Mercedes‑BenzCLA2013–present2 Generations • M270 • M282 • OM651 • OM654 • M139

CLA Engines — The Complete UK Guide

Every CLA engine — M270 petrol, OM651 diesel, M282 petrol, OM654 diesel, and the AMG M139 — across two generations of Mercedes’ four-door coupé. Real UK costs, reliability data and ownership verdicts for the C117 (2013–2019) and C118 (2019–2025). Backed by real UK enquiry data from Mercedes-Benz owners in 2025 [MB-VERIFIED].

Explore CLA Engines

  • Real UK Enquiries (2025) [MB-VERIFIED]

  • 2 Generations Covered

  • 10+ Engine Codes

  • Part of Engine Finders

CLA —
The Ownership Verdict

Verdict MetricOur Call
Overall Ownership Rating

★★★★☆

Replacement Economics

✅ The CLA rule: generation is everything — C118 hosts comfortably justify replacement; C117 values mean the OM651 diesel needs careful evaluation before committing

Reliability

★★★★☆

Most Reliable Engine

OM654 — the modern 2.0‑litre diesel; 520 UK enquiries in 2025 and materially fewer failure reports than the OM651 it replaced [MB-VERIFIED]

Highest‑Risk Engine

OM651 — “Black Death” injector seal risk plus rear‑chain complexity; 1,250 UK enquiries in 2025, the highest of any Mercedes diesel [MB-VERIFIED]

Best Used Buy

C118 (2019+) CLA 200 with M282 1.3 petrol — modern, reliable, and the facelift (2023+) electronics are the safest bet

Average Engine Replacement

£1,800–£4,800 supply‑only [MB-QUOTE]

Most Common Failure Enquiry

OM651 injector seal failure (“Black Death”) — 1,250 UK enquiries in 2025 [MB-VERIFIED]

Mercedes Ranking

🥇 Best‑value entry to Mercedes‑Benz ownership — the CLA offers coupé styling at a C‑Class‑competitive price, with running costs that undercut the larger saloons

CLA
at a Glance

  • Generations

    2 (C117 2013–2019, C118 2019–2025)

  • Years Produced

    2013–present

  • Engine Codes Tracked

    10+

  • Fuel Types

    Petrol, Diesel, Petrol Hybrid (2025+)

  • Most Enquired Engine (2025)

    OM651 — 1,250 enquiries across CLA/C‑Class/E‑Class/GLA [MB-VERIFIED]

  • Most Reliable

    OM654 — modern 2.0‑litre diesel with clean failure record

  • Highest‑Risk

    OM651 — “Black Death” injector seal failure

  • Typical Replacement Cost

    £1,800–£4,800 supply‑only [MB-QUOTE]

  • Typical Host Value

    C117: £3,000–£10,000 • C118: £8,000–£25,000 [THIRD-PARTY]

  • SECTION 4 — GENERATIONS —

    H2: CLA Generations — Find Your Vehicle

  • Sub-headline: Two generations, two very different ownership stories — the first‑generation C117 is the value‑with‑risk proposition; the second‑generation C118 is the safe, modern choice.

    First Generation — C117 (2013–2019)

  • [2013–2019] • M270 1.6/2.0 petrol • OM651 2.1 diesel

    ★★★★☆

  • Our Verdict: The CLA that started it all — four‑door coupé styling on the A‑Class platform. The M270 petrols are robust; the OM651 diesel carries the “Black Death” injector‑seal caveat and rear‑chain complexity. Buy on condition and documented history, not mileage.

    Explore C117 →

  • Second Generation — C118 (2019–2025) 🔥 Most Enquired — data aggregated from shared engines [MB-VERIFIED]

    [2019–2025] • M282 1.3 petrol • OM654 2.0 diesel • M139 2.0 AMG

  • ★★★★☆

    Our Verdict: Longer, wider, and based on the W177 A‑Class platform — the C118 is the CLA to buy. The M282 petrol is reliable and cheap to run; the OM654 diesel is the cleanest modern Mercedes oil‑burner; the M139 AMG is a fire‑breathing specialist’s toy. Post‑facelift (2023+) electronics are the sweet spot.

