure Points
Injector copper seal leaks, balancer shaft bearing wear on high-mileage units
Production Years: X166, 2013-2019
Get quotes for Mercedes-Benz GLS 2.1L diesel enginesMercedes-Benz GLS Engines Fuel Type
Mercedes-Benz GLS Engines by Fuel Type
Mercedes-Benz GLS Diesel Engines
DieselDiesel power dominates UK GLS replacements, spanning the robust OM642 V6, modern OM656 straight-six, and entry-level OM651 four-cylinder across all three generations.
Common Mercedes-Benz GLS Diesel Engine Families
- •OM642 - 3.0L V6 workhorse (GLS 350d), oil cooler seal and timing chain wear
- •OM656 - 3.0L straight-six (GLS 400d), sequential turbos, AdBlue system complexity
- •OM651 - 2.1L four-cylinder (GLS 250d), injector seal leaks, balancer shaft concerns
Found In
- •X164 GL (2006-2012) - OM642, OM629
- •X166 GLS (2012-2019) - OM642, OM651, OM656 (facelift)
- •X167 GLS (2019-present) - OM656, OM651 (early)
Known For
- •Exceptional towing capability and motorway refinement across all diesel variants
- •OM642 oil cooler seal leaks between 60k-90k miles driving replacement demand
- •OM656 AdBlue heater faults triggering engine start limitations on X167 models
Typical Diesel Models
- •GLS 250d
- •GLS 350d / 350 BlueTEC
- •GLS 400d
1 of 3
Mercedes-Benz GLS Diesel Engines
DieselDiesel power dominates UK GLS replacements, spanning the robust OM642 V6, modern OM656 straight-six, and entry-level OM651 four-cylinder across all three generations.
Common Mercedes-Benz GLS Diesel Engine Families
- •OM642 - 3.0L V6 workhorse (GLS 350d), oil cooler seal and timing chain wear
- •OM656 - 3.0L straight-six (GLS 400d), sequential turbos, AdBlue system complexity
- •OM651 - 2.1L four-cylinder (GLS 250d), injector seal leaks, balancer shaft concerns
Found In
- •X164 GL (2006-2012) - OM642, OM629
- •X166 GLS (2012-2019) - OM642, OM651, OM656 (facelift)
- •X167 GLS (2019-present) - OM656, OM651 (early)
Known For
- •Exceptional towing capability and motorway refinement across all diesel variants
- •OM642 oil cooler seal leaks between 60k-90k miles driving replacement demand
- •OM656 AdBlue heater faults triggering engine start limitations on X167 models
Typical Diesel Models
- •GLS 250d
- •GLS 350d / 350 BlueTEC
- •GLS 400d
Mercedes-Benz GLS Petrol Engines
PetrolPetrol GLS engines prioritise smooth refinement and performance, from naturally aspirated V6/V8 units to twin-turbo AMG powertrains and modern electrified straight-six designs.
Common Mercedes-Benz GLS Petrol Engine Families
- •M276 - 3.0L twin-turbo V6 (GLS 400), VANOS solenoid wear, timing chain tensioner
- •M278 - 4.7L twin-turbo V8 (GLS 500), strong torque, turbo oil feed line concerns
- •M177 - 4.0L AMG biturbo V8 (GLS 63), hand-built performance, turbo bearing sensitivity
Found In
- •X164 GL (2006-2012) - M272, M273
- •X166 GLS (2012-2019) - M276, M278, M177
- •X167 GLS (2019-present) - M256, M176, M177
Known For
- •Effortless power delivery and refined cruising character across all petrol variants
- •M276 timing chain tensioner rattle on cold starts at higher mileage
- •M177 turbocharger bearing wear under sustained high-load AMG driving
Typical Petrol Models
- •GLS 400
- •GLS 450
- •GLS 500
Mercedes-Benz GLS Mild Hybrid (MHEV) Engines
MHEVModern X167 GLS models feature 48-volt mild-hybrid technology, combining petrol efficiency with electric torque assist for seamless performance and reduced emissions.
Mercedes-Benz GLS MHEV Engine Codes
- •M256 - 3.0L straight-six petrol (GLS 450), integrated starter-generator
- •M176 - 4.0L V8 petrol (GLS 580), cylinder deactivation with electric assist
- •48-volt starter-generator recovers braking energy for electric torque fill
Found In
- •GLS 450, GLS 450 4MATIC (X167, 2019-present)
- •GLS 580, GLS 580 4MATIC (X167, 2019-present)
Important Notes
- •No plug-in hybrid or full electric GLS variant is currently sold in the UK
- •MHEV engine replacement requires specialist diagnostic equipment for ISG coding
- •Availability of rebuilt MHEV units is more limited than standard combustion engines
Not sure which fuel type your Mercedes-Benz GLS 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 GLS specialists.
Engine YearsGet quotes for 2006-2009 Mercedes-Benz GL replacement engines →
Mercedes-Benz GLS Engines by YearWhat Was Fitted & WhenMercedes-Benz GLS Engines by Year - What Was Fitted & When
This technical timeline covers all major Mercedes-Benz GLS engine changes across three generations, helping owners quickly identify their exact powerplant and compare rebuilt engine prices from UK specialists.
⚙Key Changes
- ✓Launch of X164 architecture replacing the ML-based SUV concept
- ✓Introduction of OM642 3.0L V6 diesel and M272 3.5L petrol
- ✓M273 4.6L/5.5L V8 added for flagship towing capability
- ✓OM629 4.0L V8 diesel launched for heavy-duty European markets
▣Main Engines
OM642- 3.0 diesel (GL 320 CDI / 350 CDI)
OM629- 4.0 diesel (GL 420 CDI)
M272- 3.5 petrol (GL 350)
M273- 4.6 / 5.5 petrol (GL 450 / 500)
▰Popular Models
- •Mercedes-Benz GL 350 CDI
- •Mercedes-Benz GL 420 CDI
- •Mercedes-Benz GL 450
- •Mercedes-Benz GL 500
🔧Known For
- ✓Robust ladder-frame chassis delivering exceptional off-road articulation
- ✓M272 balance shaft gear wear on early 2006-2007 production runs
- ✓OM642 oil cooler seals prone to degradation by 60,000 miles
- ✓Heavy curb weight accelerates brake and suspension component fatigue
Engine Codes Covered:
OM642OM629M272M273642.826272.967273.922Not sure which year your Mercedes-Benz GLS 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 GLS specialists.
FAQ