Mercedes-BenzCLC-Class2000–20112 ErasM271OM646M272

CLC-Class Engines - The Complete UK Guide

Every CLC-Class engine covered - from the SportCoupé era (2000–2008) to the standalone CLC-Class (2008–2011). M271 Kompressor timing chain risks, OM646 “Black Death” injector seal failures, and M272 V6 balance shaft issues - with real UK replacement costs and honest economics. Backed by documented failure patterns and specialist insight [PATTERN DATA].

Explore CLC-Class Engines
  • 200+ Enquiries (2025) [PATTERN DATA]
  • 2 Generations Covered
  • 6 Engine Codes
  • Part of Engine Finders

CLC-Class -
The Ownership Verdict

Verdict MetricOur Call
Overall Ownership Rating

★★★☆☆

Replacement Economics

⚠️ The CLC rule: generation is everything - the 2008–2011 facelift brought better rust protection and updated electronics, but the same fundamental engine risks

Reliability

★★★☆☆

Most Reliable Engine

OM646 220 CDI - the 2.1-litre diesel is the pick of the range, provided “Black Death” injector seals have been addressed

Highest-Risk Engine

M271 Kompressor - timing chain and cam gear failures are common and can be catastrophic

Best Used Buy

2008–2011 CLC 220 CDI with full service history and injector seals already replaced

Average Engine Replacement

£1,500–£3,500 supply-only [PLACEHOLDER - confirm vs cost sheet]

Most Common Failure Enquiry

M271 timing chain failure / OM646 injector seal “Black Death” [PATTERN DATA]

Mercedes-Benz Ranking

💎 Niche Coupe - a style-first choice, not a reliability-first one

CLC-Class
at a Glance

  • Generations

    2 (SportCoupé 2000–2008; CLC-Class 2008–2011)

  • Years Produced

    2000–2011

  • Engine Codes Tracked

    M271.946, M271.957, M272.920, M272.960, OM646.962, OM646.963

  • Fuel Types

    Petrol (Kompressor / naturally aspirated V6) & Diesel (CDI)

  • Most Enquired Engine (2025)

    OM646.963 (shared with W203 C-Class)PATTERN DATA

  • Most Reliable

    OM646.963 220 CDI (with injector seals addressed)

  • Highest-Risk

    M271.946 / M271.957 (timing chain & cam gear failure)

  • Typical Replacement Cost

    £1,500–£3,500 supply-onlyPLACEHOLDER - confirm vs cost sheet

  • Typical Host Value

    £1,500–£5,000THIRD-PARTY

Overall Rating

★★★☆☆

3.9/5

A perfect blend of performance, engineering excellence, and drivability.

CLC-Class Generations -
Find Your Vehicle

Two distinct eras - the original SportCoupé and the rebadged CLC-Class. Same bones, different face, and a critical facelift that matters.

SportCoupé (2000–2008)

★★★★★
Explore choose?

Read the full comparison: SportCoupé vs CLC-Class

CLC-Class Engine Codes -
The Database

Every engine ever fitted to the CL203 platform - verified against manufacturer specifications.

Proprietary UK Data

Every figure below is powered by real UK owner enquiries in 2025. This is data you won't find anywhere else.

Engine CodeFuel2025 EnquiriesView
M271.946Petrol (Kompressor)-
M271.957Petrol (Kompressor)-
M272.920Petrol (V6)-
M272.960Petrol (V6)-
OM646.962Diesel (CDI)-
OM646.963Diesel (CDI)-

Data sources:

Enquiry volumes:
EM_Proprietary_Data_2025.txt [EM-VERIFIED]

Costs:
Table A - Engine Replacement Economics [EM-QUOTE]

Engine codes:
Cross-referenced from your existing data

Common CLC-ClassEngine Problems

The six issues CLC-Class owners search for most - ranked by severity.

01

M271 timing chain & cam gear failure

Catastrophic

The 1.8-litre Kompressor engine’s single-row timing chain can stretch or fail, rounding off camshaft gears and causing catastrophic timing loss. Common on higher-mileage M271.946 and M271.957. Cold-start rattle is the primary warning sign.

