Mercedes Benz GLC Class GLC 300d Engine ReplacementCompare Prices & Get Quotes
Get quotes today from trusted UK Mercedes Benz GLC Class 300d engine specialists. Compare prices on reconditioned, rebuilt and used OM654 2.0-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 £2,800 to £4,800
Used from £1,800 · Reconditioned from £2,400 · Common codes: OM654.920, OM654.820
From £1,800
Tested, bare/short engine
From £2,400
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 300d Replacement Engineto Finding the Best Mercedes Benz GLC Class GLC 300d Replacement Engine
Most replacements completed within 3-5 days.
Variant HistoryMercedes Benz GLC Class GLC 300d - Engine History & Specs at a Glance
The Mercedes Benz GLC 300d arrived with the 2019 X253 facelift, introducing the all-new OM654 2.0-litre modular diesel engine to the GLC range - replacing the older OM651 2.1-litre unit with a lighter, more efficient and more refined powertrain that delivered 245hp and 500Nm of torque [0†L27-L28].
Variant HistoryMercedes Benz GLC Class GLC 300d - Engine History & Specs at a Glance
The Mercedes Benz GLC 300d arrived with the 2019 X253 facelift, introducing the all-new OM654 2.0-litre modular diesel engine to the GLC range - replacing the older OM651 2.1-litre unit with a lighter, more efficient and more refined powertrain that delivered 245hp and 500Nm of torque [0†L27-L28].
Mercedes Benz GLC Class GLC 300d
Fuel TypeDiesel
Engine Size2.0L (1,950cc)
Power Output Range245-269hp across the variant's historyEngine History Timeline
GLC 300d launched with X253 facelift OM654 2.0L turbo diesel, 245hp, 500Nm, 9G-Tronic automatic transmission
OM654 introduced stepped bowl combustion and reduced friction for Euro 6d compliance
X254 second-generation GLC launched GLC 300d upgraded to OM654.820 with 269hp and mild hybrid 48V system [6†L20-L21]
GLC 300d continues in X254 range with refined emissions and improved efficiency
Key Specs Snapshot
Fuel TypeDieselEngine Size2.0L (1,950cc)Power Output Range245-269hp across the variant's historyTorque Range500-550NmYears Produced2019-presentEvery OM654 diesel engine fitted to the Mercedes Benz GLC Class 300d is covered below, with UK rebuilt pricing and known failure points from real owner experience.
Mercedes Benz GLC Class 300d Engine Codes - Specifications & Replacement CostMercedes Benz GLC Class 300d Engine Codes - Specifications & Replacement Cost
2.0L Diesel (2019-2022)
Power Output245 hp (180 kW) @ 4,200 rpmTorque500 Nm @ 1,600-2,600 rpm [0†L12-L13]Displacement1,950ccConfigurationInline-4, DOHC, twin-stage turbocharger, common-rail direct injectionYears Fitted2019-2022
Compatible Trim Levels
- GLC 300d
- GLC 300d 4MATIC
- GLC 300d AMG Line
- GLC 300d Premium
- GLC 300d Premium Plus
Find your exact engine code, specs and UK replacement cost guide.
Used
Tested, ready-to-fit engine
£1,800-£3,200
Reconditioned
Addressed known issues, tested
£2,400-£3,800
Rebuilt
Full teardown, upgraded internals
£2,800-£4,800 [8†L36]
Common Failure
The OM654 is generally reliable but has well-documented issues including EGR cooler cracking (A6540940101) causing coolant loss, failing rocker arm bearings and camshaft lobe wear, NOx sensor failure triggering emissions faults, and timing chain wear on higher-mileage units.
The Mercedes Benz GLC 300d relies on the OM654 2.0-litre modular diesel - a lightweight, all-aluminium engine praised for refinement and efficiency, but not without its vulnerabilities. EGR cooler cracking, NOx sensor failure, rocker arm bearing wear, and timing chain issues dominate replacement demand. 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 300d engine failures, what they cost to fix, and when replacement is the smarter financial decision.
Why the GLC 300d Loses Coolant
Affected Vehicles
Mercedes Benz GLC Class GLC 300d (OM654.920, OM654.820, 2019-present)
Typical Failure Mileage
40,000 - 80,000 miles
Root Cause
The original EGR cooler (part A6540940101) suffers thermal stress fractures, allowing coolant to enter the exhaust system, triggering low coolant warnings, misfires, and eventually engine overheating. Coolant loss without a visible external leak is often the first sign of EGR cooler failure.
Why It Happens
The original EGR cooler (part A6540940101) suffers thermal stress fractures, allowing coolant to enter the exhaust system, triggering low coolant warnings, misfires, and eventually engine overheating. Coolant loss without a visible external leak is often the first sign of EGR cooler failure.
