Mercedes Benz GLC Class GLC 220d / GLC 250d Engine ReplacementCompare Prices & Get Quotes
Get quotes today from trusted UK Mercedes Benz GLC Class 220d and 250d engine specialists. Compare prices on reconditioned, rebuilt and used OM651 2.1-litre diesel engines - supply & fit available nationwide for both rear-wheel drive and 4MATIC variants.
Supply & Fit Available
12-Month Warranty
Nationwide Delivery
100+ Suppliers
From £2,200 to £3,900
Used from £1,200 · Reconditioned from £1,800 · Common codes: OM651.924, OM651.921
From £1,200
Tested, bare/short engine
From £1,800
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 GLC Class GLC 220d / GLC 250d Replacement Engineto Finding the Best Mercedes Benz GLC Class GLC 220d / GLC 250d Replacement Engine
Most replacements completed within 3-5 days.
Variant HistoryMercedes Benz GLC Class GLC 220d / GLC 250d - Engine History & Specs at a Glance
The Mercedes Benz GLC 220d and GLC 250d defined the diesel-powered GLC range throughout the first-generation X253 and C253 production run from 2015 to 2019, powered by the OM651 2.1-litre twin-turbo diesel engine - a unit that balanced strong torque with impressive economy but developed a reputation for timing chain and injector-related failures as mileages climbed.
Variant HistoryMercedes Benz GLC Class GLC 220d / GLC 250d - Engine History & Specs at a Glance
The Mercedes Benz GLC 220d and GLC 250d defined the diesel-powered GLC range throughout the first-generation X253 and C253 production run from 2015 to 2019, powered by the OM651 2.1-litre twin-turbo diesel engine - a unit that balanced strong torque with impressive economy but developed a reputation for timing chain and injector-related failures as mileages climbed.
Mercedes Benz GLC Class GLC 220d / GLC 250d
Fuel TypeDiesel
Engine Size2.1L (2,143cc)
Power Output Range170-204hp across the GLC 220d and GLC 250dEngine History Timeline
GLC 220d and GLC 250d launched with X253 SUV and C253 Coupe body styles OM651 2.1L twin-turbo diesel, 9G-Tronic automatic transmission
GLC 220d 170hp, 400Nm; GLC 250d: 204hp, 500Nm - both with twin-turbo configuration
Facelift introduced OM654 2.0L diesel replacing OM651 in 220d and 300d models
OM651 production ends after powering the majority of first-generation GLC diesel sales
Key Specs Snapshot
Fuel TypeDieselEngine Size2.1L (2,143cc)Power Output Range170-204hp across the GLC 220d and GLC 250dTorque Range400-500NmYears Produced2015-2019Every OM651 diesel engine fitted to the Mercedes Benz GLC Class 220d and 250d is covered below, with UK rebuilt pricing and known failure points from real owner experience.
Mercedes Benz GLC Class 220d / 250d Engine Codes - Specifications & Replacement CostMercedes Benz GLC Class 220d / 250d Engine Codes - Specifications & Replacement Cost
2.1L Twin-Turbo Diesel (2015-2019) - GLC 220d
Power Output170 hp (125 kW) @ 3,000-4,200 rpmTorque400 Nm @ 1,400-2,800 rpmDisplacement2,143ccConfigurationInline-4, DOHC, twin-turbo, common-rail direct injectionYears Fitted2015-2019
Compatible Trim Levels
- GLC 220d
- GLC 220d 4MATIC
- GLC 220d AMG Line
- GLC 220d Sport
- GLC 220d Premium
Find your exact engine code, specs and UK replacement cost guide.
Used
Tested, ready-to-fit engine
£1,200-£2,500
Reconditioned
Addressed known issues, tested
£1,800-£3,000
Rebuilt
Full teardown, upgraded internals
£2,200-£3,800
Common Failure
The OM651's timing chain tensioner can fail, causing premature chain elongation and a characteristic rattle on cold start - primarily affecting older OM651 engines. If ignored, chain skip can cause catastrophic valve-piston contact.
