Jimmy
“Thanks to EngineMarket, I saved over £1,200 on my engine replacement and got matched with a great local specialist within the hour.”
Get quotes today from trusted UK Mercedes Benz R Class engine specialists. Compare prices on reconditioned, rebuilt and used engines - supply & fit available.
-> Rebuilt units from £2,995 · Common codes: OM642.950, OM642.870, OM642.872, OM642 LS
-> Rebuilt units from £2,500 · Common codes: M272.967, M272.945, M272 E35
-> Rebuilt units from £4,500 · Common codes: M273.963, M113.970, M156.980
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Get Instant Quotes from Mercedes - Benz Engine Specialists Across the UK - 100% free, no obligation. Most replacements completed within 3-5 days.
Most replacements completed within 3-5 days.
Table shows typical UK rebuilt engine costs for Mercedes Benz R Class variants, with failure causes, chassis codes, engine codes, fuel types and sizes from verified market data.

Customer Reviews
Rated 4.8 out of 5 by 1,081 verified customers who sourced reconditioned and used Mercedes Benz R Class engines through EngineMarket.
Jimmy
“Thanks to EngineMarket, I saved over £1,200 on my engine replacement and got matched with a great local specialist within the hour.”
Pete
“Got three quotes within an hour and chose the best deal easily. The whole process was quick, clear and stress-free.”
Sophie
“I wasn't sure what I needed, but they helped me identify the right engine and connected me with a trusted garage.”
Thanks to EngineMarket, I saved over £1,200 on my engine replacement and got matched with a great local specialist within the hour.”
- Jimmy, London
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From the economical R 280 CDI to the high‑performance R 63 AMG, our network of UK Mercedes Benz R Class engine specialists helps you compare rebuilt, reconditioned and used engine prices. Typical price range for a rebuilt unit with 12‑month warranty - supply & fit available nationwide.
A full alphabetical listing of every Mercedes Benz R Class trim covered by our network. All entries link to a dedicated variant page, where prices are further broken down by engine code, model year, and condition type. Click a live link to compare quotes.
Diesel Variants
Petrol Variants
Performance Variants
Every engine code fitted to the Mercedes Benz R Class across all generations, with technical specs, compatible variants and trims, known failure points, and average rebuilt prices from UK specialists. Select any engine code to compare quotes.
Extracted from detailed diesel engine families across Mercedes Benz R Class variants.
Extracted from detailed petrol and performance engine families across Mercedes Benz R Class variants.
Can't find your engine code? Enter your registration number above - we'll instantly identify the exact unit, its technical specifications, and live replacement prices from UK Mercedes Benz R Class engine specialists. Every rebuilt engine comes with a minimum 12‑month unlimited mileage warranty.
Mercedes Benz R Class reliability is heavily influenced by the OM642 V6 diesel and M272 V6 petrol families, both of which carry well-documented failure points that often dictate replacement decisions. Every rebuilt Mercedes Benz R Class engine supplied through our network features upgraded internal components engineered to resolve these original design weaknesses. All units include a minimum 12‑month unlimited mileage warranty, giving you a clear, cost-effective alternative to uncertain partial repairs. The decision tool below compares realistic UK repair tiers against full replacement so you can make an informed, economically sound choice.
Every rebuilt engine includes a minimum 12-month unlimited mileage warranty.
Why OM642 Diesel Engines Stretch
Mercedes Benz R Class R 320 CDI, R 350 CDI, R 300 CDI (2006-2012, OM642.950, OM642.870, OM642.872)
80,000 - 120,000 miles
The rear-mounted tensioner loses hydraulic pressure over time, allowing the timing chain to stretch and prematurely wear plastic guides.
| Repair Tier | Dealer Price | Specialist Price | What It Involves | Longevity / Suitability |
|---|---|---|---|---|
Minor - Preventative Chain & Guide Replacement Minor | £1,800 - £2,800 | £1,200 - £1,900 | Full chain tension, guide swap, and updated tensioner fit without engine removal | 60k-80k miles if caught before rattling escalates |
Full Replacement - Rebuilt OM642 Engine Best Value | £4,800 - £6,500 | £3,200 - £4,800 | Engine removal, bench rebuild with upgraded timing assembly, new seals, supply & fit installation | 100k+ miles with 12-month unlimited mileage warranty |
If you hear a metallic rattle on cold start between 900-1,200rpm, act immediately. A preventative chain and guide replacement is cost-effective on low-mileage examples. Once plastic guide fragments enter the oil sump or the tensioner fully collapses, a complete Mercedes Benz R Class OM642 rebuilt engine is the safer, more economical route.
