Mercedes Benz E Class 250 CDI Engine ReplacementCompare Prices & Get Quotes
Get quotes today from trusted UK Mercedes Benz E Class 250 CDI engine specialists. Compare prices on reconditioned, rebuilt and used OM651 diesel engines - supply & fit available nationwide.
Supply & Fit Available
12-Month Warranty
Nationwide Delivery
100+ Suppliers
From £1,800 to £3,500
Used from £1,200 · Reconditioned from £1,800 · Common codes: OM651.911, OM651.924
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 E Class 250 CDI Replacement Engineto Finding the Best Mercedes Benz E Class 250 CDI Replacement Engine
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Variant HistoryMercedes Benz E Class 250 CDI - Engine History & Specs at a Glance
The E 250 CDI badge represented Mercedes-Benz's high-output diesel offering across the W212 E-Class generation. Powered by the OM651 2.1-litre inline-four turbodiesel in twin-turbo form, it delivered 204 hp and 500 Nm of torque - making it the most powerful four-cylinder diesel in the E-Class range at the time.
Variant HistoryMercedes Benz E Class 250 CDI - Engine History & Specs at a Glance
The E 250 CDI badge represented Mercedes-Benz's high-output diesel offering across the W212 E-Class generation. Powered by the OM651 2.1-litre inline-four turbodiesel in twin-turbo form, it delivered 204 hp and 500 Nm of torque - making it the most powerful four-cylinder diesel in the E-Class range at the time.
Mercedes Benz E Class 250 CDI
Fuel TypeDiesel
Engine Size2.1L (2,143 cc)
Power Output150 kW (204 hp) at 4,200 rpmEngine History Timeline
**2009** - W212 E 250 CDI BlueEFFICIENCY launched with OM651.911 engine 150 kW (204 hp), twin-turbocharged
**2009-2013** - OM651.911 fitted to rear-wheel drive E 250 CDI BlueEFFICIENCY saloon and estate
**2011** - E 250 CDI 4MATIC BlueEFFICIENCY introduced with OM651.924 engine 150 kW (204 hp), permanent all-wheel drive
**2011-2015** - OM651.924 also fitted to E 250 CDI / BlueTEC 4MATIC models (212.082 212.097)
**2014** - BlueTEC branding introduced on later E 250 CDI models with AdBlue emissions treatment
**2016** - W212 production ends; OM654 replaced OM651 in W213 generation
Key Specs Snapshot
Fuel TypeDieselEngine Size2.1L (2,143 cc)Power Output150 kW (204 hp) at 4,200 rpmTorque500 Nm at 1,600-1,800 rpmYears Produced2009-2016Every engine fitted to the Mercedes E Class 250 CDI is covered below, with UK rebuilt pricing and known failure points.
Mercedes Benz E Class 250 CDI Engine Codes - Specifications & Replacement CostMercedes Benz E Class 250 CDI Engine Codes - Specifications & Replacement Cost
2.1L Diesel (2009-2013)
Power Output150 kW (204 hp) at 4,200 rpmTorque500 Nm at 1,600-1,800 rpmYears Fitted2009-2013 (W212 E-Class)
Compatible Trim Levels
- E 250 CDI BlueEFFICIENCY (W212)
- E 250 CDI BlueEFFICIENCY Estate (S212)
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
£1,800-£2,700
Rebuilt
Full teardown, upgraded internals
£2,200-£3,200
Common Failure
Timing chain stretch on the single-row chain - cold-start rattle is the early warning sign. Injector seal leakage ("Black Death") and oil cooler seal failure are also reported. Fuel system issues including injector electrical failures can occur.
The OM651 engine that powers the E Class 250 CDI delivers impressive performance - 204 hp and 500 Nm from just 2.1 litres - but the twin-turbo design and single-row timing chain create specific failure points. Timing chain stretch is the most significant concern, with injector seal failure ("Black Death") and oil cooler leaks also featuring prominently. 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 what these failures cost to fix and when replacement is the smarter option.
Why the OM651 in the E Class 250 CDI Fails Prematurely
Affected Vehicles
Mercedes E Class 250 CDI (OM651, 2009-2016)
Typical Failure Mileage
50,000 - 120,000 miles (some fail between 50k-70k)
Root Cause
The OM651 uses a single-row timing chain mounted at the rear of the engine. The chain stretches when oil change intervals exceed 10,000 miles - extended service intervals are the primary culprit. Stop-start systems accelerate wear. Cold-start rattle lasting 2-4 seconds is the classic early warning sign.
Why It Happens
The OM651 uses a single-row timing chain mounted at the rear of the engine. The chain stretches when oil change intervals exceed 10,000 miles - extended service intervals are the primary culprit. Stop-start systems accelerate wear. Cold-start rattle lasting 2-4 seconds is the classic early warning sign.
