Mercedes Benz GLK Class 220 CDI/250 CDI Engine ReplacementCompare Prices & Get Quotes
Get quotes today from trusted UK Mercedes Benz GLK Class 220 CDI and 250 CDI engine specialists. Compare prices on reconditioned, rebuilt and used engines for the 2.1-litre OM651 twin-turbo diesel - supply & fit available nationwide.
Supply & Fit Available
12-Month Warranty
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100+ Suppliers
From £2,200 to £3,700
Used from £1,200 · Reconditioned from £2,200 · Common codes: OM651.911, OM651.912, OM651.916, OM651.921
From £1,200
Tested, bare/short engine
From £2,200
Rod bearings addressed, tested
From quote
Upgraded bearings, full teardown, revised valvetrain
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3 Simple Steps3 Simple Stepsto Finding the Best Mercedes Benz GLK Class 220 CDI/250 CDI Replacement Engineto Finding the Best Mercedes Benz GLK Class 220 CDI/250 CDI Replacement Engine
Most replacements completed within 3-5 days.
Variant HistoryMercedes Benz GLK Class 220 CDI/250 CDI - Engine History & Specs at a Glance
The GLK 220 CDI and 250 CDI represented the core of the X204 diesel lineup from launch in 2008 through to production end in 2015. Powered by the OM651 2.1-litre twin-turbo four-cylinder diesel - available in 170hp and 204hp outputs - these variants accounted for the vast majority of UK GLK sales and continue to drive the highest volume of engine replacement enquiries.
Variant HistoryMercedes Benz GLK Class 220 CDI/250 CDI - Engine History & Specs at a Glance
The GLK 220 CDI and 250 CDI represented the core of the X204 diesel lineup from launch in 2008 through to production end in 2015. Powered by the OM651 2.1-litre twin-turbo four-cylinder diesel - available in 170hp and 204hp outputs - these variants accounted for the vast majority of UK GLK sales and continue to drive the highest volume of engine replacement enquiries.
Mercedes Benz GLK Class 220 CDI/250 CDI
Fuel TypeDiesel (twin-turbo CDI)
Engine Size2.1L (2,143cc)
Power Output Range170-204hp across the variant's historyEngine History Timeline
OM651.911 2.1L twin-turbo diesel, 170hp (GLK 220 CDI, X204 launch)
OM651.921 2.1L twin-turbo diesel, 204hp (GLK 250 CDI added)
2012 - OM651.912 2.1L twin-turbo diesel, 170hp/204hp (4MATIC variants)
Facelift X204; OM651.916 introduced for 220 CDI with revised calibration
2015 - BlueTEC variants (OM651.941) with AdBlue emissions system added
Key Specs Snapshot
Fuel TypeDiesel (twin-turbo CDI)Engine Size2.1L (2,143cc)Power Output Range170-204hp across the variant's historyYears Produced2008-2015Every engine fitted to the Mercedes Benz GLK Class 220 CDI and 250 CDI is covered below, with UK rebuilt pricing and known failure points - from OM651 timing chain stretch to EGR cooler cracking and turbo actuator issues.
Mercedes Benz GLK Class 220 CDI/250 CDI Engine Codes - Specifications & Replacement CostMercedes Benz GLK Class 220 CDI/250 CDI Engine Codes - Specifications & Replacement Cost
2.1L Twin-Turbo Diesel (2008-2015)
Power Output170 hp (125 kW) @ 3,200-4,200 rpmTorque400 Nm @ 1,400-2,800 rpmYears Fitted2008-2015Displacement2,143ccCylindersInline 4, DOHC, 16-valve, twin-turbocharged
Compatible Trim Levels
- GLK 220 CDI
- GLK 220 CDI 4MATIC
- GLK 220 CDI Avantgarde
- GLK 220 CDI Sport
Find your exact engine code, specs and UK replacement cost guide.
Used
Tested, ready-to-fit engine
£1,200-£1,800
Reconditioned
Addressed known issues, tested
£2,200-£2,900
Rebuilt
Full teardown, upgraded internals
£2,400-£3,400
Common Failure
Timing chain stretch and guide wear - the OM651's single most critical failure point. The rear-mounted timing chain drives both camshafts and the high-pressure fuel pump. If it stretches beyond tolerance or a guide fails, the consequences range from misfires to catastrophic engine damage if the chain jumps a tooth. Typical failure mileage: 75,000-120,000 miles (120,000-200,000 km).
The OM651 twin-turbo diesel is the backbone of the GLK diesel range - fundamentally reliable and capable of 200,000-300,000 km with proper maintenance. However, it has well-documented weak points that drive replacement enquiries. The single most critical failure is timing chain stretch from approximately 120,000 km (75,000 miles), followed by EGR cooler cracking, turbo actuator issues, and injector failures. Every rebuilt engine supplied through EnginesMarket includes upgraded components addressing these original failure points, plus a minimum 12-month unlimited mileage warranty.