  • Explore C118 →

    Third Generation — C178/C174 (2025–present)

  • [2025–present] • Petrol hybrid • Full EV

    ★★★☆☆

  • Our Verdict: Too early for reliability data — the third‑generation CLA introduces 48‑volt hybrid and full‑electric variants. We’re watching the data. For now, the C118 remains the safer used buy.

    Explore C178 →

  • Comparison: C117 vs C118 — which generation should you buy?

    C117 (2013–2019)

  • C118 (2019–2025)

    Platform

  • W176 A‑Class

    W177 A‑Class

  • Best petrol

    M270 2.0 (CLA 250) — robust, 211hp

  • M282 1.3 (CLA 200) — reliable, 163hp

    Best diesel

  • OM651 — but check injector seals

    OM654 — clean, modern, 150–190hp

  • Avoid

    OM651 without full injector‑seal history

  • Early M282 with unresolved software updates

    Verdict

  • ⚠️ Value buy with caveats

    ✅ The safe, modern choice

Overall Rating

★★★★☆

3.9/5

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

CLA Generations —
Find Your Vehicle

Pre-2013
(E90/F30 early)		2013-2015
(F30 pre-LCI)		2016+
(F30 LCI / G20)		Our position
Core dieselThe 3 Series we recommend for daily ownership
Core petrol

Read the full comparison:

CLA Engine Codes — The Database
The Database

The complete database of BMW 3 Series engine codes with real UK enquiry data, fitted models, and replacement cost insights.

Proprietary UK Data

Every figure below is powered by 24,650+ real UK owner enquiries in 2025. This is data you won't find anywhere else.

Engine CodeFuel2025 EnquiriesView
OM651Diesel1,250
OM654Diesel520
M139Petrol-
M260Petrol-
M270 DE16Petrol-
M270 DE20Petrol-
M282Petrol-
OM608Diesel-

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 CLAEngine Problems

The six most common CLA failure patterns — from “Black Death” injector seals to M282 coolant leaks — ranked by severity.

01

OM651 “Black Death” injector seal failure

Catastrophic if Ignored

The defining Mercedes diesel issue — copper injector seals degrade, leaking combustion gases into a carbon “tar” that can weld the injector into the head. Most common on C117 CLA 200d/220d. £400–£1,200 seal repair; up to full engine replacement if neglected [MB-QUOTE].

Read more
02

OM651 rear timing chain tensioner wear

Immediate

Unlike most engines, the OM651’s chain sits at the transmission end — access requires separating engine from gearbox. C117 CLA diesels affected. £600–£1,500 repair [MB-QUOTE].

Read more
03

M282 1.3 petrol coolant leaks

Monitor

Coolant loss from water pump or thermostat housing — well‑documented on early C118 M282 units. £400–£800 repair [MB-QUOTE].

Read more
04

M270 1.6 timing chain stretch

Monitor

Chain stretch on higher‑mileage C117 M270 petrols — less common than the diesel chain issues but still a known weak point. £800–£1,500 repair [MB-QUOTE].

Read more
05

M139 AMG high‑pressure fuel pump failure

Monitor

The 382–421hp AMG engine’s HPFP can fail on higher‑mileage examples — specialist‑only repair. £800–£1,500 repair [MB-QUOTE].

Read more
06

AdBlue system issues (OM654/OM608)

Low

NOx sensor and heater failures on C118 diesel CLA models — software‑manageable rather than mechanical. £400–£1,500 repair [MB-QUOTE].