Dealer (parts + labour)
£1,100-£1,600
Specialist (parts + labour)
£700-£1,100
What it involves
Replace failed EGR cooler with revised OEM unit, drain and refill coolant, clear fault codes
Suitability
40k-80k miles. Viable if caught early with no overheating damage
1 - 2 daysDealer (parts + labour)
£1,600-£2,300
Specialist (parts + labour)
£1,000-£1,500
What it involves
EGR cooler replacement plus intake manifold cleaning to remove coolant residue and carbon
Suitability
40k-80k miles. Required if coolant has fouled intake valves
1 - 2 daysDealer (parts + labour)
£6,500-£9,000
Specialist (parts + labour)
£3,800-£5,800
What it involves
Supply & fit rebuilt OM654 with upgraded EGR cooler, new gaskets, timing components
Suitability
Full long-block warranty. Necessary when coolant ingestion has damaged cylinders
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 - EGR Cooler Replacement Minor | £1,100-£1,600 | £700-£1,100 | Replace failed EGR cooler with revised OEM unit, drain and refill coolant, clear fault codes | 40k-80k miles. Viable if caught early with no overheating damage | 1 - 2 days |
 Intermediate - Cooler Plus Intake Cleaning Best Value | £1,600-£2,300 | £1,000-£1,500 | EGR cooler replacement plus intake manifold cleaning to remove coolant residue and carbon | 40k-80k miles. Required if coolant has fouled intake valves | 1 - 2 days |
Full Replacement - Rebuilt Engine Best Value | £6,500-£9,000 | £3,800-£5,800 | Supply & fit rebuilt OM654 with upgraded EGR cooler, new gaskets, timing components | Full long-block warranty. Necessary when coolant ingestion has damaged cylinders | 1 - 2 days |
Vehicle Value Check
Vehicle Value Check
A typical GLC 300d (X253, 2019-2022) is worth £18,000-£35,000, while a second-generation X254 (2022-present) retains values of £35,000-£50,000+ - the full replacement cost of £3,800-£5,800 is modest relative to vehicle value for most examples, making a specialist rebuilt engine a sound investment.
Our Recommendation
Our Recommendation
If caught early with no overheating damage, replace just the EGR cooler - specialist pricing beats dealer by 30-40%. However, many cases present after coolant loss has caused cylinder head damage. On a GLC 300d worth £18,000-£35,000, the full engine replacement with upgraded cooler is often the safer long-term investment.
Don't Let Engine Failure Write Off Your Mercedes Benz GLC 300d
A failed OM654 engine doesn't have to mean the end of your GLC 300d. Whether you're dealing with EGR cooler cracking, NOx sensor failure, rocker arm bearing wear, or timing chain 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 OM654 prices for your Mercedes GLC 300d
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 300d. 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 300d Engine ReplacementFrequently Asked Questions
Question 1How much does it cost to replace a GLC 300d engine in the UK-
A GLC 300d engine replacement typically costs between £2,800 and £4,800 depending on condition type and whether fitting is included. OM654 2.0-litre diesel units range from £2,800 to £4,800 supply only.
- Rebuilt OM654 (GLC 300d): £2,800-£4,800 supply only
- Reconditioned units: £2,400-£3,800
- Used engines from breakers: £1,800-£3,200 but higher risk
- Labour for supply & fit adds £800-£1,500 to any engine price
Question 2Is the OM654 engine in the GLC 300d reliable-
The OM654 is a highly refined and efficient engine - a significant improvement over the OM651 it replaced. However, it has several well-documented issues.
- EGR cooler cracking - the dominant failure driver
- NOx sensor failure and AdBlue system crystallisation
- Rocker arm bearing and camshaft lobe wear
- Timing chain wear on higher-mileage units
- With regular maintenance, 150,000+ miles is realistic
Question 3What are the signs of OM654 EGR cooler failure in a GLC 300d-
The OM654's EGR cooler typically fails between 40,000-80,000 miles, with several warning signs.
- Coolant level dropping with no visible external leak
- White smoke from the exhaust
- Check engine light illuminated
- Decrease in engine performance and rough idle
- Increased fuel consumption
Question 4Should I repair or replace my GLC 300d engine-
Repair if the failure is isolated (e.g., EGR cooler, NOx sensors, AdBlue injector). Replace if there's bottom end damage, bore scoring, or catastrophic valve train failure.
- EGR cooler replacement at specialist: £700-£1,100 - excellent value if caught early
- NOx sensor pair replacement: £350-£600 - replace both as a pair
- Full OM654 rebuild: £3,800-£5,800 - for catastrophic failure or 100k+ miles
- Given GLC 300d values (£18,000-£50,000+), a rebuilt engine is typically good value
Question 5How do I know which engine code my GLC 300d 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 300d (X253, 2019-2022): OM654.920 (2.0L diesel, 245hp)
- GLC 300d (X254, 2022-present): OM654.820 (2.0L diesel, 269hp)
- Service history documents list engine type
Question 6Can I fit a used GLC 300d engine myself-
We strongly advise against DIY fitting on a GLC 300d. 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 300d engine-
Every engine supplied through EnginesMarket carries a minimum 12-month unlimited mileage warranty, with many specialists offering 24-month coverage on OM654 rebuilds. This includes parts and labour for any manufacturing defect or installation error.
- 12-month unlimited mileage is the minimum standard
- OM654 rebuilds often include 24-month warranty
- All warranties cover parts, labour, and MOT compliance
- Extended warranties available at point of purchase
Why Choose UsCompare Mercedes Benz GLC Class 300dEngine PricesToday
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12-Month Warranty on every rebuilt GLC 300d engine
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