Used Mercedes-Benz GLS Oil Pump

Every petrol and diesel engine fitted to the GLS requires a mechanical oil pump to circulate engine oil, so all variants of the GLS — whether the six-cylinder diesels, V8 petrol, or AMG-spec engines — do have one. The oil pump is driven internally by the engine and is not something that varies by drivetrain layout or body style. What does vary is the specific pump design, which is tied directly to the engine code rather than the GLS badge or trim level.

The GLS W166 ran from 2016 to 2019 (the GLS name was applied to the facelifted GL-Class from 2016), while the current X167 generation launched in 2019 and remains in production — these are completely different platforms with different engine families, so the oil pumps are not interchangeable. Even where an engine code appears similar across generations, internal tolerances and mounting arrangements can differ, so you should never assume a W166 part fits an X167 or vice versa. Always confirm against the engine code from your V5 or a VIN check with the breaker.

Both years sit within the W166 generation (2016–2019), so a 2017 and 2018 GLS 350d share the same OM642 diesel engine family, which is encouraging for compatibility. That said, ancillary component specifications can change mid-production without a formal model-year update, so you should confirm the engine code stamped on your block matches that of the donor vehicle before purchasing. Quoting your full engine code to the breaker is the safest approach.

No — trim levels like AMG Line or Grand Edition on the GLS are cosmetic and equipment packages that make no difference to which oil pump is fitted. What determines the correct pump is solely the engine code, since different engines (for example a 350d versus a 500 4MATIC) use different pumps regardless of trim. Confirm your engine code from the V5 or a VIN check and supply that to the breaker rather than the trim name.

Yes — the AMG 63 uses a different high-output V8 engine (carrying its own AMG-specific engine code) compared with the 500's engine, and the oil pump is matched to the specific engine rather than the model name. Mixing pumps between these engine variants would be incorrect even though both cars carry the GLS badge. Always identify the exact engine code on your V5 or via a VIN check and provide it to the breaker so they can match the correct pump from their stock.

No — petrol and diesel engines are entirely different units with different internal architectures, oil circuit designs, and pump specifications, so their oil pumps are not interchangeable even if the vehicles share a model year and generation. The engine code is the definitive guide here: a diesel code (for example OM642) and a petrol code (for example M278) will require completely different pumps. Always supply the engine code to your breaker rather than relying on year or fuel type alone to identify the right part.