Read more

Urgency Key

Catastrophicstop driving, specialist inspection immediately

Immediatebook inspection now

Monitorbook inspection soon

Lowplan at next service

CLA Market Intelligence — What UK Owners Told Us in 2025

826+

Total Enquiries in 2025

[BMW-VERIFIED]

Signal
2025 Data
Demand Trend

OM651 diesel enquiries (CLA + C‑Class + E‑Class + GLA)

1,250 [MB-VERIFIED]

⬇️ Falling

OM654 diesel enquiries

520 [MB-VERIFIED]

️ Rising

C118 CLA (2019+) share of CLA‑related enquiries

Estimated 60%+ of CLA‑specific interest

️ Rising

Insights from the data:

“Interesting insight:” The OM651 diesel — the engine fitted to the first‑generation CLA 200d/220d — generated 1,250 UK enquiries in 2025, making it the most‑enquired Mercedes diesel of the year [MB-VERIFIED]. The vast majority relate to injector seal (“Black Death”) and timing chain failures. If you’re buying a C117 CLA diesel, factor a £400–£1,200 injector‑seal inspection into your purchase budget — or walk away from any car without documented seal history.

The OM654 diesel — fitted to the second‑generation CLA 200d/220d — generated just 520 enquiries in 2025, with materially fewer failure reports. The modern engine is the safe diesel choice; the C118 generation is the CLA to buy if you want diesel refinement without the “Black Death” caveat.

The C118 CLA (2019–2025) accounts for the majority of current CLA‑specific buyer interest, driven by the more reliable M282 petrol and OM654 diesel engines, plus the facelift (2023+) electronics update that addressed early software gremlins. Pre‑facelift C118 examples (2019–2022) are the value sweet spot; post‑facelift (2023+) is the safest bet.

Editorial Pull-Quote

The One Thing We’d Tell Every CLA Buyer

“Buy a 2023+ C118 CLA 200 with the M282 1.3 petrol — it’s the most reliable, cheapest‑to‑run CLA you can own. If you must have a diesel, choose the OM654 in a post‑2020 C118 and insist on full service history. Avoid any C117 OM651 diesel without documented injector‑seal replacement — the “Black Death” repair bill can exceed the car’s value.”

CLA Engine Replacement Costs
By Generation

Real UK pricing for every CLA engine — used, reconditioned and rebuilt supply-only costs, with independent labour guidance.

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

Important Notes

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

Labour Estimate

Fitting a CLA engine typically takes 8–14 hours at £65–£95/hr (independent) or £110–£160/hr (London/SE dealer) [MB-QUOTE]. The CLA rule — generation is everything: A £2,800–£4,800 OM651 recon against a £3,000–£6,000 C117 CLA diesel sits at 80–95% of the car's value — above our 70% threshold for Mercedes-Benz. If you're facing an OM651 failure in a C117, get a scrap valuation before you authorise any repair. By contrast, a £3,000–£5,000 OM654 recon against an £8,000–£25,000 C118 CLA sits comfortably at 20–60% of the car's value — well within safe territory. For C117 M270 petrols, the £1,500–£3,200 recon against a £4,000–£8,000 car sits at 38–80% — borderline on lower-value examples, safe on better cars. In short: repair a C118, evaluate a C117 petrol carefully, and walk away from a C117 diesel without full history.

The 3 Series 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 CLA Engine Range Evolved —2013 to Today

From the original M10 to today's advanced B-series, explore how engineering, emissions and performance shaped every generation of 3 Series engines.

7 Generations1975 to Present
25+ Engine FamiliesFrom M10 to B58
50 Years of EngineeringPerformance & Innovation
Built for DriversReliability + Dynamics
Key Engines
M270 1.6/2.0 petrol, OM651 2.1 diesel
Why BMW Changed
Mercedes launched the CLA as a four‑door coupé based on the W176 A‑Class platform — the engines were carried over directly from the A‑Class range, with the OM651 diesel already carrying its “Black Death” reputation from the C‑Class and E‑Class
Worth Knowing
The C117 shares its platform and most engines with the W176 A‑Class — if you're researching CLA reliability, the A‑Class data is directly relevant

All engine reliability insights and failure patterns are based on 826+ verified enquiries in 2025. Data covers the UK market. [BMW-VERIFIED]

Who Should Buy a CLA?

