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Mercedes M275 Engine - Replacement Cost, Problems & CompatibilityProblems & Compatibility
The 5.5-litre and 6.0-litre twin-turbocharged V12 petrol engine fitted to flagship Mercedes-Benz models from 2002 to 2017, including the S-Class, CL-Class, and SL-Class. Reconditioned Mercedes M275 units are typically available from £8,000 , reflecting the specialist nature of V12 replacement and consistent demand for this high-performance platform.
Supply & Fit Available
12-Month Warranty
Nationwide Delivery
100+ Suppliers
Used from
£4,000
Reconditioned from
£8,000
Rebuilt from
£12,000
GB
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Quotes only from vetted UK engine specialists.
Key Specs
Mercedes M275 - Specifications at a Glance
Engine Code
M275 (M275.950, M275.960, M275.980)
Fuel
Petrol
Configuration
5.5L / 6.0L V12 twin-turbocharged
Power Output(s)
368kW (500hp) - 463kW (630hp) depending on variant
Years Produced
2002-2017
UK Models Fitted
4+ Mercedes models - full list in Compatibility below
Replaced
M137
Replaced By
M279
Most Common Failure
Turbocharger wastegate rattle and high-pressure fuel pump wear
Reconditioned Price Range
£8,000-£14,000 supply-only
Vetted UK specialists for M275 replacements
Minimum 12-month warranty on reconditioned and rebuilt options
Fitted To
Which Mercedes Models Use the M275-
TAG: Fitted To
| Model | Generation/Chassis | Badge(s) | Years | Link |
|---|---|---|---|---|
 Mercedes-Benz S-Class | W220 (Facelift) | S 600 | 2002-2005 | |
| Mercedes-Benz S-Class | W221 | S 600, S 65 AMG | 2005-2013 | |
| Mercedes-Benz S-Class | W222 | S 600, S 65 AMG | 2014-2017 | |
| Mercedes-Benz CL-Class | C215 (Facelift) | CL 600 | 2002-2006 | |
| Mercedes-Benz CL-Class | C216 | CL 600, CL 65 AMG | 2006-2014 | |
| Mercedes-Benz SL-Class | R230 | SL 600, SL 65 AMG | 2003-2011 | |
| Mercedes-Benz Maybach | W240 | 57, 62, 57 S, 62 S | 2002-2012 |
02
Mercedes-Benz S-Class
03
Mercedes-Benz S-Class
04
Mercedes-Benz CL-Class
05
Mercedes-Benz CL-Class
06
Mercedes-Benz SL-Class
07
Mercedes-Benz Maybach
CROSS-BRAND
M275 is documented across 7 BMW applications spanning S-Class, CL-Class, SL-Class, Maybach. 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 M275 fitment before any quotes are sent.
Prices
Mercedes M275 Engine Replacement Cost (UK)
Condition | Supply Only | Fitted (Independent Specialist) | Typical Warranty |
|---|---|---|---|
Used | £4,000-£8,000 | £5,200-£9,600 | 3-6 months |
Reconditioned | £8,000-£14,000 | £9,200-£15,600 | 12-24 months |
Rebuilt | £12,000-£18,000 | £13,200-£19,600 | 12-24 months |
The final cost of a Mercedes M275 engine replacement is heavily influenced by the condition of the twin turbochargers and the high-pressure fuel delivery system. If turbo failure has caused internal oil contamination or if the high-pressure fuel pumps have degraded, a standard reconditioned swap may not suffice, pushing the requirement toward a fully rebuilt unit with upgraded thermal management components. See our full reconditioned engine cost guide for a detailed breakdown of what is included at each price tier.
Labour Guide
Fitting a Mercedes M275 typically takes 18-24 hours at £65/hr (independent specialist rate) - confirm exact labour when comparing quotes, as V12 engine bay access requires significant front-end and ancillary disassembly.
Price Factors
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Common Problems
Mercedes M275 Engine Problems - What Actually Fails
Every engine has its weak points. Here are the known issues with the M275, based on real-world data and verified failure patterns.
Verified issue focus: Turbocharger wastegate rattle and high-pressure fuel pump wear.
1. Turbocharger Wastegate Rattle and Bearing Wear
1. Turbocharger Wastegate Rattle and Bearing Wear
Typical onset:
60,000-100,000 miles
What happens:
The M275's twin turbochargers are prone to wastegate actuator wear and bearing degradation. This manifests as a distinct metallic rattling noise on deceleration, boost pressure faults, and eventually, oil consumption or blue smoke if the internal seals fail and allow oil into the intake or exhaust tract.
Repair vs replace:
Early wastegate rattle can sometimes be addressed with actuator replacement or repair kits. However, if bearing wear has led to oil ingestion and internal engine scoring, a full Mercedes M275 engine replacement is the only reliable solution.
