Bucking between 1,700 and 1,900 rpm caused by soot in the OM642 EGR valve

Engine / equipment

3.0 V6 CDI OM642 in the Sprinter (906 and 907)

Period mentioned

2006–2026

Symptoms

Bucking or surging always between 1,700 and 1,900 rpm, especially on level roads with a light load; above and below that it runs fine. Sometimes with EGR valve codes and the engine warning light.

Possible cause described

Soot between the EGR valve flap and its seat slows it down, so it does not reach the position the control unit asks for in time, and the valve (and sometimes the boost control) oscillates. Mercedes describes it in information LI14.20-N-073867 (January and June 2026 versions): the EGR valve and cooler are cleaned, or the valve is replaced if the fault is electrical.

Check for the garage

Note the exact rpm at which it happens. At the garage, the manufacturer's test is to unplug the EGR valve and test drive: if the bucking disappears, the EGR is cleaned before replacing injectors or the turbo.

Cost cited in the source

No verified estimate; ask the garage for a quote.A rough figure from the original database, not an up-to-date quote.

Sources from the original database