The Mercedes Benz GLC 220d and 250d rely on the OM651 2.1-litre twin-turbo diesel - a fundamentally robust engine that regularly exceeds 200,000-300,000 km when properly maintained, but has developed a well-documented reputation for predictable failures. Timing chain stretch, piezo injector wear, swirl flap actuator failure, and water pump leaks are the most frequently cited issues. Every rebuilt engine supplied through EnginesMarket includes upgraded components designed to address the original failure point - plus a minimum 12-month unlimited mileage warranty. Below we break down the most common GLC 220d and 250d engine failures, what they cost to fix, and when replacement is the smarter financial decision.
Why the GLC 220d / 250d Rattles on Cold Start
Affected Vehicles
Mercedes Benz GLC Class GLC 220d (OM651.924) and GLC 250d (OM651.921), 2015-2019
Typical Failure Mileage
75,000 - 120,000 miles
Root Cause
The OM651's single-row timing chain drives both camshafts and the high-pressure fuel pump. A faulty chain tensioner causes premature chain elongation, producing a distinct rattle during cold starts. If ignored, chain skip can lead to cam/crank correlation codes, misfires, and catastrophic engine damage.
Why It Happens
The OM651's single-row timing chain drives both camshafts and the high-pressure fuel pump. A faulty chain tensioner causes premature chain elongation, producing a distinct rattle during cold starts. If ignored, chain skip can lead to cam/crank correlation codes, misfires, and catastrophic engine damage.
Dealer (parts + labour)
£600-£1,000
Specialist (parts + labour)
£350-£600
What it involves
Replace timing chain tensioner and guides only - valid if caught immediately when rattle first appears
Suitability
Effective only if addressed within first 500-1,000 miles of noise
1 - 2 daysDealer (parts + labour)
£1,800-£2,800
Specialist (parts + labour)
£1,200-£1,800
What it involves
Replace timing chain, tensioner, guides, sprockets - labour intensive
Suitability
80k-120k miles; corrects the root cause properly
1 - 2 daysDealer (parts + labour)
£5,500-£7,500
Specialist (parts + labour)
£3,200-£5,000
What it involves
Supply & fit rebuilt OM651 with new timing components, upgraded tensioner, new injectors, full gasket set
Suitability
Full long-block warranty. Required if chain has jumped or guides have failed
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 |
|---|---|---|---|---|---|
 Minor - Tensioner & Guides Replacement Minor | £600-£1,000 | £350-£600 | Replace timing chain tensioner and guides only - valid if caught immediately when rattle first appears | Effective only if addressed within first 500-1,000 miles of noise | 1 - 2 days |
 Intermediate - Full Timing Chain Kit Best Value | £1,800-£2,800 | £1,200-£1,800 | Replace timing chain, tensioner, guides, sprockets - labour intensive | 80k-120k miles; corrects the root cause properly | 1 - 2 days |
Full Replacement - Rebuilt Engine Best Value | £5,500-£7,500 | £3,200-£5,000 | Supply & fit rebuilt OM651 with new timing components, upgraded tensioner, new injectors, full gasket set | Full long-block warranty. Required if chain has jumped or guides have failed | 1 - 2 days |
Vehicle Value Check
Vehicle Value Check
A typical GLC 220d or 250d (X253, 2015-2019) is worth £12,000-£25,000 depending on age, mileage and condition - the full replacement cost of £3,200-£5,000 is modest relative to vehicle value for most examples. For vehicles worth under £10,000, evaluate repair options first.
Our Recommendation
Our Recommendation
If you hear the characteristic 2-3 second rattle only on cold start with no fault codes, replace the tensioner immediately - it's £350-£600 well spent. Once chain skip triggers camshaft correlation codes (P0016/P0017), the full timing kit is mandatory. If the engine has jumped timing causing valve contact, only a full replacement engine makes financial sense. With proper maintenance, OM651 diesels can exceed 250,000-300,000 miles.
Don't Let Engine Failure Write Off Your Mercedes Benz GLC 220d or GLC 250d
A failed OM651 engine doesn't have to mean the end of your GLC diesel. Whether you're dealing with timing chain stretch, piezo injector failure, or swirl flap actuator issues, EnginesMarket makes it simple to compare prices from trusted UK Mercedes Benz GLC Class specialists. Every rebuilt engine in our network includes upgraded components designed to address the original failure point, a minimum 12-month unlimited mileage warranty, and nationwide delivery with supply & fit options available.
