How much does a Mercedes X218 engine replacement cost in the UK?

A reconditioned X218 engine typically costs £2,500–£14,000 supply only [MB‑QUOTE], depending on engine — the OM651 four‑cylinder diesel runs £2,500–£4,500, while the M157 V8 in the CLS 63 AMG can cost £7,000–£14,000. Fitting adds £780–£1,430. Use our calculator for a personalised quote.

Which Mercedes X218 engine is the most reliable?

The post‑facelift M276 3.0‑litre twin‑turbo V6 (CLS 400) is the most dependable choice — it's a modern, well‑sorted engine without the balance‑shaft issues of earlier M272 units. The OM651 four‑cylinder diesel is robust but needs chain monitoring. The OM642 V6 diesel is reliable but suffers from oil‑cooler seal leaks.

What are the common problems with the Mercedes X218?

OM642 V6 diesels suffer oil‑cooler seal leaks; OM651 diesels have a rear‑mounted timing chain that can stretch; M278 V8 petrols can develop turbo coolant line failures; and M157 V8s (CLS 63) can experience cam lifter wear. Regular servicing is critical across all engines.

Is the Mercedes X218 reliable?

It depends on the engine. The M276 twin‑turbo V6 is generally excellent. The OM642 V6 diesel is robust but has a well‑documented oil‑cooler seal weakness. The OM651 needs chain monitoring. The M157 is a high‑performance engine that demands meticulous maintenance. Overall, a well‑maintained X218 can be a dependable premium estate.

Which Mercedes X218 engine should I avoid?

No engine is an outright "avoid" — but an OM642 without documented oil‑cooler seal replacement is one we'd approach with caution. Similarly, a high‑mileage CLS 63 AMG without full service history warrants careful inspection. Always get a specialist pre‑purchase inspection.

How do I know if my X218 engine needs replacing?

Key warning signs include: cold‑start rattle (OM651 chain), burning oil smell (OM642 seals), coolant loss with no visible leak (M278 coolant lines), or a top‑end tick that worsens (M157 lifters). If you experience any of these, get a diagnosis immediately — early intervention saves thousands.

Is it worth replacing a Mercedes X218 engine, or should I scrap the car?

Depends on the car's value. Against a well‑kept £20,000 X218, a £5,500 OM642 recon is 27% of the car's value — safe if the car is otherwise sound. Against a tired £8,000 example, the same recon is 69% — brushing our 70% Mercedes threshold, so evaluate scrap. Use our 70% rule as your guide.

How long do Mercedes X218 engines last?

With proper maintenance, the M276 V6 petrol can exceed 150,000 miles, and the OM651 diesel can reach 200,000+ miles with careful chain monitoring. The OM642 V6 diesel is robust but the oil‑cooler seals will need replacement at around 100,000 miles. The M157 is durable but demands expensive preventative maintenance.

What is the difference between the X218 and C218?

Both share the same platform and engines. The X218 is the 5‑door Shooting Brake estate (2012–2018, this page), while the C218 is the 4‑door coupé (2011–2018). Costs vary slightly by body style due to labour access — see the C218's own Generation Page for specifics.

How do I find my Mercedes X218 engine code?

Listed on the VIN plate (visible through the windscreen) and in the vehicle documentation. The code is stamped on the engine block — on OM651/OM642 it's on the front left, on M276/M278/M157 it's on the right side. Tell us your variant and registration year, and we'll identify it for you.

X218 Engine Replacement Cost UK

Mercedes CLS X218 Engine Codes — The Complete Database

Engine CodeFuelPowerYearsReliabilityEnquiriesAvg. Recon Cost

Overview

Mercedes CLS X218 — Overview

The X218 is the Shooting Brake (estate) body style of the second‑generation Mercedes‑Benz CLS‑Class, announced in June 2012 and produced alongside the C218 four‑door coupé until 2018.

Built on the same platform as the W212 E‑Class, it offers the coupé styling of the CLS with the practicality of a five‑door estate. A facelift in 2014 brought design changes, engine enhancements — including the introduction of twin‑turbo M276 V6 petrols replacing the naturally aspirated M276 — and the adoption of the 9G‑Tronic automatic transmission. The X218 is available with rear‑wheel drive or 4MATIC all‑wheel drive, and its engine range spans from efficient four‑cylinder diesels to the 5.5‑litre twin‑turbo M157 V8 in the CLS 63 AMG.