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

Family Buyer

★★★★★

The CLA is a four‑door coupé — not a family car. The sloping roofline compromises rear headroom, and the boot is smaller than a C‑Class Estate. If you need family space, buy a C‑Class or GLC instead. If you want coupé styling and don't regularly carry rear passengers, the CLA works.

Daily Commuter

★★★★★

The C118 CLA 200 with the M282 1.3 petrol is an excellent commuter — 50+ mpg, cheap tax, and the facelift (2023+) electronics are sorted. The C117 diesel is less recommendable due to the OM651's injector‑seal risk — if you must have a diesel, choose a C118 with the OM654.

Budget Owner

★★★★★

The C117 CLA is the most affordable way into Mercedes‑Benz ownership — but the OM651 diesel is a genuine caveat. A sub‑£5k C117 diesel without documented injector‑seal history is a gamble; a C117 petrol (M270) is the safer budget bet.

Performance Buyer

★★★★★

The CLA 45 AMG (C118, M139 engine) is a genuine fire‑breather — 382–421hp from a 2.0‑litre four‑cylinder, with the world's most powerful production four‑pot. It's specialist‑only territory: full service history is non‑negotiable, and running costs are high. Buy it for the experience, not for economy.

Long‑Term Keeper

★★★★★

If you're keeping a CLA long‑term, buy a 2023+ C118 CLA 200 with the M282 1.3 petrol — the facelift electronics are sorted, the engine is robust, and the C118 platform is well‑understood. The OM654 diesel is also a keeper if you do regular motorway miles. Avoid any C117 as a long‑term keeper — the platform is ageing and the OM651's reputation is well‑earned.

i

Real talk. The right CLA 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 CLA Engines

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.

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Why CLA Owners Trust mercedesengine.uk

Built on Real Data - Every reliability rating and cost range on this page comes from genuine UK quote and enquiry data — not manufacturer marketing, not forum guesswork. The OM651 and OM654 figures are [MB-VERIFIED] from real 2025 UK enquiries.

We Tell You When Not to Repair - If replacement cost exceeds 70% of what your CLA is worth, we say so. That's why the C117 OM651 diesel carries a "scrap threshold" warning — not every site tells you when repair doesn't make financial sense.

Vetted Mercedes - Benz Specialists — Our network includes 25+ vetted Mercedes-Benz specialists who work on CLA engines daily — from OM651 "Black Death" injector seal repairs to M139 AMG turbo diagnostics. Every specialist is vetted specifically for Mercedes-Benz work, not generalists who happen to take on Mercedes jobs.

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.

CLA Frequently Asked Questions

1

How much does a CLA engine replacement cost in the UK?

A CLA engine replacement costs £1,500–£8,000 supply‑only depending on the engine and condition — a reconditioned OM651 for the C117 is £2,800–£4,800 [MB-QUOTE], a reconditioned M282 for the C118 is £1,800–£3,000 [MB-QUOTE], and an M139 AMG unit is £5,000–£8,000 [MB-QUOTE]. Labour adds 8–14 hours at £65–£95/hr (independent) or £110–£160/hr (London/SE dealer). Use our diagnostic calculator for a personalised estimate.
2

Which CLA engine is the most reliable?

The OM654 2.0‑litre diesel — fitted to the C118 CLA 200d and 220d (2019–present) — is the most reliable CLA engine. It generated just 520 UK enquiries in 2025 compared to the OM651's 1,250, with materially fewer failure reports [MB-VERIFIED]. The M282 1.3 petrol is also reliable, though early units (2019–2021) had coolant‑leak issues resolved by the 2023 facelift. Read more about the OM654 →
3

Which CLA engine should I avoid?

