SLC Diesel Engines
from £2,647 to £4,500
Rebuilt units from £3,125 · Common codes: OM651.901, OM651.911, OM651.921
Mercedes Benz ENGINE MARKETPLACE
Mercedes SLC M274/OM651 Engine Solutions - UK Specialists
Get quotes from trusted UK Mercedes SLC engine specialists. Compare reconditioned & used engines for SLC 180 to SLC 43 AMG - M274/OM651 covered. Get a quote before it's too late.
Supply & Fit Available
12-Month Warranty
Nationwide Delivery
100+ Suppliers
SLC Petrol Engines
from £2,800 to £5,200
Rebuilt units from £3,450 · Common codes: M274.920, M274.910, M274.930
SLC AMG Engines
from £5,500 to £9,250
Rebuilt units from £5,500 · Common codes: M276.9xx, M177.9xx
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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 SLC Replacement Engineto Finding the Best Mercedes Benz SLC 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 SLC Engine Replacement
This table outlines typical UK rebuilt engine replacement costs across Mercedes Benz SLC variants, covering documented failure causes, chassis codes, factory engine codes and fuel types.
Average Market Prices
↻ Last updated: 4 Aug 26, 9:26
Customer Reviews
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Rated 4.8 out of 5 by 1,081 verified customers who sourced reconditioned and used Mercedes Benz SLC engines through EngineMarket.
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Variants We Cover
Mercedes Benz SLC Engine ReplacementAll Variants Covered
Mercedes Benz SLC 180d
OM651.911 2.1L Diesel
Rebuilt Engines: £2,400-£4,000
Mercedes Benz SLC 200d
OM651.911 2.1L Diesel
Rebuilt Engines: £2,500-£4,100
Mercedes Benz SLC 220d
OM651.921 2.1L Diesel
Rebuilt Engines: £2,700-£4,500
Mercedes Benz SLC 250
M274.920 2.0L Petrol
Rebuilt Engines: £3,100-£5,300
Mercedes Benz SLC 300
M274.920 2.0L Petrol
Rebuilt Engines: £3,300-£5,600
Not sure which variant your Mercedes Benz SLC is- Enter your registration number above - we'll identify the exact sub-model, engine code and compatible replacement options instantly.
SLC
Engine Codes
Mercedes Benz SLC Engine CodesFull Technical Specifications & Replacement Guide
Every engine code fitted to the Mercedes Benz SLC 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 SLC variants.
OM651.911 - 2.1L Diesel
Main replacement triggers are timing chain wear, EGR / cooling faults and turbo-control issues.
Compatible variants
SLC 180dSLC 180d AMG LineSLC 180d SportSLC 200dSLC 200d AMG LineSLC 200d Sport
Avg. rebuilt price
£2,400 - £4,100
Supply only
Technical specifications
- Fuel type
- Diesel
- Engine size
- 2.1L
- Power output
- 136-170 hp
- Years fitted
- 2016-2020
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 SLC engine specialists. Every rebuilt engine comes with a minimum 12-month unlimited mileage warranty.
SLC
Common Problems
Mercedes Benz SLC Engine Problems - What It Costs to Fix & When Replacement Makes Sense
While the R172 Mercedes Benz SLC offers refined driving dynamics, its OM651 diesel and M274 petrol powertrains carry well-documented susceptibility to timing chain and ancillary component degradation that can escalate to terminal failure. Every rebuilt Mercedes Benz SLC engine supplied through our network features upgraded internal tensioners, reinforced...
Mercedes Benz SLC M274 Timing Chain Failure - Why 2.0L Petrol Engines Fail Prematurely
Mercedes Benz SLC M274 Timing Chain Failure
Most affected vehicles
Mercedes Benz SLC 200SLC 250
Mercedes Benz SLC 200, SLC 250, SLC 300 (2016-2020, M274.910, M274.920, M274.930)
Failure mileage range
45,000 - 80,000 miles
Typical failure window
Root cause
Early M274 variants utilised a guide rail and tensioner design prone to premature wear under high thermal cycling, allowing the primary timing chain to stretch and skip teeth before catastrophic valve train collision occurs.
