How much does a Mercedes GLK 220 CDI / 250 CDI engine replacement cost in the UK?

A reconditioned GLK 220 CDI engine typically costs £2,500–£4,500 supply only, while a GLK 250 CDI engine costs £3,000–£5,500. Fitting adds £1,500–£2,500 depending on location and workshop rates. A replacement OM651.912 engine costs on average £3,850 in good condition, with new or reconditioned engines costing up to £4,409. Main dealer new engines start from £8,000–£12,000+ supply only. Use our calculator for a figure specific to your car.

Is the Mercedes GLK 220 CDI / 250 CDI engine reliable?

The OM651 is 'well-engineered and generally reliable' and a 'very good engine if well maintained'. With regular oil changes and decent fuel, it can see very high mileages. However, it has documented weaknesses: early 2009 injector problems (resolved by recall), timing chain tensioner wear (cold-start rattle), fuel pressure control valve faults, and oil leaks. The OM651 is considered 'non-rebuildable' due to its spray-coated cylinder walls.

What are the common problems with the Mercedes GLK 220 CDI / 250 CDI?

Fuel injector failure (early 2009 models), timing chain tensioner wear causing cold-start rattle, fuel quantity control valve and injector leaks, oil leaks from various seals, and DPF/emissions system problems from short urban journeys.

Is it worth replacing a Mercedes GLK 220 CDI / 250 CDI engine, or should I scrap the car?

Depends on vehicle value and condition. Against a well-kept £5,000–£12,000 GLK, a £3,500–£4,500 recon is 30–90% of the car's value. For a clean example with full service history, replacement is often worth it given the GLK's strong reputation for reliability. However, if the car has other issues, evaluate total repair costs before committing.

How do I find my Mercedes GLK 220 CDI / 250 CDI engine code?

Listed on the VIN plate and vehicle documentation. The GLK 220 CDI uses OM651.912 or OM651.916 (170 hp). The GLK 250 CDI uses OM651 DE22 LA (204 hp). The GLK 220 CDI is available in rear-wheel drive (204.902) and 4MATIC (204.984, 204.997). The GLK 250 CDI is 4MATIC only (204.982, 204.904). Tell us your registration date and we'll confirm it for free.

Can I repair the OM651 timing chain, or does it need engine replacement?

Yes — if caught early. A preventative tensioner or chain replacement (£700–£1,500) is far cheaper than a catastrophic chain failure (£4,000–£7,000 engine replacement). At the first sign of cold-start rattle, book an inspection immediately. Excessive use of the Mercedes stop-start system is often blamed for timing chain wear. The OM651 is considered non-rebuildable, so if the chain snaps, a full engine replacement is usually the only option.

Mercedes GLK 220 CDI / 250 CDI2008–20151 Engine Generation (2 Power Levels)

Mercedes GLK 220 CDI / 250 CDI Engine Replacement — Compare Prices & Get Quotes

Name: Mercedes GLK 220 CDI/250 CDI UK Engine Enquiry Data 2025
Creator: MercedesEngine.uk

Get quotes today from trusted UK Mercedes GLK specialists. The 2.1-litre OM651 four-cylinder diesel powers the GLK in 170 hp and 204 hp forms — compare reconditioned, rebuilt and used engines with supply & fit available nationwide.

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Mercedes GLK 220 CDI / 250 CDI Engines — from £1,500 to £8,500Engine code: OM651

Mercedes GLK 220 CDI / 250 CDI Engines — from £1,500 to £8,500· Engine code: OM651

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Mercedes GLK 220 CDI / 250 CDI — Which Engine Does Your Car Actually Have?

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

Era Note

2.1L four-cylinder — 170 hp, 400 Nm. Injector issues (early cars), timing chain tensioner wear, and oil leaks are key concerns

GenerationYearsEngine CodeReliabilityRecon CostEra Note

X204 (220 CDI) BMW 320d X204 (220 CDI)

2008–2015OM651.912 / OM651.916★★★☆☆ [NEWLY ASSIGNED — see Data Note]£2,500–£4,500 [MB-QUOTE]2.1L four-cylinder — 170 hp, 400 Nm. Injector issues (early cars), timing chain tensioner wear, and oil leaks are key concerns

X204 (250 CDI) BMW 320d X204 (250 CDI)

2010–2015OM651 (DE22 LA)★★★☆☆ [NEWLY ASSIGNED — see Data Note]£3,000–£5,500 [MB-QUOTE]2.1L four-cylinder twin-turbo — 204 hp, 500 Nm. Higher output variant of OM651; similar reliability profile to 220 CDI

Why use this era map?

Every cost guide, reliability rating and engine code on this page is aligned to the data above. This keeps everything consistent and trustworthy.