Key Facts

Platform

Mercedes‑Benz W212 E‑Class

Predecessor

None (first Shooting Brake CLS)

Successor

None (C257 CLS has no estate variant)

Sibling body styles in this generation

C218 four‑door coupé (2011–2018)

Market Intelligence

No X218‑specific enquiry figure is available; OM651 diesel enquiries dominate the broader Mercedes compact‑car parc, with 1,250 UK requests in 2025 [MB‑VERIFIED].

Mercedes CLS X218 — Overview

The X218 is the Shooting Brake (estate) body style of the second‑generation Mercedes‑Benz CLS‑Class, announced in June 2012 and produced alongside the C218 four‑door coupé until 2018.

Built on the same platform as the W212 E‑Class, it offers the coupé styling of the CLS with the practicality of a five‑door estate. A facelift in 2014 brought design changes, engine enhancements — including the introduction of twin‑turbo M276 V6 petrols replacing the naturally aspirated M276 — and the adoption of the 9G‑Tronic automatic transmission. The X218 is available with rear‑wheel drive or 4MATIC all‑wheel drive, and its engine range spans from efficient four‑cylinder diesels to the 5.5‑litre twin‑turbo M157 V8 in the CLS 63 AMG.

Key Facts

Platform

Mercedes‑Benz W212 E‑Class

Predecessor

None (first Shooting Brake CLS)

Successor

None (C257 CLS has no estate variant)

Sibling body styles in this generation

C218 four‑door coupé (2011–2018)

Market Intelligence

No X218‑specific enquiry figure is available; OM651 diesel enquiries dominate the broader Mercedes compact‑car parc, with 1,250 UK requests in 2025 [MB‑VERIFIED].

Best & Worst Engines

Mercedes CLS X218 — Ownership Economics

EngineTypical MileageCommon Major FailureRepair Cost (Specialist)Replacement Cost (Recon)Ownership Verdict

OM651.92480k–150kTiming‑chain tensioner£600–£1,500£2,500–£4,500

Watch the Chain — tensioner is the key risk

OM642 V6 diesel80k–150kOil‑cooler seal leak£800–£1,500£3,200–£5,500

V6 Torque — smooth, but seals are labour‑intensive

M276.952 (3.5)60k–100kThermostat, water pump£300–£800£3,000–£5,500

Solid Petrol — reliable naturally aspirated V6

M276 turbo (3.0)60k–100kWater pump, carbon build‑up£300–£800£3,500–£6,000

Best Petrol — modern twin‑turbo V6

M278.922 (4.7 V8)60k–100kTurbo coolant lines£800–£2,000£4,500–£8,500

V8 Grunt — fast, but hot‑vee complexity

M157.981 (5.5 V8)40k–80kCam lifters, turbo wear£1,500–£4,000£7,000–£14,000

AMG Tax — high performance, high cost

EngineTypical MileageCommon Major FailureRepair Cost (Specialist)Replacement Cost (Recon)Ownership Verdict

OM651.92480k–150kTiming‑chain tensioner£600–£1,500£2,500–£4,500

Watch the Chain — tensioner is the key risk

OM642 V6 diesel80k–150kOil‑cooler seal leak£800–£1,500£3,200–£5,500

V6 Torque — smooth, but seals are labour‑intensive

M276.952 (3.5)60k–100kThermostat, water pump£300–£800£3,000–£5,500

Solid Petrol — reliable naturally aspirated V6

M276 turbo (3.0)60k–100kWater pump, carbon build‑up£300–£800£3,500–£6,000

Best Petrol — modern twin‑turbo V6

M278.922 (4.7 V8)60k–100kTurbo coolant lines£800–£2,000£4,500–£8,500

V8 Grunt — fast, but hot‑vee complexity

M157.981 (5.5 V8)40k–80kCam lifters, turbo wear£1,500–£4,000£7,000–£14,000

AMG Tax — high performance, high cost

The X218 rule

A £3,200–£5,500 OM642 recon against a £10,000–£25,000 X218 sits at 13–55% of the car’s value — generally safe. Against a sub‑£10,000 example, the same recon brushes our 70% Mercedes threshold — we’ll honestly tell you to walk away. Against a well‑kept £20,000+ example, the same recon drops to a routine 16–28% — a straightforward repair decision. Value the car first.

Key Takeaways

Which X218 Costs Least To Own?
OM651 2.1 diesel — cheapest recon and simple repairs.
Which X218 Costs Most To Own?
M157 5.5 AMG — AMG parts and labour are eye‑wateringly expensive.
Which X218 Is Best Value?
Post‑facelift CLS 400 (M276 twin‑turbo) — modern V6 power without V8 running costs.

