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Mercedes-Benz OM647 Engine - Replacement Cost, Problems & CompatibilityProblems & Compatibility
The OM647 is Mercedes-Benz’s 2.2-litre inline-4 common-rail diesel (CDI), bridging the gap between the older OM611 and the highly prolific OM651. Reconditioned OM647 engines typically start from £2,400 , serving as a robust, efficient upgrade for classic W203, W211, and late W210 chassis.
Supply & Fit Available
12-Month Warranty
Nationwide Delivery
100+ Suppliers
Used from
£1,000
Reconditioned from
£2,400
Rebuilt from
£3,500
GB
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Key Specs
Mercedes-Benz OM647 - Specifications at a Glance
Engine Code
OM647.940
Fuel
Diesel
Configuration
2.2L inline-4, DOHC, 16-valve, common-rail (CDI)
Power Output(s)
92 kW (125 hp) - 110 kW (150 hp)
Years Produced
2002-2009
UK Models Fitted
3 Mercedes model families - full list in Compatibility below
Replaced
OM611
Replaced By
OM651
Most Common Failure
Swirl flap actuator failure and injector seal weeping
Reconditioned Price Range
£2,400-£3,800 supply-only
Vetted UK specialists for OM647 replacements
Minimum 12-month warranty on reconditioned and rebuilt options
Fitted To
Which Mercedes Models Use the OM647-
The OM647 was the definitive 4-cylinder CDI for Mercedes-Benz in the mid-2000s, offering improved refinement, lower emissions, and better fuel economy over the OM611 it replaced, before being succeeded by the OM651.
| Model | Generation/Chassis | Badge(s) | Years | Link |
|---|---|---|---|---|
 Mercedes-Benz C-Class | W203 | C 220 CDI | 2002-2007 | |
| Mercedes-Benz E-Class | W211 | E 220 CDI | 2002-2009 | |
| Mercedes-Benz E-Class | W210 | E 220 CDI (late) | 2002-2003 | |
| Mercedes-Benz Vito / Viano | W639 | 115 CDI (early) | 2003-2006 |
02
Mercedes-Benz E-Class
03
Mercedes-Benz E-Class
04
Mercedes-Benz Vito / Viano
CROSS-BRAND
OM647 is documented across 4 BMW applications spanning C-Class, E-Class, Vito / Viano. Registration lookup confirms the exact suffix before quotes are sent.
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Not sure which engine your car has- Enter your registration above - we'll confirm your exact OM647 fitment before any quotes are sent.
Prices
Mercedes-Benz OM647 Engine Replacement Cost (UK)
Condition | Supply Only | Fitted (Independent Specialist) | Typical Warranty |
|---|---|---|---|
Used | £1,000-£2,000 | £1,650-£2,850 | 3-6 months |
Reconditioned | £2,400-£3,800 | £3,050-£4,650 | 12-24 months |
Rebuilt | £3,500-£5,000 | £4,150-£5,850 | 12-24 months |
What genuinely moves the price for this engine is the condition of the swirl flap system, injector seals, and turbocharger health. Because the OM647 is an early common-rail design, recon specialists often upgrade the swirl flap mechanism to a more reliable aftermarket unit or perform a verified delete, alongside replacing all injector seals as standard. For a full breakdown of market rates, see our full reconditioned engine cost guide.
Labour Guide
Fitting an OM647 engine typically takes 8-12 hours at £65-£85/hr (independent) - confirm exact labour when comparing quotes.
Price Factors
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Common Problems
Mercedes-Benz OM647 Engine Problems - What Actually Fails
Every engine has its weak points. Here are the known issues with the OM647, based on real-world data and verified failure patterns.
Verified issue focus: Swirl flap actuator failure and injector seal weeping.
1. Swirl Flap Actuator Failure - All variants
1. Swirl Flap Actuator Failure - All variants
Typical onset:
80,000-120,000 miles
What happens:
The plastic gears inside the electronic swirl flap motor strip over time, causing the ECU to throw a check engine light and default the engine to limp mode. In some cases, the flaps themselves can seize in the inlet manifold due to heavy EGR soot buildup.