The Most Critical GLK Diesel Failure
Affected Vehicles
Mercedes GLK 220 CDI, GLK 250 CDI (OM651.911, OM651.912, OM651.916, OM651.921, 2008-2015)
Typical Failure Mileage
75,000-120,000 miles (120,000-200,000 km)
Root Cause
The OM651's timing chain drives both camshafts and the high-pressure fuel pump. A hydraulic tensioner loses pressure prematurely, allowing chain stretch and guide wear. A distinctive rattling noise on cold starts is the classic warning sign. If ignored, the chain can snap or jump a tooth, causing catastrophic valve and piston collision.
Why It Happens
The OM651's timing chain drives both camshafts and the high-pressure fuel pump. A hydraulic tensioner loses pressure prematurely, allowing chain stretch and guide wear. A distinctive rattling noise on cold starts is the classic warning sign. If ignored, the chain can snap or jump a tooth, causing catastrophic valve and piston collision.
Dealer (parts + labour)
£600-£900
Specialist (parts + labour)
£350-£550
What it involves
Replace hydraulic tensioner only
Suitability
Effective if caught immediately when rattle first appears
1 - 2 daysDealer (parts + labour)
£1,900-£2,600
Specialist (parts + labour)
£950-£1,500
What it involves
Replace timing chain, guides, tensioner, rails; no engine removal required
Suitability
If chain rattle is present but no fault codes
1 - 2 daysDealer (parts + labour)
£6,500-£8,800
Specialist (parts + labour)
£2,400-£3,700
What it involves
Complete engine swap with upgraded timing chain kit, new injectors, and upgraded EGR components fitted as standard
Suitability
If chain has jumped causing valve damage
1 - 2 daysAll prices are indicative UK market ranges based on current UK specialist supplier data.| Repair Tier | Dealer (Parts + Labour) | Specialist (Parts + Labour) | What It Involves | Suitability | Estimated Time |
|---|---|---|---|---|---|
 Preventative - Timing chain tensioner replacement Minor | £600-£900 | £350-£550 | Replace hydraulic tensioner only | Effective if caught immediately when rattle first appears | 1 - 2 days |
 Intermediate - Full timing chain kit Best Value | £1,900-£2,600 | £950-£1,500 | Replace timing chain, guides, tensioner, rails; no engine removal required | If chain rattle is present but no fault codes | 1 - 2 days |
Full Replacement - Rebuilt OM651 engine Best Value | £6,500-£8,800 | £2,400-£3,700 | Complete engine swap with upgraded timing chain kit, new injectors, and upgraded EGR components fitted as standard | If chain has jumped causing valve damage | 1 - 2 days |
Vehicle Value Check
Vehicle Value Check
A typical 2008-2015 GLK 220 CDI or 250 CDI 4MATIC is worth approximately £4,000-£12,000 depending on mileage and condition. The GLK 220/250 CDI sits in the £4,000-£12,000 band - replacement cost is typically justified for well-maintained examples, though owners of higher-mileage or lower-value examples should carefully evaluate repair costs against vehicle value.
Our Recommendation
Our Recommendation
If your GLK 220 CDI or 250 CDI exhibits a rattling noise on cold start, act immediately. The OM651's timing chain is accessible with the engine in situ for tensioner and chain replacement, though guides typically require more extensive work. Specialist pricing of £950-£1,500 for a full chain kit is significantly lower than dealer rates. However, if the engine has already suffered timing jump or oil pressure loss, a minor repair is a financial risk. We recommend a fully rebuilt OM651 unit, which includes the upgraded tensioner as standard, new injectors, and EGR components - restoring long-term reliability.
Don't Let Timing Chain Rattle, EGR Cooler Cracking, or Turbo Issues Write Off Your Mercedes GLK 220 CDI or 250 CDI
Whether you're facing OM651 timing chain stretch on your GLK 220 CDI, EGR cooler cracking, or turbo actuator failure on your GLK 250 CDI, EnginesMarket makes it simple to compare quotes from trusted UK Mercedes diesel specialists. Every rebuilt engine in our network carries upgraded components addressing the original design weakness - upgraded timing chains, stainless-steel EGR coolers, and bench-tested turbos - plus a minimum 12-month unlimited mileage warranty with nationwide delivery and supply & fit options. Don't pay main dealer premiums. Compare prices from independent Mercedes specialists who know these OM651 twin-turbo diesels inside out.