Common Problems

01

OM642

Oil‑Cooler Seal Leak

Affected models:

X218 CLS 350 CDI, CLS 350 BlueTEC, CLS 350 d (OM642 V6 diesel).

Typical failure mileage:

80,000–150,000 miles.

Root cause:

The oil‑cooler O‑rings in the V of the OM642 engine degrade with heat cycling, causing oil leaks that can drip onto the exhaust and create a burning smell. Labour is intensive as the intake manifold must be removed.

Tiered Cost Table

Preventative (Repair)

Dealer

Specialist

£1,500–£2,500

£800–£1,500

Replace oil‑cooler seals

Catastrophic (Replacement)

Dealer

Specialist

£5,000–£7,500

£3,200–£5,500

Full reconditioned engine

Our Recommendation

If you notice a burning oil smell or oil residue in the engine V, have the oil‑cooler seals replaced immediately — an £800–£1,500 repair is cheaper than the £3,200+ replacement that follows if the engine runs low on oil.

Compare OM642 engine prices for your X218

02

OM651

Timing‑Chain Tensioner Wear

Affected models:

X218 CLS 220 BlueTEC, CLS 250 BlueTEC (OM651 diesel).

Typical failure mileage:

80,000–150,000 miles.

Root cause:

The OM651 has a rear‑mounted timing chain that can stretch over time. Cold‑start rattle is the classic early warning — if ignored, the chain can jump and cause catastrophic engine damage.

Tiered Cost Table

Preventative (Repair)

Dealer

Specialist

£1,200–£2,500

£600–£1,500

Replace chain, tensioner, guides

Catastrophic (Replacement)

Dealer

Specialist

£5,000–£7,500

£2,500–£4,500

Full reconditioned engine

Our Recommendation

At the first sign of cold‑start rattle on an OM651, get the chain inspected immediately — a £600–£1,500 preventative repair is far cheaper than the £2,500+ replacement that follows if ignored.

Compare OM651 engine prices for your X218

03

M278

Turbo Coolant Line Failure

Affected models:

X218 CLS 500, CLS 500 4MATIC (M278 4.7 V8).

Typical failure mileage:

60,000–100,000 miles.

Root cause:

The M278’s hot‑vee design places the turbos in the V of the engine, and the coolant lines can degrade with heat cycling, leading to coolant loss and potential turbo damage.

Tiered Cost Table

Preventative (Repair)

Dealer

Specialist

£1,500–£3,000

£800–£2,000

Replace coolant lines, inspect turbos

Catastrophic (Replacement)

Dealer

Specialist

£7,000–£10,000

£4,500–£8,500

Full reconditioned engine

Our Recommendation

If you own a CLS 500, have the coolant system inspected annually — an £800–£2,000 repair is far cheaper than the £4,500+ replacement that follows a catastrophic failure.

Compare M278 engine prices for your X218

04

M157

Cam Lifter & Turbo Wear (CLS 63 AMG)

Affected models:

X218 CLS 63 AMG, CLS 63 AMG S‑Model (M157 5.5 V8).

M157 Cam Lifter & Turbo Wear (CLS 63 AMG)

Typical failure mileage:

40,000–80,000 miles.

Root cause:

The high‑output M157 engine can suffer from cam lifter wear and turbocharger issues, particularly if oil changes have been neglected. Ticking from the top end is the classic warning sign.

Tiered Cost Table

Preventative (Repair)

Dealer

Specialist

£3,000–£5,000

£1,500–£4,000

Replace cam lifters and adjusters

Catastrophic (Replacement)

Dealer

Specialist

£12,000–£18,000

£7,000–£14,000

Full reconditioned engine

Our Recommendation

If you’re buying a CLS 63 AMG, budget for a cam lifter inspection and insist on full service history — a £1,500–£4,000 preventative repair is a fraction of the £7,000+ replacement that follows a full failure. This is the price of AMG ownership.