Read more about this issue
2. High-Pressure Fuel Pump (HPFP) and Injector Wear
2. High-Pressure Fuel Pump (HPFP) and Injector Wear
Typical onset:
70,000-120,000 miles
What happens:
The direct-injection variants (later W221/W222 applications) and even port-injected early models can suffer from HPFP wear or injector seal degradation. This leads to rough idle, misfires, extended cranking times, and in severe cases, fuel dilution of the engine oil, which compromises lubrication.
Repair vs replace:
Individual pump or injector replacement is the standard fix. However, if fuel dilution has gone unnoticed and caused crankshaft bearing wear, a full rebuild is necessary to prevent catastrophic bottom-end failure.
Read more about this issue
Compare rebuilt M275 prices with the failure already addressed
Engine Variants
M275 Sub-Codes Explained - Which One Is in Your Car-
The M275 family covers several raw sub-codes that share the same core 90-degree V12 twin-turbo architecture but differ by displacement, output calibration, and application (standard flagship vs. AMG/Maybach). Identifying your exact sub-code is critical, as components like the ECU, turbo plumbing, and engine mounts are not universally interchangeable. - Fitted to: Mercedes S-Class (W220 Facelift S 600), CL-Class (C215 Facelift) - Key technical difference: The initial 5.5-litre iteration of the M275, featuring port fuel injection and a specific early-generation engine management calibration. - Sub-code-specific failure note: Shares the family turbo wastegate rattle pattern; early turbo actuators are particularly prone to wear. - Interchange note: Not a straight swap with the 6.0L variants; the ECU, wiring loom, and exhaust manifolds differ significantly. - Fitted to: Mercedes S-Class (W221 S 600/S 65), CL-Class (C216) , SL-Class (R230) - Key technical difference: The most widely produced M275 variant, featuring updated turbochargers, revised cooling pathways, and in later W221 models, a transition to direct injection (CGI) in some markets, though primarily port-injected in the UK. - Sub-code-specific failure note: Shares the family pattern; HPFP wear becomes a more prominent consideration on higher-mileage W221 examples. - Interchange note: Requires the correct variant-specific engine mounts and transmission bell housing alignment; not universally interchangeable between S-Class and SL-Class without bracket modifications. - Fitted to: Maybach (W240) , S 65 AMG (W221/W222), CL 65 AMG (C216) - Key technical difference: The high-output AMG and Maybach specification, featuring larger twin turbochargers, upgraded intercoolers, and a heavily reinforced bottom end to handle extreme torque loads. - Sub-code-specific failure note: Shares the family pattern, though the extreme thermal loads on AMG/Maybach applications can accelerate turbo bearing wear if oil change intervals are extended beyond 5,000 miles.
The M275 engine code is stamped on a machined pad on the engine block, typically near the oil filter housing or the bell housing. It is also clearly listed on your vehicle's V5C registration document under "Engine Number". Enter your registration above to confirm your exact M275 fitment before any quotes are sent.
Easily Confused
M137
The naturally aspirated 5.8L V12 the M275 replaced, which lacked turbochargers and featured a completely different intake and exhaust architecture, avoiding the M275's turbo-specific vulnerabilities.
Alternative / Next-Gen Code
M279
- The direct successor introduced in 2014, featuring twin-scroll turbochargers, direct injection, and a revised cooling system, largely resolving the early M275's turbo actuator and thermal management weaknesses.
Related JLR Variants
M278
- The 4.6L/5.5L V8 twin-turbo counterpart of the same modular family; owners of V8-powered S-Class, CL-Class, or SL models should look here, as the M278 shares the same turbo and fuel system architecture but differs in displacement and mounting.
Confirm the exact M275 fitment
The M275 engine code is stamped on a machined pad on the engine block, typically near the oil filter housing or the bell housing. It is also clearly listed on your vehicle's V5C registration document under "Engine Number". Enter your registration above to confirm your exact M275 fitment before any quotes are sent.
Buying Guide
Buying a Replacement Mercedes M275 - 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 Mercedes M275 is only advisable for lower-mileage host vehicles and *only* if accompanied by documented, stamped service history proving rigorous oil changes (every 5,000-8,000 miles, not the standard 10,000+) and no prior turbo or HPFP issues. The risk of inheriting thermal degradation or oil starvation damage is unacceptably high without this proof.
Reconditioned:
This is the most recommended route for the M275. A proper reconditioned unit will include brand-new or upgraded twin turbochargers, refreshed HPFP components, and new valve cover gaskets, directly addressing the V12's known weak points out of the box.
Rebuilt:
A full rebuild is justified if your original M275 suffered catastrophic turbo failure that scored the cylinder walls, or if severe fuel dilution damaged the crankshaft bearings. A specialist rebuild will machine the block, fit upgraded thermal management components, and ensure all oil galleries are clear.
Supply & Fit Line:
Sourcing a replacement is only half the job. Our network provides full supply and fit services, ensuring the engine is installed by Mercedes and V12-specialist technicians with a nationwide warranty backing both the labour and the unit.