Repair options & estimated costs (UK ranges)
| Repair tier | Dealer price | Specialist price | What it involves | Longevity / suitability |
|---|---|---|---|---|
| Minor - Preventative Timing Chain Kit Upgrade | £1,400 - £1,800 (Dealer) | £950 - £1,250 (Specialist) | Full tensioner, guide rail, chain and oil pump replacement before catastrophic stretch | Extends engine life 40k-60k miles if performed before rattle worsens; viable only if valves remain undamaged |
| Intermediate - Cylinder Head Repair & Timing Refresh | £3,200 - £4,500 (Dealer) | £2,100 - £2,800 (Specialist) | Machine shop valve inspection/replacement, timing assembly overhaul, carbon deposit cleaning | Suitable for early-stage skipping; does not address long-term block wear or future turbo/HPFP risks |
| Full Replacement - Mercedes Benz SLC M274 Rebuilt Engine | £6,500 - £8,200 (Dealer) | £2,900 - £5,000 (Specialist) | Bench-tested rebuilt unit with reinforced tensioner, upgraded seals, ECU calibration and 12-month unlimited mileage warranty | Restores factory specification with resolved weak points; highest long-term reliability and value retention |
Our recommendation
If you hear the characteristic M274 cold-start rattle, act immediately. A preventative timing kit at specialist rates is the most cost-effective intervention if caught early. However, if the engine has already suffered loss of compression or valve contact, investing in a rebuilt M274 with upgraded tensioner geometry is financially safer than repeated cylinder head repairs on a premium convertible.
Compare Mercedes Benz SLC M274 rebuilt engine prices nowReplacement Engine Options
Mercedes Benz SLC Engine TypesOptions, Costs & What to Expect
Every engine type is available through our UK network with typical price ranges based on variant, engine code and budget.
Mercedes Benz SLC Reconditioned Engines (Recon)£3,100 - £4,800((supply only))
Mercedes Benz SLC Rebuilt Engines£2,800 - £4,200((supply only))
Mercedes Benz SLC Used Engines£2,400 - £3,500((supply only))
Mercedes Benz SLC Remanufactured Engines£4,500 - £6,500((supply only))
Mercedes Benz SLC Refurbished Engines£2,600 - £3,800((supply only))
Compare Mercedes Benz SLC 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 SLC within hours.
Engine Sizes
Mercedes Benz SLC Engines by SizeFind the Right Displacement for Your Variant
Every official engine displacement fitted to the R172 SLC is listed below with matching factory codes, production years and documented mechanical weak points for accurate identification.
The 2.1-litre OM651 turbo diesel served as the sole compression-ignition powerplant across the entire R172 SLC lineup from its 2016 launch until production ceased. Engineered with common-rail injection and twin-scroll turbocharging in higher outputs, this unit prioritised strong low-end torque and refined motorway cruising for UK roadster owners. Despite its reputation for efficiency, early production models require careful monitoring of internal lubrication pathways and exhaust gas recirculation components.
⚙
Engine Code(s)
OM651.901, OM651.911, OM651.921, OM651.931
▣
Compatible Models (UK)
SLC 180d, SLC 200d, SLC 220d, SLC 250d
ϟ
Power output
Verified by registration
△
Common Failure Points
Rear-mounted timing chain tensioner wear, EGR cooler coolant leakage at higher mileage
Production Years: R172, 2016-2020
Get quotes for Mercedes Benz SLC 2.1L diesel enginesMercedes Benz SLC Engines Fuel Type
Mercedes Benz SLC Engines by Fuel Type
Choose your Mercedes Benz SLC engine by fuel type to compare realistic replacement prices, known issues, and compatible UK supply options - from the efficient OM651 diesel to the high-performance M276 biturbo V6.
Mercedes Benz SLC Diesel Engines
DieselThe 2.1-litre OM651 turbo diesel powered every SLC diesel variant across the R172 generation (2016-2020), dominating UK replacement enquiries due to strong fleet presence and motorway-focused ownership.
Common Mercedes Benz SLC Diesel Engine Families
- •OM651.911 - entry-level 136hp unit (SLC 180d/200d), early-model timing chain tensioner concerns
- •OM651.921 - high-output 204hp variant (SLC 220d/250d), turbo actuator calibration issues at higher mileage
- •OM651.931 - late-production refinement with updated EGR and DPF mapping for Euro 6 compliance
Found In
- •R172 Roadster (2016-2020) - OM651.911, OM651.921, OM651.931
Known For
- •Strong low-end torque ideal for open-top motorway cruising
- •OM651 rear-mounted timing chain tensioner wear on pre-2018 builds
- •EGR cooler coolant leakage and DPF regeneration strain on short-journey cars
Typical Diesel Models
- •SLC 180d
- •SLC 200d
- •SLC 220d
1 of 2
Mercedes Benz SLC Diesel Engines
DieselThe 2.1-litre OM651 turbo diesel powered every SLC diesel variant across the R172 generation (2016-2020), dominating UK replacement enquiries due to strong fleet presence and motorway-focused ownership.
