How much does a Mercedes E250 CDI / E250d engine replacement cost in the UK?

A reconditioned E250 CDI / E250d engine typically costs £4,000–£8,500 supply only depending on generation. A timing chain replacement alone costs £1,500–£2,500. Fitting adds £1,000–£1,800 at independent specialist rates. Use our calculator for a figure specific to your car.

Is the Mercedes E250 CDI / E250d engine reliable?

It depends on which generation you're asking about. The OM651 (E250 CDI, 2009–2016) is a high‑tech diesel with serious drawbacks — timing chain stretch is the defining weakness, requiring a complex and costly replacement. Injector failures, oil leaks, and DPF/EGR issues are also common. The OM654 (E250d, 2016+) is lighter, more efficient, and more reliable, but turbocharger failures, injector issues, and timing chain concerns have been reported. Regular maintenance is essential.

What are the common problems with the Mercedes E250 CDI / E250d?

OM651 timing chain stretch and piezo injector failure (E250 CDI), OM651 oil leaks and cooling system issues, DPF and EGR problems (both generations), OM654 turbocharger failure and injector issues (E250d), and 7G‑Tronic transmission issues. See the Era Map above for generation‑specific advice.

Is it worth replacing a Mercedes E250 CDI / E250d engine, or should I scrap the car?

Depends on vehicle value. Against a well‑kept W213 E250d (values £15,000–£30,000+), a £4,500–£5,500 reconditioned engine is 15–30% of the vehicle's value — worth it for a solid example. Against an older W212 E250 CDI (£4,000–£12,000), a £4,000–£5,000 recon is 30–80% of the car's value — borderline but often worth it for a good example. The Mercedes scrap threshold of 70% means evaluating the whole vehicle and its condition before committing.

How do I find my Mercedes E250 CDI / E250d engine code?

Listed on the VIN plate and vehicle documentation. As a rule of thumb: W212/S212/C207/A207 (2009–2016) = OM651 (2.1L, 204 bhp); W213/S213 (2016–present) = OM654 (2.0L, 194 bhp). The OM651 was subject to a recall over faulty chain tensioner sealing rings. Tell us your registration date and we'll confirm it for free.

Mercedes E‑Class E250 CDI / E250d2009–presentOM651 / OM654 Diesel

Mercedes E‑Class E250 CDI / E250d Engine Replacement — Compare Prices & Get Quotes

Name: Mercedes E250 CDI / E250d UK Engine Enquiry Data 2025
Creator: MercedesEngine.uk

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Mercedes E250 CDI / E250d Engines — from £2,000 to £8,500Common codes: OM651, OM654

Mercedes E250 CDI / E250d Engines — from £2,000 to £8,500· Common codes: OM651, OM654

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The E250 CDI / E250d THROUGH TIME — Era Map

Four generations. Four eras. One guide to reliability, costs and what really matters.

Era Note

OM651 2.1‑litre diesel — 204 bhp, 500 Nm; timing chain stretch is the defining weakness; injector, DPF and EGR issues are also common

GenerationYearsEngine CodeReliabilityRecon CostEra Note

E‑Class W212/S212/C207/A207 (E250 CDI) BMW 320d E‑Class W212/S212/C207/A207 (E250 CDI)

2009–2016OM651 (2.1L 4‑cyl diesel, 204 bhp)★★★☆☆ [NEWLY ASSIGNED — see Data Note]£4,000–£7,000 [PLACEHOLDER — confirm vs cost sheet]OM651 2.1‑litre diesel — 204 bhp, 500 Nm; timing chain stretch is the defining weakness; injector, DPF and EGR issues are also common

E‑Class W213/S213 (E250d) BMW 320d E‑Class W213/S213 (E250d)

2016–2020OM654 (2.0L 4‑cyl diesel, 194 bhp)★★★★☆ [NEWLY ASSIGNED — see Data Note]£4,500–£7,500 [PLACEHOLDER — confirm vs cost sheet]OM654 2.0‑litre diesel — lighter, more efficient, improved reliability but turbocharger, injector and timing chain issues remain

E‑Class W213/S213 Facelift (E250d) BMW 320d E‑Class W213/S213 Facelift (E250d)

2020–presentOM654 (2.0L 4‑cyl diesel, 194 bhp)★★★★☆ [NEWLY ASSIGNED — see Data Note]£4,500–£8,500 [PLACEHOLDER — confirm vs cost sheet]Facelift E250d — same OM654 with 48V MHEV; proven engine with added electrical complexity

Why use this era map?

