Mercedes-Benz ML 500 (W166) Engine Replacement - M278 4.7 Engines

Mercedes-Benz ML 500 (W166) Engines for Sale | Engine Finders

If you're looking for a reconditioned Mercedes-Benz ML 500 (W166) engine, a rebuilt M278 unit, or simply a reliable replacement for a worn-out Mercedes-Benz ML 500 (W166) M278 twin-turbo V8 engine, you're in the right place. The W166 M-Class (which was later renamed GLE) moved the ML 500 to a twin-turbocharged V8, a significant change from the naturally aspirated V8s used in the previous two ML generations. Engine Finders matches UK buyers searching for 'M278 engine for sale', 'reconditioned M278 price' or 'Mercedes-Benz ML 500 (W166) engine replacement cost' with vetted suppliers who carry the correct unit for your exact car — supply-only or supply-and-fit, used or professionally reconditioned, whichever suits your budget and timeline.

Mercedes-Benz ML 500 (W166) Replacement Engines

A replacement M278 engine for the Mercedes-Benz ML 500 (W166) is a significant purchase, so getting the exact code right matters more than the badge on the boot. The M278 is the same twin-turbocharged V8 family used in the contemporary S 500 (W222), bringing turbocharging to the mainstream ML 500 for the first time. Whether you call it a rebuilt engine, a remanufactured unit, or a reconditioned replacement, the work involved is broadly the same: a full strip-down, inspection against factory tolerances, replacement of wear parts, and bench testing before it's fitted or dispatched to you.

ML 500 (W166) Models & Engine Codes

The Mercedes-Benz ML 500 (W166) uses the M278 (4.7-litre V8, Petrol (twin-turbocharged)), fitted to ML 500 (W166) across 2011 to 2015. This is the same M278 engine family used in the W222 S 500 and R231 SL 500 of this era; confirm your exact revision from the engine number. Before ordering any used, reconditioned or rebuilt unit, confirm this code from your V5C or the number stamped on the engine block itself — the same badge can sometimes cover more than one engine across a model's production run, and getting this step right avoids an expensive mismatch.

Buy Used and Second-Hand Mercedes-Benz ML 500 (W166) Engines

Used M278 engines do come up for sale in the UK, generally sourced from donor or written-off Mercedes-Benz ML 500 (W166) cars. A used engine can look like the cheaper option at first glance, but once you've accounted for inspection, gaskets, ancillaries and the lack of a meaningful warranty, a professionally reconditioned or remanufactured M278 unit is often the better value over the life of the car.

Mercedes-Benz ML 500 (W166) Engines in Stock

We work with a UK-wide network of suppliers who carry reconditioned, rebuilt and remanufactured M278 engines for the Mercedes-Benz ML 500 (W166), along with used units where buyers prefer that route. Give us your registration and we'll confirm current stock, typical lead times, and whether supply-only or supply-and-fit makes more sense for your situation.

Warranty for Replacement Mercedes-Benz ML 500 (W166) Engines

Warranty terms for a replacement M278 engine are set individually by the supplier we match you with — typically around 12 months on a reconditioned or remanufactured unit. No workbook price exists for the M278 by name; £5,500 is our nearest-spec marker, the same price used for our S 500 (W222) and SL 500 (R231) pages, which share this engine. Always get the warranty length, what it covers, and the VAT and fitting basis confirmed in writing before you commit.

Mercedes-Benz ML 500 (W166) M278 Engine Problems & What to Check Before Buying

We have not verified catalogue-grade documented issue reports specific to this application; treat general commentary as background only. We note this as general background for anyone researching a M278 replacement, not as a confirmed finding for any specific car — ask your supplier what inspection was carried out on the unit you're being quoted, and whether known wear points for this engine family were addressed during the rebuild.

What's Included in a Reconditioned Mercedes-Benz ML 500 (W166) M278 Engine

A genuine reconditioned or remanufactured M278 unit should include a full strip, clean and inspection against factory tolerances, replacement of gaskets, seals and wear items, and a bench test before it leaves the workshop. What's not always included — ancillaries like the turbo, injectors or auxiliary belt components, and whether the price is supply-only or supply-and-fit — varies by supplier, so ask for this in writing alongside your M278 engine quote rather than assuming it's covered.