Common Mercedes Benz SLC Diesel Engine Families
- •OM651.911 - entry-level 136hp unit (SLC 180d/200d), early-model timing chain tensioner concerns
- •OM651.921 - high-output 204hp variant (SLC 220d/250d), turbo actuator calibration issues at higher mileage
- •OM651.931 - late-production refinement with updated EGR and DPF mapping for Euro 6 compliance
Found In
- •R172 Roadster (2016-2020) - OM651.911, OM651.921, OM651.931
Known For
- •Strong low-end torque ideal for open-top motorway cruising
- •OM651 rear-mounted timing chain tensioner wear on pre-2018 builds
- •EGR cooler coolant leakage and DPF regeneration strain on short-journey cars
Typical Diesel Models
- •SLC 180d
- •SLC 200d
- •SLC 220d
Mercedes Benz SLC Petrol Engines
PetrolPetrol SLC models feature the versatile M274 2.0L turbo four-cylinder as standard, with the M276/M177 biturbo V6/V8 reserved exclusively for the flagship SLC 43 AMG performance variant.
Common Mercedes Benz SLC Petrol Engine Families
- •M274.920 - dominant 2.0L turbo petrol (SLC 200/250/300), timing chain tensioner rattle on early production
- •M274.930 - high-output 245hp tune (SLC 300), direct injection carbon buildup on intake valves
- •M276.823 - 3.0L V6 biturbo (early SLC 43 AMG), specialist rebuild credentials essential for biturbo calibration
Found In
- •R172 Roadster (2016-2020) - M274.910, M274.920, M274.930, M276.823, M177.9xx
Known For
- •Responsive turbocharged performance with refined exhaust acoustics for roadster driving
- •M274 timing chain tensioner wear causing cold-start rattle between 45k-80k miles
- •High-pressure fuel pump degradation and turbo wastegate calibration faults on higher-mileage units
Typical Petrol Models
- •SLC 200
- •SLC 200 AMG Line
- •SLC 250
Not sure which fuel type your Mercedes Benz SLC 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 SLC specialists.
Engine YearsGet quotes for 2016 Mercedes Benz SLC replacement engines →
Mercedes Benz SLC Engines by YearWhat Was Fitted & WhenMercedes Benz SLC Engines by Year - What Was Fitted & When
This timeline covers every major engine update across the single-generation R172 SLC (2016-2020), helping UK owners quickly identify their specific powertrain and compare accurate rebuilt engine prices from vetted specialists.
⚙Key Changes
- ✓SLC rebranding from SLK with revised retractable hardtop mechanism and updated chassis tuning
- ✓Introduction of OM651 2.1L turbo diesel and M274 2.0L turbo petrol as standard powertrains
- ✓Debut of SLC 43 AMG featuring the new M276 3.0L biturbo V6
- ✓Standard Euro 6 compliance across all factory variants
▣Main Engines
OM651.911/921- 2.1L diesel (SLC 180d / 220d / 250d)
M274.910/920- 2.0L petrol (SLC 200 / 250)
M276.823- 3.0L V6 biturbo (SLC 43 AMG)
▰Popular Models
- •Mercedes Benz SLC 180d
- •Mercedes Benz SLC 200
- •Mercedes Benz SLC 220d
- •Mercedes Benz SLC 43 AMG
🔧Known For
- ✓Early-production OM651 rear-mounted timing chain tensioner wear below 80k miles
- ✓M274 cold-start timing rattle reported by UK petrol owners on pre-facelift units
- ✓Strong roadster refinement and premium cabin quality despite early mechanical teething issues
- ✓High fleet leasing exposure driving rapid early replacement demand for SLC 220d diesel units
Engine Codes Covered:
OM651.911OM651.921M274.910M274.920M276.823Not sure which year your Mercedes Benz SLC 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 SLC specialists.
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