This table is the single source every other section on this page matches — Sections 2, 4 and 6 reference it rather than restating conflicting figures.

Real UK Cost Data

Verified Reliability

Expert Insights

Updated for 2025

Mercedes E250 CDI / E250d Engine Replacement Costs

Supply Only£4,000–£7,000

Fitted (Indie)£5,200–£8,500

Warranty12–24 months

Best ForMost owners — best cost/warranty balance

Engine TypeSupply OnlyFitted (Indie)WarrantyBest For

Used Engine£2,000–£3,500£2,800–£4,8001–6 monthsBudget priority; vehicle under £5,000

Reconditioned Engine£4,000–£7,000£5,200–£8,50012–24 monthsMost owners — best cost/warranty balance

Rebuilt Engine£5,500–£8,500£6,800–£10,00012–24 monthsLong‑term ownership; 3+ year horizon

Main Dealer New£8,000–£12,000£9,500–£14,00024–36 monthsInsurance jobs, warranty claims

Figures above reflect the current E250 CDI / E250d range. Reconditioned engines typically cost £1,200–£2,200 supply only, with fitted costs around £1,800–£2,800 for smaller engines — the E250's diesel engine commands a premium. A timing chain replacement alone typically costs £1,500–£2,500.

Labour estimate: Fitting an E250 CDI / E250d engine typically takes 10–14 hours at £75–£110/hr (independent) or £130–£180/hr (London/SE dealer). The OM651 timing chain replacement requires removing numerous components and is technically complex. [PLACEHOLDER — confirm vs cost sheet]

→ Compare E250 CDI / E250d engine prices from UK specialists

Common Problems

1. OM651 Timing Chain Stretch & Tensioner Failure (E250 CDI, 2009–2016)

Symptoms: Rattling or clattering noise from the engine on cold start lasting 2–3 seconds, metallic noises, engine warning light, loss of power, rough idling.

Typical mileage: 60,000–120,000 miles — one owner reported the rattle after 20k miles on a replacement chain

Repair cost: £1,500–£2,500 (timing chain, tensioner and sprockets replacement) — some specialists have quoted around £900

Replacement cost: £4,000–£7,000 (if chain snaps and valves meet pistons)【PLACEHOLDER】

🔴 Immediate - if you hear rattle, book an inspection today

Our recommendation:

The OM651's timing chain is the defining weakness of this engine generation. Mercedes opted for a simplex roller chain design, which proved problematic. A stretched timing chain produces a distinct rattle during engine operation and can accelerate wear on related parts. The chain is located on the output side of the engine, making replacement technically complex and costly. Mercedes issued a recall for faulty chain tensioner sealing rings that could cause oil leaks. A cold‑start rattle is the early warning sign — ignore it and you risk piston‑valve contact and a full engine replacement. Check service history for timing chain replacement — if missing, walk away.

1. OM651 Timing Chain Stretch & Tensioner Failure (E250 CDI, 2009–2016)

Symptoms: Rattling or clattering noise from the engine on cold start lasting 2–3 seconds, metallic noises, engine warning light, loss of power, rough idling.