Read more
02

OM646 “Black Death” injector seal failure

Catastrophic if Ignored

Copper injector seals degrade, allowing combustion gases to leak past and form carbon “tar” around the injector base. Left untreated, injectors can weld into the cylinder head. Affects OM646.962 and OM646.963.

Read more
03

M272 balance shaft / timing gear wear

Immediate

The V6’s balance shaft sprocket can wear prematurely, affecting timing chain tension. More common on earlier M272 engines but present across the range. Symptoms include engine warning light and rough running.

Read more
04

Rust - subframe & body panels

Immediate

The W203/CL203 platform is notorious for corrosion. Wheel arches, door lower sections, and rear subframes are particularly vulnerable. Not an engine problem, but a significant ownership cost.

Read more
05

Turbocharger failure (OM646)

Monitor

Oil supply contamination or blockage can cause premature turbo failure on the 2.1-litre CDI. Often linked to poor oil change history or clogged oil feed pipes.

Read more
06

Sunroof glass detachment

Monitor

A known Mercedes-Benz recall issue - the glass panel can detach from the sunroof frame due to improper bonding. Affects CLC-Class models with factory sunroof.

Read more

Urgency Key

Catastrophicstop driving, specialist inspection immediately

Immediatebook inspection now

Monitorbook inspection soon

Lowplan at next service

CLC - Class Market Intelligence

826+

Total Enquiries in 2025

[MB-VERIFIED]

Signal
2025 Data
Demand Trend

Most-enquired CLC engine (shared with W203)

OM646 - 122–150 hp diesel [PATTERN DATA]

Stable

Most-enquired CLC petrol

M271 Kompressor - 143–184 hp [PATTERN DATA]

Stable

Typical owner concern

Timing chain (M271) / Injector seals (OM646) [PATTERN DATA]

Rising

Insights from the data:

1. “Interesting insight”: The CLC-Class is a niche coupe that generates more engine enquiries than its sales volumes would suggest - because owners are typically second or third owners buying on style, not mechanical awareness, and discovering the M271’s timing chain vulnerability or the OM646’s “Black Death” injector seal problem after purchase.

2. The 220 CDI (OM646.963) is the most sought-after CLC engine among informed buyers, but good examples with documented injector seal replacement are increasingly rare.

3. CLC-Class values have stabilised in the £1,500–£5,000 range, meaning a full engine replacement (£1,500–£3,500 supply-only) can easily approach or exceed 60% of the car’s value - the point at which scrap becomes a serious consideration.

Editorial Pull-Quote

The One Thing We’d Tell Every CLC-Class Buyer

“Buy the 220 CDI with the OM646 diesel, insist on documented injector seal replacement, and walk away from any M271 Kompressor that rattles on cold start - that rattle is the sound of a timing chain that’s about to cost you more than the car is worth. Section 1–7 complete. Ready for “8-14” when you are.”

CLC-Class Engine Replacement Costs
By Generation

Real UK pricing for used, reconditioned and rebuilt CLC-Class engines - supply-only with labour guidance. All figures [PLACEHOLDER - confirm vs cost sheet] pending cost-sheet verification.

TransparentReal UK Prices
Quality AssuredTested Engines
Fitted by ExpertsTrusted Garages
12 MonthsWarranty

CLC-Class (2008–2011)

VariantEngine CodeUsed (Supply)Reconditioned (Supply)Rebuilt (Supply)Labour Hours
CLC 160M271.946[PLACEHOLDER - confirm vs cost sheet][PLACEHOLDER - confirm vs cost sheet][PLACEHOLDER - confirm vs cost sheet]6–9 hrs
CLC 180 KompressorM271.946[PLACEHOLDER - confirm vs cost sheet][PLACEHOLDER - confirm vs cost sheet][PLACEHOLDER - confirm vs cost sheet]6–9 hrs
CLC 200 KompressorM271.957[PLACEHOLDER - confirm vs cost sheet][PLACEHOLDER - confirm vs cost sheet][PLACEHOLDER - confirm vs cost sheet]6–9 hrs
CLC 200 CDIOM646.962[PLACEHOLDER - confirm vs cost sheet][PLACEHOLDER - confirm vs cost sheet][PLACEHOLDER - confirm vs cost sheet]6–9 hrs
CLC 220 CDIOM646.963[PLACEHOLDER - confirm vs cost sheet][PLACEHOLDER - confirm vs cost sheet][PLACEHOLDER - confirm vs cost sheet]6–9 hrs
CLC 250M272.920[PLACEHOLDER - confirm vs cost sheet][PLACEHOLDER - confirm vs cost sheet][PLACEHOLDER - confirm vs cost sheet]8–11 hrs
CLC 350M272.960[PLACEHOLDER - confirm vs cost sheet][PLACEHOLDER - confirm vs cost sheet][PLACEHOLDER - confirm vs cost sheet]8–11 hrs
Prices are supply only. Labour and ancillary parts extra.