Navigating Mercedes Benz R Class engine problems requires balancing repair costs against the vehicle's current market value. Main dealer quotes frequently exceed the car's worth, especially when labour-intensive repairs like chain tensioners, oil cooler seals, or balance shaft replacements are required. Our network connects you directly with vetted UK Mercedes Benz R Class engine specialists who provide upgraded rebuilt units, transparent supply & fit pricing, and nationwide delivery. Compare verified quotes today and secure your engine with a guaranteed 12‑month unlimited mileage warranty, avoiding the main dealer premium without compromising on precision engineering.
Compare Mercedes Benz R Class Engine Replacement Prices Now →Mercedes Benz R Class reliability is heavily influenced by the OM642 V6 diesel and M272 V6 petrol families, both of which carry well-documented failure points that often dictate replacement decisions. Every rebuilt Mercedes Benz R Class engine supplied through our network features upgraded internal components engineered to resolve these original design weaknesses. All units include a minimum 12‑month unlimited mileage warranty, giving you a clear, cost-effective alternative to uncertain partial repairs. The decision tool below compares realistic UK repair tiers against full replacement so you can make an informed, economically sound choice.
Mercedes Benz R Class R 320 CDI, R 350 CDI, R 300 CDI (2006-2012, OM642.950, OM642.870, OM642.872)
80,000 - 120,000 miles
The rear-mounted tensioner loses hydraulic pressure over time, allowing the timing chain to stretch and prematurely wear plastic guides.
Full chain tension, guide swap, and updated tensioner fit without engine removal
Engine removal, bench rebuild with upgraded timing assembly, new seals, supply & fit installation
If you hear a metallic rattle on cold start between 900-1,200rpm, act immediately. A preventative chain and guide replacement is cost-effective on low-mileage examples. Once plastic guide fragments enter the oil sump or the tensioner fully collapses, a complete Mercedes Benz R Class OM642 rebuilt engine is the safer, more economical route.
Navigating Mercedes Benz R Class engine problems requires balancing repair costs against the vehicle's current market value. Main dealer quotes frequently exceed the car's worth, especially when labour-intensive repairs like chain tensioners, oil cooler seals, or balance shaft replacements are required. Our network connects you directly with vetted UK Mercedes Benz R Class engine specialists who provide upgraded rebuilt units, transparent supply & fit pricing, and nationwide delivery. Compare verified quotes today and secure your engine with a guaranteed 12‑month unlimited mileage warranty, avoiding the main dealer premium without compromising on precision engineering.
Compare Mercedes Benz R Class Engine Replacement Prices Now →Disclaimer: 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 EngineMarket’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 R Class and engine code. Every engine supplied through EngineMarket carries a minimum 12‑month unlimited mileage warranty - always confirm exact terms with your chosen supplier.
Every engine type is available through our uk network with typical price ranges based on your r class variant, engine code and budget requirements.
All engine types include a minimum 12‑month unlimited mileage warranty when sourced through EngineMarket. Prices are typical UK market ranges based on historical quote data from our network and depend on exact engine code, variant, mileage and supplier. Use our free comparison tool above - enter your registration to get tailored quotes for your specific Mercedes Benz R Class within hours.
The 3.0-litre OM642 V6 diesel was the sole compression-ignition powerplant offered in the UK R-Class range from launch through to the final facelift. It formed the backbone of the lineup, balancing strong low-end torque for a heavy seven-seat MPV with relatively refined NVH characteristics. Despite its robust construction, prolonged high-load usage and missed service intervals expose critical weaknesses in the timing and lubrication systems.
| Engine Code(s) | OM642.870, OM642.872, OM642.950, OM642 LS DE30 LA |
| Compatible Models (UK) | R 280 CDI, R 300 CDI, R 320 CDI, R 350 CDI, R 350 BlueTEC |
| Production Years | W251, 2006-2012 |
Rear timing chain tensioner collapse, oil cooler seal degradation leading to coolant contamination
Not sure which engine size your Mercedes Benz R Class needs? Enter your registration number above - we’ll identify the exact displacement, engine code and compatible replacement options instantly. All engines supplied through EngineMarket include a minimum 12‑month unlimited mileage warranty from UK Mercedes Benz R Class specialists.