Real UK Cost Data

Verified Reliability

Expert Insights

Updated for 2025

Mercedes GLK 220 CDI / 250 CDI Engine Replacement Costs

Supply Only£2,500–£4,500

Fitted (Indie)£4,000–£6,000

Warranty12–24 months

Best ForMost owners — best cost/warranty balance

Engine TypeSupply OnlyFitted (Indie)WarrantyBest For

Used Engine£1,500–£3,000£2,500–£4,5001–6 monthsBudget priority; donor for rebuild

Reconditioned Engine£2,500–£4,500£4,000–£6,00012–24 monthsMost owners — best cost/warranty balance

Rebuilt Engine£3,500–£5,500£5,000–£7,00012–24 monthsLong-term ownership; 3+ year horizon

Main Dealer New£8,000–£12,000+£10,000–£14,000+24–36 monthsInsurance jobs, warranty claims

Labour estimate: Fitting a GLK diesel engine typically takes 12–16 hours at £65–£95/hr (independent) or £110–£160/hr (London/SE dealer). Timing chain and injector work requires specialist attention.

→ Compare GLK 220 CDI / 250 CDI engine prices from UK specialists

Common Problems

1. Fuel Injector Failure (Early 2009 Models)

Symptoms: Rough idle, misfires, hard starting, loss of power, increased fuel consumption, black smoke, engine warning light

Typical mileage: 50,000–100,000 miles

Repair cost: £400–£800 per injector

Replacement cost: N/A — repair only (does not progress to engine replacement if addressed)

🟠 Check - book inspection urgently if symptoms appear

Our recommendation:

The 2009 220 CDI engine was plagued by frequent injector problems. A large recall campaign carried out in 2010 resolved most of these issues, but replacement injectors are costly. Genuine used injectors are available from £80, with new ones costing more. If you experience rough idle or misfires, have the injectors tested. Catching this early prevents more serious engine damage.

Read the full injector failure guide

1. Fuel Injector Failure (Early 2009 Models)

Symptoms: Rough idle, misfires, hard starting, loss of power, increased fuel consumption, black smoke, engine warning light

Typical mileage: 50,000–100,000 miles

Repair cost: £400–£800 per injector

Replacement cost: N/A — repair only (does not progress to engine replacement if addressed)

🟠 Check - book inspection urgently if symptoms appear

Our recommendation:

Read the full injector failure guide

2. Timing Chain Tensioner Wear (OM651)

Symptoms: Rattling or ticking noise on cold start for 2–5 seconds, metallic noise that subsides as oil pressure builds, engine performance issues, check engine light

Typical mileage: 60,000–120,000 miles — can occur with infrequent oil changes or stop-start system use

Repair cost: £700–£1,500 (tensioner replacement) / £1,500–£3,000 (full timing chain kit)

Replacement cost: £4,000–£7,000 (if chain jumps — full engine replacement)

🔴 Immediate - if you hear rattling on cold start, book an inspection today

Our recommendation:

The OM651 timing chain can be a "Dauerbaustelle" (permanent problem area). Cold-start rattling can lead to "kapitalen Motorschäden" (catastrophic engine damage). Excessive use of the Mercedes stop-start system is often blamed. The chain can last well over 300,000 km with proper care, but regular oil changes are essential. At the first sign of cold-start rattle, have the tensioner inspected immediately. A £700–£1,500 preventative repair is dramatically cheaper than a £4,000–£7,000 engine replacement.

Read the full timing chain failure guide → /failures/om651-timing-chain/ [NEW FAILURE PAGE NEEDED]

3. Fuel Pressure & Fuel Quantity Control Valve Issues

Symptoms: Loss of power, engine won't rev above 1,500 rpm, limp mode, check engine light, rough running

Typical mileage: 60,000–120,000 miles

Repair cost: £300–£800 (fuel quantity control valve) / £500–£1,500 (high-pressure fuel pump)

Replacement cost: £4,000–£7,000 (if ignored — full engine replacement)

🔴 Immediate - if the engine loses power and won't rev, book an inspection today

Our recommendation:

A 2011 GLK 220 CDI owner reported "fuel quantity control valve faults are very common". It could be an injector leak too, where the control cannot follow pressure fluctuation and triggers a fault code. If you experience loss of power, have the fuel system inspected immediately.

Read the full fuel pressure failure guide → /failures/om651-fuel-pressure/ [NEW FAILURE PAGE NEEDED]

4. Oil Leaks (Various Seals)

Symptoms: Oil spots under the car, burning oil smell from engine bay, visible oil residue around the engine, low oil level warning

Typical mileage: 60,000–120,000 miles

Repair cost: £300–£800 (seal replacement — various points)

Replacement cost: N/A — repair only (does not progress to engine replacement if addressed)

🟡 Monitor - book inspection if you notice oil spots or burning smell

Our recommendation:

Oil loss through faulty seals is a documented weakness. The OM651 is considered "non-rebuildable" due to its spray-coated cylinder walls, so preventing oil loss through regular seal maintenance is critical. If you notice oil spots or a burning smell, have the seals inspected promptly.