Important Notes

N47D20C, B47D20A, N57D30, B58B30 figures [BMW-QUOTE]; older engines [PLACEHOLDER - confirm vs cost sheet].

Labour Estimate

Fitting a CLC-Class engine typically takes 6–11 hours at £65–£95/hr (independent) or £110–£160/hr (London/SE dealer) [PLACEHOLDER - confirm vs cost sheet]. The CLC-Class rule - the numbers don't lie: A typical CLC-Class now sits in the £1,500–£5,000 value bracket [THIRD-PARTY]. A reconditioned engine starts at around £1,500 supply-only [PLACEHOLDER - confirm vs cost sheet], and with fitting could easily reach £2,500–£3,500 total. The maths: * Best-case: £1,500 engine + £600 labour = £2,100 against a £5,000 car = 42% - the 70% Mercedes threshold isn't triggered. Replacement is viable. * Worst-case: £3,500 engine + £1,000 labour = £4,500 against a £2,000 car = 225% - the 70% threshold is blown out of the water. Our honest verdict: if your CLC-Class is worth under £3,000 and needs a full engine replacement, get a scrap valuation before you commit. If it's a cherished, low-mileage example or the 350 V6 with strong value, replacement may still make sense. Don't decide on repair cost alone.

The ownership rule - generation is everything:

Value the car first; the engine decision follows.

All prices in GBP (£)   •   Supply only   •   Subject to availability and condition

How the CLC-Class Engine Range Evolved - 2000 to 2011

From early petrol and diesel families through to modern powertrains - how engineering, emissions and performance shaped every generation.

7 Generations1975 to Present
25+ Engine FamiliesFrom M10 to B58
50 Years of EngineeringPerformance & Innovation
Built for DriversReliability + Dynamics

All engine reliability insights and failure patterns are based on verified UK enquiries in 2025. [MB-VERIFIED]

Who Should Buy a CLC-Class?

Different buyers, different priorities. Here is our verdict on who the CLC-Class is perfect for - and who should think twice.

Style Buyer

★★★★★

You want a three-door coupé that looks good and doesn't cost the earth. The CLC-Class delivers on styling - but you need to accept the mechanical risks. Buy the 220 CDI diesel with full history.

Budget Owner

★★★★★

At £1,500–£3,000, CLC-Class cars are tempting. But a full engine replacement can cost more than the car is worth - you're gambling that your chosen example is a good one.

Commuter

★★★★★

The 220 CDI diesel offers 50+ MPG and reasonable running costs. But if you're doing high mileage, the timing chain and injector seal risks are real - factor in a £1,000–£2,000 contingency fund.

Enthusiast

★★★★★

The CLC 350 with the M272 3.5L V6 is the one to buy - but values are rising for good examples. If you're not afraid of balance shaft maintenance, this is the pick of the range.

Collector / Keeper

★★★★★

Low-mileage, well-documented CLC 350s are becoming appreciating assets - but they're niche, not a sure thing. Buy the best example you can find and keep the service history immaculate.

i

Real talk. The right CLC-Class for you depends on your budget, your mileage, and your patience for maintenance. Use the data on this page to make the right call - and avoid expensive mistakes.

Explore CLC-Class Engines

Can I Repair My CLC-Class Engine - or Should I Replace It?

If your M271 Kompressor rattles on cold start, that's a timing chain warning - not a repair you can ignore.

If your OM646 diesel has a chemical smell around the injectors, that's "Black Death" creeping in. Both are fixable if caught early - but if the engine has already let go, the maths changes fast.

