Mercedes M279 Engine - Replacement Cost, Problems & Compatibility

A Mercedes M279 engine replacement typically costs between £8,000 and £14,000 for a reconditioned supply-only unit . Fitted costs generally add £1,170-£1,730 for independent specialist labour due to V12 biturbo complexity, and fully rebuilt units with upgraded thermal management components can reach £12,000-£18,000 supply-only.

• Fitted costs generally add £1,170-£1,730 for independent specialist labour due to V12 biturbo complexity.
• Fully rebuilt units with upgraded thermal management components can reach £12,000-£18,000 supply-only.

The most documented failure patterns for the M279 are timing chain stretch/guide wear and turbocharger wastegate rattle or bearing wear. Early warning signs include a metallic rattle on cold starts, camshaft correlation fault codes, or boost pressure faults, and if the chain jumps teeth or turbo bearing wear leads to oil ingestion, a full engine replacement is required to prevent catastrophic damage.

• Early warning signs include a metallic rattle on cold starts, camshaft correlation fault codes, or boost pressure faults.
• If the chain jumps teeth or turbo bearing wear leads to oil ingestion, a full engine replacement is required to prevent catastrophic damage.

The M279.980 is fitted to flagship Mercedes-Benz all-wheel-drive sedans, coupes, and ultra-luxury derivatives from 2014 to 2020. This includes the S-Class (W222), S-Class Coupe (C217), Maybach (X222), and G-Class (W463), and you should always verify your exact fitment via registration lookup before ordering parts, as these are highly specialized applications.

• This includes the S-Class (W222), S-Class Coupe (C217), Maybach (X222), and G-Class (W463).
• You should always verify your exact fitment via registration lookup before ordering parts, as these are highly specialized applications.

A reconditioned Mercedes M279 is strongly recommended over a used unit due to the well-documented timing chain and turbocharger failure risks. Used units carry a high probability of inheriting the same latent wear unless accompanied by stamped proof of preventative maintenance and no oil consumption complaints, whereas a proper reconditioned M279 includes verified cylinder bore integrity, new timing chain components, refreshed valley pan seals, and tested twin turbochargers as standard.

• Used units carry a high probability of inheriting the same latent wear unless accompanied by stamped proof of preventative maintenance and no oil consumption complaints.
• A proper reconditioned M279 includes verified cylinder bore integrity, new timing chain components, refreshed valley pan seals, and tested twin turbochargers as standard.

The M279.980 engine code is stamped on the engine block near the oil filter housing and is listed on your V5C registration document. It is commonly confused with the older M275 or the newer V8 M177, but fitting an M275 or M177 will result in severe ECU, wiring loom, and exhaust manifold incompatibilities, making like-for-like replacement essential.

• It is commonly confused with the older M275 or the newer V8 M177.
• Fitting an M275 or M177 will result in severe ECU, wiring loom, and exhaust manifold incompatibilities, making like-for-like replacement essential.