Compare M157 engine prices for your CLS 63 AMG

X218 Engine Replacement Costs — By Engine and Condition

VariantEngine CodeUsed (Supply)Reconditioned (Supply)Rebuilt (Supply)Labour Hours

CLS 220 BlueTEC, CLS 250 BlueTECOM651.924£1,200–£2,500£2,500–£4,500£4,000–£6,50010–14 hrs

CLS 350 CDI, CLS 350 BlueTEC, CLS 350 dOM642.852 / .853 / .854 / .858£1,800–£3,200£3,200–£5,500£5,000–£7,50012–16 hrs

CLS 350 (pre‑facelift)M276.952£1,500–£3,000£3,000–£5,500£4,500–£7,00010–14 hrs

CLS 400, CLS 400 4MATIC (post‑facelift)M276.820 / .850£1,800–£3,500£3,500–£6,000£5,000–£8,00010–14 hrs

CLS 500, CLS 500 4MATICM278.922£2,500–£4,500£4,500–£8,500£7,000–£12,00014–18 hrs

CLS 63 AMG, CLS 63 AMG S‑ModelM157.981£4,000–£7,000£7,000–£14,000£10,000–£18,00016–22 hrs

No Generation variance from the Model Page’s baseline figures — X218 shares its engine bay architecture with the C218 coupé and W212 E‑Class, so costs are inherited directly per the Authority Model, with no divergence note required. OM651, OM642, and M276 costs carried forward from the EM data’s Table A.

Core Variants

Diesel Variants

CLS 220 BlueTECCLS 220 dCLS 250 BlueTECCLS 250 dCLS 350 CDICLS 350 BlueTECCLS 350 d

Petrol Variants

CLS 350CLS 400CLS 400 4MATICCLS 500CLS 500 4MATICCLS 63 AMGCLS 63 AMG S‑Model

Scope note: All variants listed are X218 Shooting Brake only. C218 four‑door coupé shares most of these engines but is covered on its own Generation Page, since fitment and labour access vary slightly by body style.

Core Variants

Diesel Variants

CLS 220 BlueTECCLS 220 dCLS 250 BlueTECCLS 250 dCLS 350 CDICLS 350 BlueTECCLS 350 d

Petrol Variants

CLS 350CLS 400CLS 400 4MATICCLS 500CLS 500 4MATICCLS 63 AMGCLS 63 AMG S‑Model

Scope note: All variants listed are X218 Shooting Brake only. C218 four‑door coupé shares most of these engines but is covered on its own Generation Page, since fitment and labour access vary slightly by body style.

Market Intelligence

Most Requested E90 Engines (2025)

Most Requested E90 Variants

Average E90 Replacement Cost

Most Common E90 Failures

FAQ

BMW 3 Series E90 rear three-quarter view

Why UK Mercedes X218 Owners Trust MercedesEngines.uk

Trusted X218 Engine Suppliers
every garage and engine rebuilder in our network is vetted, rated and reviewed by real X218 owners, as part of the Engine Finders network.
Compare X218 Engine Replacement Companies
see prices, warranty terms and supply‑&‑fit options side‑by‑side before you commit.
UK Engine Replacement Services for X218
covering every variant from CLS 220 BlueTEC to CLS 63 AMG, with supply‑only or full supply‑&‑fit available nationwide.

Find the best Mercedes X218 engine replacement UK drivers rely on. Compare real prices from trusted specialists on EnginesMarket today and get back on the road with confidence.

Compare Mercedes CLS X218 Engine Prices on EnginesMarket

Why UK Mercedes X218 Owners Trust MercedesEngines.uk

Trusted X218 Engine Suppliers
every garage and engine rebuilder in our network is vetted, rated and reviewed by real X218 owners, as part of the Engine Finders network.
Compare X218 Engine Replacement Companies
see prices, warranty terms and supply‑&‑fit options side‑by‑side before you commit.
UK Engine Replacement Services for X218
covering every variant from CLS 220 BlueTEC to CLS 63 AMG, with supply‑only or full supply‑&‑fit available nationwide.

Find the best Mercedes X218 engine replacement UK drivers rely on. Compare real prices from trusted specialists on EnginesMarket today and get back on the road with confidence.

Compare Mercedes CLS X218 Engine Prices on EnginesMarket

Mercedes CLS X218 Engines — The Complete UK Guide

Mercedes CLS X218 Engine Codes — The Complete Database

Mercedes CLS X218 — Overview

Mercedes CLS X218 — Overview

Best & Worst Engines

Mercedes CLS X218 — Ownership Economics

Common Problems

X218 Engine Replacement Costs — By Engine and Condition

Core Variants

Core Variants

Market Intelligence

FAQ

Why UK Mercedes X218 Owners Trust MercedesEngines.uk

Why UK Mercedes X218 Owners Trust MercedesEngines.uk