Repair vs replace:
The actuator motor can be replaced independently and relatively cheaply. However, if the flaps are seized or the manifold is heavily carboned, a full inlet manifold replacement or verified delete is required.
Read more about this issue
2. Injector Seal Weeping ("Black Death") - All variants
2. Injector Seal Weeping ("Black Death") - All variants
Typical onset:
100,000+ miles
What happens:
The copper washer seals at the base of the injectors degrade, allowing high-pressure combustion gases to escape. This creates a black, crusty carbon buildup around the injector heads, leading to a distinct tapping noise, rough idling, and a strong smell of exhaust in the cabin.
Repair vs replace:
This is a routine maintenance item, not a terminal failure. Replacing the seals and cleaning the cylinder head is inexpensive and should be done preventatively.
Read more about this issue
3. Timing Chain and Guide Wear - High-mileage units
3. Timing Chain and Guide Wear - High-mileage units
Typical onset:
120,000+ miles
What happens:
While more robust than the OM611 it replaced, the OM647 timing chain and plastic guide rails can still stretch and wear at very high mileages, leading to a rattling noise on cold starts.
Repair vs replace:
If caught early, a timing chain and guide kit replacement is straightforward. If ignored, it can jump a tooth, causing valve-to-piston contact and requiring a full OM647 engine replacement.
Read more about this issue
Post-2005 units with revised swirl flap motors and updated ECU mapping show significantly fewer limp-mode events, making them the most desirable examples of this engine family .
Compare rebuilt OM647 engine prices with the failure already addressed
Engine Variants
How to Confirm You Have the Mercedes-Benz OM647
The engine code is stamped on the right-hand side of the cylinder block, just above the oil filter housing. It will also be listed on your V5C logbook under "Engine Capacity" or visible via a VIN decode. The OM647 is sometimes confused with the older OM611 (which has slightly different injection mapping and earlier common-rail teething issues) or the newer OM651 (which features revised emissions hardware and a different timing chain layout). Fitting the wrong revision or assuming interchangeability matters significantly: the OM647 requires specific ECU mapping, turbo plumbing, and engine mount configurations that will not function correctly if swapped with an OM611 or an OM651 without significant modification.
Not sure which engine your car has- Enter your registration above - we'll confirm your exact OM647 fitment before any quotes are sent.
Easily Confused
OM611
the 2.1L/2.2L inline-4 CDI that the OM647 refined, sharing the same common-rail architecture but with improved emissions compliance and a more robust timing chain design.
Alternative / Next-Gen Code
OM651
the highly prolific 2.1L/2.2L inline-4 CDI that replaced the OM647, featuring further refined common-rail injection, improved fuel economy, and wider application across the Mercedes range.
Related JLR Variants
OM646
the slightly later 2.1L inline-4 CDI variant that shared the same core architecture and failure profile, often found in W211 and W203 chassis with slightly different tuning and output calibration.
Confirm the exact OM647 fitment
Not sure which engine your car has- Enter your registration above - we'll confirm your exact OM647 fitment before any quotes are sent.
Buying Guide
Buying a Replacement OM647 Engine - What to Choose
Choosing the right replacement route depends on your budget, risk tolerance, and ownership goals. Here's a breakdown of your options.
Used:
A used OM647 engine makes sense only if it comes with verifiable service history and documented replacement of the swirl flap actuator and injector seals. Given the age of these vehicles, the primary risk is hidden carbon buildup or degraded rubber components, so a compression test is mandatory before purchase.
Reconditioned:
A proper reconditioned OM647 engine is the sweet spot for most buyers. A reputable rebuild will address the common failure points by upgrading or replacing the swirl flap system, fitting new injector seals, and refreshing the timing chain and guides, giving the engine a fresh lease on life.
Rebuilt:
A full OM647 engine rebuild is justified for high-mileage W211/W203 restorations where originality and maximum longevity are required. An upgraded rebuild should include line-boring the block, new pistons/rings, and a balanced crankshaft.
Supply & Fit Line:
Sourcing and fitting through our vetted network ensures your OM647 engine is installed by specialists familiar with early Mercedes CDI systems, backed by a nationwide warranty.
