Mercedes

Mercedes diesel: from the OM601 of the 1980s to the post-2016 OM654, engine families and gearbox families are not interchangeable

This is the classic pitfall with Mercedes: the same Sprinter or the same C-Class in 2.2 CDI can conceal radically different engine codes depending on the year of first registration. The 2.2 CDI of the Sprinter W906 is built around the OM651 (codes 651913, 651921, 651930, 651950, 651955…), whereas a Vito or an earlier-generation C-Class may carry an OM646 or an OM611 — architectures with no parts in common whatsoever. The same logic applies to the 3.0 CDI: the OM642 V6 (642826, 642890, 642940, 642961) is fitted to the ML, GLK, E-Class and Viano, but its bore dimensions and valve timing have nothing in common with the older 3.0 D or the indirect-injection 3.0 CDI V6. The engine code stamped on the block — not the engine capacity — is the only reliable reference for identifying the correct part.

Gearboxes, engines and transfer cases: three families for a very wide vehicle parc

The collection covers three part families: gearboxes (the majority of the catalogue), engines reconditioned and a transfer case. The gearboxes listed are exclusively 5- or 6-speed manuals; no automatic or dual-clutch gearbox is included within this range. Engines are offered as bare units. The vehicle parc covered spans 1988 to 2021 and includes heavy commercials (Sprinter, Vito, Viano, MB100) as well as saloons and SUVs (C-Class, E-Class, A-Class, B-Class, GLK, GLA, GLC, GLE, G-Class, ML300, ML320, ML350, SLK). One particular case worth noting: the Citan is fitted with an OM607 block derived from the Renault K9K — its gearbox and engine share no references with the rest of the Mercedes range.

Identification references: Mercedes engine codes to check first

For diesel blocks, the OM601, OM611, OM617, OM640, OM646, OM651 and OM654 families cover the bulk of the catalogue from 1988 to 2021. Each family encompasses several power variants identified by the last four digits of the code (e.g. OM651.924 ≠ OM651.955). On the petrol side, the 1.8 Kompressor (C-Class, SLK) and the naturally aspirated 1.6 or 2.0 units (A-Class, B-Class) belong to distinct families. Before browsing the product listings, make sure you have the full engine code to hand: it is stamped on the block itself and can also be found on the V5C registration document under entry P5.