A while back something went wrong with it, loud noise followed by massive vibrations and the inevitable warning light on the dashboard. Renault said it was one of the four 'coils' in the engine, and they were supposedly replaced. Since then, it's been slow as #$%#. Lately it's been cutting out a lot, and generally got even slower. It needs new oil for one thing, but because it was meant to be going in for a service soon, we've left it. Anyways, I'm driving down the road...and bang, it starts shuddering and the warning light appears again. I tend to think the same thing has gone wrong again. Oh and we started it up a few times, and it sounds terrible, rickety. Any ideas?