Compare rebuilt OM651 Mercedes Benz GLC Class 220d / 250d engine prices
12-Month Minimum
UK Specialists Vetted
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 Benz GLC Class 220d or 250d. Every engine supplied through EnginesMarket carries a minimum 12-month unlimited mileage warranty - always confirm exact terms with your chosen supplier."
Mercedes Benz GLC Class 220d / 250d Engine ReplacementFrequently Asked Questions
Question 1How much does it cost to replace a GLC 220d or GLC 250d engine in the UK-
A GLC 220d or GLC 250d engine replacement typically costs between £2,200 and £3,900 depending on condition type and whether fitting is included. OM651 2.1-litre diesel units range from £2,200 to £3,900 supply only.
- Rebuilt OM651 (GLC 220d / 250d): £2,200-£3,900 supply only
- Reconditioned units: £1,800-£3,200
- Used engines from breakers: £1,200-£2,800 but higher risk
- Labour for supply & fit adds £800-£1,500 to any engine price
Question 2Is the OM651 engine in the GLC 220d and 250d reliable-
The OM651 is fundamentally reliable - 200,000-300,000 km examples are common - but has predictable weak points.
- Timing chain stretch from ~120,000 km - the single most critical failure point
- Piezo injector wear from neglected oil changes
- EGR clogging from short journeys
- Water pump leaks on higher-mileage units
- With regular servicing (10,000 miles / 12 months with MB 229.51/229.52 oil), these engines regularly exceed 250,000 miles
Question 3What are the signs of OM651 timing chain failure in a GLC diesel-
The OM651's timing chain typically shows warning signs before complete failure.
- Rattling or clanking noise on cold start - the earliest warning sign
- Rattle that lasts more than 2-3 seconds indicates significant chain stretch
- Check engine light with cam/crank correlation codes (P0016/P0017)
- If ignored, the chain can jump teeth and destroy the engine
Question 4Should I repair or replace my GLC 220d or 250d engine-
Repair if the failure is isolated (e.g., timing chain tensioner, injectors, EGR cleaning). Replace if there's bottom end damage, bore scoring, or catastrophic timing chain failure.
- Timing chain tensioner replacement at specialist: £350-£600 - do this at first sign of rattle
- Injector cleaning: £200-£350 - excellent value for warm-start issues
- Full OM651 rebuild: £3,200-£5,000 - for catastrophic failure or 120k+ miles
- Given GLC 220d / 250d values (£12,000-£25,000), a rebuilt engine is typically good value
Question 5How do I know which engine code my GLC 220d or 250d has-
Check your vehicle log book (V5C) for the engine number, which includes the engine code prefix.
- V5C log book shows full engine number with code prefix
- Engine code stamped on cylinder block
- GLC 220d (2015-2019): OM651.924 (2.1L diesel, 170hp)
- GLC 250d (2015-2019): OM651.921 (2.1L diesel, 204hp)
- Service history documents list engine type
Question 6Can I fit a used GLC 220d or 250d engine myself-
We strongly advise against DIY fitting on a GLC diesel. The longitudinal engine layout, 9G-Tronic gearbox alignment, and ECU coding requirements demand specialist equipment and expertise.
- Longitudinal engine mounting requires specialist alignment
- 9G-Tronic transmission alignment needs precise setup
- ECU coding and immobiliser synchronisation required
- Specialist supply & fit costs £800-£1,500 - worth every penny
Question 7What warranty comes with a reconditioned GLC 220d or 250d engine-
Every engine supplied through EnginesMarket carries a minimum 12-month unlimited mileage warranty, with many specialists offering 24-month coverage on OM651 rebuilds. This includes parts and labour for any manufacturing defect or installation error.
- 12-month unlimited mileage is the minimum standard
- OM651 rebuilds often include 24-month warranty
- All warranties cover parts, labour, and MOT compliance
- Extended warranties available at point of purchase
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