Vehicle Value Note:
Because the OM647 is typically found in W203, W211, and W639 vehicles valued between £2,000 and £8,000, a full replacement can represent a significant portion of the host's worth. If the lowest viable replacement cost exceeds approximately 60% of the vehicle's current market value, evaluate scrap value before committing .
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Related Engines
Engines Related to the Mercedes-Benz OM647
Explore engines that are closely related to the Mercedes-Benz OM647, including its predecessor, successor, and key family variants.
Predecessor
OM611
the 2.1L/2.2L inline-4 CDI that the OM647 refined, sharing the same common-rail architecture but with improved emissions compliance and a more robust timing chain design.
Successor
OM651
the highly prolific 2.1L/2.2L inline-4 CDI that replaced the OM647, featuring further refined common-rail injection, improved fuel economy, and wider application across the Mercedes range.
Sibling
OM646
the slightly later 2.1L inline-4 CDI variant that shared the same core architecture and failure profile, often found in W211 and W203 chassis with slightly different tuning and output calibration.
FAQ
Mercedes-Benz OM647Frequently Asked Questions
Question 1How much does a Mercedes OM647 engine replacement cost-
A reconditioned Mercedes OM647 engine typically costs between £2,400 and £3,800 for supply only . Fitted costs generally range from £3,050 to £4,650 depending on the specialist, while used units can be found from £1,000 but carry higher risk due to the engine's age. Compare OM647 engine replacement quotes today
Compare OM647 quotesQuestion 2What is the most common failure on the OM647 engine-
The most documented issues are swirl flap actuator failure, injector seal weeping ("Black Death"), and timing chain guide wear at high mileage. Swirl flap motor failure triggers limp mode and is a routine fix, whereas injector seal failure causes black carbon buildup and rough idling but is a cheap and preventative maintenance item. Get quotes for a rebuilt OM647 with these issues resolved
Compare OM647 quotesQuestion 3Which Mercedes models use the OM647 engine-
The OM647 was fitted to the W203 C-Class (C 220 CDI), the W211 E-Class (E 220 CDI), the late W210 E-Class (E 220 CDI), and the early W639 Vito/Viano (115 CDI), serving as the definitive 4-cylinder diesel for these chassis between 2002 and 2009. Check your registration to confirm your exact OM647 fitment
Compare OM647 quotesQuestion 4Should I buy a used or reconditioned OM647 engine-
A reconditioned OM647 is strongly recommended over a used unit. A proper rebuild will proactively address the common failure points by upgrading or replacing the swirl flap system, fitting new injector seals, and refreshing the timing chain and guides, whereas used engines often hide stretched chains and carboned manifolds. Compare reconditioned OM647 engine prices from UK specialists
Compare OM647 quotesQuestion 5How do I know if my car has the OM647 and not the OM611 or OM651-
The OM647 is a distinct 2.2L inline-4 CDI. The engine code is stamped on the right-hand side of the cylinder block above the oil filter housing and is also listed on your V5C logbook. It requires specific ECU mapping and turbo plumbing that will not function correctly if swapped with an OM611 or an OM651 without significant modification. Enter your reg above to identify your exact engine code ═══════════════════════════════════════
Compare OM647 quotesCompare Mercedes-Benz OM647 Engine Prices Today
Vetted UK specialists who work on classic Mercedes CDI systems like the OM647 every week Minimum 12-month warranty on every reconditioned and rebuilt OM647 engine Nationwide delivery - supply-only or full supply & fit available across the UK Get a free, no-obligation comparison of OM647 engine prices tailored to your exact vehicle. Our registration lookup confirms your fitment before any quotes are sent, ensuring you receive the correct unit with matching ancillary components. With reconditioned OM647 engines starting from an estimated £2,400, comparing takes two minutes and could save you hundreds on labour and unexpected teardowns.
Vetted UK Specialists
Vetted UK specialists for OM647 replacements
Minimum 12-Month Warranty
Minimum 12-month warranty on reconditioned and rebuilt options
Nationwide Delivery
Nationwide delivery plus supply and fit availability
Expert Support
Secure enquiry - no spam. Quotes only from vetted UK engine specialists.
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