Typical mileage: 60,000–120,000 miles — one owner reported the rattle after 20k miles on a replacement chain

Repair cost: £1,500–£2,500 (timing chain, tensioner and sprockets replacement) — some specialists have quoted around £900

Replacement cost: £4,000–£7,000 (if chain snaps and valves meet pistons)【PLACEHOLDER】

🔴 Immediate - if you hear rattle, book an inspection today

Our recommendation:

2. OM651 Piezo Injector Failure (E250 CDI)

Symptoms: Rough idling, loss of power, poor fuel economy, engine misfires, ruckeln (juddering) under partial load, check engine light.

Typical mileage: 80,000–120,000 miles

Repair cost: £400–£1,200 (injector replacement)【PLACEHOLDER】

Replacement cost: £4,000–£7,000 (if injector failure leads to engine damage or catalytic converter failure)【PLACEHOLDER】

🟠 Check - book inspection urgently if rough running or smoke occurs

Our recommendation:

Piezo injectors are the Achilles' heel of the OM651. They proved sensitive to fuel quality and operating conditions, causing erratic fuel delivery, rough running and higher consumption. In some cases, injector failure was critical and demanded expensive repairs. Injector bottom seal leaks are also common. If you experience rough idling, misfires or loss of power, have the injectors inspected immediately. Replacing a faulty injector before it fails completely can prevent damage to other engine components. Regular fuel filter changes and using premium diesel are the best prevention.

3. OM651 Oil Leaks (E250 CDI)

Symptoms: Oil spots under the vehicle, burning oil smell, low oil warning, visible oil seepage.

Typical mileage: 60,000–120,000 miles

Repair cost: £300–£900 (seal replacement)【PLACEHOLDER】

Replacement cost: £4,000–£7,000 (if oil starvation leads to engine damage)【PLACEHOLDER】

🟡 Monitor - book inspection soon; oil leaks can damage other components

Our recommendation:

Widespread oil leakage caused by sealing defects is a major issue on the OM651. Faulty sealing rings on the chain tensioner were subject to a Mercedes recall. Oil leaks can contaminate components, speed up wear, and in extreme cases, oil spots could ignite if fluid reached hot elements. Regular seal replacements add notably to the cost of running an OM651‑equipped vehicle. If you notice oil spots under the car or a burning smell, have the system inspected promptly. Check whether the chain tensioner recall has been completed.

4. OM651 Cooling System Issues (E250 CDI)

Symptoms: Coolant loss with no visible external leak, low coolant warning, temperature fluctuations, overheating.

Typical mileage: 60,000–120,000 miles

Repair cost: £300–£900 (cooling system component replacement)【PLACEHOLDER】

Replacement cost: £4,000–£7,000 (if overheating leads to engine damage)【PLACEHOLDER】

🟠 Check - book inspection urgently if coolant loss or overheating occurs

Our recommendation:

The OM651's cooling system has several weak points, including an unreliable cylinder head coolant connection that can leak. Coolant loss can lead to overheating and deform pistons and valves. This issue was addressed by a service campaign, but as with many recalls, actual completion depends on previous owners' maintenance behaviour. If you notice coolant loss or temperature fluctuations, have the cooling system pressure‑tested immediately.

5. DPF & EGR System Issues (Both Generations)

Symptoms: DPF warning light, reduced power, increased fuel consumption, frequent regeneration cycles, engine management light.

Typical mileage: 40,000–80,000 miles (urban‑driven cars are at highest risk)

Repair cost: £200–£800 (DPF clean, forced regeneration, or sensor replacement)【PLACEHOLDER】

Replacement cost: £1,500–£3,000 (DPF replacement)【PLACEHOLDER】

🟠 Check - book inspection urgently if DPF warning appears

Our recommendation:

DPF clogging is one of the most common issues on both the OM651 and OM654, particularly on cars driven mostly in the city. Failed EGR systems are also common. If you see a DPF warning light, take the car for a sustained motorway run at 2,000–2,500 rpm. If the light persists, have the DPF inspected. Regular motorway driving and using premium diesel can help keep the DPF healthy.

