Mercedes

Mercedes diesel: from the OM601 of the 1980s to the OM654, three decades of engines that share not a single part

The most common pitfall with Mercedes vehicles concerns the 2.2 CDI: this commercial designation actually covers several distinct engine codes — OM611, OM646, OM651 — depending on the generation of the vehicle. A Sprinter or a Classe E carrying the same "2.2 CDI" entry on the registration document may be fitted with engines and gearboxes that are entirely incompatible with one another. Only the code stamped on the engine itself makes it possible to identify the correct reference in this collection.

Sprinter, Vito, Classe C and Classe E: the models most represented in the collection

The Sprinter and the Vito alone account for the majority of references in gearboxes and turbos, with engines ranging from the 2.1 CDI (OM651) to the 3.0 CDI (OM642). The Classe C and Classe E cover a wider spectrum, from the 1.6 CDI through to the 3.0 CDI, with families of reconditioned or new turbos available depending on the exact engine code — in particular the OM651 (codes 651913, 651921, 651930, 651950, 651955) and the OM642 (642826, 642890, 642940, 642961). The Citan stands apart thanks to its OM607 engine, derived from the Renault K9K block, which means it requires a specific search outside the standard Mercedes engine families.

Four part families, with very different applications depending on the model

The Mercedes collection is split mainly between turbos (the largest family, available new and reconditioned), 5- and 6-speed manual gearboxes, bare engines, and a transfer case for 4-wheel drive versions. Light commercial vehicles such as the Sprinter place greater demand on turbos and gearboxes, whilst Classe E and Classe C saloons generate more requests for engine blocks. For petrol engines — found on the Classe A, Classe B and certain Classe C models — the range is more limited: checking compatibility by engine code remains essential before placing any order, especially as the collection spans model years from 1988 à 2021, representing generations that are technically worlds apart.