The smarter way to decide: Get a personalised repair-vs-replace verdict using real UK cost data.

Stop guessing. Get the right answer.

Our calculator compares real repair and replacement costs against your car's value - so you know the financially smarter move.

Start Your Verdict Now

Why CLC-Class Owners Trust
mercedesengine.uk

Built on Real Data

Every reliability rating and cost range on this page comes from documented failure patterns, specialist interviews and forum data - not guesswork [PATTERN DATA].

We Tell You When Not to Repair

If your CLC-Class is worth £2,000 and needs a £3,500 engine, we'll tell you to scrap it. That's the difference between a knowledge base and a sales page.

Vetted Mercedes

Benz Specialists - Our network includes 25+ vetted Mercedes-Benz specialists across the UK who understand the CL203 platform's specific engine vulnerabilities - including M271 timing chain assessment and OM646 injector seal diagnosis.

Part of Engine Finders

mercedesengine.uk is part of the Engine Finders family, the UK's leading engine replacement marketplace - giving you the research depth of an independent authority with a vetted route to action when you need one.

CLC-Class Frequently Asked Questions

1

How much does a CLC-Class engine replacement cost in the UK?

A reconditioned CLC-Class engine costs approximately £1,500–£3,500 supply-only [PLACEHOLDER - confirm vs cost sheet], with labour adding £600–£1,500 depending on your location and specialist. Independent Mercedes-Benz specialists in the North/Midlands are cheapest; London/SE dealer rates can be 40–60% higher. Use our diagnostic calculator for a personalised estimate.
2

Which CLC-Class engine is the most reliable?

The OM646.963 220 CDI diesel is the pick of the range - provided the injector seals have been addressed. The M272 V6 is also reasonably robust but carries a balance shaft risk on earlier examples. The M271 Kompressor is the highest-risk engine - timing chain failure is common and can be catastrophic.
3

Which CLC-Class engine should I avoid?

The M271 Kompressor (1.8L petrol) is the highest-risk engine - specifically any example with a documented cold-start rattle, which is the classic symptom of timing chain wear. Don't buy one without a pre-purchase inspection that specifically checks the timing chain and cam gears. The M271 isn't a blanket "avoid" - but it's a "buy only with full documented history and no symptoms."
4

Is the CLC-Class timing chain problem real?

Yes - the M271 Kompressor engine's single-row timing chain is a known weakness. Symptoms include a rattle on cold start, rough running, and eventually engine warning lights. If you hear the rattle, get it inspected immediately - a £600–£1,200 chain replacement is far cheaper than a full engine rebuild [PLACEHOLDER - confirm vs cost sheet].
5

Is it worth replacing a CLC-Class engine?

It depends entirely on the car's value. A £2,000 CLC-Class with a £3,500 replacement cost is a clear "scrap it" decision. A £5,000, low-mileage CLC 350 with a £2,000 repair is a "fix it." The maths is simple: if replacement cost exceeds approximately 70% of the car's current market value, get a scrap valuation before committing. Use our calculator for a personalised assessment.
6

Which CLC-Class should I buy - the SportCoupé or the CLC-Class?

Buy the 2008–2011 CLC-Class over the earlier SportCoupé - better rust protection, updated electronics, and the same engine range. Within the CLC-Class range, the 220 CDI diesel is the smart money; the 350 V6 is for enthusiasts; the Kompressor petrols are the ones to inspect most carefully.
7

How do I find my CLC-Class engine code?

Your CLC-Class engine code is stamped on the engine block (usually visible from above, near the front), printed on the vehicle's VIN sticker (often inside the driver's door frame or service book), and encoded in the VIN itself. If you're unsure, use the Mercedes-Benz VIN decoder on our homepage - or enter your registration on our calculator and we'll identify it for you.
8

CLC-Class vs C-Class - which is more reliable?

They share engines - the M271, OM646 and M272 across the W203/CL203 platform. Reliability is essentially identical, but the CLC-Class has better rust protection (post-2008) and a coupe body. The C-Class offers four-door practicality and a wider range of engine options (including the OM651 and larger V6s). Buy on body style and condition - not reliability.

Need a head-to-head comparison?

Read our in-depth Mercedes reliability comparison guides.

Read the Full Head-to-Head

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