6. OM654 Turbocharger & Injector Issues (E250d, 2016+)

Symptoms: Reduced power, odd noises, excess exhaust smoke, rough running, misfires, poor acceleration

Typical mileage: 30,000–70,000 miles

Repair cost: £800–£2,000 (turbocharger repair or injector replacement)【PLACEHOLDER】

Replacement cost: £4,500–£8,500 (if turbo failure sends debris into the engine)【PLACEHOLDER】

🟠 Check - book inspection urgently if power loss or odd noises occur

Our recommendation:

The OM654 engine has its own set of issues. Premature turbocharger failures have been reported, with axial wear on the turbocharger rotor being a characteristic failure pattern. High‑pressure fuel pump failures are also reported, often related to injector issues or fuel contamination, potentially causing misfires and poor acceleration. Owners have also reported rocker arm bearing wear. If you experience power loss, odd noises, or rough running, have the vehicle inspected by a specialist.

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Mercedes E250 CDI / E250d — Repair, Buy, or Replace?

Every 320d has a story. Make the right call with clear data, real-world costs, and honest guidance from UK specialists.

Mercedes E250 CDI / E250d — Repair, Buy, or Replace?

Every 320d has a story. Make the right call with clear data, real-world costs, and honest guidance from UK specialists.

Can It Be Repaired?

ProblemRepairable?Typical CostWhen It Makes SenseOM651 timing chain stretch (preventative)✅ Yes£1,500–£2,500Catch it early — far cheaper than engine replacement; chain is on output side, making it labour‑intensiveOM651 injector failure✅ Yes£400–£1,200Catch it before engine damage occursOM651 oil leaks✅ Yes£300–£900Address seal issues promptly; recall may cover some workOM651 cooling system issues✅ Yes£300–£900Proactive repair prevents overheating damageDPF / EGR issues✅ Yes£200–£800Cleaning or forced regeneration is cost‑effectiveOM654 turbocharger issues✅ Yes£800–£2,000Viable if caught before debris enters engineSnapped timing chain❌ Usually NoEngine replacementPiston‑valve contact means little is left to repair

Buying This E250 CDI / E250d? Check These First

Buy If

Full service history with regular oil changes using Mercedes‑approved oil
OM651 (2009–2016): timing chain tensioner replaced or inspected; chain recall completed
OM651 (2009–2016): injectors replaced or functioning correctly (no rough idle, no smoke)
OM654 (2016+): no turbocharger issues or odd noises
DPF health checked — regular motorway use is a good sign
Post‑2014 models often include TSB fixes for earlier issues
The OM651 is widely used in European taxis and can handle high mileage with proper maintenance

Avoid If

No proof of regular maintenance — these engines are unforgiving of neglect
OM651 with cold‑start rattle — timing chain work is imminent and expensive
Any DPF or EGR warning lights — emissions system repairs can be costly
OM654 with turbocharger noise or power loss — expensive turbo work ahead
Any engine warning light without diagnosis — these engines can hide expensive faults
"Cheap" examples — the purchase price is the least of your worries

Closing Verdict

The Mercedes E250 CDI and E250d represent the sweet spot in the E‑Class diesel range — strong performance, excellent fuel economy, and a refined driving experience. However, the engine choice matters significantly. The OM651 (E250 CDI, 2009–2016) is a high‑tech diesel with serious drawbacks: timing chain stretch is the defining weakness, requiring a complex and costly replacement. Injector failures, oil leaks, cooling system issues, and DPF/EGR problems are also common. The OM654 (E250d, 2016+) is lighter, more efficient, and more reliable, but turbocharger failures, injector issues, and timing chain concerns have been reported. As one specialist put it: "The OM651 is a very good engine if well maintained and looked after. Regular oil changes and decent fuel will see very high mileages". Across all generations, regular maintenance is absolutely essential.

Don't guess.Get the right engine at the right price.

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Buying Checklist

Before you buy a used Mercedes E250 CDI or E250d (or before you commit to an engine replacement), check these:

Cold Start — Listen for rattle from the engine (OM651 timing chain warning — critical)

Service History — Including which engine era (OM651/OM654) and confirmed oil‑change discipline

Timing Chain Work (OM651) — Any history of chain/tensioner replacement? Chain recall completed?

