[SomeRandomer123]

Recently, we have noticed that on idle, our 330d has a small amount of excessive vibration and rough noise. It's a small change - if you haven't owned the car, you would never notice. It happens at any engine temperature and it seems the longer it is idling, the worse it gets. As soon as you leave idle, the engine is back to normal and as powerful as ever! Return it to idle and it starts again from smooth to rough. It's as if one of the six cylinders is firing just out of time so I'm tempted to believe it's an injector problem but more of an electrical injection problem perhaps?

54,000 Miles

Subjected to lows of -21 Degrees C during winter months.

Any ideas or experiences?

Thanks

Daniel