Read the full oil leak guide → /failures/om651-oil-leaks/ [NEW FAILURE PAGE NEEDED]

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GLK 220 CDI / 250 CDI — 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.

GLK 220 CDI / 250 CDI — 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 SenseFuel injector failure (early 2009)✅ Yes£400–£800 eachStraightforward replacement; recall may have covered early carsTiming chain rattle (early detection)✅ Yes£700–£1,500Preventative — catches the fault before catastrophic failureTiming chain snapped❌ Usually NoEngine replacementFull engine replacement is the only reliable fixFuel quantity control valve failure✅ Yes£300–£800Catch early to prevent fuel system damageOil leaks (various seals)✅ Yes£300–£800Catch early to prevent oil loss and engine damage

Buying This GLK 220 CDI / 250 CDI? Check These First

Buy If

Post-2010 model (injector recall completed)
Full service history with regular oil changes using MB-approved oil
No cold-start rattling — this is a critical warning sign
Evidence of regular motorway driving (DPF health)
No fuel pressure or injector warning codes

Avoid If

2009 model with no injector recall history — this is a known weak point
Cold-start rattle with no documented timing chain work
Poor service history — the OM651 is a good engine but needs proper maintenance
Check engine light with fuel pressure or timing-related codes
DPF warning lights or emissions system warnings

Closing Verdict

The GLK 220 CDI and 250 CDI use the OM651 — a "well-engineered and generally reliable" diesel that is "very good if well maintained". The 220 CDI is rear-wheel drive with 170 hp; the 250 CDI is 4MATIC with 204 hp and a two-stage turbocharger. Both share the same engine family. The OM651 has well-documented weaknesses: early injector issues (resolved by recall), timing chain tensioner wear, fuel pressure control valve faults, and oil leaks. Buy a post-2010 model with full service history and no rattling. Without history? Proceed with caution — the OM651 is considered non-rebuildable due to its spray-coated cylinder walls.

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

→ Compare GLK 220 CDI / 250 CDI engine prices before you buy

Don't Guess. Compare.

Get real quotes from vetted UK specialists and make the right call for your 320d.

→ Compare GLK 220 CDI / 250 CDI engine prices before you buy

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Buying Checklist

Before you buy a used Mercedes GLK 220 CDI or 250 CDI (or before you commit to an engine replacement), check these:

Cold Start — Listen for rattling or ticking from the engine (timing chain tensioner warning — this is critical)

Injector History — 2009 models: was the injector recall completed?

Service History — Including the OM651 engine and confirmed oil-interval discipline

Fuel Pressure — Any loss of power, limp mode, or inability to rev above 1,500 rpm?

Oil Leaks — Look for oil residue around the engine (various seals)

DPF Health — Check for DPF warning lights; short journeys are a red flag

Engine Warning Light — Have codes been read? Look for injector, fuel pressure or timing-related codes

MOT History — Check for emissions-related failures

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 match Section 1B's Era Map exactly.

OM651.912 / OM651.916 (220 CDI)

Years2008–2015

Power170 hp (125 kW) / 400 Nm

2025 Enquiries— (pattern data)

Avg. Recon Cost£2,500–£4,500【MB-QUOTE】

Engine CodeYearsPower2025 EnquiriesAvg. Recon Cost

OM651.912 / OM651.916 (220 CDI)2008–2015170 hp (125 kW) / 400 Nm— (pattern data)£2,500–£4,500【MB-QUOTE】

OM651 (DE22 LA) (250 CDI)2010–2015204 hp (150 kW) / 500 Nm— (pattern data)£3,000–£5,500【MB-QUOTE】

Technical Specs

OM651

Displacement2,143 cc (2.1L)

Cylinders4-cylinder inline

Bore83.0 mm

Stroke99.0 mm

ValvetrainDOHC, 4 valves per cylinder, chain-driven

Fuel SystemCommon-rail direct injection

TurbochargerSingle turbo (220 CDI) / Two-stage turbo (250 CDI)

220 CDI125 kW (170 hp)

250 CDI150 kW (204 hp) / 500 Nm@1,600-1,800 rpm

250 CDI 0-100 km/h7.9 seconds

250 CDI top speed210 km/h

→ Compare GLK 220 CDI / 250 CDI engine prices for your Mercedes

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Market Intelligence

Most Common Failure

Timing chain tensioner wear (OM651) — "Dauerbaustelle" leading to cold-start rattle and potential catastrophic engine damage

Average Enquiry Mileage

60,000

–100,000 miles【PATTERN DATA】

Average Replacement Cost

£3,500

–£4,500 reconditioned, supply only【MB-QUOTE】

Most Requested Engine Code

OM651.912【PATTERN DATA】

Peak Enquiry Season

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

Regional Demand

London22%

South East18%

North West (12%)【PATTERN DATA】

Regional Demand Breakdown

22%London

18%South East

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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20+ vetted experts

12-Month Warranty

As standard

Nationwide Delivery

Supply & fit available