Injector Health (OM651) — Any rough idle or smoke? (injector failure warning)

Oil Leaks (OM651) — Check for oil spots under the car; sealing defects are common

Coolant Level — Check cold and hot; any loss indicates potential cooling system issues

DPF Health — Any warning lights? Ask about regeneration frequency; urban cars will have more issues

Turbo Health (OM654) — Any whistling, power loss, or odd noises? (turbo failure warning)

Transmission — Any jerky shifts or delays? 7G‑Tronic issues may be developing

Engine Warning Light — Have codes been read? Timing, injector, DPF, EGR, or turbo codes are most common

Buy smart. Drive with confidence.

A few checks today can save thousands tomorrow. Use this checklist to avoid the most common 320d pitfalls.

Buy smart. Drive with confidence.

A few checks today can save thousands tomorrow. Use this checklist to avoid the most common 320d pitfalls.

Engine Codes

This table's rows exactly match Section 1B's Era Map — the same engine codes, years, and generation coverage.

OM651 (E250 CDI)

Years2009–2016

Power204 bhp (150 kW) @ 4,200 rpm · 500 Nm @ 1,600–1,800 rpm

2025 Enquiries— (pattern data)【PATTERN DATA】

Avg. Recon Cost£4,000–£7,000【PLACEHOLDER — confirm vs cost sheet】

Engine CodeYearsPower2025 EnquiriesAvg. Recon Cost

OM651 (E250 CDI)2009–2016204 bhp (150 kW) @ 4,200 rpm · 500 Nm @ 1,600–1,800 rpm— (pattern data)【PATTERN DATA】£4,000–£7,000【PLACEHOLDER — confirm vs cost sheet】

OM654 (E250d)2016–present194 bhp (143 kW) @ 3,800 rpm · 400 Nm @ 1,600–2,800 rpm— (pattern data)【PATTERN DATA】£4,500–£8,500【PLACEHOLDER — confirm vs cost sheet】

Technical Specs

OM654 — E250d

Displacement2,143 cc

Cylinders4‑cylinder inline, 16 valves, DOHC

Compression Ratio16.2:1

Fuel SystemCommon‑rail direct injection (piezo injectors)

TurbochargerSingle variable‑geometry turbocharger

Timing DriveSimplex roller chain (output side)

ConstructionCast‑iron block with spray‑coated cylinder walls

Displacement1,950 cc

Cylinders4‑cylinder inline, 16 valves, DOHC

Compression Ratio15.5:1

Fuel System4th‑generation common rail (2,050 bar piezo injectors)

TurbochargerSingle VGT, water‑cooled

ConstructionAluminium block with Nanoslide cylinder coating

Dry Weight~168 kg

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Market Intelligence

Most Common Failure

OM651 timing chain stretch and piezo injector failure — approximately 60% of E250 CDI‑related enquiries cite chain or injector concerns【PATTERN DATA】

Average Enquiry Mileage

60,000

–100,000 miles【PATTERN DATA】

Average Replacement Cost

£5,500

reconditioned, supply only【PLACEHOLDER】

Most Requested Engine Code

OM651 — W212‑era E250 CDI is the most common E‑Class diesel on UK roads【PATTERN DATA】

Peak Enquiry Season

Winter — cold starts expose timing chain and injector issues【PATTERN DATA】

Regional Demand

South East22%

London18%

North West (13%)【PATTERN DATA】

Regional Demand Breakdown

22%South East

18%London

Frequently Asked Questions

All prices are indicative UK market ranges based on historical quote data from our network of engine specialists. Actual costs vary by variant, engine code, damage severity and workshop location. Use our free comparison tool to get tailored quotes. Every engine supplied through EnginesMarket carries a minimum 12‑month unlimited‑mileage warranty — always confirm terms with your chosen supplier.

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