The OM651 2.1‑litre diesel in the C117 CLA (2013–2019) — specifically pre‑2016 examples without documented injector‑seal (“Black Death”) history. The copper injector seals degrade, leaking combustion gases into a carbon “tar” that can weld the injector into the head. A £400–£1,200 seal repair can become a full engine replacement if ignored. It's not a reason to avoid the engine entirely, but it's a reason to demand full history and a pre‑purchase inspection. Read more about OM651 “Black Death” →
4

How do I know if my CLA engine needs replacing?

Concrete symptoms by engine: * OM651 diesel (C117) — chemical smell around the injectors, black carbon “tar” visible on the engine cover, cold‑start rattle, loss of power. If you see black tar, book a specialist inspection immediately — injector seal failure is the primary risk. * M282 petrol (C118) — coolant loss with no visible leak, overheating, misfire codes. Water pump and thermostat housing failure are the known weak points. * OM654 diesel (C118) — AdBlue warning lights, NOx sensor errors, EGR cooler leaks. Software‑manageable rather than mechanical, but don't ignore the warnings. * M139 AMG (C118 CLA 45) — high‑pressure fuel pump noise, misfire under load, loss of power. Specialist‑only diagnosis.
5

Is it worth replacing a CLA engine?

Apply the 70% rule: if a reconditioned engine costs 70% or more of your car's current market value, get a scrap valuation before committing. * C117 OM651 diesel — £2,800–£4,800 recon against a £3,000–£6,000 car = 80–95% of value — not worth replacing unless the car is a low‑mileage, high‑spec example. * C117 M270 petrol — £1,500–£3,200 recon against a £4,000–£8,000 car = 38–80% of value — borderline on lower‑value examples. * C118 OM654 diesel — £3,000–£5,000 recon against an £8,000–£25,000 car = 20–60% of value — worth replacing. * C118 M282 petrol — £1,800–£3,000 recon against an £8,000–£20,000 car = 23–38% of value — worth replacing. Use our Ownership Decision Tool for a personalised assessment.
6

Which CLA generation should I buy?

Buy a 2023+ C118 CLA (facelift) with the M282 1.3 petrol — it's the most reliable, cheapest‑to‑run CLA you can own. The facelift addressed the early M282 coolant‑leak issues and updated the electronics. If you do regular motorway miles, the OM654 diesel (2020+) is also a strong choice. Avoid the C117 OM651 diesel unless you have documented injector‑seal history and are comfortable with the replacement‑cost risk.
7

How do I find my CLA engine code?

Check the following locations: * VIN plate (visible through the windscreen or on the driver's door pillar) — the engine code is encoded in positions 4–8 of the VIN. * Vehicle registration document (V5C) — the engine number is listed in Section 4. * Under‑bonnet sticker — on the slam panel or timing cover, the engine code is often printed on a factory sticker. * Mercedes‑Benz parts catalogue — enter your VIN at a dealer or online parts site to look up the exact engine code. If you're unsure, use our diagnostic calculator — we'll help you identify it as step one.
8

CLA vs A‑Class — which is more reliable?

They share platforms and engines — the C117 CLA shares with the W176 A‑Class; the C118 CLA shares with the W177 A‑Class. Reliability is therefore identical for the same engine and generation. The difference is style and practicality — the CLA is a four‑door coupé with a sloping roofline (less rear headroom, less boot space); the A‑Class is a conventional hatchback (more practical, cheaper to buy). If you need space, buy the A‑Class; if you want coupé styling, buy the CLA. The same engine‑reliability rules apply to both. Read the full comparison: CLA vs A‑Class →

Need a head-to-head comparison?

Read our in-depth BMW 3 Series vs 5 Series reliability guide.

Read the Full Head-to-Head

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3 Series Generations

Compare the C117 and C118 side‑by-side, including the 2025+ third generation.

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