🟡 Mercedes Vito W447 2.1 CDI OM651 timing chain fault

Rattling noise from the engine on cold start on the Mercedes Vito W447 with the 2.1 CDI engine. The OM651 secondary balance shaft timing chain and tensioner fault affects the Vito as well as C-Class and E-Class models. The Vito is often used for high-mileage commercial applications, accelerating wear. Regular oil changes with 5W-30 fully synthetic oil are essential. If the rattle persists beyond 10 seconds after cold start, immediate inspection is required.