Vehicle Value Note:
For flagship hosts like the W221 S-Class or C216 CL-Class, current UK market values typically sit between £8,000 and £25,000 . With a reconditioned M275 replacement costing from £8,000 (plus £1,200-£1,600 fitting), the repair cost can represent 40-60% of the vehicle's value. While financially viable for well-maintained examples, we strongly advise evaluating the car's overall condition and scrap value before committing to a V12 engine replacement on sub-£10,000 hosts.
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Related Engines
Engines Related to the Mercedes M275
Explore engines that are closely related to the Mercedes-Benz M275, including its predecessor, successor, and key family variants.
Predecessor
M137
The naturally aspirated 5.8L V12 the M275 replaced, which lacked turbochargers and featured a completely different intake and exhaust architecture, avoiding the M275's turbo-specific vulnerabilities.
Successor
M279
- The direct successor introduced in 2014, featuring twin-scroll turbochargers, direct injection, and a revised cooling system, largely resolving the early M275's turbo actuator and thermal management weaknesses.
Sibling
M278
- The 4.6L/5.5L V8 twin-turbo counterpart of the same modular family; owners of V8-powered S-Class, CL-Class, or SL models should look here, as the M278 shares the same turbo and fuel system architecture but differs in displacement and mounting.
FAQ
Mercedes M275Frequently Asked Questions
Question 1How much does a Mercedes M275 engine replacement cost in the UK-
A Mercedes M275 engine replacement typically costs between £8,000 and £14,000 for a reconditioned supply-only unit . Fitted costs generally add £1,200-£1,600 for independent specialist labour due to V12 complexity, and fully rebuilt units with upgraded thermal management components can reach £12,000-£18,000 supply-only.
- Fitted costs generally add £1,200-£1,600 for independent specialist labour due to V12 complexity.
- Fully rebuilt units with upgraded thermal management components can reach £12,000-£18,000 supply-only.
Question 2What is the most common failure with the Mercedes M275 engine-
The most documented failure patterns for the M275 are turbocharger wastegate rattle/bearing wear and high-pressure fuel pump (HPFP) degradation. Early warning signs include a metallic rattle on deceleration, boost pressure faults, or rough idle and extended cranking times, and if turbo bearing wear leads to oil ingestion, or fuel dilution damages the crankshaft bearings, a full engine replacement is required.
- Early warning signs include a metallic rattle on deceleration, boost pressure faults, or rough idle and extended cranking times.
- If turbo bearing wear leads to oil ingestion, or fuel dilution damages the crankshaft bearings, a full engine replacement is required.
Question 3Which Mercedes models use the M275 engine-
The M275 is fitted to Mercedes-Benz flagship models from 2002 to 2017, including the S-Class (W220, W221, W222), CL-Class (C215, C216), SL-Class (R230), and Maybach (W240). It powers badges ranging from the S 600 and CL 600 to the S 65 AMG and Maybach 62, and you should always verify your exact sub-code via registration lookup before ordering parts.
- It powers badges ranging from the S 600 and CL 600 to the S 65 AMG and Maybach 62.
- You should always verify your exact sub-code via registration lookup before ordering parts.
Question 4Should I buy a used or reconditioned Mercedes M275 engine-
A reconditioned Mercedes M275 is strongly recommended over a used unit due to the well-documented turbocharger and HPFP failure risks. Used units carry a high probability of inheriting the same latent thermal degradation or oil starvation damage unless accompanied by stamped proof of preventative turbo/HPFP replacement, whereas a proper reconditioned M275 includes new or upgraded twin turbochargers, refreshed HPFP components, and new valve cover gaskets as standard.
- Used units carry a high probability of inheriting the same latent thermal degradation or oil starvation damage unless accompanied by stamped proof of preventative turbo/HPFP replacement.
- A proper reconditioned M275 includes new or upgraded twin turbochargers, refreshed HPFP components, and new valve cover gaskets as standard.
Question 5What is the difference between the M275.950, M275.960, and M275.980-
The M275.950 is the early 5.5L variant, the M275.960 is the widely produced 5.5L/6.0L standard variant, and the M275.980 is the high-output 6.0L AMG and Maybach specification. While they share the same core 90-degree V12 twin-turbo architecture, they differ in displacement, turbo sizing, and ECU calibration, meaning fitting a .950 or .980 as a direct replacement for a .960 will result in severe ECU, wiring loom, and exhaust manifold incompatibilities.
- While they share the same core 90-degree V12 twin-turbo architecture, they differ in displacement, turbo sizing, and ECU calibration.
- Fitting a .950 or .980 as a direct replacement for a .960 will result in severe ECU, wiring loom, and exhaust manifold incompatibilities.
Compare Mercedes M275 Engine Prices Today
Get a free, no-obligation comparison for your exact Mercedes M275 engine code and sub-code. Our registration lookup confirms your precise fitment before any quotes are sent, ensuring you receive accurate pricing for your specific vehicle. With reconditioned M275 units starting from an estimated £8,000, comparing specialist quotes takes just two minutes and could save you thousands on your replacement.
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Minimum 12-Month Warranty
Minimum 12-month warranty on reconditioned and rebuilt options
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