Compare rebuilt OM651 Mercedes GLK 220 CDI/250 CDI engine prices
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Best Price GuidanceImportant Information
Important Information
"All prices are indicative UK market ranges based on historical quote data and repair requests from our network of engine specialists. Dealer pricing is estimated based on published main dealer labour rates and genuine OEM parts pricing. Specialist pricing reflects actual quote data from EnginesMarket's UK network. Actual costs vary depending on damage severity, vehicle condition, variant, and workshop location within the UK. Use our free comparison tool to get tailored quotes for your specific Mercedes GLK Class 220 CDI or 250 CDI. Every engine supplied through EnginesMarket carries a minimum 12-month unlimited mileage warranty - always confirm exact terms with your chosen supplier."
Mercedes Benz GLK Class 220 CDI/250 CDI Engine ReplacementFrequently Asked Questions
Question 1How much does a Mercedes GLK 220 CDI or 250 CDI engine replacement cost in the UK-
Short summary: A rebuilt OM651 engine for the GLK 220 CDI costs £2,400-£3,400 supply-only; a rebuilt OM651 engine for the GLK 250 CDI costs £2,800-£3,700 supply-only. Fitting adds £700-£1,300 depending on complexity.
- GLK 220 CDI (OM651.911/916): rebuilt unit £2,400-£3,400; used engine from £1,200
- GLK 250 CDI (OM651.912/921): rebuilt unit £2,800-£3,700; used engine from £1,500
- OM651 timing chain kit (labour only): £950-£1,500 at specialist
- OM651 EGR cooler replacement: £500-£750 at specialist
Question 2What are the signs of timing chain failure on a Mercedes GLK 220 CDI or 250 CDI-
Short summary: A rattling noise on cold start is the classic warning sign on the OM651 engine. If ignored, it can lead to misfires, cam/crank correlation codes, and catastrophic engine damage if the chain jumps a tooth.
- Cold start rattle that disappears after oil pressure builds - earliest warning
- Check engine light with cam/crank correlation codes
- Metallic swarf in engine oil indicates chain guides wearing away
- Preventative tensioner replacement costs £350-550 - full chain kit £950-1,500
Question 3Is the Mercedes GLK 220 CDI or 250 CDI engine (OM651) reliable-
Short summary: The OM651 is fundamentally reliable - 200,000-300,000 km examples are common. However, it has predictable weak points: timing chain stretch from approximately 120,000 km, early Delphi injector failures, EGR clogging, and water pump leaks. All are manageable with the right maintenance schedule and proactive attention.
- Timing chain stretch is the single most critical failure point
- EGR cooler cracking affects all OM651-powered GLK 220/250 CDI variants
- Early Delphi piezo injectors prone to failure - later magnetic types more durable
- Well-maintained OM651 engines exceed 150,000 miles
Question 4How long do Mercedes GLK 220 CDI and 250 CDI engines last-
Short summary: Properly maintained OM651 engines routinely reach 150,000-200,000+ miles (200,000-300,000 km) before major work is needed. With timely timing chain service and regular maintenance, these engines demonstrate exceptional longevity.
- OM651 (220/250 CDI): 150,000-200,000+ miles with regular servicing
- Timing chain inspection recommended from 75,000 miles (120,000 km)
- Service interval is 10,000 miles or 12 months - use Mercedes-spec low-SAPS oil
- Late oil changes accelerate timing chain wear and EGR clogging
Question 5Is it worth replacing the engine in my Mercedes GLK 220 CDI or 250 CDI-
Short summary: Yes, if the GLK is otherwise in good condition with no rust or major electrical faults. A rebuilt OM651 costs £2,400-£3,700 - comparable to or less than replacing a £4,000-£12,000 vehicle, especially when factoring in the cost of finding a comparable replacement SUV.
- GLK 220/250 CDI values: £4,000-£12,000 depending on year, mileage and condition
- Rebuilt engine with upgraded components fixes original weak points
- Supply & fit typically £3,200-£5,000 depending on engine code
- New engine includes 12-month unlimited mileage warranty
Question 6What oil does my Mercedes GLK 220 CDI or 250 CDI need-
Short summary: Mercedes-Benz specifies low-SAPS oil meeting MB 229.51 or 229.52 - typically 5W-30. The OM651 requires approximately 6.5 litres with filter.
- OM651 (220/250 CDI): MB 229.51/229.52 5W-30 low-SAPS - protects DPF and emissions systems
- Never use non-approved oil - destroys timing chain tensioners and hydraulic lifters
- Change every 10,000 miles or 12 months - stretched intervals cause timing chain wear and EGR clogging
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500+ OM651 twin-turbo diesel engines supplied through our network
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Comparing quotes for your Mercedes GLK 220 CDI or 250 CDI is completely free, with no obligation and no pressure. Enter your registration above to get tailored quotes from UK Mercedes diesel specialists who understand the OM651 twin-turbo engine inside out. Whether you need a used engine, a reconditioned unit, or a full rebuilt engine with upgraded timing chain components, EGR coolers, and injectors, we'll connect you with the right specialist for your exact GLK - with a minimum 12-month warranty on every engine supplied.
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