Dealer (parts + labour)
£800-£1,200
Specialist (parts + labour)
£400-£700
What it involves
Replacement of timing chain tensioner only
Suitability
50,000-80,000 miles; effective if rattle is brief (under 2 seconds) and chain has not stretched
1 - 2 daysDealer (parts + labour)
£1,800-£2,800
Specialist (parts + labour)
£900-£1,500
What it involves
Replacement of timing chain, tensioner, guides and sprockets
Suitability
When chain has stretched or rattle persists beyond start-up
1 - 2 daysDealer (parts + labour)
£4,000-£6,000
Specialist (parts + labour)
£2,200-£3,500
What it involves
Supply & fit of rebuilt OM651 with new timing components and upgraded parts
Suitability
When chain has jumped and bent valves, or engine has suffered consequential 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 | £800-£1,200 | £400-£700 | Replacement of timing chain tensioner only | 50,000-80,000 miles; effective if rattle is brief (under 2 seconds) and chain has not stretched | 1 - 2 days |
 Major - Full Timing Chain & Sprockets Best Value | £1,800-£2,800 | £900-£1,500 | Replacement of timing chain, tensioner, guides and sprockets | When chain has stretched or rattle persists beyond start-up | 1 - 2 days |
Full Replacement - Rebuilt Engine Best Value | £4,000-£6,000 | £2,200-£3,500 | Supply & fit of rebuilt OM651 with new timing components and upgraded parts | When chain has jumped and bent valves, or engine has suffered consequential damage | 1 - 2 days |
Vehicle Value Check
Vehicle Value Check
A typical W212 E Class 250 CDI is worth £4,000-£10,000 depending on condition and mileage【INDUSTRY ESTIMATE】. Given the strong residual value of the 250 CDI (the most powerful four-cylinder diesel in the range), a rebuilt engine with warranty is usually justifiable if the rest of the car is sound.
Our Recommendation
Our Recommendation
The cold-start rattle is your early warning - don't ignore it. A specialist timing chain replacement at £900-£1,500 is significantly cheaper than the £2,000+ valvetrain rebuild if the chain jumps. Given the OM651's single-row chain design, preventative replacement at 80,000-100,000 miles is a wise investment on a high-value E 250 CDI. If the chain has already jumped, a rebuilt engine with upgraded components and warranty typically offers better value than a dealer-led rebuild.
Don't Let Engine Failure Write Off Your Mercedes E Class 250 CDI
Whether your E Class 250 CDI is suffering from timing chain rattle, injector "Black Death", or oil cooler leaks, EnginesMarket makes it simple to compare prices from trusted UK Mercedes specialists. Every rebuilt engine in our network includes upgraded components designed to address the original failure point - plus a minimum 12-month unlimited mileage warranty and nationwide delivery. Compare prices, choose a specialist, and get back on the road without the main dealer premium.
Compare rebuilt OM651 Mercedes E Class 250 CDI 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 E Class 250 CDI. Every engine supplied through EnginesMarket carries a minimum 12-month unlimited mileage warranty - always confirm exact terms with your chosen supplier."
Mercedes E Class 250 CDI Engine ReplacementFrequently Asked Questions
Question 1How much does a Mercedes E Class 250 CDI engine replacement cost in the UK-
Short summary: Supply-only rebuilt OM651 engines range from £2,200 to £3,500 depending on engine code and condition. With specialist fitting, budget £2,600-£4,300 total.
- OM651.911 (E 250 CDI, 204 hp, 2009-2013): rebuilt £2,200-£3,200
- OM651.924 (E 250 CDI 4MATIC / BlueTEC, 204 hp, 2011-2016): rebuilt £2,400-£3,500
- Labour adds £400-£800 depending on specialist location
Question 2What are the signs of timing chain failure in an E Class 250 CDI-
Short summary: Cold-start rattle lasting 2-4 seconds is the classic early warning sign. If ignored, the chain can jump, causing limp mode, loss of power, and eventually catastrophic engine failure.
- Rattle on cold start that disappears after a few seconds
- Metallic clanging sounds from the engine
- Loss of power or limp mode (engine won't rev over 3,000 RPM)
- Timing chain replacement at a specialist costs £900-£1,500
Question 3Is it worth replacing the engine on an E Class 250 CDI-
Short summary: Yes, if the car is otherwise sound. W212 E 250 CDI examples with good service history still command £4,000-£10,000 used, making replacement viable【INDUSTRY ESTIMATE】.
- A quality rebuilt OM651 costs £2,200-£3,500 supply only
- The 250 CDI is the most powerful four-cylinder diesel in the range - desirable on the used market
- A replacement engine with warranty costs less than financing a newer car
- Specialist fitting adds £400-£800, not dealer rates of £1,500+
Question 4What causes the OM651 timing chain to fail on E Class 250 CDI models-
Short summary: The OM651 uses a single-row timing chain mounted at the rear of the engine. Extended oil change intervals (over 10,000 miles) are the primary culprit. Stop-start systems accelerate wear.
- Chain stretch typically occurs between 50,000-120,000 miles
- Cold-start rattle that disappears after a few seconds is the early warning
- Full chain replacement at a specialist costs £900-£1,500
- Some OM651 examples exceed 150,000 miles on the original chain with frequent oil changes
Question 5What is the difference between the OM651.911 and OM651.924 engines in the E Class 250 CDI-
Short summary: Both are 2.1-litre twin-turbo diesels producing 204 hp and 500 Nm. The OM651.924 was introduced for 4MATIC (all-wheel drive) models and later BlueTEC emissions treatment.
- OM651.911 fitted to rear-wheel drive E 250 CDI BlueEFFICIENCY (2009-2013)
- OM651.924 fitted to E 250 CDI 4MATIC and BlueTEC models (2011-2016)
- Both share the same 83mm bore × 99mm stroke, 2,143 cc displacement
- Both suffer from the same timing chain and injector seal issues
Question 6How long does a Mercedes E Class 250 CDI engine last-
Short summary: With proper maintenance and 8,000-10,000 mile oil changes, OM651 engines regularly reach 200,000-300,000 miles. Some examples exceed 250,000 miles in taxi and fleet use.
- OM651 bottom ends are robust when properly maintained
- Timing chain replacement at 80k-100k miles is recommended for peace of mind
- Injector seal replacement at 60k-120k miles is key maintenance
- Short oil change intervals (8k miles) are critical for timing chain life
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