Hello 310K KMs.. (195K Miles for US friends). Car shudders very noticeably/audibly when below 20KM/h on low battery, on 2 bars. Once battery charge is above 2 bars, the shudders reduce in intensity significantly but it is still there as long as ICE is running. I can tell because as soon as I drop into using electric engine only, car is fairly quiet. EGR was cleaned out as per previous owner. The low battery shudder was always there since I bought it earlier this year. The shudder at all times is recent. What are some /likely possibilities here?
Is the shudder worse when engine is cold? Are you having to add coolant regularly? Any check engine lights (error codes) or other symptoms?
No, the engine temp doesn't seem to matter regarding shuddering. Coolant levels are within threshold and not running low/refilled. No engine lights either
Intermittent shaking? Or consistent shaking when down to two bars? This points to issues with motor generator, but there hasn't been an issue at all with that part of the Prius since 2000-2003. Maybe @ChapmanF might have some input?