Mercedes Benz R Class Engines Fuel Type
The 3.0-litre OM642 V6 diesel powered every UK R-Class diesel variant from launch to end of production, dominating replacement enquiries due to timing chain and oil cooler seal vulnerabilities.
Not sure which fuel type your Mercedes Benz R Class has? Enter your registration number above to instantly identify your engine code, fuel system and compatible replacement options - all backed by a minimum 12‑month unlimited mileage warranty from UK Mercedes Benz R Class specialists.
This technical timeline tracks every engine introduction, facelift update, and fuel system change across the W251/V251 generation so you can instantly identify your unit and compare rebuilt prices from UK specialists.
Not sure which year your Mercedes Benz R Class was built? Enter your registration number and we'll identify the exact engine, model year, and compatible replacement options instantly - all backed by a minimum 12‑month warranty from UK Mercedes Benz R Class specialists.
FAQ
Question 1
A rebuilt Mercedes Benz R Class OM642 diesel engine typically costs £2,800-£4,600 supply-only in the UK, while petrol M272 units range £2,400-£4,200. Adding supply-and-fit installation increases total cost by £800-£1,500 depending on workshop location. Prices vary by engine code, variant specification, and supplier. Always confirm warranty terms and component upgrades before accepting any quote.
Key points
Question 2
Replacing a Mercedes Benz R Class engine is worth it if the chassis, transmission and interior remain in good condition. With vehicle values at £3,000-£8,000 and rebuilt OM642 engines at £2,800-£4,600, the decision hinges on overall vehicle health and your intended ownership period.
Key points
Question 3
The Mercedes Benz R Class OM642 timing chain fails due to rear-mounted tensioner wear allowing chain stretch, which damages plastic guides. This typically occurs between 80,000-120,000 miles on R320 CDI and R350 CDI variants if oil service intervals are extended or missed.
Key points
Question 4
Post-2009 Mercedes Benz R Class OM642 diesel engines are generally more reliable than pre-2007 M272 petrol units, which suffer balance shaft sprocket wear. However, all OM642 variants require strict oil service adherence to avoid timing chain and oil cooler seal issues common on the R Class platform.
Key points
Question 5
A properly rebuilt Mercedes Benz R Class OM642 engine with upgraded timing components and seals can reliably deliver 100,000+ miles when maintained to manufacturer specifications. The critical factor is using a specialist who addresses the original design weaknesses during the rebuild process.
Key points
Question 6
Yes, a used Mercedes Benz R Class engine can be a budget option at £1,500-£2,800, but carries higher risk without comprehensive testing or warranty. Reconditioned OM642 units at £2,800-£4,600 include upgraded components addressing known R Class failure points and come with 12-month warranty protection.
Key points
Question 7
Every Mercedes Benz R Class engine supplied through EngineMarket includes a minimum 12-month unlimited mileage warranty covering parts and labour. Always confirm the exact warranty terms with your chosen specialist, as coverage can vary between suppliers for OM642 and M272 rebuilt units.
Key points
Question 8
Your Mercedes Benz R Class engine code appears on the engine block stamping, vehicle V5C registration document, or by entering your registration on the EngineMarket lookup tool. Common codes include OM642.950 for R320 CDI and M272.967 for R350 petrol variants.
Key points
Question 9
The Mercedes Benz R Class OM642 and M272 engines share architecture with contemporary ML-Class and M-Class models, but mounting points, wiring looms and ECU calibration differ. Never assume cross-model compatibility - always verify your specific Mercedes Benz R Class engine code against donor vehicle specifications.
Key points
Question 10
EngineMarket connects Mercedes Benz R Class owners with vetted UK specialists experienced in W251 chassis engine swaps and 4MATIC drivetrain disconnection. Our network ensures supply-and-fit quotes include proper handling of R Class-specific mounting and electronic integration requirements.
Key points
Why Choose Us
Join thousands of UK drivers who compare Mercedes Benz R Class engine prices through our network of trusted specialists - every rebuilt and reconditioned unit backed by a minimum 12‑month unlimited mileage warranty and nationwide delivery.
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UK Engine Replacement Services for Mercedes Benz R Class
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